tktextdisp.c

linux系统下的音频通信

	    if (index.charIndex == dlPtr->index.charIndex) {
		/*
		 * Case (a) -- can use existing display line as-is.
		 */

		if ((dlPtr->flags & HAS_3D_BORDER) && (prevPtr != NULL)
			&& (prevPtr->flags & (NEW_LAYOUT))) {
		    dlPtr->oldY = -1;
		}
		goto lineOK;
	    }
	    if (index.charIndex < dlPtr->index.charIndex) {
		goto makeNewDLine;
	    }

	    /*
	     * Case (c) -- dlPtr is useless.  Discard it and start
	     * again with the next display line.
	     */

	    newPtr = dlPtr->nextPtr;
	    FreeDLines(textPtr, dlPtr, newPtr, 0);
	    dlPtr = newPtr;
	    if (prevPtr != NULL) {
		prevPtr->nextPtr = newPtr;
	    } else {
		dInfoPtr->dLinePtr = newPtr;
	    }
	    continue;
	}

	/*
	 * Advance to the start of the next line.
	 */

	lineOK:
	dlPtr->y = y;
	y += dlPtr->height;
	TkTextIndexForwChars(&index, dlPtr->count, &index);
	prevPtr = dlPtr;
	dlPtr = dlPtr->nextPtr;

	/*
	 * If we switched text lines, delete any DLines left for the
	 * old text line.
	 */

	if (index.linePtr != prevPtr->index.linePtr) {
	    register DLine *nextPtr;

	    nextPtr = dlPtr;
	    while ((nextPtr != NULL)
		    && (nextPtr->index.linePtr == prevPtr->index.linePtr)) {
		nextPtr = nextPtr->nextPtr;
	    }
	    if (nextPtr != dlPtr) {
		FreeDLines(textPtr, dlPtr, nextPtr, 0);
		prevPtr->nextPtr = nextPtr;
		dlPtr = nextPtr;
	    }
	}

	/*
	 * It's important to have the following check here rather than in
	 * the while statement for the loop, so that there's always at least
	 * one DLine generated, regardless of how small the window is.  This
	 * keeps a lot of other code from breaking.
	 */

	if (y >= maxY) {
	    break;
	}
    }

    /*
     * Delete any DLine structures that don't fit on the screen.
     */

    FreeDLines(textPtr, dlPtr, (DLine *) NULL, 1);

    /*
     *--------------------------------------------------------------
     * If there is extra space at the bottom of the window (because
     * we've hit the end of the text), then bring in more lines at
     * the top of the window, if there are any, to fill in the view.
     *--------------------------------------------------------------
     */

    if (y < maxY) {
	int lineNum, spaceLeft, charsToCount;
	DLine *lowestPtr;

	/*
	 * Layout an entire text line (potentially > 1 display line),
	 * then link in as many display lines as fit without moving
	 * the bottom line out of the window.  Repeat this until
	 * all the extra space has been used up or we've reached the
	 * beginning of the text.
	 */

	spaceLeft = maxY - y;
	lineNum = TkBTreeLineIndex(dInfoPtr->dLinePtr->index.linePtr);
	charsToCount = dInfoPtr->dLinePtr->index.charIndex;
	if (charsToCount == 0) {
	    charsToCount = INT_MAX;
	    lineNum--;
	}
	for ( ; (lineNum >= 0) && (spaceLeft > 0); lineNum--) {
	    index.linePtr = TkBTreeFindLine(textPtr->tree, lineNum);
	    index.charIndex = 0;
	    lowestPtr = NULL;
	    do {
		dlPtr = LayoutDLine(textPtr, &index);
		dlPtr->nextPtr = lowestPtr;
		lowestPtr = dlPtr;
		TkTextIndexForwChars(&index, dlPtr->count, &index);
		charsToCount -= dlPtr->count;
	    } while ((charsToCount > 0)
		    && (index.linePtr == lowestPtr->index.linePtr));

	    /*
	     * Scan through the display lines from the bottom one up to
	     * the top one.
	     */

	    while (lowestPtr != NULL) {
		dlPtr = lowestPtr;
		spaceLeft -= dlPtr->height;
		if (spaceLeft < 0) {
		    break;
		}
		lowestPtr = dlPtr->nextPtr;
		dlPtr->nextPtr = dInfoPtr->dLinePtr;
		dInfoPtr->dLinePtr = dlPtr;
		if (tkTextDebug) {
		    char string[TK_POS_CHARS];

		    TkTextPrintIndex(&dlPtr->index, string);
		    Tcl_SetVar2(textPtr->interp, "tk_textRelayout",
			    (char *) NULL, string,
			    TCL_GLOBAL_ONLY|TCL_APPEND_VALUE|TCL_LIST_ELEMENT);
		}
	    }
	    FreeDLines(textPtr, lowestPtr, (DLine *) NULL, 0);
	    charsToCount = INT_MAX;
	}

	/*
	 * Now we're all done except that the y-coordinates in all the
	 * DLines are wrong and the top index for the text is wrong.
	 * Update them.
	 */

	textPtr->topIndex = dInfoPtr->dLinePtr->index;
	y = dInfoPtr->y;
	for (dlPtr = dInfoPtr->dLinePtr; dlPtr != NULL;
		dlPtr = dlPtr->nextPtr) {
	    if (y > dInfoPtr->maxY) {
		panic("Added too many new lines in UpdateDisplayInfo");
	    }
	    dlPtr->y = y;
	    y += dlPtr->height; 
	}
    }

    /*
     *--------------------------------------------------------------
     * If the old top or bottom line has scrolled elsewhere on the
     * screen, we may not be able to re-use its old contents by
     * copying bits (e.g., a beveled edge that was drawn when it was
     * at the top or bottom won't be drawn when the line is in the
     * middle and its neighbor has a matching background).  Similarly,
     * if the new top or bottom line came from somewhere else on the
     * screen, we may not be able to copy the old bits.
     *--------------------------------------------------------------
     */

    dlPtr = dInfoPtr->dLinePtr;
    if ((dlPtr->flags & HAS_3D_BORDER) && !(dlPtr->flags & TOP_LINE)) {
	dlPtr->oldY = -1;
    }
    while (1) {
	if ((dlPtr->flags & TOP_LINE) && (dlPtr != dInfoPtr->dLinePtr)
		&& (dlPtr->flags & HAS_3D_BORDER)) {
	    dlPtr->oldY = -1;
	}
	if ((dlPtr->flags & BOTTOM_LINE) && (dlPtr->nextPtr != NULL)
		&& (dlPtr->flags & HAS_3D_BORDER)) {
	    dlPtr->oldY = -1;
	}
	if (dlPtr->nextPtr == NULL) {
	    if ((dlPtr->flags & HAS_3D_BORDER)
		    && !(dlPtr->flags & BOTTOM_LINE)) {
		dlPtr->oldY = -1;
	    }
	    dlPtr->flags &= ~TOP_LINE;
	    dlPtr->flags |= BOTTOM_LINE;
	    break;
	}
	dlPtr->flags &= ~(TOP_LINE|BOTTOM_LINE);
	dlPtr = dlPtr->nextPtr;
    }
    dInfoPtr->dLinePtr->flags |= TOP_LINE;

    /*
     * Arrange for scrollbars to be updated.
     */

    textPtr->flags |= UPDATE_SCROLLBARS;

    /*
     *--------------------------------------------------------------
     * Deal with horizontal scrolling:
     * 1. If there's empty space to the right of the longest line,
     *    shift the screen to the right to fill in the empty space.
     * 2. If the desired horizontal scroll position has changed,
     *    force a full redisplay of all the lines in the widget.
     * 3. If the wrap mode isn't "none" then re-scroll to the base
     *    position.
     *--------------------------------------------------------------
     */

    dInfoPtr->maxLength = 0;
    for (dlPtr = dInfoPtr->dLinePtr; dlPtr != NULL;
	    dlPtr = dlPtr->nextPtr) {
	if (dlPtr->length > dInfoPtr->maxLength) {
	    dInfoPtr->maxLength = dlPtr->length;
	}
    }
    maxOffset = (dInfoPtr->maxLength - (dInfoPtr->maxX - dInfoPtr->x)
	    + textPtr->charWidth - 1)/textPtr->charWidth;
    if (dInfoPtr->newCharOffset > maxOffset) {
	dInfoPtr->newCharOffset = maxOffset;
    }
    if (dInfoPtr->newCharOffset < 0) {
	dInfoPtr->newCharOffset = 0;
    }
    pixelOffset = dInfoPtr->newCharOffset * textPtr->charWidth;
    if (pixelOffset != dInfoPtr->curPixelOffset) {
	dInfoPtr->curPixelOffset = pixelOffset;
	for (dlPtr = dInfoPtr->dLinePtr; dlPtr != NULL;
		dlPtr = dlPtr->nextPtr) {
	    dlPtr->oldY = -1;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FreeDLines --
 *
 *	This procedure is called to free up all of the resources
 *	associated with one or more DLine structures.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory gets freed and various other resources are released.
 *
 *----------------------------------------------------------------------
 */

static void
FreeDLines(textPtr, firstPtr, lastPtr, unlink)
    TkText *textPtr;			/* Information about overall text
					 * widget. */
    register DLine *firstPtr;		/* Pointer to first DLine to free up. */
    DLine *lastPtr;			/* Pointer to DLine just after last
					 * one to free (NULL means everything
					 * starting with firstPtr). */
    int unlink;				/* 1 means DLines are currently linked
					 * into the list rooted at
					 * textPtr->dInfoPtr->dLinePtr and
					 * they have to be unlinked.  0 means
					 * just free without unlinking. */
{
    register TkTextDispChunk *chunkPtr, *nextChunkPtr;
    register DLine *nextDLinePtr;

    if (unlink) {
	if (textPtr->dInfoPtr->dLinePtr == firstPtr) {
	    textPtr->dInfoPtr->dLinePtr = lastPtr;
	} else {
	    register DLine *prevPtr;
	    for (prevPtr = textPtr->dInfoPtr->dLinePtr;
		    prevPtr->nextPtr != firstPtr; prevPtr = prevPtr->nextPtr) {
		/* Empty loop body. */
	    }
	    prevPtr->nextPtr = lastPtr;
	}
    }
    while (firstPtr != lastPtr) {
	nextDLinePtr = firstPtr->nextPtr;
	for (chunkPtr = firstPtr->chunkPtr; chunkPtr != NULL;
		chunkPtr = nextChunkPtr) {
	    if (chunkPtr->undisplayProc != NULL) {
		(*chunkPtr->undisplayProc)(textPtr, chunkPtr);
	    }
	    FreeStyle(textPtr, chunkPtr->stylePtr);
	    nextChunkPtr = chunkPtr->nextPtr;
	    ckfree((char *) chunkPtr);
	}
	ckfree((char *) firstPtr);
	firstPtr = nextDLinePtr;
    }
    textPtr->dInfoPtr->dLinesInvalidated = 1;
}

/*
 *----------------------------------------------------------------------
 *
 * DisplayDLine --
 *
 *	This procedure is invoked to draw a single line on the
 *	screen.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The line given by dlPtr is drawn at its correct position in
 *	textPtr's window.  Note that this is one *display* line, not
 *	one *text* line.
 *
 *----------------------------------------------------------------------
 */

static void
DisplayDLine(textPtr, dlPtr, prevPtr, pixmap)
    TkText *textPtr;		/* Text widget in which to draw line. */
    register DLine *dlPtr;	/* Information about line to draw. */
    DLine *prevPtr;		/* Line just before one to draw, or NULL
				 * if dlPtr is the top line. */
    Pixmap pixmap;		/* Pixmap to use for double-buffering.
				 * Caller must make sure it's large enough
				 * to hold line. */
{
    register TkTextDispChunk *chunkPtr;
    TextDInfo *dInfoPtr = textPtr->dInfoPtr;
    Display *display;
    int height, x;

    /*
     * First, clear the area of the line to the background color for the
     * text widget.
     */

    display = Tk_Display(textPtr->tkwin);
    Tk_Fill3DRectangle(textPtr->tkwin, pixmap, textPtr->border, 0, 0,
	    Tk_Width(textPtr->tkwin), dlPtr->height, 0, TK_RELIEF_FLAT);

    /*
     * Next, draw background information for the whole line.
     */

    DisplayLineBackground(textPtr, dlPtr, prevPtr, pixmap);

    /*
     * Make another pass through all of the chunks to redraw the
     * insertion cursor, if it is visible on this line.  Must do
     * it here rather than in the foreground pass below because
     * otherwise a wide insertion cursor will obscure the character
     * to its left.
     */

    if (textPtr->state == tkNormalUid) {
	for (chunkPtr = dlPtr->chunkPtr; (chunkPtr != NULL);
		chunkPtr = chunkPtr->nextPtr) {
	    x = chunkPtr->x + dInfoPtr->x - dInfoPtr->curPixelOffset;
	    if (chunkPtr->displayProc == TkTextInsertDisplayProc) {
		(*chunkPtr->displayProc)(chunkPtr, x, dlPtr->spaceAbove,
			dlPtr->height - dlPtr->spaceAbove - dlPtr->spaceBelow,
			dlPtr->baseline - dlPtr->spaceAbove, display, pixmap,
			dlPtr->y + dlPtr->spaceAbove);
	    }
	}
    }

    /*
     * Make yet another pass through all of the chunks to redraw all of
     * foreground information.  Note:  we have to call the displayProc
     * even for chunks that are off-screen.  This is needed, for
     * example, so that embedded windows can be unmapped in this case.
     * Conve
     */

    for (chunkPtr = dlPtr->chunkPtr; (chunkPtr != NULL);
	    chunkPtr = chunkPtr->nextPtr) {
	if (chunkPtr->displayProc == TkTextInsertDisplayProc) {
	    /*
	     * Already displayed the insertion cursor above.  Don't
	     * do it again here.
	     */

	    continue;
	}
	x = chunkPtr->x + dInfoPtr->x - dInfoPtr->curPixelOffset;
	if ((x + chunkPtr->width <= 0) || (x >= dInfoPtr->maxX)) {
	    /*
	     * Note:  we have to call the displayProc even for chunks
	     * that are off-screen.  This is needed, for example, so
	     * that embedded windows can be unmapped in this case.