Selection issue with Multiple containers when text re-flows

Question

Hi,
I am building an EPUB reader in Flex 4.51. using TLF 2.0.3. I have text running across multiple containers. We add the controllers dynamically to ensure that there are as many containers as the content can have. Now, we updateAllControllers when status of a graphic element changes or when there's an increase in font size. So, after each activity we add more controllers if required. The text and images correctly reflow to the next container in this case. However, the issue comes with selection. If a piece of text reflows from one container and moves to another, when we try to select it, it doesn't highlight.
The SelectionChange event triggers and the values are mostly correct but no highlighing. We noticed that if we remove all controllers and recreate them, the issue is resolved. But, we cannot remove and add containers each time font size changes.
Kindly help and let me know where can the issue be? Remember that the text correctly reflows to containers and it's only the selection that doesn't work. This is a very common scenario for a reflowable content holder so I am sure I am missing something obvious. Please help.

Answer 1

I found the root cause of the bug is in removeAndRecycleTextLines() of ContainerController.as. The private "_textBlock" properties of some paragraph elements are incorrectly set as null there. When we want to get TextLine from TextFlowLine by getTextLine(), because paragraph._textBlock is null, TLF actually recreates some new, unused TextLines to return, which are not the ones on the sprite....
The fixed function is as follows and the bold, italic lines is the fix. I just modified a condition. It passed all existing test cases. I'm not sure it could be all right with your project. If it is still not OK for any of your scenarios, please tell us and we will appricate your feedback.
private function removeAndRecycleTextLines (beginIndex:int, endIndex:int):void
            var backgroundManager:BackgroundManager = textFlow.backgroundManager;
            var child:TextLine;
            var textBlock:TextBlock;
            for (var index:int = beginIndex; index < endIndex; index++)
                child = _shapeChildren[index];                   
                removeTextLine(child);
                CONFIG::debug { Debugging.traceFTECall(null,_container,"removeTextLine",child); }
                // when we've removed all the lines in the paragraph in shapeChildren, run through the textBlock and if all lines are not in view,
                // release the lines from the TextBlock, and release the TextBlock itself.
                if (child.textBlock != textBlock)       
                    if (textBlock)
                        releaseLinesInBlock(textBlock);
                    textBlock = child.textBlock;
            // Bug #2988783  -By Jin Huang
            // releaseLinesInBlock() be called here only when
            // 1. the end of final container
            // 2. the end line of TextBlock is the end line of the container
            if (textBlock && (textBlock.lastLine == child || flowComposer.getControllerIndex(this) == flowComposer.numControllers - 1))
                releaseLinesInBlock(textBlock);
            // Recycle lines not in view and not in the TextBlock
            if (TextLineRecycler.textLineRecyclerEnabled)
                while (beginIndex < endIndex)
                    child = _shapeChildren[beginIndex++];
                    // Recycle if its not displayed and not connected to the textblock
                    if (!child.parent)
                        if (child.userData == null)
                            TextLineRecycler.addLineForReuse(child);
                            if (backgroundManager)
                                backgroundManager.removeLineFromCache(child);
                        else
                            var tfl:TextFlowLine = child.userData as TextFlowLine;
                            if (tfl && tfl.controller != this)        // don't release lines that belong to other containers
                                continue;
                            if (child.validity == TextLineValidity.INVALID || (child.nextLine == null && child.previousLine == null && (!child.textBlock || child.textBlock.firstLine != child)))
                                child.userData = null;
                                TextLineRecycler.addLineForReuse(child);
                                if (backgroundManager)
                                    backgroundManager.removeLineFromCache(child);