Quantcast
Channel: ferocia animi
Viewing all articles
Browse latest Browse all 33

Zoom and page changed events for FlowDocumentPageViewer

$
0
0
Download source files - here

My old known Bala send to me this link.
Kent Boogaart has written an article that describes approach searching and highlighting text in FlowDocumentPageViewer - Search and Highlight Text in an Arbitrary Visual Tree. Unfortunate, two serious issues present there. I copy theirs description from msdn forum:
  1. When I change the pages of the FlowDocumentPageViewer, my Rectangular highlighted area remains the same and it is not sinking with the Text.
  2. When I zoom in or zoom out of the FlowDocumentPageViewer, the text gets zoomed but the Highlight rectangle remains in the same position.
Seems.. solution should be easy - just add DoSeach() method in PageChanged and ZoomChanged event handler methods of FlowDocumentPageViewer but it doesn't have events for notice these actions. So I decided just to implement these events :). FlowDocumentPageViewer doesn't have protected and virtual methods like OnZoomChanged or OnPageChanged. It was bad. But I found four protected and virtual methods that could help me they are OnNextPageCommand(), OnPreviousPageCommand(), OnIncreaseZoomCommand() and OnDecreaseZoomCommand(). When I added call to rise my events in theirs override methods I found that this approach wasn't work. It happened because command logic works through concurrency approach. I called the rise methods through BeginInvoke for delay the calls rise methods - and problem was solved.
You can download sources with fix above.

PS: I didn't have time for full investigate sources.. but one question. Why did Kent use SearchRectangle class? In my opinion common Rect is enough.

Viewing all articles
Browse latest Browse all 33

Trending Articles