archie/tk4.2/generic/tkCanvImg.c
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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.
*
* SCCS: @(#) tkCanvImg.c 1.17 96/02/17 17:18:43
*/
#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 = imgPtr->x + ((imgPtr->x >= 0) ? 0.5 : - 0.5);
y = 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));
}