/// <summary> /// Adds the renderer hook to a screen that has a viewRangen named WindowManager.VR_CENTER_NAME. /// </summary> /// <param name="screen">The screen.</param> private void addRendererHookToScreen(BrailleIOScreen screen) { if (screen != null) { //try to get the main view range if (screen.HasViewRange(WindowManager.VR_CENTER_NAME)) { BrailleIOViewRange vr = screen.GetViewRange(WindowManager.VR_CENTER_NAME); if (vr != null) { if (vr.IsImage() && vr.ContentRender != null && vr.ContentRender is IBrailleIOHookableRenderer) { ((IBrailleIOHookableRenderer)vr.ContentRender).RegisterHook(BrailleDomFocusRenderer); ((IBrailleIOHookableRenderer)vr.ContentRender).RegisterHook(DrawSelectFocusRenderer); ((IBrailleIOHookableRenderer)vr.ContentRender).RegisterHook(TextRendererHook); } else { vr.RendererChanged += new EventHandler <EventArgs>(vr_RendererChanged); } } } } }