After looking at my AppleScript to resize windows, I’ve decided to make a few updates. Instead of manually doing the math for each resolution, I’ve created a new variable, desired_width, which is exactly what it sounds like: how wide you want your windows to be. I’ve also made the other variable names more human-friendly: _nl and _nr are now left_bound and right_bound, respectively, for example. After adding iTunes to my script, I noticed that it was being resized behind the menubar, so instead of setting the upper bound for all windows at 0, I’ve defined the variable top_bound, which defaults to 22 to account for the height of the menu bar. If you find that this setting is incorrect (e.g. if you’ve enabled some accessibility settings that change font sizes and therefore the size of the menu bar) you may need to change it; I haven’t found a way to get the height of the menu bar in AppleScript yet—so far I’ve only found it in Java—so if anyone knows feel free to leave a comment. Finally, after seeing this post by Jamie Matthews, I added some functionality to automatically set bottom_bound to the height of the Dock.
After all of these updates, the script now takes a desired width and moves applications that support AppleScript such that they range horizontally to your desired width, centered on the screen, and stretching from the bottom of the menu bar to the top of the Dock. In the future, I’d like to make a separate application, perhaps AppleScript-based, that will allow for user customization of how the windows are arranged, allow for custom application settings, and perhaps Spaces integration.