Initial revision

1 files changed, 898 insertions, 0 deletions

diff --git a/generic/tkTextImage.c b/generic/tkTextImage.c
new file mode 100644
index 0000000..b5e363f
--- /dev/null
+++ b/generic/tkTextImage.c
@@ -0,0 +1,898 @@
+/* 
+ * tkImage.c --
+ *
+ *	This file contains code that allows images to be
+ *	nested inside text widgets.  It also implements the "image"
+ *	widget command for texts.
+ *
+ * Copyright (c) 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: @(#) tkTextImage.c 1.7 97/08/25 15:47:27
+ */
+
+#include "tk.h"
+#include "tkText.h"
+#include "tkPort.h"
+
+/*
+ * Definitions for alignment values:
+ */
+
+#define ALIGN_BOTTOM		0
+#define ALIGN_CENTER		1
+#define ALIGN_TOP		2
+#define ALIGN_BASELINE		3
+
+/*
+ * Macro that determines the size of an embedded image segment:
+ */
+
+#define EI_SEG_SIZE ((unsigned) (Tk_Offset(TkTextSegment, body) \
+	+ sizeof(TkTextEmbImage)))
+
+/*
+ * Prototypes for procedures defined in this file:
+ */
+
+static int		AlignParseProc _ANSI_ARGS_((ClientData clientData,
+			    Tcl_Interp *interp, Tk_Window tkwin, char *value,
+			    char *widgRec, int offset));
+static char *		AlignPrintProc _ANSI_ARGS_((ClientData clientData,
+			    Tk_Window tkwin, char *widgRec, int offset,
+			    Tcl_FreeProc **freeProcPtr));
+static TkTextSegment *	EmbImageCleanupProc _ANSI_ARGS_((TkTextSegment *segPtr,
+			    TkTextLine *linePtr));
+static void		EmbImageCheckProc _ANSI_ARGS_((TkTextSegment *segPtr,
+			    TkTextLine *linePtr));
+static void		EmbImageBboxProc _ANSI_ARGS_((TkTextDispChunk *chunkPtr,
+			    int index, int y, int lineHeight, int baseline,
+			    int *xPtr, int *yPtr, int *widthPtr,
+			    int *heightPtr));
+static int		EmbImageConfigure _ANSI_ARGS_((TkText *textPtr,
+			    TkTextSegment *eiPtr, int argc, char **argv));
+static int		EmbImageDeleteProc _ANSI_ARGS_((TkTextSegment *segPtr,
+			    TkTextLine *linePtr, int treeGone));
+static void		EmbImageDisplayProc _ANSI_ARGS_((
+			    TkTextDispChunk *chunkPtr, int x, int y,
+			    int lineHeight, int baseline, Display *display,
+			    Drawable dst, int screenY));
+static int		EmbImageLayoutProc _ANSI_ARGS_((TkText *textPtr,
+			    TkTextIndex *indexPtr, TkTextSegment *segPtr,
+			    int offset, int maxX, int maxChars,
+			    int noCharsYet, Tk_Uid wrapMode,
+			    TkTextDispChunk *chunkPtr));
+static void		EmbImageProc _ANSI_ARGS_((ClientData clientData,
+			    int x, int y, int width, int height,
+			    int imageWidth, int imageHeight));
+
+/*
+ * The following structure declares the "embedded image" segment type.
+ */
+
+static Tk_SegType tkTextEmbImageType = {
+    "image",					/* name */
+    0,						/* leftGravity */
+    (Tk_SegSplitProc *) NULL,			/* splitProc */
+    EmbImageDeleteProc,				/* deleteProc */
+    EmbImageCleanupProc,			/* cleanupProc */
+    (Tk_SegLineChangeProc *) NULL,		/* lineChangeProc */
+    EmbImageLayoutProc,				/* layoutProc */
+    EmbImageCheckProc				/* checkProc */
+};
+
+/*
+ * Information used for parsing image configuration options:
+ */
+
+static Tk_CustomOption alignOption = {AlignParseProc, AlignPrintProc,
+	(ClientData) NULL};
+
+static Tk_ConfigSpec configSpecs[] = {
+    {TK_CONFIG_CUSTOM, "-align", (char *) NULL, (char *) NULL,
+	"center", 0, TK_CONFIG_DONT_SET_DEFAULT, &alignOption},
+    {TK_CONFIG_PIXELS, "-padx", (char *) NULL, (char *) NULL,
+	"0", Tk_Offset(TkTextEmbImage, padX),
+	TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_PIXELS, "-pady", (char *) NULL, (char *) NULL,
+	"0", Tk_Offset(TkTextEmbImage, padY),
+	TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_STRING, "-image", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextEmbImage, imageString),
+	TK_CONFIG_DONT_SET_DEFAULT|TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-name", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextEmbImage, imageName),
+	TK_CONFIG_DONT_SET_DEFAULT|TK_CONFIG_NULL_OK},
+    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, 0}
+};
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextImageCmd --
+ *
+ *	This procedure implements the "image" widget command
+ *	for text widgets.  See the user documentation for details
+ *	on what it does.
+ *
+ * Results:
+ *	A standard Tcl result or error.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+TkTextImageCmd(textPtr, interp, argc, argv)
+    register TkText *textPtr;	/* Information about text widget. */
+    Tcl_Interp *interp;		/* Current interpreter. */
+    int argc;			/* Number of arguments. */
+    char **argv;		/* Argument strings.  Someone else has already
+				 * parsed this command enough to know that
+				 * argv[1] is "image". */
+{
+    size_t length;
+    register TkTextSegment *eiPtr;
+
+    if (argc < 3) {
+	Tcl_AppendResult(interp, "wrong # args: should be \"",
+		argv[0], " image option ?arg arg ...?\"", (char *) NULL);
+	return TCL_ERROR;
+    }
+    length = strlen(argv[2]);
+    if ((strncmp(argv[2], "cget", length) == 0) && (length >= 2)) {
+	TkTextIndex index;
+	TkTextSegment *eiPtr;
+
+	if (argc != 5) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " image cget index option\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	if (TkTextGetIndex(interp, textPtr, argv[3], &index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	eiPtr = TkTextIndexToSeg(&index, (int *) NULL);
+	if (eiPtr->typePtr != &tkTextEmbImageType) {
+	    Tcl_AppendResult(interp, "no embedded image at index \"",
+		    argv[3], "\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	return Tk_ConfigureValue(interp, textPtr->tkwin, configSpecs,
+		(char *) &eiPtr->body.ei, argv[4], 0);
+    } else if ((strncmp(argv[2], "configure", length) == 0) && (length >= 2)) {
+	TkTextIndex index;
+	TkTextSegment *eiPtr;
+
+	if (argc < 4) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " image configure index ?option value ...?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	if (TkTextGetIndex(interp, textPtr, argv[3], &index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	eiPtr = TkTextIndexToSeg(&index, (int *) NULL);
+	if (eiPtr->typePtr != &tkTextEmbImageType) {
+	    Tcl_AppendResult(interp, "no embedded image at index \"",
+		    argv[3], "\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	if (argc == 4) {
+	    return Tk_ConfigureInfo(interp, textPtr->tkwin, configSpecs,
+		    (char *) &eiPtr->body.ei, (char *) NULL, 0);
+	} else if (argc == 5) {
+	    return Tk_ConfigureInfo(interp, textPtr->tkwin, configSpecs,
+		    (char *) &eiPtr->body.ei, argv[4], 0);
+	} else {
+	    TkTextChanged(textPtr, &index, &index);
+	    return EmbImageConfigure(textPtr, eiPtr, argc-4, argv+4);
+	}
+    } else if ((strncmp(argv[2], "create", length) == 0) && (length >= 2)) {
+	TkTextIndex index;
+	int lineIndex;
+
+	/*
+	 * Add a new image.  Find where to put the new image, and
+	 * mark that position for redisplay.
+	 */
+
+	if (argc < 4) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " image create index ?option value ...?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	if (TkTextGetIndex(interp, textPtr, argv[3], &index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+
+	/*
+	 * Don't allow insertions on the last (dummy) line of the text.
+	 */
+    
+	lineIndex = TkBTreeLineIndex(index.linePtr);
+	if (lineIndex == TkBTreeNumLines(textPtr->tree)) {
+	    lineIndex--;
+	    TkTextMakeIndex(textPtr->tree, lineIndex, 1000000, &index);
+	}
+
+	/*
+	 * Create the new image segment and initialize it.
+	 */
+
+	eiPtr = (TkTextSegment *) ckalloc(EI_SEG_SIZE);
+	eiPtr->typePtr = &tkTextEmbImageType;
+	eiPtr->size = 1;
+	eiPtr->body.ei.textPtr = textPtr;
+	eiPtr->body.ei.linePtr = NULL;
+	eiPtr->body.ei.imageName = NULL;
+	eiPtr->body.ei.imageString = NULL;
+	eiPtr->body.ei.name = NULL;
+	eiPtr->body.ei.image = NULL;
+	eiPtr->body.ei.align = ALIGN_CENTER;
+	eiPtr->body.ei.padX = eiPtr->body.ei.padY = 0;
+	eiPtr->body.ei.chunkCount = 0;
+
+	/*
+	 * Link the segment into the text widget, then configure it (delete
+	 * it again if the configuration fails).
+	 */
+
+	TkTextChanged(textPtr, &index, &index);
+	TkBTreeLinkSegment(eiPtr, &index);
+	if (EmbImageConfigure(textPtr, eiPtr, argc-4, argv+4) != TCL_OK) {
+	    TkTextIndex index2;
+
+	    TkTextIndexForwChars(&index, 1, &index2);
+	    TkBTreeDeleteChars(&index, &index2);
+	    return TCL_ERROR;
+	}
+    } else if (strncmp(argv[2], "names", length) == 0) {
+	Tcl_HashSearch search;
+	Tcl_HashEntry *hPtr;
+
+	if (argc != 3) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " image names\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	for (hPtr = Tcl_FirstHashEntry(&textPtr->imageTable, &search);
+		hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
+	    Tcl_AppendElement(interp,
+		    Tcl_GetHashKey(&textPtr->markTable, hPtr));
+	}
+    } else {
+	Tcl_AppendResult(interp, "bad image option \"", argv[2],
+		"\": must be cget, configure, create, or names",
+		(char *) NULL);
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageConfigure --
+ *
+ *	This procedure is called to handle configuration options
+ *	for an embedded image, using an argc/argv list.
+ *
+ * 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 for the embedded image changes,
+ *	such as alignment, or name of the image.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+EmbImageConfigure(textPtr, eiPtr, argc, argv)
+    TkText *textPtr;		/* Information about text widget that
+				 * contains embedded image. */
+    TkTextSegment *eiPtr;	/* Embedded image to be configured. */
+    int argc;			/* Number of strings in argv. */
+    char **argv;		/* Array of strings describing configuration
+				 * options. */
+{
+    Tk_Image image;
+    Tcl_DString newName;
+    Tcl_HashEntry *hPtr;
+    Tcl_HashSearch search;
+    int new;
+    char *name;
+    int count = 0;		/* The counter for picking a unique name */
+    int conflict = 0;		/* True if we have a name conflict */
+    unsigned int len;		/* length of image name */
+
+    if (Tk_ConfigureWidget(textPtr->interp, textPtr->tkwin, configSpecs,
+	    argc, argv, (char *) &eiPtr->body.ei,TK_CONFIG_ARGV_ONLY)
+	    != 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 (eiPtr->body.ei.imageString != NULL) {
+	image = Tk_GetImage(textPtr->interp, textPtr->tkwin, eiPtr->body.ei.imageString,
+		EmbImageProc, (ClientData) eiPtr);
+	if (image == NULL) {
+	    return TCL_ERROR;
+	}
+    } else {
+	image = NULL;
+    }
+    if (eiPtr->body.ei.image != NULL) {
+	Tk_FreeImage(eiPtr->body.ei.image);
+    }
+    eiPtr->body.ei.image = image;
+
+    if (eiPtr->body.ei.name != NULL) {
+    	return TCL_OK;
+    }
+
+    /* 
+     * Find a unique name for this image.  Use imageName (or imageString)
+     * if available, otherwise tack on a #nn and use it.  If a name is already
+     * associated with this image, delete the name.
+     */
+
+    name = eiPtr->body.ei.imageName;
+    if (name == NULL) {
+    	name = eiPtr->body.ei.imageString;
+    }
+    if (name == NULL) {
+        Tcl_AppendResult(textPtr->interp,"Either a \"-name\" ",
+		"or a \"-image\" argument must be provided ",
+		"to the \"image create\" subcommand.",
+		(char *) NULL);
+	return TCL_ERROR;
+    }
+    len = strlen(name);
+    for (hPtr = Tcl_FirstHashEntry(&textPtr->imageTable, &search);
+	    hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
+	char *haveName = Tcl_GetHashKey(&textPtr->imageTable, hPtr);
+	if (strncmp(name, haveName, len) == 0) {
+	    new = 0;
+	    sscanf(haveName+len,"#%d",&new);
+	    if (new > count) {
+		count = new;
+	    }
+	    if (len == (int) strlen(haveName)) {
+	    	conflict = 1;
+	    }
+	}
+    }
+
+    Tcl_DStringInit(&newName);
+    Tcl_DStringAppend(&newName,name, -1);
+
+    if (conflict) {
+    	char buf[10];
+	sprintf(buf, "#%d",count+1);
+	Tcl_DStringAppend(&newName,buf, -1);
+    }
+    name = Tcl_DStringValue(&newName);
+    hPtr = Tcl_CreateHashEntry(&textPtr->imageTable, name, &new);
+    Tcl_SetHashValue(hPtr, eiPtr);
+    Tcl_AppendResult(textPtr->interp, name , (char *) NULL);
+    eiPtr->body.ei.name = ckalloc((unsigned) Tcl_DStringLength(&newName)+1);
+    strcpy(eiPtr->body.ei.name,name);
+    Tcl_DStringFree(&newName);
+
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * AlignParseProc --
+ *
+ *	This procedure is invoked by Tk_ConfigureWidget during
+ *	option processing to handle "-align" options for embedded
+ *	images.
+ *
+ * Results:
+ *	A standard Tcl return value.
+ *
+ * Side effects:
+ *	The alignment for the embedded image may change.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+AlignParseProc(clientData, interp, tkwin, value, widgRec, offset)
+    ClientData clientData;		/* Not used.*/
+    Tcl_Interp *interp;			/* Used for reporting errors. */
+    Tk_Window tkwin;			/* Window for text widget. */
+    char *value;			/* Value of option. */
+    char *widgRec;			/* Pointer to TkTextEmbWindow
+					 * structure. */
+    int offset;				/* Offset into item (ignored). */
+{
+    register TkTextEmbImage *embPtr = (TkTextEmbImage *) widgRec;
+
+    if (strcmp(value, "baseline") == 0) {
+	embPtr->align = ALIGN_BASELINE;
+    } else if (strcmp(value, "bottom") == 0) {
+	embPtr->align = ALIGN_BOTTOM;
+    } else if (strcmp(value, "center") == 0) {
+	embPtr->align = ALIGN_CENTER;
+    } else if (strcmp(value, "top") == 0) {
+	embPtr->align = ALIGN_TOP;
+    } else {
+	Tcl_AppendResult(interp, "bad alignment \"", value,
+		"\": must be baseline, bottom, center, or top",
+		(char *) NULL);
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * AlignPrintProc --
+ *
+ *	This procedure is invoked by the Tk configuration code
+ *	to produce a printable string for the "-align" configuration
+ *	option for embedded images.
+ *
+ * Results:
+ *	The return value is a string describing the embedded
+ *	images's current alignment.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static char *
+AlignPrintProc(clientData, tkwin, widgRec, offset, freeProcPtr)
+    ClientData clientData;		/* Ignored. */
+    Tk_Window tkwin;			/* Window for text widget. */
+    char *widgRec;			/* Pointer to TkTextEmbImage
+					 * structure. */
+    int offset;				/* Ignored. */
+    Tcl_FreeProc **freeProcPtr;		/* Pointer to variable to fill in with
+					 * information about how to reclaim
+					 * storage for return string. */
+{
+    switch (((TkTextEmbImage *) widgRec)->align) {
+	case ALIGN_BASELINE:
+	    return "baseline";
+	case ALIGN_BOTTOM:
+	    return "bottom";
+	case ALIGN_CENTER:
+	    return "center";
+	case ALIGN_TOP:
+	    return "top";
+	default:
+	    return "??";
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageDeleteProc --
+ *
+ *	This procedure is invoked by the text B-tree code whenever
+ *	an embedded image lies in a range of characters being deleted.
+ *
+ * Results:
+ *	Returns 0 to indicate that the deletion has been accepted.
+ *
+ * Side effects:
+ *	The embedded image is deleted, if it exists, and any resources
+ *	associated with it are released.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+EmbImageDeleteProc(eiPtr, linePtr, treeGone)
+    TkTextSegment *eiPtr;		/* Segment being deleted. */
+    TkTextLine *linePtr;		/* Line containing segment. */
+    int treeGone;			/* Non-zero means the entire tree is
+					 * being deleted, so everything must
+					 * get cleaned up. */
+{
+    Tcl_HashEntry *hPtr;
+
+    if (eiPtr->body.ei.image != NULL) {
+	hPtr = Tcl_FindHashEntry(&eiPtr->body.ei.textPtr->imageTable,
+		eiPtr->body.ei.name);
+	if (hPtr != NULL) {
+	    /*
+	     * (It's possible for there to be no hash table entry for this
+	     * image, if an error occurred while creating the image segment
+	     * but before the image got added to the table)
+	     */
+
+	    Tcl_DeleteHashEntry(hPtr);
+	}
+	Tk_FreeImage(eiPtr->body.ei.image);
+    }
+    Tk_FreeOptions(configSpecs, (char *) &eiPtr->body.ei,
+	    eiPtr->body.ei.textPtr->display, 0);
+    if (eiPtr->body.ei.name != NULL) {
+	ckfree(eiPtr->body.ei.name);
+    }
+    ckfree((char *) eiPtr);
+    return 0;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageCleanupProc --
+ *
+ *	This procedure is invoked by the B-tree code whenever a
+ *	segment containing an embedded image is moved from one
+ *	line to another.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The linePtr field of the segment gets updated.
+ *
+ *--------------------------------------------------------------
+ */
+
+static TkTextSegment *
+EmbImageCleanupProc(eiPtr, linePtr)
+    TkTextSegment *eiPtr;		/* Mark segment that's being moved. */
+    TkTextLine *linePtr;		/* Line that now contains segment. */
+{
+    eiPtr->body.ei.linePtr = linePtr;
+    return eiPtr;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageLayoutProc --
+ *
+ *	This procedure is the "layoutProc" for embedded image
+ *	segments.
+ *
+ * Results:
+ *	1 is returned to indicate that the segment should be
+ *	displayed.  The chunkPtr structure is filled in.
+ *
+ * Side effects:
+ *	None, except for filling in chunkPtr.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/*ARGSUSED*/
+static int
+EmbImageLayoutProc(textPtr, indexPtr, eiPtr, offset, maxX, maxChars,
+	noCharsYet, wrapMode, chunkPtr)
+    TkText *textPtr;		/* Text widget being layed out. */
+    TkTextIndex *indexPtr;	/* Identifies first character in chunk. */
+    TkTextSegment *eiPtr;	/* Segment corresponding to indexPtr. */
+    int offset;			/* Offset within segPtr corresponding to
+				 * indexPtr (always 0). */
+    int maxX;			/* Chunk must not occupy pixels at this
+				 * position or higher. */
+    int maxChars;		/* Chunk must not include more than this
+				 * many characters. */
+    int noCharsYet;		/* Non-zero means no characters have been
+				 * assigned to this line yet. */
+    Tk_Uid wrapMode;		/* Wrap mode to use for line: tkTextCharUid,
+				 * tkTextNoneUid, or tkTextWordUid. */
+    register TkTextDispChunk *chunkPtr;
+				/* Structure to fill in with information
+				 * about this chunk.  The x field has already
+				 * been set by the caller. */
+{
+    int width, height;
+
+    if (offset != 0) {
+	panic("Non-zero offset in EmbImageLayoutProc");
+    }
+
+    /*
+     * See if there's room for this image on this line.
+     */
+
+    if (eiPtr->body.ei.image == NULL) {
+	width = 0;
+	height = 0;
+    } else {
+	Tk_SizeOfImage(eiPtr->body.ei.image, &width, &height);
+	width += 2*eiPtr->body.ei.padX;
+	height += 2*eiPtr->body.ei.padY;
+    }
+    if ((width > (maxX - chunkPtr->x))
+	    && !noCharsYet && (textPtr->wrapMode != tkTextNoneUid)) {
+	return 0;
+    }
+
+    /*
+     * Fill in the chunk structure.
+     */
+
+    chunkPtr->displayProc = EmbImageDisplayProc;
+    chunkPtr->undisplayProc = (Tk_ChunkUndisplayProc *) NULL;
+    chunkPtr->measureProc = (Tk_ChunkMeasureProc *) NULL;
+    chunkPtr->bboxProc = EmbImageBboxProc;
+    chunkPtr->numChars = 1;
+    if (eiPtr->body.ei.align == ALIGN_BASELINE) {
+	chunkPtr->minAscent = height - eiPtr->body.ei.padY;
+	chunkPtr->minDescent = eiPtr->body.ei.padY;
+	chunkPtr->minHeight = 0;
+    } else {
+	chunkPtr->minAscent = 0;
+	chunkPtr->minDescent = 0;
+	chunkPtr->minHeight = height;
+    }
+    chunkPtr->width = width;
+    chunkPtr->breakIndex = -1;
+    chunkPtr->breakIndex = 1;
+    chunkPtr->clientData = (ClientData) eiPtr;
+    eiPtr->body.ei.chunkCount += 1;
+    return 1;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageCheckProc --
+ *
+ *	This procedure is invoked by the B-tree code to perform
+ *	consistency checks on embedded images.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The procedure panics if it detects anything wrong with
+ *	the embedded image.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+EmbImageCheckProc(eiPtr, linePtr)
+    TkTextSegment *eiPtr;		/* Segment to check. */
+    TkTextLine *linePtr;		/* Line containing segment. */
+{
+    if (eiPtr->nextPtr == NULL) {
+	panic("EmbImageCheckProc: embedded image is last segment in line");
+    }
+    if (eiPtr->size != 1) {
+	panic("EmbImageCheckProc: embedded image has size %d", eiPtr->size);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageDisplayProc --
+ *
+ *	This procedure is invoked by the text displaying code
+ *	when it is time to actually draw an embedded image
+ *	chunk on the screen.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The embedded image gets moved to the correct location
+ *	and drawn onto the display.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+EmbImageDisplayProc(chunkPtr, x, y, lineHeight, baseline, display, dst, screenY)
+    TkTextDispChunk *chunkPtr;		/* Chunk that is to be drawn. */
+    int x;				/* X-position in dst at which to
+					 * draw this chunk (differs from
+					 * the x-position in the chunk because
+					 * of scrolling). */
+    int y;				/* Top of rectangular bounding box
+					 * for line: tells where to draw this
+					 * chunk in dst (x-position is in
+					 * the chunk itself). */
+    int lineHeight;			/* Total height of line. */
+    int baseline;			/* Offset of baseline from y. */
+    Display *display;			/* Display to use for drawing. */
+    Drawable dst;			/* Pixmap or window in which to draw */
+    int screenY;			/* Y-coordinate in text window that
+					 * corresponds to y. */
+{
+    TkTextSegment *eiPtr = (TkTextSegment *) chunkPtr->clientData;
+    int lineX, imageX, imageY, width, height;
+    Tk_Image image;
+
+    image = eiPtr->body.ei.image;
+    if (image == NULL) {
+	return;
+    }
+    if ((x + chunkPtr->width) <= 0) {
+	return;
+    }
+
+    /*
+     * Compute the image's location and size in the text widget, taking
+     * into account the align value for the image.
+     */
+
+    EmbImageBboxProc(chunkPtr, 0, y, lineHeight, baseline, &lineX,
+	    &imageY, &width, &height);
+    imageX = lineX - chunkPtr->x + x;
+
+    Tk_RedrawImage(image, 0, 0, width, height, dst,
+	    imageX, imageY);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageBboxProc --
+ *
+ *	This procedure is called to compute the bounding box of
+ *	the area occupied by an embedded image.
+ *
+ * Results:
+ *	There is no return value.  *xPtr and *yPtr are filled in
+ *	with the coordinates of the upper left corner of the
+ *	image, and *widthPtr and *heightPtr are filled in with
+ *	the dimensions of the image in pixels.  Note:  not all
+ *	of the returned bbox is necessarily visible on the screen
+ *	(the rightmost part might be off-screen to the right,
+ *	and the bottommost part might be off-screen to the bottom).
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+EmbImageBboxProc(chunkPtr, index, y, lineHeight, baseline, xPtr, yPtr,
+	widthPtr, heightPtr)
+    TkTextDispChunk *chunkPtr;		/* Chunk containing desired char. */
+    int index;				/* Index of desired character within
+					 * the chunk. */
+    int y;				/* Topmost pixel in area allocated
+					 * for this line. */
+    int lineHeight;			/* Total height of line. */
+    int baseline;			/* Location of line's baseline, in
+					 * pixels measured down from y. */
+    int *xPtr, *yPtr;			/* Gets filled in with coords of
+					 * character's upper-left pixel. */
+    int *widthPtr;			/* Gets filled in with width of
+					 * character, in pixels. */
+    int *heightPtr;			/* Gets filled in with height of
+					 * character, in pixels. */
+{
+    TkTextSegment *eiPtr = (TkTextSegment *) chunkPtr->clientData;
+    Tk_Image image;
+
+    image = eiPtr->body.ei.image;
+    if (image != NULL) {
+	Tk_SizeOfImage(image, widthPtr, heightPtr);
+    } else {
+	*widthPtr = 0;
+	*heightPtr = 0;
+    }
+    *xPtr = chunkPtr->x + eiPtr->body.ei.padX;
+    switch (eiPtr->body.ei.align) {
+	case ALIGN_BOTTOM:
+	    *yPtr = y + (lineHeight - *heightPtr - eiPtr->body.ei.padY);
+	    break;
+	case ALIGN_CENTER:
+	    *yPtr = y + (lineHeight - *heightPtr)/2;
+	    break;
+	case ALIGN_TOP:
+	    *yPtr = y + eiPtr->body.ei.padY;
+	    break;
+	case ALIGN_BASELINE:
+	    *yPtr = y + (baseline - *heightPtr);
+	    break;
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextImageIndex --
+ *
+ *	Given the name of an embedded image within a text widget,
+ *	returns an index corresponding to the image's position
+ *	in the text.
+ *
+ * Results:
+ *	The return value is 1 if there is an embedded image by
+ *	the given name in the text widget, 0 otherwise.  If the
+ *	image exists, *indexPtr is filled in with its index.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+TkTextImageIndex(textPtr, name, indexPtr)
+    TkText *textPtr;		/* Text widget containing image. */
+    char *name;			/* Name of image. */
+    TkTextIndex *indexPtr;	/* Index information gets stored here. */
+{
+    Tcl_HashEntry *hPtr;
+    TkTextSegment *eiPtr;
+
+    hPtr = Tcl_FindHashEntry(&textPtr->imageTable, name);
+    if (hPtr == NULL) {
+	return 0;
+    }
+    eiPtr = (TkTextSegment *) Tcl_GetHashValue(hPtr);
+    indexPtr->tree = textPtr->tree;
+    indexPtr->linePtr = eiPtr->body.ei.linePtr;
+    indexPtr->charIndex = TkTextSegToOffset(eiPtr, indexPtr->linePtr);
+    return 1;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * EmbImageProc --
+ *
+ *	This procedure is called by the image code whenever an
+ *	image or its contents changes.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The image will be redisplayed.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+EmbImageProc(clientData, x, y, width, height, imgWidth, imgHeight)
+    ClientData clientData;              /* Pointer to widget record. */
+    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. */
+
+{
+    TkTextSegment *eiPtr = (TkTextSegment *) clientData;
+    TkTextIndex index;
+
+    index.tree = eiPtr->body.ei.textPtr->tree;
+    index.linePtr = eiPtr->body.ei.linePtr;
+    index.charIndex = TkTextSegToOffset(eiPtr, eiPtr->body.ei.linePtr);
+    TkTextChanged(eiPtr->body.ei.textPtr, &index, &index);
+}