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/*

 * tkCanvImg.c --

 *

 *      This file implements image items for canvas widgets.

 *

 * Copyright (c) 1994 The Regents of the University of California.

 * Copyright (c) 1994-1996 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: tkCanvImg.c,v 1.1.1.1 2002-01-16 10:25:50 markom Exp $

 */

#include <stdio.h>

#include "tkInt.h"

#include "tkPort.h"

#include "tkCanvas.h"

/*

 * The structure below defines the record for each image item.

 */

typedef struct ImageItem  {

    Tk_Item header;             /* Generic stuff that's the same for all

                                 * types.  MUST BE FIRST IN STRUCTURE. */

    Tk_Canvas canvas;           /* Canvas containing the image. */

    double x, y;                /* Coordinates of positioning point for

                                 * image. */

    Tk_Anchor anchor;           /* Where to anchor image relative to

                                 * (x,y). */

    char *imageString;          /* String describing -image option (malloc-ed).

                                 * NULL means no image right now. */

    Tk_Image image;             /* Image to display in window, or NULL if

                                 * no image at present. */

} ImageItem;

/*

 * Information used for parsing configuration specs:

 */

static Tk_CustomOption tagsOption = {Tk_CanvasTagsParseProc,

    Tk_CanvasTagsPrintProc, (ClientData) NULL

};

static Tk_ConfigSpec configSpecs[] = {

    {TK_CONFIG_ANCHOR, "-anchor", (char *) NULL, (char *) NULL,

        "center", Tk_Offset(ImageItem, anchor), TK_CONFIG_DONT_SET_DEFAULT},

    {TK_CONFIG_STRING, "-image", (char *) NULL, (char *) NULL,

        (char *) NULL, Tk_Offset(ImageItem, imageString), TK_CONFIG_NULL_OK},

    {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL,

        (char *) NULL, 0, TK_CONFIG_NULL_OK, &tagsOption},

    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,

        (char *) NULL, 0, 0}

};

/*

 * Prototypes for procedures defined in this file:

 */

static void             ImageChangedProc _ANSI_ARGS_((ClientData clientData,

                            int x, int y, int width, int height, int imgWidth,

                            int imgHeight));

static int              ImageCoords _ANSI_ARGS_((Tcl_Interp *interp,

                            Tk_Canvas canvas, Tk_Item *itemPtr, int argc,

                            char **argv));

static int              ImageToArea _ANSI_ARGS_((Tk_Canvas canvas,

                            Tk_Item *itemPtr, double *rectPtr));

static double           ImageToPoint _ANSI_ARGS_((Tk_Canvas canvas,

                            Tk_Item *itemPtr, double *coordPtr));

static void             ComputeImageBbox _ANSI_ARGS_((Tk_Canvas canvas,

                            ImageItem *imgPtr));

static int              ConfigureImage _ANSI_ARGS_((Tcl_Interp *interp,

                            Tk_Canvas canvas, Tk_Item *itemPtr, int argc,

                            char **argv, int flags));

static int              CreateImage _ANSI_ARGS_((Tcl_Interp *interp,

                            Tk_Canvas canvas, struct Tk_Item *itemPtr,

                            int argc, char **argv));

static void             DeleteImage _ANSI_ARGS_((Tk_Canvas canvas,

                            Tk_Item *itemPtr, Display *display));

static void             DisplayImage _ANSI_ARGS_((Tk_Canvas canvas,

                            Tk_Item *itemPtr, Display *display, Drawable dst,

                            int x, int y, int width, int height));

static void             ScaleImage _ANSI_ARGS_((Tk_Canvas canvas,

                            Tk_Item *itemPtr, double originX, double originY,

                            double scaleX, double scaleY));

static void             TranslateImage _ANSI_ARGS_((Tk_Canvas canvas,

                            Tk_Item *itemPtr, double deltaX, double deltaY));

/*

 * The structures below defines the image item type in terms of

 * procedures that can be invoked by generic item code.

 */

Tk_ItemType tkImageType = {

    "image",                            /* name */

    sizeof(ImageItem),                  /* itemSize */

    CreateImage,                        /* createProc */

    configSpecs,                        /* configSpecs */

    ConfigureImage,                     /* configureProc */

    ImageCoords,                        /* coordProc */

    DeleteImage,                        /* deleteProc */

    DisplayImage,                       /* displayProc */

    0,                                   /* alwaysRedraw */

    ImageToPoint,                       /* pointProc */

    ImageToArea,                        /* areaProc */

    (Tk_ItemPostscriptProc *) NULL,     /* postscriptProc */

    ScaleImage,                         /* scaleProc */

    TranslateImage,                     /* translateProc */

    (Tk_ItemIndexProc *) NULL,          /* indexProc */

    (Tk_ItemCursorProc *) NULL,         /* icursorProc */

    (Tk_ItemSelectionProc *) NULL,      /* selectionProc */

    (Tk_ItemInsertProc *) NULL,         /* insertProc */

    (Tk_ItemDCharsProc *) NULL,         /* dTextProc */

    (Tk_ItemType *) NULL                /* nextPtr */

};

/*

 *--------------------------------------------------------------

 *

 * CreateImage --

 *

 *      This procedure is invoked to create a new image

 *      item in a canvas.

 *

 * Results:

 *      A standard Tcl return value.  If an error occurred in

 *      creating the item, then an error message is left in

 *      interp->result;  in this case itemPtr is left uninitialized,

 *      so it can be safely freed by the caller.

 *

 * Side effects:

 *      A new image item is created.

 *

 *--------------------------------------------------------------

 */

static int

CreateImage(interp, canvas, itemPtr, argc, argv)

    Tcl_Interp *interp;                 /* Interpreter for error reporting. */

    Tk_Canvas canvas;                   /* Canvas to hold new item. */

    Tk_Item *itemPtr;                   /* Record to hold new item;  header

                                         * has been initialized by caller. */

    int argc;                           /* Number of arguments in argv. */

    char **argv;                        /* Arguments describing rectangle. */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    if (argc < 2) {

        Tcl_AppendResult(interp, "wrong # args: should be \"",

                Tk_PathName(Tk_CanvasTkwin(canvas)), " create ",

                itemPtr->typePtr->name, " x y ?options?\"",

                (char *) NULL);

        return TCL_ERROR;

    }

    /*

     * Initialize item's record.

     */

    imgPtr->canvas = canvas;

    imgPtr->anchor = TK_ANCHOR_CENTER;

    imgPtr->imageString = NULL;

    imgPtr->image = NULL;

    /*

     * Process the arguments to fill in the item record.

     */

    if ((Tk_CanvasGetCoord(interp, canvas, argv[0], &imgPtr->x) != TCL_OK)

            || (Tk_CanvasGetCoord(interp, canvas, argv[1], &imgPtr->y)

                != TCL_OK)) {

        return TCL_ERROR;

    }

    if (ConfigureImage(interp, canvas, itemPtr, argc-2, argv+2, 0) != TCL_OK) {

        DeleteImage(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas)));

        return TCL_ERROR;

    }

    return TCL_OK;

}

/*

 *--------------------------------------------------------------

 *

 * ImageCoords --

 *

 *      This procedure is invoked to process the "coords" widget

 *      command on image items.  See the user documentation for

 *      details on what it does.

 *

 * Results:

 *      Returns TCL_OK or TCL_ERROR, and sets interp->result.

 *

 * Side effects:

 *      The coordinates for the given item may be changed.

 *

 *--------------------------------------------------------------

 */

static int

ImageCoords(interp, canvas, itemPtr, argc, argv)

    Tcl_Interp *interp;                 /* Used for error reporting. */

    Tk_Canvas canvas;                   /* Canvas containing item. */

    Tk_Item *itemPtr;                   /* Item whose coordinates are to be

                                         * read or modified. */

    int argc;                           /* Number of coordinates supplied in

                                         * argv. */

    char **argv;                        /* Array of coordinates: x1, y1,

                                         * x2, y2, ... */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    char x[TCL_DOUBLE_SPACE], y[TCL_DOUBLE_SPACE];

    if (argc == 0) {

        Tcl_PrintDouble(interp, imgPtr->x, x);

        Tcl_PrintDouble(interp, imgPtr->y, y);

        Tcl_AppendResult(interp, x, " ", y, (char *) NULL);

    } else if (argc == 2) {

        if ((Tk_CanvasGetCoord(interp, canvas, argv[0], &imgPtr->x) != TCL_OK)

                || (Tk_CanvasGetCoord(interp, canvas, argv[1],

                    &imgPtr->y) != TCL_OK)) {

            return TCL_ERROR;

        }

        ComputeImageBbox(canvas, imgPtr);

    } else {

        sprintf(interp->result,

                "wrong # coordinates: expected 0 or 2, got %d", argc);

        return TCL_ERROR;

    }

    return TCL_OK;

}

/*

 *--------------------------------------------------------------

 *

 * ConfigureImage --

 *

 *      This procedure is invoked to configure various aspects

 *      of an image item, such as its anchor position.

 *

 * Results:

 *      A standard Tcl result code.  If an error occurs, then

 *      an error message is left in interp->result.

 *

 * Side effects:

 *      Configuration information may be set for itemPtr.

 *

 *--------------------------------------------------------------

 */

static int

ConfigureImage(interp, canvas, itemPtr, argc, argv, flags)

    Tcl_Interp *interp;         /* Used for error reporting. */

    Tk_Canvas canvas;           /* Canvas containing itemPtr. */

    Tk_Item *itemPtr;           /* Image item to reconfigure. */

    int argc;                   /* Number of elements in argv.  */

    char **argv;                /* Arguments describing things to configure. */

    int flags;                  /* Flags to pass to Tk_ConfigureWidget. */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    Tk_Window tkwin;

    Tk_Image image;

    tkwin = Tk_CanvasTkwin(canvas);

    if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc,

            argv, (char *) imgPtr, flags) != TCL_OK) {

        return TCL_ERROR;

    }

    /*

     * Create the image.  Save the old image around and don't free it

     * until after the new one is allocated.  This keeps the reference

     * count from going to zero so the image doesn't have to be recreated

     * if it hasn't changed.

     */

    if (imgPtr->imageString != NULL) {

        image = Tk_GetImage(interp, tkwin, imgPtr->imageString,

                ImageChangedProc, (ClientData) imgPtr);

        if (image == NULL) {

            return TCL_ERROR;

        }

    } else {

        image = NULL;

    }

    if (imgPtr->image != NULL) {

        Tk_FreeImage(imgPtr->image);

    }

    imgPtr->image = image;

    ComputeImageBbox(canvas, imgPtr);

    return TCL_OK;

}

/*

 *--------------------------------------------------------------

 *

 * DeleteImage --

 *

 *      This procedure is called to clean up the data structure

 *      associated with a image item.

 *

 * Results:

 *      None.

 *

 * Side effects:

 *      Resources associated with itemPtr are released.

 *

 *--------------------------------------------------------------

 */

static void

DeleteImage(canvas, itemPtr, display)

    Tk_Canvas canvas;                   /* Info about overall canvas widget. */

    Tk_Item *itemPtr;                   /* Item that is being deleted. */

    Display *display;                   /* Display containing window for

                                         * canvas. */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    if (imgPtr->imageString != NULL) {

        ckfree(imgPtr->imageString);

    }

    if (imgPtr->image != NULL) {

        Tk_FreeImage(imgPtr->image);

    }

}

/*

 *--------------------------------------------------------------

 *

 * ComputeImageBbox --

 *

 *      This procedure is invoked to compute the bounding box of

 *      all the pixels that may be drawn as part of a image item.

 *      This procedure is where the child image's placement is

 *      computed.

 *

 * Results:

 *      None.

 *

 * Side effects:

 *      The fields x1, y1, x2, and y2 are updated in the header

 *      for itemPtr.

 *

 *--------------------------------------------------------------

 */

        /* ARGSUSED */

static void

ComputeImageBbox(canvas, imgPtr)

    Tk_Canvas canvas;                   /* Canvas that contains item. */

    ImageItem *imgPtr;                  /* Item whose bbox is to be

                                         * recomputed. */

{

    int width, height;

    int x, y;

    x = (int) (imgPtr->x + ((imgPtr->x >= 0) ? 0.5 : - 0.5));

    y = (int) (imgPtr->y + ((imgPtr->y >= 0) ? 0.5 : - 0.5));

    if (imgPtr->image == None) {

        imgPtr->header.x1 = imgPtr->header.x2 = x;

        imgPtr->header.y1 = imgPtr->header.y2 = y;

        return;

    }

    /*

     * Compute location and size of image, using anchor information.

     */

    Tk_SizeOfImage(imgPtr->image, &width, &height);

    switch (imgPtr->anchor) {

        case TK_ANCHOR_N:

            x -= width/2;

            break;

        case TK_ANCHOR_NE:

            x -= width;

            break;

        case TK_ANCHOR_E:

            x -= width;

            y -= height/2;

            break;

        case TK_ANCHOR_SE:

            x -= width;

            y -= height;

            break;

        case TK_ANCHOR_S:

            x -= width/2;

            y -= height;

            break;

        case TK_ANCHOR_SW:

            y -= height;

            break;

        case TK_ANCHOR_W:

            y -= height/2;

            break;

        case TK_ANCHOR_NW:

            break;

        case TK_ANCHOR_CENTER:

            x -= width/2;

            y -= height/2;

            break;

    }

    /*

     * Store the information in the item header.

     */

    imgPtr->header.x1 = x;

    imgPtr->header.y1 = y;

    imgPtr->header.x2 = x + width;

    imgPtr->header.y2 = y + height;

}

/*

 *--------------------------------------------------------------

 *

 * DisplayImage --

 *

 *      This procedure is invoked to draw a image item in a given

 *      drawable.

 *

 * Results:

 *      None.

 *

 * Side effects:

 *      ItemPtr is drawn in drawable using the transformation

 *      information in canvas.

 *

 *--------------------------------------------------------------

 */

static void

DisplayImage(canvas, itemPtr, display, drawable, x, y, width, height)

    Tk_Canvas canvas;                   /* Canvas that contains item. */

    Tk_Item *itemPtr;                   /* Item to be displayed. */

    Display *display;                   /* Display on which to draw item. */

    Drawable drawable;                  /* Pixmap or window in which to draw

                                         * item. */

    int x, y, width, height;            /* Describes region of canvas that

                                         * must be redisplayed (not used). */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    short drawableX, drawableY;

    if (imgPtr->image == NULL) {

        return;

    }

    /*

     * Translate the coordinates to those of the image, then redisplay it.

     */

    Tk_CanvasDrawableCoords(canvas, (double) x, (double) y,

            &drawableX, &drawableY);

    Tk_RedrawImage(imgPtr->image, x - imgPtr->header.x1, y - imgPtr->header.y1,

            width, height, drawable, drawableX, drawableY);

}

/*

 *--------------------------------------------------------------

 *

 * ImageToPoint --

 *

 *      Computes the distance from a given point to a given

 *      rectangle, in canvas units.

 *

 * Results:

 *      The return value is 0 if the point whose x and y coordinates

 *      are coordPtr[0] and coordPtr[1] is inside the image.  If the

 *      point isn't inside the image then the return value is the

 *      distance from the point to the image.

 *

 * Side effects:

 *      None.

 *

 *--------------------------------------------------------------

 */

static double

ImageToPoint(canvas, itemPtr, coordPtr)

    Tk_Canvas canvas;           /* Canvas containing item. */

    Tk_Item *itemPtr;           /* Item to check against point. */

    double *coordPtr;           /* Pointer to x and y coordinates. */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    double x1, x2, y1, y2, xDiff, yDiff;

    x1 = imgPtr->header.x1;

    y1 = imgPtr->header.y1;

    x2 = imgPtr->header.x2;

    y2 = imgPtr->header.y2;

    /*

     * Point is outside rectangle.

     */

    if (coordPtr[0] < x1) {

        xDiff = x1 - coordPtr[0];

    } else if (coordPtr[0] > x2)  {

        xDiff = coordPtr[0] - x2;

    } else {

        xDiff = 0;

    }

    if (coordPtr[1] < y1) {

        yDiff = y1 - coordPtr[1];

    } else if (coordPtr[1] > y2)  {

        yDiff = coordPtr[1] - y2;

    } else {

        yDiff = 0;

    }

    return hypot(xDiff, yDiff);

}

/*

 *--------------------------------------------------------------

 *

 * ImageToArea --

 *

 *      This procedure is called to determine whether an item

 *      lies entirely inside, entirely outside, or overlapping

 *      a given rectangle.

 *

 * Results:

 *      -1 is returned if the item is entirely outside the area

 *      given by rectPtr, 0 if it overlaps, and 1 if it is entirely

 *      inside the given area.

 *

 * Side effects:

 *      None.

 *

 *--------------------------------------------------------------

 */

static int

ImageToArea(canvas, itemPtr, rectPtr)

    Tk_Canvas canvas;           /* Canvas containing item. */

    Tk_Item *itemPtr;           /* Item to check against rectangle. */

    double *rectPtr;            /* Pointer to array of four coordinates

                                 * (x1, y1, x2, y2) describing rectangular

                                 * area.  */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    if ((rectPtr[2] <= imgPtr->header.x1)

            || (rectPtr[0] >= imgPtr->header.x2)

            || (rectPtr[3] <= imgPtr->header.y1)

            || (rectPtr[1] >= imgPtr->header.y2)) {

        return -1;

    }

    if ((rectPtr[0] <= imgPtr->header.x1)

            && (rectPtr[1] <= imgPtr->header.y1)

            && (rectPtr[2] >= imgPtr->header.x2)

            && (rectPtr[3] >= imgPtr->header.y2)) {

        return 1;

    }

    return 0;

}

/*

 *--------------------------------------------------------------

 *

 * ScaleImage --

 *

 *      This procedure is invoked to rescale an item.

 *

 * Results:

 *      None.

 *

 * Side effects:

 *      The item referred to by itemPtr is rescaled so that the

 *      following transformation is applied to all point coordinates:

 *              x' = originX + scaleX*(x-originX)

 *              y' = originY + scaleY*(y-originY)

 *

 *--------------------------------------------------------------

 */

static void

ScaleImage(canvas, itemPtr, originX, originY, scaleX, scaleY)

    Tk_Canvas canvas;                   /* Canvas containing rectangle. */

    Tk_Item *itemPtr;                   /* Rectangle to be scaled. */

    double originX, originY;            /* Origin about which to scale rect. */

    double scaleX;                      /* Amount to scale in X direction. */

    double scaleY;                      /* Amount to scale in Y direction. */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    imgPtr->x = originX + scaleX*(imgPtr->x - originX);

    imgPtr->y = originY + scaleY*(imgPtr->y - originY);

    ComputeImageBbox(canvas, imgPtr);

}

/*

 *--------------------------------------------------------------

 *

 * TranslateImage --

 *

 *      This procedure is called to move an item by a given amount.

 *

 * Results:

 *      None.

 *

 * Side effects:

 *      The position of the item is offset by (xDelta, yDelta), and

 *      the bounding box is updated in the generic part of the item

 *      structure.

 *

 *--------------------------------------------------------------

 */

static void

TranslateImage(canvas, itemPtr, deltaX, deltaY)

    Tk_Canvas canvas;                   /* Canvas containing item. */

    Tk_Item *itemPtr;                   /* Item that is being moved. */

    double deltaX, deltaY;              /* Amount by which item is to be

                                         * moved. */

{

    ImageItem *imgPtr = (ImageItem *) itemPtr;

    imgPtr->x += deltaX;

    imgPtr->y += deltaY;

    ComputeImageBbox(canvas, imgPtr);

}

/*

 *----------------------------------------------------------------------

 *

 * ImageChangedProc --

 *

 *      This procedure is invoked by the image code whenever the manager

 *      for an image does something that affects the image's size or

 *      how it is displayed.

 *

 * Results:

 *      None.

 *

 * Side effects:

 *      Arranges for the canvas to get redisplayed.

 *

 *----------------------------------------------------------------------

 */

static void

ImageChangedProc(clientData, x, y, width, height, imgWidth, imgHeight)

    ClientData clientData;              /* Pointer to canvas item for image. */

    int x, y;                           /* Upper left pixel (within image)

                                         * that must be redisplayed. */

    int width, height;                  /* Dimensions of area to redisplay

                                         * (may be <= 0). */

    int imgWidth, imgHeight;            /* New dimensions of image. */

{

    ImageItem *imgPtr = (ImageItem *) clientData;

    /*

     * If the image's size changed and it's not anchored at its

     * northwest corner then just redisplay the entire area of the

     * image.  This is a bit over-conservative, but we need to do

     * something because a size change also means a position change.

     */

    if (((imgPtr->header.x2 - imgPtr->header.x1) != imgWidth)

            || ((imgPtr->header.y2 - imgPtr->header.y1) != imgHeight)) {

        x = y = 0;

        width = imgWidth;

        height = imgHeight;

        Tk_CanvasEventuallyRedraw(imgPtr->canvas, imgPtr->header.x1,

                imgPtr->header.y1, imgPtr->header.x2, imgPtr->header.y2);

    }

    ComputeImageBbox(imgPtr->canvas, imgPtr);

    Tk_CanvasEventuallyRedraw(imgPtr->canvas, imgPtr->header.x1 + x,

            imgPtr->header.y1 + y, (int) (imgPtr->header.x1 + x + width),

            (int) (imgPtr->header.y1 + y + height));

}