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/*
 * tkListbox.c --
 *
 *      This module implements listbox widgets for the Tk
 *      toolkit.  A listbox displays a collection of strings,
 *      one per line, and provides scrolling and selection.
 *
 * Copyright (c) 1990-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tkListbox.c,v 1.1.1.1 2002-01-16 10:25:52 markom Exp $
 */
 
#include "tkPort.h"
#include "default.h"
#include "tkInt.h"
 
/*
 * One record of the following type is kept for each element
 * associated with a listbox widget:
 */
 
typedef struct Element {
    int textLength;             /* # non-NULL characters in text. */
    int lBearing;               /* Distance from first character's
                                 * origin to left edge of character. */
    int pixelWidth;             /* Total width of element in pixels (including
                                 * left bearing and right bearing). */
    int selected;               /* 1 means this item is selected, 0 means
                                 * it isn't. */
    struct Element *nextPtr;    /* Next in list of all elements of this
                                 * listbox, or NULL for last element. */
    char text[4];               /* Characters of this element, NULL-
                                 * terminated.  The actual space allocated
                                 * here will be as large as needed (> 4,
                                 * most likely).  Must be the last field
                                 * of the record. */
} Element;
 
#define ElementSize(stringLength) \
        ((unsigned) (sizeof(Element) - 3 + stringLength))
 
/*
 * A data structure of the following type is kept for each listbox
 * widget managed by this file:
 */
 
typedef struct {
    Tk_Window tkwin;            /* Window that embodies the listbox.  NULL
                                 * means that the window has been destroyed
                                 * but the data structures haven't yet been
                                 * cleaned up.*/
    Display *display;           /* Display containing widget.  Used, among
                                 * other things, so that resources can be
                                 * freed even after tkwin has gone away. */
    Tcl_Interp *interp;         /* Interpreter associated with listbox. */
    Tcl_Command widgetCmd;      /* Token for listbox's widget command. */
    int numElements;            /* Total number of elements in this listbox. */
    Element *firstPtr;          /* First in list of elements (NULL if no
                                 * elements). */
    Element *lastPtr;           /* Last in list of elements (NULL if no
                                 * elements). */
 
    /*
     * Information used when displaying widget:
     */
 
    Tk_3DBorder normalBorder;   /* Used for drawing border around whole
                                 * window, plus used for background. */
    int borderWidth;            /* Width of 3-D border around window. */
    int relief;                 /* 3-D effect: TK_RELIEF_RAISED, etc. */
    int highlightWidth;         /* Width in pixels of highlight to draw
                                 * around widget when it has the focus.
                                 * <= 0 means don't draw a highlight. */
    XColor *highlightBgColorPtr;
                                /* Color for drawing traversal highlight
                                 * area when highlight is off. */
    XColor *highlightColorPtr;  /* Color for drawing traversal highlight. */
    int inset;                  /* Total width of all borders, including
                                 * traversal highlight and 3-D border.
                                 * Indicates how much interior stuff must
                                 * be offset from outside edges to leave
                                 * room for borders. */
    Tk_Font tkfont;             /* Information about text font, or NULL. */
    XColor *fgColorPtr;         /* Text color in normal mode. */
    GC textGC;                  /* For drawing normal text. */
    Tk_3DBorder selBorder;      /* Borders and backgrounds for selected
                                 * elements. */
    int selBorderWidth;         /* Width of border around selection. */
    XColor *selFgColorPtr;      /* Foreground color for selected elements. */
    GC selTextGC;               /* For drawing selected text. */
    int width;                  /* Desired width of window, in characters. */
    int height;                 /* Desired height of window, in lines. */
    int lineHeight;             /* Number of pixels allocated for each line
                                 * in display. */
    int topIndex;               /* Index of top-most element visible in
                                 * window. */
    int fullLines;              /* Number of lines that fit are completely
                                 * visible in window.  There may be one
                                 * additional line at the bottom that is
                                 * partially visible. */
    int partialLine;            /* 0 means that the window holds exactly
                                 * fullLines lines.  1 means that there is
                                 * one additional line that is partially
                                 * visble. */
    int setGrid;                /* Non-zero means pass gridding information
                                 * to window manager. */
 
    /*
     * Information to support horizontal scrolling:
     */
 
    int maxWidth;               /* Width (in pixels) of widest string in
                                 * listbox. */
    int xScrollUnit;            /* Number of pixels in one "unit" for
                                 * horizontal scrolling (window scrolls
                                 * horizontally in increments of this size).
                                 * This is an average character size. */
    int xOffset;                /* The left edge of each string in the
                                 * listbox is offset to the left by this
                                 * many pixels (0 means no offset, positive
                                 * means there is an offset). */
 
    /*
     * Information about what's selected or active, if any.
     */
 
    Tk_Uid selectMode;          /* Selection style: single, browse, multiple,
                                 * or extended.  This value isn't used in C
                                 * code, but the Tcl bindings use it. */
    int numSelected;            /* Number of elements currently selected. */
    int selectAnchor;           /* Fixed end of selection (i.e. element
                                 * at which selection was started.) */
    int exportSelection;        /* Non-zero means tie internal listbox
                                 * to X selection. */
    int active;                 /* Index of "active" element (the one that
                                 * has been selected by keyboard traversal).
                                 * -1 means none. */
 
    /*
     * Information for scanning:
     */
 
    int scanMarkX;              /* X-position at which scan started (e.g.
                                 * button was pressed here). */
    int scanMarkY;              /* Y-position at which scan started (e.g.
                                 * button was pressed here). */
    int scanMarkXOffset;        /* Value of "xOffset" field when scan
                                 * started. */
    int scanMarkYIndex;         /* Index of line that was at top of window
                                 * when scan started. */
 
    /*
     * Miscellaneous information:
     */
 
    Tk_Cursor cursor;           /* Current cursor for window, or None. */
    char *takeFocus;            /* Value of -takefocus option;  not used in
                                 * the C code, but used by keyboard traversal
                                 * scripts.  Malloc'ed, but may be NULL. */
    char *yScrollCmd;           /* Command prefix for communicating with
                                 * vertical scrollbar.  NULL means no command
                                 * to issue.  Malloc'ed. */
    char *xScrollCmd;           /* Command prefix for communicating with
                                 * horizontal scrollbar.  NULL means no command
                                 * to issue.  Malloc'ed. */
    int flags;                  /* Various flag bits:  see below for
                                 * definitions. */
} Listbox;
 
/*
 * Flag bits for listboxes:
 *
 * REDRAW_PENDING:              Non-zero means a DoWhenIdle handler
 *                              has already been queued to redraw
 *                              this window.
 * UPDATE_V_SCROLLBAR:          Non-zero means vertical scrollbar needs
 *                              to be updated.
 * UPDATE_H_SCROLLBAR:          Non-zero means horizontal scrollbar needs
 *                              to be updated.
 * GOT_FOCUS:                   Non-zero means this widget currently
 *                              has the input focus.
 */
 
#define REDRAW_PENDING          1
#define UPDATE_V_SCROLLBAR      2
#define UPDATE_H_SCROLLBAR      4
#define GOT_FOCUS               8
 
/*
 * Information used for argv parsing:
 */
 
static Tk_ConfigSpec configSpecs[] = {
    {TK_CONFIG_BORDER, "-background", "background", "Background",
        DEF_LISTBOX_BG_COLOR, Tk_Offset(Listbox, normalBorder),
        TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_BORDER, "-background", "background", "Background",
        DEF_LISTBOX_BG_MONO, Tk_Offset(Listbox, normalBorder),
        TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_SYNONYM, "-bd", "borderWidth", (char *) NULL,
        (char *) NULL, 0, 0},
    {TK_CONFIG_SYNONYM, "-bg", "background", (char *) NULL,
        (char *) NULL, 0, 0},
    {TK_CONFIG_PIXELS, "-borderwidth", "borderWidth", "BorderWidth",
        DEF_LISTBOX_BORDER_WIDTH, Tk_Offset(Listbox, borderWidth), 0},
    {TK_CONFIG_ACTIVE_CURSOR, "-cursor", "cursor", "Cursor",
        DEF_LISTBOX_CURSOR, Tk_Offset(Listbox, cursor), TK_CONFIG_NULL_OK},
    {TK_CONFIG_BOOLEAN, "-exportselection", "exportSelection",
        "ExportSelection", DEF_LISTBOX_EXPORT_SELECTION,
        Tk_Offset(Listbox, exportSelection), 0},
    {TK_CONFIG_SYNONYM, "-fg", "foreground", (char *) NULL,
        (char *) NULL, 0, 0},
    {TK_CONFIG_FONT, "-font", "font", "Font",
        DEF_LISTBOX_FONT, Tk_Offset(Listbox, tkfont), 0},
    {TK_CONFIG_COLOR, "-foreground", "foreground", "Foreground",
        DEF_LISTBOX_FG, Tk_Offset(Listbox, fgColorPtr), 0},
    {TK_CONFIG_INT, "-height", "height", "Height",
        DEF_LISTBOX_HEIGHT, Tk_Offset(Listbox, height), 0},
    {TK_CONFIG_COLOR, "-highlightbackground", "highlightBackground",
        "HighlightBackground", DEF_LISTBOX_HIGHLIGHT_BG,
        Tk_Offset(Listbox, highlightBgColorPtr), 0},
    {TK_CONFIG_COLOR, "-highlightcolor", "highlightColor", "HighlightColor",
        DEF_LISTBOX_HIGHLIGHT, Tk_Offset(Listbox, highlightColorPtr), 0},
    {TK_CONFIG_PIXELS, "-highlightthickness", "highlightThickness",
        "HighlightThickness",
        DEF_LISTBOX_HIGHLIGHT_WIDTH, Tk_Offset(Listbox, highlightWidth), 0},
    {TK_CONFIG_RELIEF, "-relief", "relief", "Relief",
        DEF_LISTBOX_RELIEF, Tk_Offset(Listbox, relief), 0},
    {TK_CONFIG_BORDER, "-selectbackground", "selectBackground", "Foreground",
        DEF_LISTBOX_SELECT_COLOR, Tk_Offset(Listbox, selBorder),
        TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_BORDER, "-selectbackground", "selectBackground", "Foreground",
        DEF_LISTBOX_SELECT_MONO, Tk_Offset(Listbox, selBorder),
        TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_PIXELS, "-selectborderwidth", "selectBorderWidth", "BorderWidth",
        DEF_LISTBOX_SELECT_BD, Tk_Offset(Listbox, selBorderWidth), 0},
    {TK_CONFIG_COLOR, "-selectforeground", "selectForeground", "Background",
        DEF_LISTBOX_SELECT_FG_COLOR, Tk_Offset(Listbox, selFgColorPtr),
        TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_COLOR, "-selectforeground", "selectForeground", "Background",
        DEF_LISTBOX_SELECT_FG_MONO, Tk_Offset(Listbox, selFgColorPtr),
        TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_UID, "-selectmode", "selectMode", "SelectMode",
        DEF_LISTBOX_SELECT_MODE, Tk_Offset(Listbox, selectMode), 0},
    {TK_CONFIG_BOOLEAN, "-setgrid", "setGrid", "SetGrid",
        DEF_LISTBOX_SET_GRID, Tk_Offset(Listbox, setGrid), 0},
    {TK_CONFIG_STRING, "-takefocus", "takeFocus", "TakeFocus",
        DEF_LISTBOX_TAKE_FOCUS, Tk_Offset(Listbox, takeFocus),
        TK_CONFIG_NULL_OK},
    {TK_CONFIG_INT, "-width", "width", "Width",
        DEF_LISTBOX_WIDTH, Tk_Offset(Listbox, width), 0},
    {TK_CONFIG_STRING, "-xscrollcommand", "xScrollCommand", "ScrollCommand",
        DEF_LISTBOX_SCROLL_COMMAND, Tk_Offset(Listbox, xScrollCmd),
        TK_CONFIG_NULL_OK},
    {TK_CONFIG_STRING, "-yscrollcommand", "yScrollCommand", "ScrollCommand",
        DEF_LISTBOX_SCROLL_COMMAND, Tk_Offset(Listbox, yScrollCmd),
        TK_CONFIG_NULL_OK},
    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
        (char *) NULL, 0, 0}
};
 
/*
 * Forward declarations for procedures defined later in this file:
 */
 
static void             ChangeListboxOffset _ANSI_ARGS_((Listbox *listPtr,
                            int offset));
static void             ChangeListboxView _ANSI_ARGS_((Listbox *listPtr,
                            int index));
static int              ConfigureListbox _ANSI_ARGS_((Tcl_Interp *interp,
                            Listbox *listPtr, int argc, char **argv,
                            int flags));
static void             DeleteEls _ANSI_ARGS_((Listbox *listPtr, int first,
                            int last));
static void             DestroyListbox _ANSI_ARGS_((char *memPtr));
static void             DisplayListbox _ANSI_ARGS_((ClientData clientData));
static int              GetListboxIndex _ANSI_ARGS_((Tcl_Interp *interp,
                            Listbox *listPtr, char *string, int endIsSize,
                            int *indexPtr));
static void             InsertEls _ANSI_ARGS_((Listbox *listPtr, int index,
                            int argc, char **argv));
static void             ListboxCmdDeletedProc _ANSI_ARGS_((
                            ClientData clientData));
static void             ListboxComputeGeometry _ANSI_ARGS_((Listbox *listPtr,
                            int fontChanged, int maxIsStale, int updateGrid));
static void             ListboxEventProc _ANSI_ARGS_((ClientData clientData,
                            XEvent *eventPtr));
static int              ListboxFetchSelection _ANSI_ARGS_((
                            ClientData clientData, int offset, char *buffer,
                            int maxBytes));
static void             ListboxLostSelection _ANSI_ARGS_((
                            ClientData clientData));
static void             ListboxRedrawRange _ANSI_ARGS_((Listbox *listPtr,
                            int first, int last));
static void             ListboxScanTo _ANSI_ARGS_((Listbox *listPtr,
                            int x, int y));
static void             ListboxSelect _ANSI_ARGS_((Listbox *listPtr,
                            int first, int last, int select));
static void             ListboxUpdateHScrollbar _ANSI_ARGS_((Listbox *listPtr));
static void             ListboxUpdateVScrollbar _ANSI_ARGS_((Listbox *listPtr));
static int              ListboxWidgetCmd _ANSI_ARGS_((ClientData clientData,
                            Tcl_Interp *interp, int argc, char **argv));
static void             ListboxWorldChanged _ANSI_ARGS_((
                            ClientData instanceData));
static int              NearestListboxElement _ANSI_ARGS_((Listbox *listPtr,
                            int y));
 
/*
 * The structure below defines button class behavior by means of procedures
 * that can be invoked from generic window code.
 */
 
static TkClassProcs listboxClass = {
    NULL,                       /* createProc. */
    ListboxWorldChanged,        /* geometryProc. */
    NULL                        /* modalProc. */
};
 
 
/*
 *--------------------------------------------------------------
 *
 * Tk_ListboxCmd --
 *
 *      This procedure is invoked to process the "listbox" Tcl
 *      command.  See the user documentation for details on what
 *      it does.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *--------------------------------------------------------------
 */
 
int
Tk_ListboxCmd(clientData, interp, argc, argv)
    ClientData clientData;      /* Main window associated with
                                 * interpreter. */
    Tcl_Interp *interp;         /* Current interpreter. */
    int argc;                   /* Number of arguments. */
    char **argv;                /* Argument strings. */
{
    register Listbox *listPtr;
    Tk_Window new;
    Tk_Window tkwin = (Tk_Window) clientData;
 
    if (argc < 2) {
        Tcl_AppendResult(interp, "wrong # args: should be \"",
                argv[0], " pathName ?options?\"", (char *) NULL);
        return TCL_ERROR;
    }
 
    new = Tk_CreateWindowFromPath(interp, tkwin, argv[1], (char *) NULL);
    if (new == NULL) {
        return TCL_ERROR;
    }
 
    /*
     * Initialize the fields of the structure that won't be initialized
     * by ConfigureListbox, or that ConfigureListbox requires to be
     * initialized already (e.g. resource pointers).
     */
 
    listPtr = (Listbox *) ckalloc(sizeof(Listbox));
    listPtr->tkwin = new;
    listPtr->display = Tk_Display(new);
    listPtr->interp = interp;
    listPtr->widgetCmd = Tcl_CreateCommand(interp,
            Tk_PathName(listPtr->tkwin), ListboxWidgetCmd,
            (ClientData) listPtr, ListboxCmdDeletedProc);
    listPtr->numElements = 0;
    listPtr->firstPtr = NULL;
    listPtr->lastPtr = NULL;
    listPtr->normalBorder = NULL;
    listPtr->borderWidth = 0;
    listPtr->relief = TK_RELIEF_RAISED;
    listPtr->highlightWidth = 0;
    listPtr->highlightBgColorPtr = NULL;
    listPtr->highlightColorPtr = NULL;
    listPtr->inset = 0;
    listPtr->tkfont = NULL;
    listPtr->fgColorPtr = NULL;
    listPtr->textGC = None;
    listPtr->selBorder = NULL;
    listPtr->selBorderWidth = 0;
    listPtr->selFgColorPtr = None;
    listPtr->selTextGC = None;
    listPtr->width = 0;
    listPtr->height = 0;
    listPtr->lineHeight = 0;
    listPtr->topIndex = 0;
    listPtr->fullLines = 1;
    listPtr->partialLine = 0;
    listPtr->setGrid = 0;
    listPtr->maxWidth = 0;
    listPtr->xScrollUnit = 1;
    listPtr->xOffset = 0;
    listPtr->selectMode = NULL;
    listPtr->numSelected = 0;
    listPtr->selectAnchor = 0;
    listPtr->exportSelection = 1;
    listPtr->active = 0;
    listPtr->scanMarkX = 0;
    listPtr->scanMarkY = 0;
    listPtr->scanMarkXOffset = 0;
    listPtr->scanMarkYIndex = 0;
    listPtr->cursor = None;
    listPtr->takeFocus = NULL;
    listPtr->xScrollCmd = NULL;
    listPtr->yScrollCmd = NULL;
    listPtr->flags = 0;
 
    Tk_SetClass(listPtr->tkwin, "Listbox");
    TkSetClassProcs(listPtr->tkwin, &listboxClass, (ClientData) listPtr);
    Tk_CreateEventHandler(listPtr->tkwin,
            ExposureMask|StructureNotifyMask|FocusChangeMask,
            ListboxEventProc, (ClientData) listPtr);
    Tk_CreateSelHandler(listPtr->tkwin, XA_PRIMARY, XA_STRING,
            ListboxFetchSelection, (ClientData) listPtr, XA_STRING);
    if (ConfigureListbox(interp, listPtr, argc-2, argv+2, 0) != TCL_OK) {
        goto error;
    }
 
    interp->result = Tk_PathName(listPtr->tkwin);
    return TCL_OK;
 
    error:
    Tk_DestroyWindow(listPtr->tkwin);
    return TCL_ERROR;
}
 
/*
 *--------------------------------------------------------------
 *
 * ListboxWidgetCmd --
 *
 *      This procedure is invoked to process the Tcl command
 *      that corresponds to a widget managed by this module.
 *      See the user documentation for details on what it does.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *--------------------------------------------------------------
 */
 
static int
ListboxWidgetCmd(clientData, interp, argc, argv)
    ClientData clientData;              /* Information about listbox widget. */
    Tcl_Interp *interp;                 /* Current interpreter. */
    int argc;                           /* Number of arguments. */
    char **argv;                        /* Argument strings. */
{
    register Listbox *listPtr = (Listbox *) clientData;
    int result = TCL_OK;
    size_t length;
    int c;
    Tk_FontMetrics fm;
 
    if (argc < 2) {
        Tcl_AppendResult(interp, "wrong # args: should be \"",
                argv[0], " option ?arg arg ...?\"", (char *) NULL);
        return TCL_ERROR;
    }
    Tcl_Preserve((ClientData) listPtr);
    c = argv[1][0];
    length = strlen(argv[1]);
    if ((c == 'a') && (strncmp(argv[1], "activate", length) == 0)) {
        int index;
 
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " activate index\"",
                    (char *) NULL);
            goto error;
        }
        ListboxRedrawRange(listPtr, listPtr->active, listPtr->active);
        if (GetListboxIndex(interp, listPtr, argv[2], 0, &index) != TCL_OK) {
            goto error;
        }
        if (index >= listPtr->numElements) {
            index = listPtr->numElements-1;
        }
        if (index < 0) {
            index = 0;
        }
        listPtr->active = index;
        ListboxRedrawRange(listPtr, listPtr->active, listPtr->active);
    } else if ((c == 'b') && (strncmp(argv[1], "bbox", length) == 0)) {
        int index, x, y, i;
        Element *elPtr;
 
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " bbox index\"", (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[2], 0, &index) != TCL_OK) {
            goto error;
        }
        if ((index >= listPtr->numElements) || (index < 0)) {
            goto done;
        }
        for (i = 0, elPtr = listPtr->firstPtr; i < index;
                i++, elPtr = elPtr->nextPtr) {
            /* Empty loop body. */
        }
        if ((index >= listPtr->topIndex) && (index < listPtr->numElements)
                    && (index < (listPtr->topIndex + listPtr->fullLines
                    + listPtr->partialLine))) {
            x = listPtr->inset + listPtr->selBorderWidth - listPtr->xOffset;
            y = ((index - listPtr->topIndex)*listPtr->lineHeight)
                    + listPtr->inset + listPtr->selBorderWidth;
            Tk_GetFontMetrics(listPtr->tkfont, &fm);
            sprintf(interp->result, "%d %d %d %d", x, y, elPtr->pixelWidth,
                    fm.linespace);
        }
    } else if ((c == 'c') && (strncmp(argv[1], "cget", length) == 0)
            && (length >= 2)) {
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " cget option\"",
                    (char *) NULL);
            goto error;
        }
        result = Tk_ConfigureValue(interp, listPtr->tkwin, configSpecs,
                (char *) listPtr, argv[2], 0);
    } else if ((c == 'c') && (strncmp(argv[1], "configure", length) == 0)
            && (length >= 2)) {
        if (argc == 2) {
            result = Tk_ConfigureInfo(interp, listPtr->tkwin, configSpecs,
                    (char *) listPtr, (char *) NULL, 0);
        } else if (argc == 3) {
            result = Tk_ConfigureInfo(interp, listPtr->tkwin, configSpecs,
                    (char *) listPtr, argv[2], 0);
        } else {
            result = ConfigureListbox(interp, listPtr, argc-2, argv+2,
                    TK_CONFIG_ARGV_ONLY);
        }
    } else if ((c == 'c') && (strncmp(argv[1], "curselection", length) == 0)
            && (length >= 2)) {
        int i, count;
        char index[20];
        Element *elPtr;
 
        if (argc != 2) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " curselection\"",
                    (char *) NULL);
            goto error;
        }
        count = 0;
        for (i = 0, elPtr = listPtr->firstPtr; elPtr != NULL;
                i++, elPtr = elPtr->nextPtr) {
            if (elPtr->selected) {
                sprintf(index, "%d", i);
                Tcl_AppendElement(interp, index);
                count++;
            }
        }
        if (count != listPtr->numSelected) {
            panic("ListboxWidgetCmd: selection count incorrect");
        }
    } else if ((c == 'd') && (strncmp(argv[1], "delete", length) == 0)) {
        int first, last;
 
        if ((argc < 3) || (argc > 4)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " delete firstIndex ?lastIndex?\"",
                    (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[2], 0, &first) != TCL_OK) {
            goto error;
        }
        if (first < listPtr->numElements) {
            if (argc == 3) {
                last = first;
            } else {
                if (GetListboxIndex(interp, listPtr, argv[3], 0,
                        &last) != TCL_OK) {
                    goto error;
                }
                if (last >= listPtr->numElements) {
                    last = listPtr->numElements-1;
                }
            }
            DeleteEls(listPtr, first, last);
        }
    } else if ((c == 'g') && (strncmp(argv[1], "get", length) == 0)) {
        int first, last, i;
        Element *elPtr;
 
        if ((argc != 3) && (argc != 4)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " get first ?last?\"", (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[2], 0, &first) != TCL_OK) {
            goto error;
        }
        if ((argc == 4) && (GetListboxIndex(interp, listPtr, argv[3],
                0, &last) != TCL_OK)) {
            goto error;
        }
        if (first >= listPtr->numElements) {
            goto done;
        }
        if (last >= listPtr->numElements) {
            last = listPtr->numElements-1;
        }
 
        for (elPtr = listPtr->firstPtr, i = 0; i < first;
                i++, elPtr = elPtr->nextPtr) {
            /* Empty loop body. */
        }
        if (elPtr != NULL) {
            if (argc == 3) {
                if (first >= 0) {
                    interp->result = elPtr->text;
                }
            } else {
                for (  ; i <= last; i++, elPtr = elPtr->nextPtr) {
                    Tcl_AppendElement(interp, elPtr->text);
                }
            }
        }
    } else if ((c == 'i') && (strncmp(argv[1], "index", length) == 0)
            && (length >= 3)) {
        int index;
 
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " index index\"",
                    (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[2], 1, &index)
                != TCL_OK) {
            goto error;
        }
        sprintf(interp->result, "%d", index);
    } else if ((c == 'i') && (strncmp(argv[1], "insert", length) == 0)
            && (length >= 3)) {
        int index;
 
        if (argc < 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " insert index ?element element ...?\"",
                    (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[2], 1, &index)
                != TCL_OK) {
            goto error;
        }
        InsertEls(listPtr, index, argc-3, argv+3);
    } else if ((c == 'n') && (strncmp(argv[1], "nearest", length) == 0)) {
        int index, y;
 
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " nearest y\"", (char *) NULL);
            goto error;
        }
        if (Tcl_GetInt(interp, argv[2], &y) != TCL_OK) {
            goto error;
        }
        index = NearestListboxElement(listPtr, y);
        sprintf(interp->result, "%d", index);
    } else if ((c == 's') && (length >= 2)
            && (strncmp(argv[1], "scan", length) == 0)) {
        int x, y;
 
        if (argc != 5) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " scan mark|dragto x y\"", (char *) NULL);
            goto error;
        }
        if ((Tcl_GetInt(interp, argv[3], &x) != TCL_OK)
                || (Tcl_GetInt(interp, argv[4], &y) != TCL_OK)) {
            goto error;
        }
        if ((argv[2][0] == 'm')
                && (strncmp(argv[2], "mark", strlen(argv[2])) == 0)) {
            listPtr->scanMarkX = x;
            listPtr->scanMarkY = y;
            listPtr->scanMarkXOffset = listPtr->xOffset;
            listPtr->scanMarkYIndex = listPtr->topIndex;
        } else if ((argv[2][0] == 'd')
                && (strncmp(argv[2], "dragto", strlen(argv[2])) == 0)) {
            ListboxScanTo(listPtr, x, y);
        } else {
            Tcl_AppendResult(interp, "bad scan option \"", argv[2],
                    "\": must be mark or dragto", (char *) NULL);
            goto error;
        }
    } else if ((c == 's') && (strncmp(argv[1], "see", length) == 0)
            && (length >= 3)) {
        int index, diff;
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " see index\"",
                    (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[2], 0, &index) != TCL_OK) {
            goto error;
        }
        if (index >= listPtr->numElements) {
            index = listPtr->numElements-1;
        }
        if (index < 0) {
            index = 0;
        }
        diff = listPtr->topIndex-index;
        if (diff > 0) {
            if (diff <= (listPtr->fullLines/3)) {
                ChangeListboxView(listPtr, index);
            } else {
                ChangeListboxView(listPtr, index - (listPtr->fullLines-1)/2);
            }
        } else {
            diff = index - (listPtr->topIndex + listPtr->fullLines - 1);
            if (diff > 0) {
                if (diff <= (listPtr->fullLines/3)) {
                    ChangeListboxView(listPtr, listPtr->topIndex + diff);
                } else {
                    ChangeListboxView(listPtr,
                            index - (listPtr->fullLines-1)/2);
                }
            }
        }
    } else if ((c == 's') && (length >= 3)
            && (strncmp(argv[1], "selection", length) == 0)) {
        int first, last;
 
        if ((argc != 4) && (argc != 5)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " selection option index ?index?\"",
                    (char *) NULL);
            goto error;
        }
        if (GetListboxIndex(interp, listPtr, argv[3], 0, &first) != TCL_OK) {
            goto error;
        }
        if (argc == 5) {
            if (GetListboxIndex(interp, listPtr, argv[4], 0, &last) != TCL_OK) {
                goto error;
            }
        } else {
            last = first;
        }
        length = strlen(argv[2]);
        c = argv[2][0];
        if ((c == 'a') && (strncmp(argv[2], "anchor", length) == 0)) {
            if (argc != 4) {
                Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " selection anchor index\"", (char *) NULL);
                goto error;
            }
            if (first >= listPtr->numElements) {
                first = listPtr->numElements-1;
            }
            if (first < 0) {
                first = 0;
            }
            listPtr->selectAnchor = first;
        } else if ((c == 'c') && (strncmp(argv[2], "clear", length) == 0)) {
            ListboxSelect(listPtr, first, last, 0);
        } else if ((c == 'i') && (strncmp(argv[2], "includes", length) == 0)) {
            int i;
            Element *elPtr;
 
            if (argc != 4) {
                Tcl_AppendResult(interp, "wrong # args: should be \"",
                        argv[0], " selection includes index\"", (char *) NULL);
                goto error;
            }
            if ((first < 0) || (first >= listPtr->numElements)) {
                interp->result = "0";
                goto done;
            }
            for (elPtr = listPtr->firstPtr, i = 0; i < first;
                    i++, elPtr = elPtr->nextPtr) {
                /* Empty loop body. */
            }
            if (elPtr->selected) {
                interp->result = "1";
            } else {
                interp->result = "0";
            }
        } else if ((c == 's') && (strncmp(argv[2], "set", length) == 0)) {
            ListboxSelect(listPtr, first, last, 1);
        } else {
            Tcl_AppendResult(interp, "bad selection option \"", argv[2],
                    "\": must be anchor, clear, includes, or set",
                    (char *) NULL);
            goto error;
        }
    } else if ((c == 's') && (length >= 2)
            && (strncmp(argv[1], "size", length) == 0)) {
        if (argc != 2) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " size\"", (char *) NULL);
            goto error;
        }
        sprintf(interp->result, "%d", listPtr->numElements);
    } else if ((c == 'x') && (strncmp(argv[1], "xview", length) == 0)) {
        int index, count, type, windowWidth, windowUnits;
        int offset = 0;          /* Initialized to stop gcc warnings. */
        double fraction, fraction2;
 
        windowWidth = Tk_Width(listPtr->tkwin)
            - 2*(listPtr->inset + listPtr->selBorderWidth);
        if (argc == 2) {
            if (listPtr->maxWidth == 0) {
                interp->result = "0 1";
            } else {
                fraction = listPtr->xOffset/((double) listPtr->maxWidth);
                fraction2 = (listPtr->xOffset + windowWidth)
                        /((double) listPtr->maxWidth);
                if (fraction2 > 1.0) {
                    fraction2 = 1.0;
                }
                sprintf(interp->result, "%g %g", fraction, fraction2);
            }
        } else if (argc == 3) {
            if (Tcl_GetInt(interp, argv[2], &index) != TCL_OK) {
                goto error;
            }
            ChangeListboxOffset(listPtr, index*listPtr->xScrollUnit);
        } else {
            type = Tk_GetScrollInfo(interp, argc, argv, &fraction, &count);
            switch (type) {
                case TK_SCROLL_ERROR:
                    goto error;
                case TK_SCROLL_MOVETO:
                    offset = (int) (fraction*listPtr->maxWidth + 0.5);
                    break;
                case TK_SCROLL_PAGES:
                    windowUnits = windowWidth/listPtr->xScrollUnit;
                    if (windowUnits > 2) {
                        offset = listPtr->xOffset
                                + count*listPtr->xScrollUnit*(windowUnits-2);
                    } else {
                        offset = listPtr->xOffset + count*listPtr->xScrollUnit;
                    }
                    break;
                case TK_SCROLL_UNITS:
                    offset = listPtr->xOffset + count*listPtr->xScrollUnit;
                    break;
            }
            ChangeListboxOffset(listPtr, offset);
        }
    } else if ((c == 'y') && (strncmp(argv[1], "yview", length) == 0)) {
        int index, count, type;
        double fraction, fraction2;
 
        if (argc == 2) {
            if (listPtr->numElements == 0) {
                interp->result = "0 1";
            } else {
                fraction = listPtr->topIndex/((double) listPtr->numElements);
                fraction2 = (listPtr->topIndex+listPtr->fullLines)
                        /((double) listPtr->numElements);
                if (fraction2 > 1.0) {
                    fraction2 = 1.0;
                }
                sprintf(interp->result, "%g %g", fraction, fraction2);
            }
        } else if (argc == 3) {
            if (GetListboxIndex(interp, listPtr, argv[2], 0, &index)
                    != TCL_OK) {
                goto error;
            }
            ChangeListboxView(listPtr, index);
        } else {
            type = Tk_GetScrollInfo(interp, argc, argv, &fraction, &count);
            switch (type) {
                case TK_SCROLL_ERROR:
                    goto error;
                case TK_SCROLL_MOVETO:
                    index = (int) (listPtr->numElements*fraction + 0.5);
                    break;
                case TK_SCROLL_PAGES:
                    if (listPtr->fullLines > 2) {
                        index = listPtr->topIndex
                                + count*(listPtr->fullLines-2);
                    } else {
                        index = listPtr->topIndex + count;
                    }
                    break;
                case TK_SCROLL_UNITS:
                    index = listPtr->topIndex + count;
                    break;
            }
            ChangeListboxView(listPtr, index);
        }
    } else {
        Tcl_AppendResult(interp, "bad option \"", argv[1],
                "\": must be activate, bbox, cget, configure, ",
                "curselection, delete, get, index, insert, nearest, ",
                "scan, see, selection, size, ",
                "xview, or yview", (char *) NULL);
        goto error;
    }
    done:
    Tcl_Release((ClientData) listPtr);
    return result;
 
    error:
    Tcl_Release((ClientData) listPtr);
    return TCL_ERROR;
}
 
/*
 *----------------------------------------------------------------------
 *
 * DestroyListbox --
 *
 *      This procedure is invoked by Tcl_EventuallyFree or Tcl_Release
 *      to clean up the internal structure of a listbox at a safe time
 *      (when no-one is using it anymore).
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Everything associated with the listbox is freed up.
 *
 *----------------------------------------------------------------------
 */
 
static void
DestroyListbox(memPtr)
    char *memPtr;       /* Info about listbox widget. */
{
    register Listbox *listPtr = (Listbox *) memPtr;
    register Element *elPtr, *nextPtr;
 
    /*
     * Free up all of the list elements.
     */
 
    for (elPtr = listPtr->firstPtr; elPtr != NULL; ) {
        nextPtr = elPtr->nextPtr;
        ckfree((char *) elPtr);
        elPtr = nextPtr;
    }
 
    /*
     * Free up all the stuff that requires special handling, then
     * let Tk_FreeOptions handle all the standard option-related
     * stuff.
     */
 
    if (listPtr->textGC != None) {
        Tk_FreeGC(listPtr->display, listPtr->textGC);
    }
    if (listPtr->selTextGC != None) {
        Tk_FreeGC(listPtr->display, listPtr->selTextGC);
    }
    Tk_FreeOptions(configSpecs, (char *) listPtr, listPtr->display, 0);
    ckfree((char *) listPtr);
}
 
/*
 *----------------------------------------------------------------------
 *
 * ConfigureListbox --
 *
 *      This procedure is called to process an argv/argc list, plus
 *      the Tk option database, in order to configure (or reconfigure)
 *      a listbox widget.
 *
 * Results:
 *      The return value is a standard Tcl result.  If TCL_ERROR is
 *      returned, then interp->result contains an error message.
 *
 * Side effects:
 *      Configuration information, such as colors, border width,
 *      etc. get set for listPtr;  old resources get freed,
 *      if there were any.
 *
 *----------------------------------------------------------------------
 */
 
static int
ConfigureListbox(interp, listPtr, argc, argv, flags)
    Tcl_Interp *interp;         /* Used for error reporting. */
    register Listbox *listPtr;  /* Information about widget;  may or may
                                 * not already have values for some fields. */
    int argc;                   /* Number of valid entries in argv. */
    char **argv;                /* Arguments. */
    int flags;                  /* Flags to pass to Tk_ConfigureWidget. */
{
    int oldExport;
 
    oldExport = listPtr->exportSelection;
    if (Tk_ConfigureWidget(interp, listPtr->tkwin, configSpecs,
            argc, argv, (char *) listPtr, flags) != TCL_OK) {
        return TCL_ERROR;
    }
 
    /*
     * A few options need special processing, such as setting the
     * background from a 3-D border.
     */
 
    Tk_SetBackgroundFromBorder(listPtr->tkwin, listPtr->normalBorder);
 
    if (listPtr->highlightWidth < 0) {
        listPtr->highlightWidth = 0;
    }
    listPtr->inset = listPtr->highlightWidth + listPtr->borderWidth;
 
    /*
     * Claim the selection if we've suddenly started exporting it and
     * there is a selection to export.
     */
 
    if (listPtr->exportSelection && !oldExport
            && (listPtr->numSelected != 0)) {
        Tk_OwnSelection(listPtr->tkwin, XA_PRIMARY, ListboxLostSelection,
                (ClientData) listPtr);
    }
 
    ListboxWorldChanged((ClientData) listPtr);
    return TCL_OK;
}
 
/*
 *---------------------------------------------------------------------------
 *
 * ListboxWorldChanged --
 *
 *      This procedure is called when the world has changed in some
 *      way and the widget needs to recompute all its graphics contexts
 *      and determine its new geometry.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Listbox will be relayed out and redisplayed.
 *
 *---------------------------------------------------------------------------
 */
 
static void
ListboxWorldChanged(instanceData)
    ClientData instanceData;    /* Information about widget. */
{
    XGCValues gcValues;
    GC gc;
    unsigned long mask;
    Listbox *listPtr;
 
    listPtr = (Listbox *) instanceData;
 
    gcValues.foreground = listPtr->fgColorPtr->pixel;
    gcValues.font = Tk_FontId(listPtr->tkfont);
    gcValues.graphics_exposures = False;
    mask = GCForeground | GCFont | GCGraphicsExposures;
    gc = Tk_GetGCColor(listPtr->tkwin, mask, &gcValues, listPtr->fgColorPtr,
                       NULL);
    if (listPtr->textGC != None) {
        Tk_FreeGC(listPtr->display, listPtr->textGC);
    }
    listPtr->textGC = gc;
 
    gcValues.foreground = listPtr->selFgColorPtr->pixel;
    gcValues.font = Tk_FontId(listPtr->tkfont);
    mask = GCForeground | GCFont;
    gc = Tk_GetGCColor(listPtr->tkwin, mask, &gcValues, listPtr->selFgColorPtr,
                       NULL);
    if (listPtr->selTextGC != None) {
        Tk_FreeGC(listPtr->display, listPtr->selTextGC);
    }
    listPtr->selTextGC = gc;
 
    /*
     * Register the desired geometry for the window and arrange for
     * the window to be redisplayed.
     */
 
    ListboxComputeGeometry(listPtr, 1, 1, 1);
    listPtr->flags |= UPDATE_V_SCROLLBAR|UPDATE_H_SCROLLBAR;
    ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
}
 
/*
 *--------------------------------------------------------------
 *
 * DisplayListbox --
 *
 *      This procedure redraws the contents of a listbox window.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Information appears on the screen.
 *
 *--------------------------------------------------------------
 */
 
static void
DisplayListbox(clientData)
    ClientData clientData;      /* Information about window. */
{
    register Listbox *listPtr = (Listbox *) clientData;
    register Tk_Window tkwin = listPtr->tkwin;
    register Element *elPtr;
    GC gc;
    int i, limit, x, y, width, prevSelected;
    Tk_FontMetrics fm;
    int left, right;                    /* Non-zero values here indicate
                                         * that the left or right edge of
                                         * the listbox is off-screen. */
    Pixmap pixmap;
 
    listPtr->flags &= ~REDRAW_PENDING;
    if (listPtr->flags & UPDATE_V_SCROLLBAR) {
        ListboxUpdateVScrollbar(listPtr);
    }
    if (listPtr->flags & UPDATE_H_SCROLLBAR) {
        ListboxUpdateHScrollbar(listPtr);
    }
    listPtr->flags &= ~(REDRAW_PENDING|UPDATE_V_SCROLLBAR|UPDATE_H_SCROLLBAR);
    if ((listPtr->tkwin == NULL) || !Tk_IsMapped(tkwin)) {
        return;
    }
 
    /*
     * Redrawing is done in a temporary pixmap that is allocated
     * here and freed at the end of the procedure.  All drawing is
     * done to the pixmap, and the pixmap is copied to the screen
     * at the end of the procedure.  This provides the smoothest
     * possible visual effects (no flashing on the screen).
     */
 
    pixmap = Tk_GetPixmap(listPtr->display, Tk_WindowId(tkwin),
            Tk_Width(tkwin), Tk_Height(tkwin), Tk_Depth(tkwin));
    Tk_Fill3DRectangle(tkwin, pixmap, listPtr->normalBorder, 0, 0,
            Tk_Width(tkwin), Tk_Height(tkwin), 0, TK_RELIEF_FLAT);
 
    /*
     * Iterate through all of the elements of the listbox, displaying each
     * in turn.  Selected elements use a different GC and have a raised
     * background.
     */
 
    limit = listPtr->topIndex + listPtr->fullLines + listPtr->partialLine - 1;
    if (limit >= listPtr->numElements) {
        limit = listPtr->numElements-1;
    }
    left = right = 0;
    if (listPtr->xOffset > 0) {
        left = listPtr->selBorderWidth+1;
    }
    if ((listPtr->maxWidth - listPtr->xOffset) > (Tk_Width(listPtr->tkwin)
            - 2*(listPtr->inset + listPtr->selBorderWidth)))  {
        right = listPtr->selBorderWidth+1;
    }
    prevSelected = 0;
    for (elPtr = listPtr->firstPtr, i = 0; (elPtr != NULL) && (i <= limit);
            prevSelected = elPtr->selected, elPtr = elPtr->nextPtr, i++) {
        if (i < listPtr->topIndex) {
            continue;
        }
        x = listPtr->inset;
        y = ((i - listPtr->topIndex) * listPtr->lineHeight)
                + listPtr->inset;
        gc = listPtr->textGC;
        if (elPtr->selected) {
            gc = listPtr->selTextGC;
            width = Tk_Width(tkwin) - 2*listPtr->inset;
            Tk_Fill3DRectangle(tkwin, pixmap, listPtr->selBorder, x, y,
                    width, listPtr->lineHeight, 0, TK_RELIEF_FLAT);
 
            /*
             * Draw beveled edges around the selection, if there are visible
             * edges next to this element.  Special considerations:
             * 1. The left and right bevels may not be visible if horizontal
             *    scrolling is enabled (the "left" and "right" variables
             *    are zero to indicate that the corresponding bevel is
             *    visible).
             * 2. Top and bottom bevels are only drawn if this is the
             *    first or last seleted item.
             * 3. If the left or right bevel isn't visible, then the "left"
             *    and "right" variables, computed above, have non-zero values
             *    that extend the top and bottom bevels so that the mitered
             *    corners are off-screen.
             */
 
            if (left == 0) {
                Tk_3DVerticalBevel(tkwin, pixmap, listPtr->selBorder,
                        x, y, listPtr->selBorderWidth, listPtr->lineHeight,
                        1, TK_RELIEF_RAISED);
            }
            if (right == 0) {
                Tk_3DVerticalBevel(tkwin, pixmap, listPtr->selBorder,
                        x + width - listPtr->selBorderWidth, y,
                        listPtr->selBorderWidth, listPtr->lineHeight,
                        0, TK_RELIEF_RAISED);
            }
            if (!prevSelected) {
                Tk_3DHorizontalBevel(tkwin, pixmap, listPtr->selBorder,
                        x-left, y, width+left+right, listPtr->selBorderWidth,
                        1, 1, 1, TK_RELIEF_RAISED);
            }
            if ((elPtr->nextPtr == NULL) || !elPtr->nextPtr->selected) {
                Tk_3DHorizontalBevel(tkwin, pixmap, listPtr->selBorder, x-left,
                        y + listPtr->lineHeight - listPtr->selBorderWidth,
                        width+left+right, listPtr->selBorderWidth, 0, 0, 0,
                        TK_RELIEF_RAISED);
            }
        }
        Tk_GetFontMetrics(listPtr->tkfont, &fm);
        y += fm.ascent + listPtr->selBorderWidth;
        x = listPtr->inset + listPtr->selBorderWidth - elPtr->lBearing
                - listPtr->xOffset;
        Tk_DrawChars(listPtr->display, pixmap, gc, listPtr->tkfont,
                elPtr->text, elPtr->textLength, x, y);
 
        /*
         * If this is the active element, underline it.
         */
 
        if ((i == listPtr->active) && (listPtr->flags & GOT_FOCUS)) {
            Tk_UnderlineChars(listPtr->display, pixmap, gc, listPtr->tkfont,
                    elPtr->text, x, y, 0, elPtr->textLength);
        }
    }
 
    /*
     * Redraw the border for the listbox to make sure that it's on top
     * of any of the text of the listbox entries.
     */
 
    Tk_Draw3DRectangle(tkwin, pixmap, listPtr->normalBorder,
            listPtr->highlightWidth, listPtr->highlightWidth,
            Tk_Width(tkwin) - 2*listPtr->highlightWidth,
            Tk_Height(tkwin) - 2*listPtr->highlightWidth,
            listPtr->borderWidth, listPtr->relief);
    if (listPtr->highlightWidth > 0) {
        GC gc;
 
        if (listPtr->flags & GOT_FOCUS) {
            gc = Tk_GCForColor(listPtr->highlightColorPtr, pixmap);
        } else {
            gc = Tk_GCForColor(listPtr->highlightBgColorPtr, pixmap);
        }
        Tk_DrawFocusHighlight(tkwin, gc, listPtr->highlightWidth, pixmap);
    }
    XCopyArea(listPtr->display, pixmap, Tk_WindowId(tkwin),
            listPtr->textGC, 0, 0, (unsigned) Tk_Width(tkwin),
            (unsigned) Tk_Height(tkwin), 0, 0);
    Tk_FreePixmap(listPtr->display, pixmap);
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxComputeGeometry --
 *
 *      This procedure is invoked to recompute geometry information
 *      such as the sizes of the elements and the overall dimensions
 *      desired for the listbox.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Geometry information is updated and a new requested size is
 *      registered for the widget.  Internal border and gridding
 *      information is also set.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxComputeGeometry(listPtr, fontChanged, maxIsStale, updateGrid)
    Listbox *listPtr;           /* Listbox whose geometry is to be
                                 * recomputed. */
    int fontChanged;            /* Non-zero means the font may have changed
                                 * so per-element width information also
                                 * has to be computed. */
    int maxIsStale;             /* Non-zero means the "maxWidth" field may
                                 * no longer be up-to-date and must
                                 * be recomputed.  If fontChanged is 1 then
                                 * this must be 1. */
    int updateGrid;             /* Non-zero means call Tk_SetGrid or
                                 * Tk_UnsetGrid to update gridding for
                                 * the window. */
{
    register Element *elPtr;
    int width, height, pixelWidth, pixelHeight;
    Tk_FontMetrics fm;
 
    if (fontChanged  || maxIsStale) {
        listPtr->xScrollUnit = Tk_TextWidth(listPtr->tkfont, "0", 1);
        if (listPtr->xScrollUnit == 0) {
            listPtr->xScrollUnit = 1;
        }
        listPtr->maxWidth = 0;
        for (elPtr = listPtr->firstPtr; elPtr != NULL; elPtr = elPtr->nextPtr) {
            if (fontChanged) {
                elPtr->pixelWidth = Tk_TextWidth(listPtr->tkfont,
                        elPtr->text, elPtr->textLength);
                elPtr->lBearing = 0;
            }
            if (elPtr->pixelWidth > listPtr->maxWidth) {
                listPtr->maxWidth = elPtr->pixelWidth;
            }
        }
    }
 
    Tk_GetFontMetrics(listPtr->tkfont, &fm);
    listPtr->lineHeight = fm.linespace + 1 + 2*listPtr->selBorderWidth;
    width = listPtr->width;
    if (width <= 0) {
        width = (listPtr->maxWidth + listPtr->xScrollUnit - 1)
                /listPtr->xScrollUnit;
        if (width < 1) {
            width = 1;
        }
    }
    pixelWidth = width*listPtr->xScrollUnit + 2*listPtr->inset
            + 2*listPtr->selBorderWidth;
    height = listPtr->height;
    if (listPtr->height <= 0) {
        height = listPtr->numElements;
        if (height < 1) {
            height = 1;
        }
    }
    pixelHeight = height*listPtr->lineHeight + 2*listPtr->inset;
    Tk_GeometryRequest(listPtr->tkwin, pixelWidth, pixelHeight);
    Tk_SetInternalBorder(listPtr->tkwin, listPtr->inset);
    if (updateGrid) {
        if (listPtr->setGrid) {
            Tk_SetGrid(listPtr->tkwin, width, height, listPtr->xScrollUnit,
                    listPtr->lineHeight);
        } else {
            Tk_UnsetGrid(listPtr->tkwin);
        }
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * InsertEls --
 *
 *      Add new elements to a listbox widget.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      New information gets added to listPtr;  it will be redisplayed
 *      soon, but not immediately.
 *
 *----------------------------------------------------------------------
 */
 
static void
InsertEls(listPtr, index, argc, argv)
    register Listbox *listPtr;  /* Listbox that is to get the new
                                 * elements. */
    int index;                  /* Add the new elements before this
                                 * element. */
    int argc;                   /* Number of new elements to add. */
    char **argv;                /* New elements (one per entry). */
{
    register Element *prevPtr, *newPtr;
    int length, i, oldMaxWidth;
 
    /*
     * Find the element before which the new ones will be inserted.
     */
 
    if (index <= 0) {
        index = 0;
    }
    if (index > listPtr->numElements) {
        index = listPtr->numElements;
    }
    if (index == 0) {
        prevPtr = NULL;
    } else if (index == listPtr->numElements) {
          prevPtr = listPtr->lastPtr;
    } else {
        for (prevPtr = listPtr->firstPtr, i = index - 1; i > 0; i--) {
            prevPtr = prevPtr->nextPtr;
        }
    }
 
    /*
     * For each new element, create a record, initialize it, and link
     * it into the list of elements.
     */
 
    oldMaxWidth = listPtr->maxWidth;
    for (i = argc ; i > 0; i--, argv++, prevPtr = newPtr) {
        length = strlen(*argv);
        newPtr = (Element *) ckalloc(ElementSize(length));
        newPtr->textLength = length;
        strcpy(newPtr->text, *argv);
        newPtr->pixelWidth = Tk_TextWidth(listPtr->tkfont, newPtr->text,
                newPtr->textLength);
        newPtr->lBearing = 0;
        if (newPtr->pixelWidth > listPtr->maxWidth) {
            listPtr->maxWidth = newPtr->pixelWidth;
        }
        newPtr->selected = 0;
        if (prevPtr == NULL) {
            newPtr->nextPtr = listPtr->firstPtr;
            listPtr->firstPtr = newPtr;
        } else {
            newPtr->nextPtr = prevPtr->nextPtr;
            prevPtr->nextPtr = newPtr;
        }
    }
    if ((prevPtr != NULL) && (prevPtr->nextPtr == NULL)) {
        listPtr->lastPtr = prevPtr;
    }
    listPtr->numElements += argc;
 
    /*
     * Update the selection and other indexes to account for the
     * renumbering that has just occurred.  Then arrange for the new
     * information to be displayed.
     */
 
    if (index <= listPtr->selectAnchor) {
        listPtr->selectAnchor += argc;
    }
    if (index < listPtr->topIndex) {
        listPtr->topIndex += argc;
    }
    if (index <= listPtr->active) {
        listPtr->active += argc;
        if ((listPtr->active >= listPtr->numElements)
                && (listPtr->numElements > 0)) {
            listPtr->active = listPtr->numElements-1;
        }
    }
    listPtr->flags |= UPDATE_V_SCROLLBAR;
    if (listPtr->maxWidth != oldMaxWidth) {
        listPtr->flags |= UPDATE_H_SCROLLBAR;
    }
    ListboxComputeGeometry(listPtr, 0, 0, 0);
    ListboxRedrawRange(listPtr, index, listPtr->numElements-1);
}
 
/*
 *----------------------------------------------------------------------
 *
 * DeleteEls --
 *
 *      Remove one or more elements from a listbox widget.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Memory gets freed, the listbox gets modified and (eventually)
 *      redisplayed.
 *
 *----------------------------------------------------------------------
 */
 
static void
DeleteEls(listPtr, first, last)
    register Listbox *listPtr;  /* Listbox widget to modify. */
    int first;                  /* Index of first element to delete. */
    int last;                   /* Index of last element to delete. */
{
    register Element *prevPtr, *elPtr;
    int count, i, widthChanged;
 
    /*
     * Adjust the range to fit within the existing elements of the
     * listbox, and make sure there's something to delete.
     */
 
    if (first < 0) {
        first = 0;
    }
    if (last >= listPtr->numElements) {
        last = listPtr->numElements-1;
    }
    count = last + 1 - first;
    if (count <= 0) {
        return;
    }
 
    /*
     * Find the element just before the ones to delete.
     */
 
    if (first == 0) {
        prevPtr = NULL;
    } else {
        for (i = first-1, prevPtr = listPtr->firstPtr; i > 0; i--) {
            prevPtr = prevPtr->nextPtr;
        }
    }
 
    /*
     * Delete the requested number of elements.
     */
 
    widthChanged = 0;
    for (i = count; i > 0; i--) {
        if (prevPtr == NULL) {
            elPtr = listPtr->firstPtr;
            listPtr->firstPtr = elPtr->nextPtr;
            if (listPtr->firstPtr == NULL) {
                listPtr->lastPtr = NULL;
            }
        } else {
            elPtr = prevPtr->nextPtr;
            prevPtr->nextPtr = elPtr->nextPtr;
            if (prevPtr->nextPtr == NULL) {
                listPtr->lastPtr = prevPtr;
            }
        }
        if (elPtr->pixelWidth == listPtr->maxWidth) {
            widthChanged = 1;
        }
        if (elPtr->selected) {
            listPtr->numSelected -= 1;
        }
        ckfree((char *) elPtr);
    }
    listPtr->numElements -= count;
 
    /*
     * Update the selection and viewing information to reflect the change
     * in the element numbering, and redisplay to slide information up over
     * the elements that were deleted.
     */
 
    if (first <= listPtr->selectAnchor) {
        listPtr->selectAnchor -= count;
        if (listPtr->selectAnchor < first) {
            listPtr->selectAnchor = first;
        }
    }
    if (first <= listPtr->topIndex) {
        listPtr->topIndex -= count;
        if (listPtr->topIndex < first) {
            listPtr->topIndex = first;
        }
    }
    if (listPtr->topIndex > (listPtr->numElements - listPtr->fullLines)) {
        listPtr->topIndex = listPtr->numElements - listPtr->fullLines;
        if (listPtr->topIndex < 0) {
            listPtr->topIndex = 0;
        }
    }
    if (listPtr->active > last) {
        listPtr->active -= count;
    } else if (listPtr->active >= first) {
        listPtr->active = first;
        if ((listPtr->active >= listPtr->numElements)
                && (listPtr->numElements > 0)) {
            listPtr->active = listPtr->numElements-1;
        }
    }
    listPtr->flags |= UPDATE_V_SCROLLBAR;
    ListboxComputeGeometry(listPtr, 0, widthChanged, 0);
    if (widthChanged) {
        listPtr->flags |= UPDATE_H_SCROLLBAR;
    }
    ListboxRedrawRange(listPtr, first, listPtr->numElements-1);
}
 
/*
 *--------------------------------------------------------------
 *
 * ListboxEventProc --
 *
 *      This procedure is invoked by the Tk dispatcher for various
 *      events on listboxes.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      When the window gets deleted, internal structures get
 *      cleaned up.  When it gets exposed, it is redisplayed.
 *
 *--------------------------------------------------------------
 */
 
static void
ListboxEventProc(clientData, eventPtr)
    ClientData clientData;      /* Information about window. */
    XEvent *eventPtr;           /* Information about event. */
{
    Listbox *listPtr = (Listbox *) clientData;
 
    if (eventPtr->type == Expose) {
        ListboxRedrawRange(listPtr,
                NearestListboxElement(listPtr, eventPtr->xexpose.y),
                NearestListboxElement(listPtr, eventPtr->xexpose.y
                + eventPtr->xexpose.height));
    } else if (eventPtr->type == DestroyNotify) {
        if (listPtr->tkwin != NULL) {
            if (listPtr->setGrid) {
                Tk_UnsetGrid(listPtr->tkwin);
            }
            listPtr->tkwin = NULL;
            Tcl_DeleteCommandFromToken(listPtr->interp, listPtr->widgetCmd);
        }
        if (listPtr->flags & REDRAW_PENDING) {
            Tcl_CancelIdleCall(DisplayListbox, (ClientData) listPtr);
        }
        Tcl_EventuallyFree((ClientData) listPtr, DestroyListbox);
    } else if (eventPtr->type == ConfigureNotify) {
        int vertSpace;
 
        vertSpace = Tk_Height(listPtr->tkwin) - 2*listPtr->inset;
        listPtr->fullLines = vertSpace / listPtr->lineHeight;
        if ((listPtr->fullLines*listPtr->lineHeight) < vertSpace) {
            listPtr->partialLine = 1;
        } else {
            listPtr->partialLine = 0;
        }
        listPtr->flags |= UPDATE_V_SCROLLBAR|UPDATE_H_SCROLLBAR;
        ChangeListboxView(listPtr, listPtr->topIndex);
        ChangeListboxOffset(listPtr, listPtr->xOffset);
 
        /*
         * Redraw the whole listbox.  It's hard to tell what needs
         * to be redrawn (e.g. if the listbox has shrunk then we
         * may only need to redraw the borders), so just redraw
         * everything for safety.
         */
 
        ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
    } else if (eventPtr->type == FocusIn) {
        if (eventPtr->xfocus.detail != NotifyInferior) {
            listPtr->flags |= GOT_FOCUS;
            ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
        }
    } else if (eventPtr->type == FocusOut) {
        if (eventPtr->xfocus.detail != NotifyInferior) {
            listPtr->flags &= ~GOT_FOCUS;
            ListboxRedrawRange(listPtr, 0, listPtr->numElements-1);
        }
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxCmdDeletedProc --
 *
 *      This procedure is invoked when a widget command is deleted.  If
 *      the widget isn't already in the process of being destroyed,
 *      this command destroys it.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The widget is destroyed.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxCmdDeletedProc(clientData)
    ClientData clientData;      /* Pointer to widget record for widget. */
{
    Listbox *listPtr = (Listbox *) clientData;
    Tk_Window tkwin = listPtr->tkwin;
 
    /*
     * This procedure could be invoked either because the window was
     * destroyed and the command was then deleted (in which case tkwin
     * is NULL) or because the command was deleted, and then this procedure
     * destroys the widget.
     */
 
    if (tkwin != NULL) {
        if (listPtr->setGrid) {
            Tk_UnsetGrid(listPtr->tkwin);
        }
        listPtr->tkwin = NULL;
        Tk_DestroyWindow(tkwin);
    }
}
 
/*
 *--------------------------------------------------------------
 *
 * GetListboxIndex --
 *
 *      Parse an index into a listbox and return either its value
 *      or an error.
 *
 * Results:
 *      A standard Tcl result.  If all went well, then *indexPtr is
 *      filled in with the index (into listPtr) corresponding to
 *      string.  Otherwise an error message is left in interp->result.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */
 
static int
GetListboxIndex(interp, listPtr, string, endIsSize, indexPtr)
    Tcl_Interp *interp;         /* For error messages. */
    Listbox *listPtr;           /* Listbox for which the index is being
                                 * specified. */
    char *string;               /* Specifies an element in the listbox. */
    int endIsSize;              /* If 1, "end" refers to the number of
                                 * entries in the listbox.  If 0, "end"
                                 * refers to 1 less than the number of
                                 * entries. */
    int *indexPtr;              /* Where to store converted index. */
{
    int c;
    size_t length;
 
    length = strlen(string);
    c = string[0];
    if ((c == 'a') && (strncmp(string, "active", length) == 0)
            && (length >= 2)) {
        *indexPtr = listPtr->active;
    } else if ((c == 'a') && (strncmp(string, "anchor", length) == 0)
            && (length >= 2)) {
        *indexPtr = listPtr->selectAnchor;
    } else if ((c == 'e') && (strncmp(string, "end", length) == 0)) {
        if (endIsSize) {
            *indexPtr = listPtr->numElements;
        } else {
            *indexPtr = listPtr->numElements - 1;
        }
    } else if (c == '@') {
        int y;
        char *p, *end;
 
        p = string+1;
        strtol(p, &end, 0);
        if ((end == p) || (*end != ',')) {
            goto badIndex;
        }
        p = end+1;
        y = strtol(p, &end, 0);
        if ((end == p) || (*end != 0)) {
            goto badIndex;
        }
        *indexPtr = NearestListboxElement(listPtr, y);
    } else {
        if (Tcl_GetInt(interp, string, indexPtr) != TCL_OK) {
            Tcl_ResetResult(interp);
            goto badIndex;
        }
    }
    return TCL_OK;
 
    badIndex:
    Tcl_AppendResult(interp, "bad listbox index \"", string,
            "\": must be active, anchor, end, @x,y, or a number",
            (char *) NULL);
    return TCL_ERROR;
}
 
/*
 *----------------------------------------------------------------------
 *
 * ChangeListboxView --
 *
 *      Change the view on a listbox widget so that a given element
 *      is displayed at the top.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      What's displayed on the screen is changed.  If there is a
 *      scrollbar associated with this widget, then the scrollbar
 *      is instructed to change its display too.
 *
 *----------------------------------------------------------------------
 */
 
static void
ChangeListboxView(listPtr, index)
    register Listbox *listPtr;          /* Information about widget. */
    int index;                          /* Index of element in listPtr
                                         * that should now appear at the
                                         * top of the listbox. */
{
    if (index >= (listPtr->numElements - listPtr->fullLines)) {
        index = listPtr->numElements - listPtr->fullLines;
    }
    if (index < 0) {
        index = 0;
    }
    if (listPtr->topIndex != index) {
        listPtr->topIndex = index;
        if (!(listPtr->flags & REDRAW_PENDING)) {
            Tcl_DoWhenIdle(DisplayListbox, (ClientData) listPtr);
            listPtr->flags |= REDRAW_PENDING;
        }
        listPtr->flags |= UPDATE_V_SCROLLBAR;
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * ChangListboxOffset --
 *
 *      Change the horizontal offset for a listbox.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The listbox may be redrawn to reflect its new horizontal
 *      offset.
 *
 *----------------------------------------------------------------------
 */
 
static void
ChangeListboxOffset(listPtr, offset)
    register Listbox *listPtr;          /* Information about widget. */
    int offset;                         /* Desired new "xOffset" for
                                         * listbox. */
{
    int maxOffset;
 
    /*
     * Make sure that the new offset is within the allowable range, and
     * round it off to an even multiple of xScrollUnit.
     */
 
    maxOffset = listPtr->maxWidth - (Tk_Width(listPtr->tkwin) -
            2*listPtr->inset - 2*listPtr->selBorderWidth)
            + listPtr->xScrollUnit - 1;
    if (offset > maxOffset) {
        offset = maxOffset;
    }
    if (offset < 0) {
        offset = 0;
    }
    offset -= offset % listPtr->xScrollUnit;
    if (offset != listPtr->xOffset) {
        listPtr->xOffset = offset;
        listPtr->flags |= UPDATE_H_SCROLLBAR;
        ListboxRedrawRange(listPtr, 0, listPtr->numElements);
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxScanTo --
 *
 *      Given a point (presumably of the curent mouse location)
 *      drag the view in the window to implement the scan operation.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The view in the window may change.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxScanTo(listPtr, x, y)
    register Listbox *listPtr;          /* Information about widget. */
    int x;                              /* X-coordinate to use for scan
                                         * operation. */
    int y;                              /* Y-coordinate to use for scan
                                         * operation. */
{
    int newTopIndex, newOffset, maxIndex, maxOffset;
 
    maxIndex = listPtr->numElements - listPtr->fullLines;
    maxOffset = listPtr->maxWidth + (listPtr->xScrollUnit - 1)
            - (Tk_Width(listPtr->tkwin) - 2*listPtr->inset
            - 2*listPtr->selBorderWidth - listPtr->xScrollUnit);
 
    /*
     * Compute new top line for screen by amplifying the difference
     * between the current position and the place where the scan
     * started (the "mark" position).  If we run off the top or bottom
     * of the list, then reset the mark point so that the current
     * position continues to correspond to the edge of the window.
     * This means that the picture will start dragging as soon as the
     * mouse reverses direction (without this reset, might have to slide
     * mouse a long ways back before the picture starts moving again).
     */
 
    newTopIndex = listPtr->scanMarkYIndex
            - (10*(y - listPtr->scanMarkY))/listPtr->lineHeight;
    if (newTopIndex > maxIndex) {
        newTopIndex = listPtr->scanMarkYIndex = maxIndex;
        listPtr->scanMarkY = y;
    } else if (newTopIndex < 0) {
        newTopIndex = listPtr->scanMarkYIndex = 0;
        listPtr->scanMarkY = y;
    }
    ChangeListboxView(listPtr, newTopIndex);
 
    /*
     * Compute new left edge for display in a similar fashion by amplifying
     * the difference between the current position and the place where the
     * scan started.
     */
 
    newOffset = listPtr->scanMarkXOffset - (10*(x - listPtr->scanMarkX));
    if (newOffset > maxOffset) {
        newOffset = listPtr->scanMarkXOffset = maxOffset;
        listPtr->scanMarkX = x;
    } else if (newOffset < 0) {
        newOffset = listPtr->scanMarkXOffset = 0;
        listPtr->scanMarkX = x;
    }
    ChangeListboxOffset(listPtr, newOffset);
}
 
/*
 *----------------------------------------------------------------------
 *
 * NearestListboxElement --
 *
 *      Given a y-coordinate inside a listbox, compute the index of
 *      the element under that y-coordinate (or closest to that
 *      y-coordinate).
 *
 * Results:
 *      The return value is an index of an element of listPtr.  If
 *      listPtr has no elements, then 0 is always returned.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
 
static int
NearestListboxElement(listPtr, y)
    register Listbox *listPtr;          /* Information about widget. */
    int y;                              /* Y-coordinate in listPtr's window. */
{
    int index;
 
    index = (y - listPtr->inset)/listPtr->lineHeight;
    if (index >= (listPtr->fullLines + listPtr->partialLine)) {
        index = listPtr->fullLines + listPtr->partialLine - 1;
    }
    if (index < 0) {
        index = 0;
    }
    index += listPtr->topIndex;
    if (index >= listPtr->numElements) {
        index = listPtr->numElements-1;
    }
    return index;
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxSelect --
 *
 *      Select or deselect one or more elements in a listbox..
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      All of the elements in the range between first and last are
 *      marked as either selected or deselected, depending on the
 *      "select" argument.  Any items whose state changes are redisplayed.
 *      The selection is claimed from X when the number of selected
 *      elements changes from zero to non-zero.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxSelect(listPtr, first, last, select)
    register Listbox *listPtr;          /* Information about widget. */
    int first;                          /* Index of first element to
                                         * select or deselect. */
    int last;                           /* Index of last element to
                                         * select or deselect. */
    int select;                         /* 1 means select items, 0 means
                                         * deselect them. */
{
    int i, firstRedisplay, increment, oldCount;
    Element *elPtr;
 
    if (last < first) {
        i = first;
        first = last;
        last = i;
    }
    if ((last < 0) || (first >= listPtr->numElements)) {
        return;
    }
    if (first < 0) {
        first = 0;
    }
    if (last >= listPtr->numElements) {
        last = listPtr->numElements - 1;
    }
    oldCount = listPtr->numSelected;
    firstRedisplay = -1;
    increment = select ? 1 : -1;
    for (i = 0, elPtr = listPtr->firstPtr; i < first;
            i++, elPtr = elPtr->nextPtr) {
        /* Empty loop body. */
    }
    for ( ; i <= last; i++, elPtr = elPtr->nextPtr) {
        if (elPtr->selected == select) {
            continue;
        }
        listPtr->numSelected += increment;
        elPtr->selected = select;
        if (firstRedisplay < 0) {
            firstRedisplay = i;
        }
    }
    if (firstRedisplay >= 0) {
        ListboxRedrawRange(listPtr, first, last);
    }
    if ((oldCount == 0) && (listPtr->numSelected > 0)
            && (listPtr->exportSelection)) {
        Tk_OwnSelection(listPtr->tkwin, XA_PRIMARY, ListboxLostSelection,
                (ClientData) listPtr);
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxFetchSelection --
 *
 *      This procedure is called back by Tk when the selection is
 *      requested by someone.  It returns part or all of the selection
 *      in a buffer provided by the caller.
 *
 * Results:
 *      The return value is the number of non-NULL bytes stored
 *      at buffer.  Buffer is filled (or partially filled) with a
 *      NULL-terminated string containing part or all of the selection,
 *      as given by offset and maxBytes.  The selection is returned
 *      as a Tcl list with one list element for each element in the
 *      listbox.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
 
static int
ListboxFetchSelection(clientData, offset, buffer, maxBytes)
    ClientData clientData;              /* Information about listbox widget. */
    int offset;                         /* Offset within selection of first
                                         * byte to be returned. */
    char *buffer;                       /* Location in which to place
                                         * selection. */
    int maxBytes;                       /* Maximum number of bytes to place
                                         * at buffer, not including terminating
                                         * NULL character. */
{
    register Listbox *listPtr = (Listbox *) clientData;
    register Element *elPtr;
    Tcl_DString selection;
    int length, count, needNewline;
 
    if (!listPtr->exportSelection) {
        return -1;
    }
 
    /*
     * Use a dynamic string to accumulate the contents of the selection.
     */
 
    needNewline = 0;
    Tcl_DStringInit(&selection);
    for (elPtr = listPtr->firstPtr; elPtr != NULL; elPtr = elPtr->nextPtr) {
        if (elPtr->selected) {
            if (needNewline) {
                Tcl_DStringAppend(&selection, "\n", 1);
            }
            Tcl_DStringAppend(&selection, elPtr->text, elPtr->textLength);
            needNewline = 1;
        }
    }
 
    length = Tcl_DStringLength(&selection);
    if (length == 0) {
        return -1;
    }
 
    /*
     * Copy the requested portion of the selection to the buffer.
     */
 
    count = length - offset;
    if (count <= 0) {
        count = 0;
    } else {
        if (count > maxBytes) {
            count = maxBytes;
        }
        memcpy((VOID *) buffer,
                (VOID *) (Tcl_DStringValue(&selection) + offset),
                (size_t) count);
    }
    buffer[count] = '\0';
    Tcl_DStringFree(&selection);
    return count;
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxLostSelection --
 *
 *      This procedure is called back by Tk when the selection is
 *      grabbed away from a listbox widget.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The existing selection is unhighlighted, and the window is
 *      marked as not containing a selection.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxLostSelection(clientData)
    ClientData clientData;              /* Information about listbox widget. */
{
    register Listbox *listPtr = (Listbox *) clientData;
 
    if ((listPtr->exportSelection) && (listPtr->numElements > 0)) {
        ListboxSelect(listPtr, 0, listPtr->numElements-1, 0);
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxRedrawRange --
 *
 *      Ensure that a given range of elements is eventually redrawn on
 *      the display (if those elements in fact appear on the display).
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Information gets redisplayed.
 *
 *----------------------------------------------------------------------
 */
 
        /* ARGSUSED */
static void
ListboxRedrawRange(listPtr, first, last)
    register Listbox *listPtr;          /* Information about widget. */
    int first;                          /* Index of first element in list
                                         * that needs to be redrawn. */
    int last;                           /* Index of last element in list
                                         * that needs to be redrawn.  May
                                         * be less than first;
                                         * these just bracket a range. */
{
    if ((listPtr->tkwin == NULL) || !Tk_IsMapped(listPtr->tkwin)
            || (listPtr->flags & REDRAW_PENDING)) {
        return;
    }
    Tcl_DoWhenIdle(DisplayListbox, (ClientData) listPtr);
    listPtr->flags |= REDRAW_PENDING;
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxUpdateVScrollbar --
 *
 *      This procedure is invoked whenever information has changed in
 *      a listbox in a way that would invalidate a vertical scrollbar
 *      display.  If there is an associated scrollbar, then this command
 *      updates it by invoking a Tcl command.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      A Tcl command is invoked, and an additional command may be
 *      invoked to process errors in the command.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxUpdateVScrollbar(listPtr)
    register Listbox *listPtr;          /* Information about widget. */
{
    char string[100];
    double first, last;
    int result;
    Tcl_Interp *interp;
 
    if (listPtr->yScrollCmd == NULL) {
        return;
    }
    if (listPtr->numElements == 0) {
        first = 0.0;
        last = 1.0;
    } else {
        first = listPtr->topIndex/((double) listPtr->numElements);
        last = (listPtr->topIndex+listPtr->fullLines)
                /((double) listPtr->numElements);
        if (last > 1.0) {
            last = 1.0;
        }
    }
    sprintf(string, " %g %g", first, last);
 
    /*
     * We must hold onto the interpreter from the listPtr because the data
     * at listPtr might be freed as a result of the Tcl_VarEval.
     */
 
    interp = listPtr->interp;
    Tcl_Preserve((ClientData) interp);
    result = Tcl_VarEval(interp, listPtr->yScrollCmd, string,
            (char *) NULL);
    if (result != TCL_OK) {
        Tcl_AddErrorInfo(interp,
                "\n    (vertical scrolling command executed by listbox)");
        Tcl_BackgroundError(interp);
    }
    Tcl_Release((ClientData) interp);
}
 
/*
 *----------------------------------------------------------------------
 *
 * ListboxUpdateHScrollbar --
 *
 *      This procedure is invoked whenever information has changed in
 *      a listbox in a way that would invalidate a horizontal scrollbar
 *      display.  If there is an associated horizontal scrollbar, then
 *      this command updates it by invoking a Tcl command.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      A Tcl command is invoked, and an additional command may be
 *      invoked to process errors in the command.
 *
 *----------------------------------------------------------------------
 */
 
static void
ListboxUpdateHScrollbar(listPtr)
    register Listbox *listPtr;          /* Information about widget. */
{
    char string[60];
    int result, windowWidth;
    double first, last;
    Tcl_Interp *interp;
 
    if (listPtr->xScrollCmd == NULL) {
        return;
    }
    windowWidth = Tk_Width(listPtr->tkwin) - 2*(listPtr->inset
            + listPtr->selBorderWidth);
    if (listPtr->maxWidth == 0) {
        first = 0;
        last = 1.0;
    } else {
        first = listPtr->xOffset/((double) listPtr->maxWidth);
        last = (listPtr->xOffset + windowWidth)
                /((double) listPtr->maxWidth);
        if (last > 1.0) {
            last = 1.0;
        }
    }
    sprintf(string, " %g %g", first, last);
 
    /*
     * We must hold onto the interpreter because the data referred to at
     * listPtr might be freed as a result of the call to Tcl_VarEval.
     */
 
    interp = listPtr->interp;
    Tcl_Preserve((ClientData) interp);
    result = Tcl_VarEval(interp, listPtr->xScrollCmd, string,
            (char *) NULL);
    if (result != TCL_OK) {
        Tcl_AddErrorInfo(interp,
                "\n    (horizontal scrolling command executed by listbox)");
        Tcl_BackgroundError(interp);
    }
    Tcl_Release((ClientData) interp);
}
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[/] [or1k/] [tags/] [start/] [insight/] [tk/] [generic/] [tkListbox.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	578	markom	`/*`
2			`* tkListbox.c --`
3			`*`
4			`* This module implements listbox widgets for the Tk`
5			`* toolkit. A listbox displays a collection of strings,`
6			`* one per line, and provides scrolling and selection.`
7			`*`
8			`* Copyright (c) 1990-1994 The Regents of the University of California.`
9			`* Copyright (c) 1994-1997 Sun Microsystems, Inc.`
10			`*`
11			`* See the file "license.terms" for information on usage and redistribution`
12			`* of this file, and for a DISCLAIMER OF ALL WARRANTIES.`
13			`*`
14			`* RCS: @(#) $Id: tkListbox.c,v 1.1.1.1 2002-01-16 10:25:52 markom Exp $`
15			`*/`
16
17			`#include "tkPort.h"`
18			`#include "default.h"`
19			`#include "tkInt.h"`
20
21			`/*`
22			`* One record of the following type is kept for each element`
23			`* associated with a listbox widget:`
24			`*/`
25
26			`typedef struct Element {`
27			`int textLength; /* # non-NULL characters in text. */`
28			`int lBearing; /* Distance from first character's`
29			`* origin to left edge of character. */`
30			`int pixelWidth; /* Total width of element in pixels (including`
31			`* left bearing and right bearing). */`
32			`int selected; /* 1 means this item is selected, 0 means`
33			`* it isn't. */`
34			`struct Element nextPtr; / Next in list of all elements of this`
35			`* listbox, or NULL for last element. */`
36			`char text[4]; /* Characters of this element, NULL-`
37			`* terminated. The actual space allocated`
38			`* here will be as large as needed (> 4,`
39			`* most likely). Must be the last field`
40			`* of the record. */`