Sometimes you need a quick and dirty window and you don't want to go through all the hassle of registering a class for it. For example, you might need a window to do a brief snippet of DDE, or you just need a window to own a message box. To save yourself the trouble of registering a class for every single weenie thing you might need a window for...
As we noted at the end of part 3, now that you know the conventions surrounding the message you can put them to your advantage. The more robust you want the function to be, the more work you need to do. Here's the cheap version, based on the sample in the Knowledge Base, but with some additional bug fixes. This function acts just ...
Earlier we saw the importance of setting the right owner window for modal UI. It is also important, when manipulating a window, to respect its modality. For example, consider the program we ended up with last time, the one which calls the function to display a modal dialog. If we wanted to get that program to exit and sent a message to the mai...
Here is the very simple fix for the buggy program we presented last time. We have fixed the problem by passing the correct owner window for the modal UI. Since is modal, it disables the owner while the modal UI is being displayed, thereby preventing the user from destroying or changing the owner window's state when it is not expecting it. ...
If you decide to display some modal UI, it is important that you set the correct owner for that UI. If you fail to heed this rule, you will find yourself chasing some very strange bugs. Let's return to our scratch program and intentionally introduce a bug related to incorrect owner windows, so that we can see the consequences. Run this prog...
After our two quick introductions to modality, we're now going to dig in a little deeper. The trick with modality is that when you call a modal function, the responsibility of message dispatch is handled by that function rather than by your main program. Consequently, if you have customized your main program's message pump, those customizatio...
Last time, we saw an example of code that was UI-modal but not code-modal. The opposite is also true: You can have code-modality without UI-modality. In fact, this is far more common than the UI-modal-but-not-code-modal scenario. You encounter modal loops without a visible change in UI state when you drag the scroll bar thumb, drag the window capt...
From the end-users' point of view, modality occurs when the users are locked into completing a task once it is begun, with the only escape being to cancel the entire operation. Opening a file is an example of a modal operation: Once the "Open" command has been selected, users have no choice but to select a file for opening (or to cancel the operat...
It waits only for messages that have arrived since the last time you checked.
The Animation control in the shell common controls library supports only a very limited class of AVI files. Why all these restrictions? Because the purpose of the Animation control is to be able to show simple animations. If you have a complex animation, you should be using one of the more advanced animation controls, like the MCIWnd window c...
