On Jun 10, 2006, at 2:49 AM, Jerry wrote:
We use a hybrid approach: For drawing of any selections, e.g. selected shape outlines, handles and so on we use an overlay and draw directly into it with a manually-created CGContext. Updates to the main drawing area are done via HIViewSetNeedsDisplay, but for fast painting, we draw directly into the view with a CGContext created in the mouse down handler. This works fine, but Eric has said that it's possible that this will break in the future, although I suspect it won't. We release updates often enough that we'll just fix it when the time comes, if ever.
That sounds like to approach used in Apple's developer example CarbonSketch. They create an overlay window and draw into that context while tracking the mouse.
Also the MouseTracking demo from last years developer conference might be helpful.
My biggest concern is that
I've been told the context is unreliable during a mouse event.
That's something I don't understand: how mousing could work
properly if there is no proper CGContext (that establishes
coordinate transformations)?
