tkcanvtext.c

linux系统下的音频通信

 *--------------------------------------------------------------
 */

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);
	    }
	}