CW_USEDEFAULT: An underappreciated UX feature
Say you're writing code for a desktop PC application. It's very common for people to have multiple displays/screens for their desktop setups nowadays. When the user launches your program, how do you know which screen it should appear on to provide the least-jarring user experience? Many applications seem to get this wrong, opting for whatever display happens to be set as primary, or for whatever display the program was last closed on, or whatever screen there happens to be a mouse pointer on, either at some arbitrary time after the app started executing its code or each time it gets around to creating a window. While those approaches would make for good choices that the user can pick between in your app's settings, they're all poor defaults and even worse for the first-launch experience. It's actually a trick question. The correct answer is to let the window manager decide. That can vary based on operating system and desktop environment, but the general principle ...