2010-02-09

Simplifying the API Part 3

When I introduced the context-sensitive shift-click menu I ran into a bit of a problem. Clicks are automatically propagated down through the gadget hierarchy until the gadget that the stylus is touching is found. But what happens if we’re trying to capture a shift-click on a gadget that isn’t exactly the gadget that we clicked? Suppose we shift-click a button, but we want the window that contains the button to show a context-sensitive menu?

My solution was to introduce a new flag in the Gadget class, “shiftClickChildren”, that would prevent clicks from propagating down if it was set. This definitely worked, but it added more complexity to getting the context menu working. It also introduces some subtle problems - a gadget cannot have a context menu if its parent has a context menu.

I’ve changed the way that this works and removed the shiftClickChildren concept from Woopsi. Instead, shift-clicks propagate down through the hierarchy, but then propagate back up again until a gadget is located that defines a context menu. Thus, if a window contains a context menu definition it will be shown regardless of which sub-gadget is clicked. If one of those sub-gadgets contains a context menu definition, however, that will be shown instead.

Much simpler.

Along with this, I have fixed the Window gadget’s dragging routines so that they work correctly if the window’s parent is not a screen. In other words, windows can now contain other windows without it causing graphical glitches, should you feel like putting such an abomination together.

Lastly, I’ve added test projects for the Alert and Requester classes.