tktextdisp.c

linux系统下的音频通信

    lastCharChunkPtr = NULL;

    /*
     * Find the first segment to consider for the line.  Can't call
     * TkTextIndexToSeg for this because it won't return a segment
     * with zero size (such as the insertion cursor's mark).
     */

    for (offset = curIndex.charIndex, segPtr = curIndex.linePtr->segPtr;
	    (offset > 0) && (offset >= segPtr->size);
	    offset -= segPtr->size, segPtr = segPtr->nextPtr) {
	/* Empty loop body. */
    }

    while (segPtr != NULL) {
	if (segPtr->typePtr->layoutProc == NULL) {
	    segPtr = segPtr->nextPtr;
	    offset = 0;
	    continue;
	}
	if (chunkPtr == NULL) {
	    chunkPtr = (TkTextDispChunk *) ckalloc(sizeof(TkTextDispChunk));
	    chunkPtr->nextPtr = NULL;
	}
	chunkPtr->stylePtr = GetStyle(textPtr, &curIndex);

	/*
	 * Save style information such as justification and indentation,
	 * up until the first character is encountered, then retain that
	 * information for the rest of the line.
	 */

	if (noCharsYet) {
	    tabArrayPtr = chunkPtr->stylePtr->sValuePtr->tabArrayPtr;
	    justify = chunkPtr->stylePtr->sValuePtr->justify;
	    rMargin = chunkPtr->stylePtr->sValuePtr->rMargin;
	    wrapMode = chunkPtr->stylePtr->sValuePtr->wrapMode;
	    x = ((curIndex.charIndex == 0)
		    ? chunkPtr->stylePtr->sValuePtr->lMargin1
		    : chunkPtr->stylePtr->sValuePtr->lMargin2);
	    if (wrapMode == tkTextNoneUid) {
		maxX = INT_MAX;
	    } else {
		maxX = textPtr->dInfoPtr->maxX - textPtr->dInfoPtr->x
			- rMargin;
		if (maxX < x) {
		    maxX = x;
		}
	    }
	}

	/*
	 * See if there is a tab in the current chunk; if so, only
	 * layout characters up to (and including) the tab.
	 */

	gotTab = 0;
	maxChars = segPtr->size - offset;
	if (justify == TK_JUSTIFY_LEFT) {
	    if (segPtr->typePtr == &tkTextCharType) {
		char *p;

		for (p = segPtr->body.chars  + offset; *p != 0; p++) {
		    if (*p == '\t') {
			maxChars = (p + 1 - segPtr->body.chars) - offset;
			gotTab = 1;
			break;
		    }
		}
	    }
	}

	chunkPtr->x = x;
	code = (*segPtr->typePtr->layoutProc)(textPtr, &curIndex, segPtr,
		offset, maxX-tabSize, maxChars, noCharsYet, wrapMode,
		chunkPtr);
	if (code <= 0) {
	    FreeStyle(textPtr, chunkPtr->stylePtr);
	    if (code < 0) {
		/*
		 * This segment doesn't wish to display itself (e.g. most
		 * marks).
		 */

		segPtr = segPtr->nextPtr;
		offset = 0;
		continue;
	    }

	    /*
	     * No characters from this segment fit in the window: this
	     * means we're at the end of the display line.
	     */

	    if (chunkPtr != NULL) {
		ckfree((char *) chunkPtr);
	    }
	    break;
	}
	if (chunkPtr->numChars > 0) {
	    noCharsYet = 0;
	    lastCharChunkPtr = chunkPtr;
	}
	if (lastChunkPtr == NULL) {
	    dlPtr->chunkPtr = chunkPtr;
	} else {
	    lastChunkPtr->nextPtr = chunkPtr;
	}
	lastChunkPtr = chunkPtr;
	x += chunkPtr->width;
	if (chunkPtr->breakIndex > 0) {
	    breakCharOffset = chunkPtr->breakIndex;
	    breakIndex = curIndex;
	    breakChunkPtr = chunkPtr;
	}
	if (chunkPtr->numChars != maxChars) {
	    break;
	}

	/*
	 * If we're at a new tab, adjust the layout for all the chunks
	 * pertaining to the previous tab.  Also adjust the amount of
	 * space left in the line to account for space that will be eaten
	 * up by the tab.
	 */

	if (gotTab) {
	    if (tabIndex >= 0) {
		AdjustForTab(textPtr, tabArrayPtr, tabIndex, tabChunkPtr);
		x = chunkPtr->x + chunkPtr->width;
	    }
	    tabIndex++;
	    tabChunkPtr = chunkPtr;
	    tabSize = SizeOfTab(textPtr, tabArrayPtr, tabIndex, x, maxX);
	    if (tabSize >= (maxX - x)) {
		break;
	    }
	}
	curIndex.charIndex += chunkPtr->numChars;
	offset += chunkPtr->numChars;
	if (offset >= segPtr->size) {
	    offset = 0;
	    segPtr = segPtr->nextPtr;
	}
	chunkPtr = NULL;
    }
    if (noCharsYet) {
	panic("LayoutDLine couldn't place any characters on a line");
    }
    wholeLine = (segPtr == NULL);

    /*
     * We're at the end of the display line.  Throw away everything
     * after the most recent word break, if there is one;  this may
     * potentially require the last chunk to be layed out again.
     */

    if (breakChunkPtr == NULL) {
	/*
	 * This code makes sure that we don't accidentally display
	 * chunks with no characters at the end of the line (such as
	 * the insertion cursor).  These chunks belong on the next
	 * line.  So, throw away everything after the last chunk that
	 * has characters in it.
	 */

	breakChunkPtr = lastCharChunkPtr;
	breakCharOffset = breakChunkPtr->numChars;
    }
    if ((breakChunkPtr != NULL) && ((lastChunkPtr != breakChunkPtr)
	    || (breakCharOffset != lastChunkPtr->numChars))) {
	while (1) {
	    chunkPtr = breakChunkPtr->nextPtr;
	    if (chunkPtr == NULL) {
		break;
	    }
	    FreeStyle(textPtr, chunkPtr->stylePtr);
	    breakChunkPtr->nextPtr = chunkPtr->nextPtr;
	    (*chunkPtr->undisplayProc)(textPtr, chunkPtr);
	    ckfree((char *) chunkPtr);
	}
	if (breakCharOffset != breakChunkPtr->numChars) {
	    (*breakChunkPtr->undisplayProc)(textPtr, breakChunkPtr);
	    segPtr = TkTextIndexToSeg(&breakIndex, &offset);
	    (*segPtr->typePtr->layoutProc)(textPtr, &breakIndex,
		    segPtr, offset, maxX, breakCharOffset, 0, 
		    wrapMode, breakChunkPtr);
	}
	lastChunkPtr = breakChunkPtr;
	wholeLine = 0;
    }

    /*
     * Make tab adjustments for the last tab stop, if there is one.
     */

    if ((tabIndex >= 0) && (tabChunkPtr != NULL)) {
	AdjustForTab(textPtr, tabArrayPtr, tabIndex, tabChunkPtr);
    }

    /*
     * Make one more pass over the line to recompute various things
     * like its height, length, and total number of characters.  Also
     * modify the x-locations of chunks to reflect justification.
     * If we're not wrapping, I'm not sure what is the best way to
     * handle left and center justification:  should the total length,
     * for purposes of justification, be (a) the window width, (b)
     * the length of the longest line in the window, or (c) the length
     * of the longest line in the text?  (c) isn't available, (b) seems
     * weird, since it can change with vertical scrolling, so (a) is
     * what is implemented below.
     */

    if (wrapMode == tkTextNoneUid) {
	maxX = textPtr->dInfoPtr->maxX - textPtr->dInfoPtr->x - rMargin;
    }
    dlPtr->length = lastChunkPtr->x + lastChunkPtr->width;
    if (justify == TK_JUSTIFY_LEFT) {
	jIndent = 0;
    } else if (justify == TK_JUSTIFY_RIGHT) {
	jIndent = maxX - dlPtr->length;
    } else {
	jIndent = (maxX - dlPtr->length)/2;
    }
    ascent = descent = 0;
    for (chunkPtr = dlPtr->chunkPtr; chunkPtr != NULL;
	    chunkPtr = chunkPtr->nextPtr) {
	chunkPtr->x += jIndent;
	dlPtr->count += chunkPtr->numChars;
	if (chunkPtr->minAscent > ascent) {
	    ascent = chunkPtr->minAscent;
	}
	if (chunkPtr->minDescent > descent) {
	    descent = chunkPtr->minDescent;
	}
	if (chunkPtr->minHeight > dlPtr->height) {
	    dlPtr->height = chunkPtr->minHeight;
	}
	sValuePtr = chunkPtr->stylePtr->sValuePtr;
	if ((sValuePtr->borderWidth > 0)
		&& (sValuePtr->relief != TK_RELIEF_FLAT)) {
	    dlPtr->flags |= HAS_3D_BORDER;
	}
    }
    if (dlPtr->height < (ascent + descent)) {
	dlPtr->height = ascent + descent;
	dlPtr->baseline = ascent;
    } else {
	dlPtr->baseline = ascent + (dlPtr->height - ascent - descent)/2;
    }
    sValuePtr = dlPtr->chunkPtr->stylePtr->sValuePtr;
    if (dlPtr->index.charIndex == 0) {
	dlPtr->spaceAbove = sValuePtr->spacing1;
    } else {
	dlPtr->spaceAbove = sValuePtr->spacing2 - sValuePtr->spacing2/2;
    }
    if (wholeLine) {
	dlPtr->spaceBelow = sValuePtr->spacing3;
    } else {
	dlPtr->spaceBelow = sValuePtr->spacing2/2;
    }
    dlPtr->height += dlPtr->spaceAbove + dlPtr->spaceBelow;
    dlPtr->baseline += dlPtr->spaceAbove;

    /*
     * Recompute line length:  may have changed because of justification.
     */

    dlPtr->length = lastChunkPtr->x + lastChunkPtr->width;
    return dlPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * UpdateDisplayInfo --
 *
 *	This procedure is invoked to recompute some or all of the
 *	DLine structures for a text widget.  At the time it is called
 *	the DLine structures still left in the widget are guaranteed
 *	to be correct except that (a) the y-coordinates aren't
 *	necessarily correct, (b) there may be missing structures
 *	(the DLine structures get removed as soon as they are potentially
 *	out-of-date), and (c) DLine structures that don't start at the
 *	beginning of a line may be incorrect if previous information in
 *	the same line changed size in a way that moved a line boundary
 *	(DLines for any info that changed will have been deleted, but
 *	not DLines for unchanged info in the same text line).
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Upon return, the DLine information for textPtr correctly reflects
 *	the positions where characters will be displayed.  However, this
 *	procedure doesn't actually bring the display up-to-date.
 *
 *----------------------------------------------------------------------
 */

static void
UpdateDisplayInfo(textPtr)
    TkText *textPtr;			/* Text widget to update. */
{
    register TextDInfo *dInfoPtr = textPtr->dInfoPtr;
    register DLine *dlPtr, *prevPtr;
    TkTextIndex index;
    TkTextLine *lastLinePtr;
    int y, maxY, pixelOffset, maxOffset;

    if (!(dInfoPtr->flags & DINFO_OUT_OF_DATE)) {
	return;
    }
    dInfoPtr->flags &= ~DINFO_OUT_OF_DATE;

    /*
     * Delete any DLines that are now above the top of the window.
     */

    index = textPtr->topIndex;
    dlPtr = FindDLine(dInfoPtr->dLinePtr, &index);
    if ((dlPtr != NULL) && (dlPtr != dInfoPtr->dLinePtr)) {
	FreeDLines(textPtr, dInfoPtr->dLinePtr, dlPtr, 1);
    }

    /*
     *--------------------------------------------------------------
     * Scan through the contents of the window from top to bottom,
     * recomputing information for lines that are missing.
     *--------------------------------------------------------------
     */

    lastLinePtr = TkBTreeFindLine(textPtr->tree,
	    TkBTreeNumLines(textPtr->tree));
    dlPtr = dInfoPtr->dLinePtr;
    prevPtr = NULL;
    y = dInfoPtr->y;
    maxY = dInfoPtr->maxY;
    while (1) {
	register DLine *newPtr;

	if (index.linePtr == lastLinePtr) {
	    break;
	}

	/*
	 * There are three possibilities right now:
	 * (a) the next DLine (dlPtr) corresponds exactly to the next
	 *     information we want to display: just use it as-is.
	 * (b) the next DLine corresponds to a different line, or to
	 *     a segment that will be coming later in the same line:
	 *     leave this DLine alone in the hopes that we'll be able
	 *     to use it later, then create a new DLine in front of
	 *     it.
	 * (c) the next DLine corresponds to a segment in the line we
	 *     want, but it's a segment that has already been processed
	 *     or will never be processed.  Delete the DLine and try
	 *     again.
	 *
	 * One other twist on all this.  It's possible for 3D borders
	 * to interact between lines (see DisplayLineBackground) so if
	 * a line is relayed out and has styles with 3D borders, its
	 * neighbors have to be redrawn if they have 3D borders too,
	 * since the interactions could have changed (the neighbors
	 * don't have to be relayed out, just redrawn).
	 */

	if ((dlPtr == NULL) || (dlPtr->index.linePtr != index.linePtr)) {
	    /*
	     * Case (b) -- must make new DLine.
	     */

	    makeNewDLine:
	    if (tkTextDebug) {
		char string[TK_POS_CHARS];

		/*
		 * Debugging is enabled, so keep a log of all the lines
		 * that were re-layed out.  The test suite uses this
		 * information.
		 */

		TkTextPrintIndex(&index, string);
		Tcl_SetVar2(textPtr->interp, "tk_textRelayout", (char *) NULL,
			string,
			TCL_GLOBAL_ONLY|TCL_APPEND_VALUE|TCL_LIST_ELEMENT);
	    }
	    newPtr = LayoutDLine(textPtr, &index);
	    if (prevPtr == NULL) {
		dInfoPtr->dLinePtr = newPtr;
	    } else {
		prevPtr->nextPtr = newPtr;
		if (prevPtr->flags & HAS_3D_BORDER) {
		    prevPtr->oldY = -1;
		}
	    }
	    newPtr->nextPtr = dlPtr;
	    dlPtr = newPtr;
	} else {
	    /*
	     * DlPtr refers to the line we want.  Next check the
	     * index within the line.
	     */