protected abstract void OnRenderCore(DrawingContext dc, RenderState state);
protected sealed override void OnRender(DrawingContext drawingContext)
{
if (Viewport == null)
{
return;
}
Rect output = Viewport.Output;
if (output.Width == 0 || output.Height == 0)
{
return;
}
if (output.IsEmpty)
{
return;
}
if (Visibility != Visibility.Visible)
{
return;
}
if (shouldReRender || manualTranslate || renderTarget == RenderTo.Image || beforeFirstUpdate || updateCalled)
{
if (graphContents == null)
{
graphContents = new DrawingGroup();
}
if (beforeFirstUpdate)
{
Update();
}
using (DrawingContext context = graphContents.Open())
{
if (renderTarget == RenderTo.Screen)
{
RenderState state = CreateRenderState(Viewport.Visible, RenderTo.Screen);
OnRenderCore(context, state);
}
else
{
// for future use
}
}
updateCalled = false;
}
// thumbnail is not created, if
// 1) CreateThumbnail is false
// 2) this graph has IsLayer property, set to false
if (ShouldCreateThumbnail)
{
RenderThumbnail();
}
if (!manualClip)
{
drawingContext.PushClip(new RectangleGeometry(output));
}
bool translate = !manualTranslate && IsTranslated;
if (translate)
{
drawingContext.PushTransform(new TranslateTransform(offset.X, offset.Y));
}
drawingContext.DrawDrawing(graphContents);
if (translate)
{
drawingContext.Pop();
}
if (!manualClip)
{
drawingContext.Pop();
}
shouldReRender = true;
}