Initial revision

1 files changed, 1313 insertions, 0 deletions

diff --git a/generic/tkCanvText.c b/generic/tkCanvText.c
new file mode 100644
index 0000000..2938ba1
--- /dev/null
+++ b/generic/tkCanvText.c
@@ -0,0 +1,1313 @@
+/* 
+ * tkCanvText.c --
+ *
+ *	This file implements text items for canvas widgets.
+ *
+ * Copyright (c) 1991-1994 The Regents of the University of California.
+ * Copyright (c) 1994-1995 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: @(#) tkCanvText.c 1.68 97/10/09 17:44:53
+ */
+
+#include <stdio.h>
+#include "tkInt.h"
+#include "tkCanvas.h"
+#include "tkPort.h"
+#include "default.h"
+
+/*
+ * The structure below defines the record for each text item.
+ */
+
+typedef struct TextItem  {
+    Tk_Item header;		/* Generic stuff that's the same for all
+				 * types.  MUST BE FIRST IN STRUCTURE. */
+    Tk_CanvasTextInfo *textInfoPtr;
+				/* Pointer to a structure containing
+				 * information about the selection and
+				 * insertion cursor.  The structure is owned
+				 * by (and shared with) the generic canvas
+				 * code. */
+    /*
+     * Fields that are set by widget commands other than "configure".
+     */
+     
+    double x, y;		/* Positioning point for text. */
+    int insertPos;		/* Insertion cursor is displayed just to left
+				 * of character with this index. */
+
+    /*
+     * Configuration settings that are updated by Tk_ConfigureWidget.
+     */
+
+    Tk_Anchor anchor;		/* Where to anchor text relative to (x,y). */
+    XColor *color;		/* Color for text. */
+    Tk_Font tkfont;		/* Font for drawing text. */
+    Tk_Justify justify;		/* Justification mode for text. */
+    Pixmap stipple;		/* Stipple bitmap for text, or None. */
+    char *text;			/* Text for item (malloc-ed). */
+    int width;			/* Width of lines for word-wrap, pixels.
+				 * Zero means no word-wrap. */
+
+    /*
+     * Fields whose values are derived from the current values of the
+     * configuration settings above.
+     */
+
+    int numChars;		/* Number of non-NULL characters in text. */
+    Tk_TextLayout textLayout;	/* Cached text layout information. */
+    int leftEdge;		/* Pixel location of the left edge of the
+				 * text item; where the left border of the
+				 * text layout is drawn. */
+    int rightEdge;		/* Pixel just to right of right edge of
+				 * area of text item.  Used for selecting up
+				 * to end of line. */
+    GC gc;			/* Graphics context for drawing text. */
+    GC selTextGC;		/* Graphics context for selected text. */
+    GC cursorOffGC;		/* If not None, this gives a graphics context
+				 * to use to draw the insertion cursor when
+				 * it's off.  Used if the selection and
+				 * insertion cursor colors are the same.  */
+} TextItem;
+
+/*
+ * 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(TextItem, anchor),
+	TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL,
+	"black", Tk_Offset(TextItem, color), 0},
+    {TK_CONFIG_FONT, "-font", (char *) NULL, (char *) NULL,
+	DEF_CANVTEXT_FONT, Tk_Offset(TextItem, tkfont), 0},
+    {TK_CONFIG_JUSTIFY, "-justify", (char *) NULL, (char *) NULL,
+	"left", Tk_Offset(TextItem, justify),
+	TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TextItem, stipple), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, TK_CONFIG_NULL_OK, &tagsOption},
+    {TK_CONFIG_STRING, "-text", (char *) NULL, (char *) NULL,
+	"", Tk_Offset(TextItem, text), 0},
+    {TK_CONFIG_PIXELS, "-width", (char *) NULL, (char *) NULL,
+	"0", Tk_Offset(TextItem, width), TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, 0}
+};
+
+/*
+ * Prototypes for procedures defined in this file:
+ */
+
+static void		ComputeTextBbox _ANSI_ARGS_((Tk_Canvas canvas,
+			    TextItem *textPtr));
+static int		ConfigureText _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr, int argc,
+			    char **argv, int flags));
+static int		CreateText _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, struct Tk_Item *itemPtr,
+			    int argc, char **argv));
+static void		DeleteText _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, Display *display));
+static void		DisplayCanvText _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, Display *display, Drawable dst,
+			    int x, int y, int width, int height));
+static int		GetSelText _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, int offset, char *buffer,
+			    int maxBytes));
+static int		GetTextIndex _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr,
+			    char *indexString, int *indexPtr));
+static void		ScaleText _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double originX, double originY,
+			    double scaleX, double scaleY));
+static void		SetTextCursor _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, int index));
+static int		TextCoords _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr,
+			    int argc, char **argv));
+static void		TextDeleteChars _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, int first, int last));
+static void		TextInsert _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, int beforeThis, char *string));
+static int		TextToArea _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double *rectPtr));
+static double		TextToPoint _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double *pointPtr));
+static int		TextToPostscript _ANSI_ARGS_((Tcl_Interp *interp,
+			    Tk_Canvas canvas, Tk_Item *itemPtr, int prepass));
+static void		TranslateText _ANSI_ARGS_((Tk_Canvas canvas,
+			    Tk_Item *itemPtr, double deltaX, double deltaY));
+
+/*
+ * The structures below defines the rectangle and oval item types
+ * by means of procedures that can be invoked by generic item code.
+ */
+
+Tk_ItemType tkTextType = {
+    "text",				/* name */
+    sizeof(TextItem),			/* itemSize */
+    CreateText,				/* createProc */
+    configSpecs,			/* configSpecs */
+    ConfigureText,			/* configureProc */
+    TextCoords,				/* coordProc */
+    DeleteText,				/* deleteProc */
+    DisplayCanvText,			/* displayProc */
+    0,					/* alwaysRedraw */
+    TextToPoint,			/* pointProc */
+    TextToArea,				/* areaProc */
+    TextToPostscript,			/* postscriptProc */
+    ScaleText,				/* scaleProc */
+    TranslateText,			/* translateProc */
+    GetTextIndex,			/* indexProc */
+    SetTextCursor,			/* icursorProc */
+    GetSelText,				/* selectionProc */
+    TextInsert,				/* insertProc */
+    TextDeleteChars,			/* dTextProc */
+    (Tk_ItemType *) NULL		/* nextPtr */
+};
+
+/*
+ *--------------------------------------------------------------
+ *
+ * CreateText --
+ *
+ *	This procedure is invoked to create a new text 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 text item is created.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+CreateText(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. */
+{
+    TextItem *textPtr = (TextItem *) 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;
+    }
+
+    /*
+     * Carry out initialization that is needed in order to clean
+     * up after errors during the the remainder of this procedure.
+     */
+
+    textPtr->textInfoPtr = Tk_CanvasGetTextInfo(canvas);
+
+    textPtr->insertPos	= 0;
+
+    textPtr->anchor	= TK_ANCHOR_CENTER;
+    textPtr->color	= NULL;
+    textPtr->tkfont	= NULL;
+    textPtr->justify	= TK_JUSTIFY_LEFT;
+    textPtr->stipple	= None;
+    textPtr->text	= NULL;
+    textPtr->width	= 0;
+
+    textPtr->numChars	= 0;
+    textPtr->textLayout = NULL;
+    textPtr->leftEdge	= 0;
+    textPtr->rightEdge	= 0;
+    textPtr->gc		= None;
+    textPtr->selTextGC	= None;
+    textPtr->cursorOffGC = None;
+
+    /*
+     * Process the arguments to fill in the item record.
+     */
+
+    if ((Tk_CanvasGetCoord(interp, canvas, argv[0], &textPtr->x) != TCL_OK)
+	    || (Tk_CanvasGetCoord(interp, canvas, argv[1], &textPtr->y)
+		!= TCL_OK)) {
+	return TCL_ERROR;
+    }
+
+    if (ConfigureText(interp, canvas, itemPtr, argc-2, argv+2, 0) != TCL_OK) {
+	DeleteText(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas)));
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TextCoords --
+ *
+ *	This procedure is invoked to process the "coords" widget
+ *	command on text 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
+TextCoords(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, ... */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    char x[TCL_DOUBLE_SPACE], y[TCL_DOUBLE_SPACE];
+
+    if (argc == 0) {
+	Tcl_PrintDouble(interp, textPtr->x, x);
+	Tcl_PrintDouble(interp, textPtr->y, y);
+	Tcl_AppendResult(interp, x, " ", y, (char *) NULL);
+    } else if (argc == 2) {
+	if ((Tk_CanvasGetCoord(interp, canvas, argv[0], &textPtr->x) != TCL_OK)
+		|| (Tk_CanvasGetCoord(interp, canvas, argv[1],
+		    &textPtr->y) != TCL_OK)) {
+	    return TCL_ERROR;
+	}
+	ComputeTextBbox(canvas, textPtr);
+    } else {
+	sprintf(interp->result,
+		"wrong # coordinates: expected 0 or 2, got %d", argc);
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ConfigureText --
+ *
+ *	This procedure is invoked to configure various aspects
+ *	of a text item, such as its border and background colors.
+ *
+ * Results:
+ *	A standard Tcl result code.  If an error occurs, then
+ *	an error message is left in interp->result.
+ *
+ * Side effects:
+ *	Configuration information, such as colors and stipple
+ *	patterns, may be set for itemPtr.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+ConfigureText(interp, canvas, itemPtr, argc, argv, flags)
+    Tcl_Interp *interp;		/* Interpreter for error reporting. */
+    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
+    Tk_Item *itemPtr;		/* Rectangle 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. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    XGCValues gcValues;
+    GC newGC, newSelGC;
+    unsigned long mask;
+    Tk_Window tkwin;
+    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
+    XColor *selBgColorPtr;
+
+    tkwin = Tk_CanvasTkwin(canvas);
+    if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv,
+	    (char *) textPtr, flags) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * A few of the options require additional processing, such as
+     * graphics contexts.
+     */
+
+    newGC = newSelGC = None;
+    if ((textPtr->color != NULL) && (textPtr->tkfont != NULL)) {
+	gcValues.foreground = textPtr->color->pixel;
+	gcValues.font = Tk_FontId(textPtr->tkfont);
+	mask = GCForeground|GCFont;
+	if (textPtr->stipple != None) {
+	    gcValues.stipple = textPtr->stipple;
+	    gcValues.fill_style = FillStippled;
+	    mask |= GCForeground|GCStipple|GCFillStyle;
+	}
+	newGC = Tk_GetGC(tkwin, mask, &gcValues);
+	gcValues.foreground = textInfoPtr->selFgColorPtr->pixel;
+	newSelGC = Tk_GetGC(tkwin, mask, &gcValues);
+    }
+    if (textPtr->gc != None) {
+	Tk_FreeGC(Tk_Display(tkwin), textPtr->gc);
+    }
+    textPtr->gc = newGC;
+    if (textPtr->selTextGC != None) {
+	Tk_FreeGC(Tk_Display(tkwin), textPtr->selTextGC);
+    }
+    textPtr->selTextGC = newSelGC;
+
+    selBgColorPtr = Tk_3DBorderColor(textInfoPtr->selBorder);
+    if (Tk_3DBorderColor(textInfoPtr->insertBorder)->pixel
+	    == selBgColorPtr->pixel) {
+	if (selBgColorPtr->pixel == BlackPixelOfScreen(Tk_Screen(tkwin))) {
+	    gcValues.foreground = WhitePixelOfScreen(Tk_Screen(tkwin));
+	} else {
+	    gcValues.foreground = BlackPixelOfScreen(Tk_Screen(tkwin));
+	}
+	newGC = Tk_GetGC(tkwin, GCForeground, &gcValues);
+    } else {
+	newGC = None;
+    }
+    if (textPtr->cursorOffGC != None) {
+	Tk_FreeGC(Tk_Display(tkwin), textPtr->cursorOffGC);
+    }
+    textPtr->cursorOffGC = newGC;
+
+
+    /*
+     * If the text was changed, move the selection and insertion indices
+     * to keep them inside the item.
+     */
+
+    textPtr->numChars = strlen(textPtr->text);
+    if (textInfoPtr->selItemPtr == itemPtr) {
+	if (textInfoPtr->selectFirst >= textPtr->numChars) {
+	    textInfoPtr->selItemPtr = NULL;
+	} else {
+	    if (textInfoPtr->selectLast >= textPtr->numChars) {
+		textInfoPtr->selectLast = textPtr->numChars-1;
+	    }
+	    if ((textInfoPtr->anchorItemPtr == itemPtr)
+		    && (textInfoPtr->selectAnchor >= textPtr->numChars)) {
+		textInfoPtr->selectAnchor = textPtr->numChars-1;
+	    }
+	}
+    }
+    if (textPtr->insertPos >= textPtr->numChars) {
+	textPtr->insertPos = textPtr->numChars;
+    }
+
+    ComputeTextBbox(canvas, textPtr);
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * DeleteText --
+ *
+ *	This procedure is called to clean up the data structure
+ *	associated with a text item.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Resources associated with itemPtr are released.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+DeleteText(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. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+
+    if (textPtr->color != NULL) {
+	Tk_FreeColor(textPtr->color);
+    }
+    Tk_FreeFont(textPtr->tkfont);
+    if (textPtr->stipple != None) {
+	Tk_FreeBitmap(display, textPtr->stipple);
+    }
+    if (textPtr->text != NULL) {
+	ckfree(textPtr->text);
+    }
+
+    Tk_FreeTextLayout(textPtr->textLayout);
+    if (textPtr->gc != None) {
+	Tk_FreeGC(display, textPtr->gc);
+    }
+    if (textPtr->selTextGC != None) {
+	Tk_FreeGC(display, textPtr->selTextGC);
+    }
+    if (textPtr->cursorOffGC != None) {
+	Tk_FreeGC(display, textPtr->cursorOffGC);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ComputeTextBbox --
+ *
+ *	This procedure is invoked to compute the bounding box of
+ *	all the pixels that may be drawn as part of a text item.
+ *	In addition, it recomputes all of the geometry information
+ *	used to display a text item or check for mouse hits.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The fields x1, y1, x2, and y2 are updated in the header
+ *	for itemPtr, and the linePtr structure is regenerated
+ *	for itemPtr.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+ComputeTextBbox(canvas, textPtr)
+    Tk_Canvas canvas;			/* Canvas that contains item. */
+    TextItem *textPtr;			/* Item whose bbos is to be
+					 * recomputed. */
+{
+    Tk_CanvasTextInfo *textInfoPtr;
+    int leftX, topY, width, height, fudge;
+
+    Tk_FreeTextLayout(textPtr->textLayout);
+    textPtr->textLayout = Tk_ComputeTextLayout(textPtr->tkfont,
+	    textPtr->text, textPtr->numChars, textPtr->width,
+	    textPtr->justify, 0, &width, &height);
+
+    /*
+     * Use overall geometry information to compute the top-left corner
+     * of the bounding box for the text item.
+     */
+
+    leftX = (int) (textPtr->x + 0.5);
+    topY = (int) (textPtr->y + 0.5);
+    switch (textPtr->anchor) {
+	case TK_ANCHOR_NW:
+	case TK_ANCHOR_N:
+	case TK_ANCHOR_NE:
+	    break;
+
+	case TK_ANCHOR_W:
+	case TK_ANCHOR_CENTER:
+	case TK_ANCHOR_E:
+	    topY -= height / 2;
+	    break;
+
+	case TK_ANCHOR_SW:
+	case TK_ANCHOR_S:
+	case TK_ANCHOR_SE:
+	    topY -= height;
+	    break;
+    }
+    switch (textPtr->anchor) {
+	case TK_ANCHOR_NW:
+	case TK_ANCHOR_W:
+	case TK_ANCHOR_SW:
+	    break;
+
+	case TK_ANCHOR_N:
+	case TK_ANCHOR_CENTER:
+	case TK_ANCHOR_S:
+	    leftX -= width / 2;
+	    break;
+
+	case TK_ANCHOR_NE:
+	case TK_ANCHOR_E:
+	case TK_ANCHOR_SE:
+	    leftX -= width;
+	    break;
+    }
+
+    textPtr->leftEdge  = leftX;
+    textPtr->rightEdge = leftX + width;
+
+    /*
+     * Last of all, update the bounding box for the item.  The item's
+     * bounding box includes the bounding box of all its lines, plus
+     * an extra fudge factor for the cursor border (which could
+     * potentially be quite large).
+     */
+
+    textInfoPtr = textPtr->textInfoPtr;
+    fudge = (textInfoPtr->insertWidth + 1) / 2;
+    if (textInfoPtr->selBorderWidth > fudge) {
+	fudge = textInfoPtr->selBorderWidth;
+    }
+    textPtr->header.x1 = leftX - fudge;
+    textPtr->header.y1 = topY;
+    textPtr->header.x2 = leftX + width + fudge;
+    textPtr->header.y2 = topY + height;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * DisplayCanvText --
+ *
+ *	This procedure is invoked to draw a text item in a given
+ *	drawable.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	ItemPtr is drawn in drawable using the transformation
+ *	information in canvas.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+DisplayCanvText(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). */
+{
+    TextItem *textPtr;
+    Tk_CanvasTextInfo *textInfoPtr;
+    int selFirst, selLast;
+    short drawableX, drawableY;
+
+    textPtr = (TextItem *) itemPtr;
+    textInfoPtr = textPtr->textInfoPtr;
+
+    if (textPtr->gc == None) {
+	return;
+    }
+
+    /*
+     * If we're stippling, then modify the stipple offset in the GC.  Be
+     * sure to reset the offset when done, since the GC is supposed to be
+     * read-only.
+     */
+
+    if (textPtr->stipple != None) {
+	Tk_CanvasSetStippleOrigin(canvas, textPtr->gc);
+    }
+
+    selFirst = -1;
+    selLast = 0;		/* lint. */
+    if (textInfoPtr->selItemPtr == itemPtr) {
+	selFirst = textInfoPtr->selectFirst;
+	selLast = textInfoPtr->selectLast;
+	if (selLast >= textPtr->numChars) {
+	    selLast = textPtr->numChars - 1;
+	}
+	if ((selFirst >= 0) && (selFirst <= selLast)) {
+	    /*
+	     * Draw a special background under the selection.
+	     */
+
+	    int xFirst, yFirst, hFirst;
+	    int xLast, yLast, wLast;
+
+	    Tk_CharBbox(textPtr->textLayout, selFirst,
+		    &xFirst, &yFirst, NULL, &hFirst);
+	    Tk_CharBbox(textPtr->textLayout, selLast,
+		    &xLast, &yLast, &wLast, NULL);
+
+	    /*
+	     * If the selection spans the end of this line, then display
+	     * selection background all the way to the end of the line.
+	     * However, for the last line we only want to display up to the
+	     * last character, not the end of the line.
+	     */
+
+	    x = xFirst;
+	    height = hFirst;
+	    for (y = yFirst ; y <= yLast; y += height) {
+		if (y == yLast) {
+		    width = (xLast + wLast) - x;
+		} else {	    
+		    width = textPtr->rightEdge - textPtr->leftEdge - x;
+		}
+		Tk_CanvasDrawableCoords(canvas,
+			(double) (textPtr->leftEdge + x
+				- textInfoPtr->selBorderWidth),
+			(double) (textPtr->header.y1 + y),
+			&drawableX, &drawableY);
+		Tk_Fill3DRectangle(Tk_CanvasTkwin(canvas), drawable,
+			textInfoPtr->selBorder, drawableX, drawableY,
+			width + 2 * textInfoPtr->selBorderWidth,
+			height, textInfoPtr->selBorderWidth, TK_RELIEF_RAISED);
+		x = 0;
+	    }
+	}
+    }
+
+    /*
+     * If the insertion point should be displayed, then draw a special
+     * background for the cursor before drawing the text.  Note:  if
+     * we're the cursor item but the cursor is turned off, then redraw
+     * background over the area of the cursor.  This guarantees that
+     * the selection won't make the cursor invisible on mono displays,
+     * where both are drawn in the same color.
+     */
+
+    if ((textInfoPtr->focusItemPtr == itemPtr) && (textInfoPtr->gotFocus)) {
+	if (Tk_CharBbox(textPtr->textLayout, textPtr->insertPos,
+		&x, &y, NULL, &height)) {
+	    Tk_CanvasDrawableCoords(canvas,
+		    (double) (textPtr->leftEdge + x
+			    - (textInfoPtr->insertWidth / 2)),
+		    (double) (textPtr->header.y1 + y),
+		    &drawableX, &drawableY);
+	    if (textInfoPtr->cursorOn) {
+		Tk_Fill3DRectangle(Tk_CanvasTkwin(canvas), drawable,
+			textInfoPtr->insertBorder,
+			drawableX, drawableY,
+			textInfoPtr->insertWidth, height,
+			textInfoPtr->insertBorderWidth, TK_RELIEF_RAISED);
+	    } else if (textPtr->cursorOffGC != None) {
+		/*
+		 * Redraw the background over the area of the cursor,
+		 * even though the cursor is turned off.  This
+		 * guarantees that the selection won't make the cursor
+		 * invisible on mono displays, where both may be drawn
+		 * in the same color.
+		 */
+
+		XFillRectangle(display, drawable, textPtr->cursorOffGC,
+			drawableX, drawableY,
+			(unsigned) textInfoPtr->insertWidth,
+			(unsigned) height);
+	    }
+	}
+    }
+
+
+    /*
+     * Display the text in two pieces: draw the entire text item, then
+     * draw the selected text on top of it.  The selected text then
+     * will only need to be drawn if it has different attributes (such
+     * as foreground color) than regular text.
+     */
+
+    Tk_CanvasDrawableCoords(canvas, (double) textPtr->leftEdge,
+	    (double) textPtr->header.y1, &drawableX, &drawableY);
+    Tk_DrawTextLayout(display, drawable, textPtr->gc, textPtr->textLayout,
+	    drawableX, drawableY, 0, -1);
+
+    if ((selFirst >= 0) && (textPtr->selTextGC != textPtr->gc)) {
+	Tk_DrawTextLayout(display, drawable, textPtr->selTextGC,
+	    textPtr->textLayout, drawableX, drawableY, selFirst,
+	    selLast + 1);
+    }
+
+    if (textPtr->stipple != None) {
+	XSetTSOrigin(display, textPtr->gc, 0, 0);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TextInsert --
+ *
+ *	Insert characters into a text item at a given position.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The text in the given item is modified.  The cursor and
+ *	selection positions are also modified to reflect the
+ *	insertion.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+TextInsert(canvas, itemPtr, beforeThis, string)
+    Tk_Canvas canvas;		/* Canvas containing text item. */
+    Tk_Item *itemPtr;		/* Text item to be modified. */
+    int beforeThis;		/* Index of character before which text is
+				 * to be inserted. */
+    char *string;		/* New characters to be inserted. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    int length;
+    char *new;
+    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
+
+    length = strlen(string);
+    if (length == 0) {
+	return;
+    }
+    if (beforeThis < 0) {
+	beforeThis = 0;
+    }
+    if (beforeThis > textPtr->numChars) {
+	beforeThis = textPtr->numChars;
+    }
+
+    new = (char *) ckalloc((unsigned) (textPtr->numChars + length + 1));
+    strncpy(new, textPtr->text, (size_t) beforeThis);
+    strcpy(new+beforeThis, string);
+    strcpy(new+beforeThis+length, textPtr->text+beforeThis);
+    ckfree(textPtr->text);
+    textPtr->text = new;
+    textPtr->numChars += length;
+
+    /*
+     * Inserting characters invalidates indices such as those for the
+     * selection and cursor.  Update the indices appropriately.
+     */
+
+    if (textInfoPtr->selItemPtr == itemPtr) {
+	if (textInfoPtr->selectFirst >= beforeThis) {
+	    textInfoPtr->selectFirst += length;
+	}
+	if (textInfoPtr->selectLast >= beforeThis) {
+	    textInfoPtr->selectLast += length;
+	}
+	if ((textInfoPtr->anchorItemPtr == itemPtr)
+		&& (textInfoPtr->selectAnchor >= beforeThis)) {
+	    textInfoPtr->selectAnchor += length;
+	}
+    }
+    if (textPtr->insertPos >= beforeThis) {
+	textPtr->insertPos += length;
+    }
+    ComputeTextBbox(canvas, textPtr);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TextDeleteChars --
+ *
+ *	Delete one or more characters from a text item.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Characters between "first" and "last", inclusive, get
+ *	deleted from itemPtr, and things like the selection
+ *	position get updated.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+TextDeleteChars(canvas, itemPtr, first, last)
+    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
+    Tk_Item *itemPtr;		/* Item in which to delete characters. */
+    int first;			/* Index of first character to delete. */
+    int last;			/* Index of last character to delete. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    int count;
+    char *new;
+    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
+
+    if (first < 0) {
+	first = 0;
+    }
+    if (last >= textPtr->numChars) {
+	last = textPtr->numChars-1;
+    }
+    if (first > last) {
+	return;
+    }
+    count = last + 1 - first;
+
+    new = (char *) ckalloc((unsigned) (textPtr->numChars + 1 - count));
+    strncpy(new, textPtr->text, (size_t) first);
+    strcpy(new+first, textPtr->text+last+1);
+    ckfree(textPtr->text);
+    textPtr->text = new;
+    textPtr->numChars -= count;
+
+    /*
+     * Update indexes for the selection and cursor to reflect the
+     * renumbering of the remaining characters.
+     */
+
+    if (textInfoPtr->selItemPtr == itemPtr) {
+	if (textInfoPtr->selectFirst > first) {
+	    textInfoPtr->selectFirst -= count;
+	    if (textInfoPtr->selectFirst < first) {
+		textInfoPtr->selectFirst = first;
+	    }
+	}
+	if (textInfoPtr->selectLast >= first) {
+	    textInfoPtr->selectLast -= count;
+	    if (textInfoPtr->selectLast < (first-1)) {
+		textInfoPtr->selectLast = (first-1);
+	    }
+	}
+	if (textInfoPtr->selectFirst > textInfoPtr->selectLast) {
+	    textInfoPtr->selItemPtr = NULL;
+	}
+	if ((textInfoPtr->anchorItemPtr == itemPtr)
+		&& (textInfoPtr->selectAnchor > first)) {
+	    textInfoPtr->selectAnchor -= count;
+	    if (textInfoPtr->selectAnchor < first) {
+		textInfoPtr->selectAnchor = first;
+	    }
+	}
+    }
+    if (textPtr->insertPos > first) {
+	textPtr->insertPos -= count;
+	if (textPtr->insertPos < first) {
+	    textPtr->insertPos = first;
+	}
+    }
+    ComputeTextBbox(canvas, textPtr);
+    return;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TextToPoint --
+ *
+ *	Computes the distance from a given point to a given
+ *	text item, in canvas units.
+ *
+ * Results:
+ *	The return value is 0 if the point whose x and y coordinates
+ *	are pointPtr[0] and pointPtr[1] is inside the text item.  If
+ *	the point isn't inside the text item then the return value
+ *	is the distance from the point to the text item.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static double
+TextToPoint(canvas, itemPtr, pointPtr)
+    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
+    Tk_Item *itemPtr;		/* Item to check against point. */
+    double *pointPtr;		/* Pointer to x and y coordinates. */
+{
+    TextItem *textPtr;
+
+    textPtr = (TextItem *) itemPtr;
+    return (double) Tk_DistanceToTextLayout(textPtr->textLayout,
+	    (int) pointPtr[0] - textPtr->leftEdge,
+	    (int) pointPtr[1] - textPtr->header.y1);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TextToArea --
+ *
+ *	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
+TextToArea(canvas, itemPtr, rectPtr)
+    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
+    Tk_Item *itemPtr;		/* Item to check against rectangle. */
+    double *rectPtr;		/* Pointer to array of four coordinates
+				 * (x1, y1, x2, y2) describing rectangular
+				 * area.  */
+{
+    TextItem *textPtr;
+
+    textPtr = (TextItem *) itemPtr;
+    return Tk_IntersectTextLayout(textPtr->textLayout,
+	    (int) (rectPtr[0] + 0.5) - textPtr->leftEdge,
+	    (int) (rectPtr[1] + 0.5) - textPtr->header.y1,
+	    (int) (rectPtr[2] - rectPtr[0] + 0.5),
+	    (int) (rectPtr[3] - rectPtr[1] + 0.5));
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ScaleText --
+ *
+ *	This procedure is invoked to rescale a text item.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Scales the position of the text, but not the size
+ *	of the font for the text.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static void
+ScaleText(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. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+
+    textPtr->x = originX + scaleX*(textPtr->x - originX);
+    textPtr->y = originY + scaleY*(textPtr->y - originY);
+    ComputeTextBbox(canvas, textPtr);
+    return;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TranslateText --
+ *
+ *	This procedure is called to move a text item by a
+ *	given amount.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The position of the text item is offset by (xDelta, yDelta),
+ *	and the bounding box is updated in the generic part of the
+ *	item structure.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+TranslateText(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. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+
+    textPtr->x += deltaX;
+    textPtr->y += deltaY;
+    ComputeTextBbox(canvas, textPtr);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetTextIndex --
+ *
+ *	Parse an index into a text item 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 itemPtr) corresponding to
+ *	string.  Otherwise an error message is left in
+ *	interp->result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+GetTextIndex(interp, canvas, itemPtr, string, indexPtr)
+    Tcl_Interp *interp;		/* Used for error reporting. */
+    Tk_Canvas canvas;		/* Canvas containing item. */
+    Tk_Item *itemPtr;		/* Item for which the index is being
+				 * specified. */
+    char *string;		/* Specification of a particular character
+				 * in itemPtr's text. */
+    int *indexPtr;		/* Where to store converted index. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    size_t length;
+    int c;
+    TkCanvas *canvasPtr = (TkCanvas *) canvas;
+    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
+
+    c = string[0];
+    length = strlen(string);
+
+    if ((c == 'e') && (strncmp(string, "end", length) == 0)) {
+	*indexPtr = textPtr->numChars;
+    } else if ((c == 'i') && (strncmp(string, "insert", length) == 0)) {
+	*indexPtr = textPtr->insertPos;
+    } else if ((c == 's') && (strncmp(string, "sel.first", length) == 0)
+	    && (length >= 5)) {
+	if (textInfoPtr->selItemPtr != itemPtr) {
+	    interp->result = "selection isn't in item";
+	    return TCL_ERROR;
+	}
+	*indexPtr = textInfoPtr->selectFirst;
+    } else if ((c == 's') && (strncmp(string, "sel.last", length) == 0)
+	    && (length >= 5)) {
+	if (textInfoPtr->selItemPtr != itemPtr) {
+	    interp->result = "selection isn't in item";
+	    return TCL_ERROR;
+	}
+	*indexPtr = textInfoPtr->selectLast;
+    } else if (c == '@') {
+	int x, y;
+	double tmp;
+	char *end, *p;
+
+	p = string+1;
+	tmp = strtod(p, &end);
+	if ((end == p) || (*end != ',')) {
+	    goto badIndex;
+	}
+	x = (int) ((tmp < 0) ? tmp - 0.5 : tmp + 0.5);
+	p = end+1;
+	tmp = strtod(p, &end);
+	if ((end == p) || (*end != 0)) {
+	    goto badIndex;
+	}
+	y = (int) ((tmp < 0) ? tmp - 0.5 : tmp + 0.5);
+	*indexPtr = Tk_PointToChar(textPtr->textLayout,
+		x + canvasPtr->scrollX1 - textPtr->leftEdge,
+		y + canvasPtr->scrollY1 - textPtr->header.y1);
+    } else if (Tcl_GetInt(interp, string, indexPtr) == TCL_OK) {
+	if (*indexPtr < 0){
+	    *indexPtr = 0;
+	} else if (*indexPtr > textPtr->numChars) {
+	    *indexPtr = textPtr->numChars;
+	}
+    } else {
+	/*
+	 * Some of the paths here leave messages in interp->result,
+	 * so we have to clear it out before storing our own message.
+	 */
+
+	badIndex:
+	Tcl_SetResult(interp, (char *) NULL, TCL_STATIC);
+	Tcl_AppendResult(interp, "bad index \"", string, "\"",
+		(char *) NULL);
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * SetTextCursor --
+ *
+ *	Set the position of the insertion cursor in this item.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The cursor position will change.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static void
+SetTextCursor(canvas, itemPtr, index)
+    Tk_Canvas canvas;			/* Record describing canvas widget. */
+    Tk_Item *itemPtr;			/* Text item in which cursor position
+					 * is to be set. */
+    int index;				/* Index of character just before which
+					 * cursor is to be positioned. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+
+    if (index < 0) {
+	textPtr->insertPos = 0;
+    } else  if (index > textPtr->numChars) {
+	textPtr->insertPos = textPtr->numChars;
+    } else {
+	textPtr->insertPos = index;
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetSelText --
+ *
+ *	This procedure is invoked to return the selected portion
+ *	of a text item.  It is only called when this item has
+ *	the selection.
+ *
+ * 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.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+GetSelText(canvas, itemPtr, offset, buffer, maxBytes)
+    Tk_Canvas canvas;			/* Canvas containing selection. */
+    Tk_Item *itemPtr;			/* Text item containing selection. */
+    int offset;				/* Offset within selection of first
+					 * character 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. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    int count;
+    Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
+
+    count = textInfoPtr->selectLast + 1 - textInfoPtr->selectFirst - offset;
+    if (textInfoPtr->selectLast == textPtr->numChars) {
+	count -= 1;
+    }
+    if (count > maxBytes) {
+	count = maxBytes;
+    }
+    if (count <= 0) {
+	return 0;
+    }
+    strncpy(buffer, textPtr->text + textInfoPtr->selectFirst + offset,
+	    (size_t) count);
+    buffer[count] = '\0';
+    return count;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TextToPostscript --
+ *
+ *	This procedure is called to generate Postscript for
+ *	text items.
+ *
+ * Results:
+ *	The return value is a standard Tcl result.  If an error
+ *	occurs in generating Postscript then an error message is
+ *	left in interp->result, replacing whatever used
+ *	to be there.  If no error occurs, then Postscript for the
+ *	item is appended to the result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+TextToPostscript(interp, canvas, itemPtr, prepass)
+    Tcl_Interp *interp;			/* Leave Postscript or error message
+					 * here. */
+    Tk_Canvas canvas;			/* Information about overall canvas. */
+    Tk_Item *itemPtr;			/* Item for which Postscript is
+					 * wanted. */
+    int prepass;			/* 1 means this is a prepass to
+					 * collect font information;  0 means
+					 * final Postscript is being created. */
+{
+    TextItem *textPtr = (TextItem *) itemPtr;
+    int x, y;
+    Tk_FontMetrics fm;
+    char *justify;
+    char buffer[500];
+
+    if (textPtr->color == NULL) {
+	return TCL_OK;
+    }
+
+    if (Tk_CanvasPsFont(interp, canvas, textPtr->tkfont) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (prepass != 0) {
+	return TCL_OK;
+    }
+    if (Tk_CanvasPsColor(interp, canvas, textPtr->color) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (textPtr->stipple != None) {
+	Tcl_AppendResult(interp, "/StippleText {\n    ",
+		(char *) NULL);
+	Tk_CanvasPsStipple(interp, canvas, textPtr->stipple);
+	Tcl_AppendResult(interp, "} bind def\n", (char *) NULL);
+    }
+
+    sprintf(buffer, "%.15g %.15g [\n", textPtr->x,
+	    Tk_CanvasPsY(canvas, textPtr->y));
+    Tcl_AppendResult(interp, buffer, (char *) NULL);
+
+    Tk_TextLayoutToPostscript(interp, textPtr->textLayout);
+
+    x = 0;  y = 0;  justify = NULL;	/* lint. */
+    switch (textPtr->anchor) {
+	case TK_ANCHOR_NW:	x = 0; y = 0;	break;
+	case TK_ANCHOR_N:	x = 1; y = 0;	break;
+	case TK_ANCHOR_NE:	x = 2; y = 0;	break;
+	case TK_ANCHOR_E:	x = 2; y = 1;	break;
+	case TK_ANCHOR_SE:	x = 2; y = 2;	break;
+	case TK_ANCHOR_S:	x = 1; y = 2;	break;
+	case TK_ANCHOR_SW:	x = 0; y = 2;	break;
+	case TK_ANCHOR_W:	x = 0; y = 1;	break;
+	case TK_ANCHOR_CENTER:	x = 1; y = 1;	break;
+    }
+    switch (textPtr->justify) {
+        case TK_JUSTIFY_LEFT:	justify = "0";	break;
+	case TK_JUSTIFY_CENTER: justify = "0.5";break;
+	case TK_JUSTIFY_RIGHT:  justify = "1";	break;
+    }
+
+    Tk_GetFontMetrics(textPtr->tkfont, &fm);
+    sprintf(buffer, "] %d %g %g %s %s DrawText\n",
+	    fm.linespace, x / -2.0, y / 2.0, justify,
+	    ((textPtr->stipple == None) ? "false" : "true"));
+    Tcl_AppendResult(interp, buffer, (char *) NULL);
+
+    return TCL_OK;
+}