Implement this interface to draw "decorations" in Viewports. More...
#include <IViewManager.h>
Protected Member Functions | |
| virtual bool | _DrawDecoration (IndexedViewportR viewport)=0 |
| Called when view's content has been redrawn to an offscreen buffer and before it is copied to the screen (visible) buffer. More... | |
Implement this interface to draw "decorations" in Viewports.
Register IViewDecorations by calling IViewManager::AddViewDecoration. A "decoration" is information drawn in a viewport to provide feedback to the user about something related to the view. Decorations are not part of any model, and are not stored in the "backing store" of the viewport. Therefore, decorations must be re-drawn every "frame" (that is, every time _DrawDecoration is called) or they disappear. It is the responsbility of the application to call Viewport::SetNeedsRefresh if the decorator needs to display something different from the last time it was called. Tools with decorations based on the cursor location might call Viewport::SetNeedsRefresh from the DgnTool::_OnModelMotion event.
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protectedpure virtual |
Called when view's content has been redrawn to an offscreen buffer and before it is copied to the screen (visible) buffer.
Implementers must re-draw decorations every time this method is called to keep the decoration visible.