Increase window height only until it reaches the Dock - macos

Question

I am increasing the height of an NSWindow but if the window is positioned too far down the screen, the window increases in height and extends underneath the Dock. I want to prevent that from occurring.
When I researching this I stumbled upon this question which states the opposite problem - they said by default it will not extend underneath the Dock and they wanted it to. Perhaps this has changed in OS X Yosemite. In any case, I want to obtain either one of these two behaviors:
When the window is going to extend in height underneath the Dock,
resizing should stop and cause the window to sit flush with the Dock, so the window height is less than what was desired, or
resizing should continue, but resize from the top of the window instead of from the bottom, so it does not go underneath the Dock and is still the intended size
This is how the window resizing is triggered:
[self.window setFrame:windowFrame display:YES animate:YES];
This occurs in AppDelegate, and I have not overridden constrainFrameRect: toScreen:.
Also note this should also occur if their Dock is placed on the side and the window will go beyond the available screen space.

Answer 1

The area of the screen which is not occupied by the menu bar or the Dock is given by the visibleFrame property of NSScreen.
You maybe should override -constrainFrameRect:toScreen:. If not, you would adjust windowFrame before calling -setFrame:.... In the latter case, you can obtain the NSScreen from the window's screen property (assuming the frame you're assigning isn't moving it to a different screen).
You might use logic like this:
if (NSHeight(windowFrame) > NSHeight(screen.visibleFrame))
{
windowFrame.origin.y = NSMinY(screen.visibleFrame);
windowFrame.size.height = NSHeight(screen.visibleFrame);
}
else if (NSMinY(windowFrame) < NSMinY(screen.visibleFrame))
{
windowFrame.origin.y = NSMinY(screen.visibleFrame);
}
if (NSWidth(windowFrame) > NSWidth(screen.visibleFrame))
{
windowFrame.origin.x = NSMinX(screen.visibleFrame);
windowFrame.size.width = NSWidth(screen.visibleFrame);
}
else if (NSMinX(windowFrame) < NSMinX(screen.visibleFrame))
{
windowFrame.origin.x = NSMinX(screen.visibleFrame);
}
else if (NSMaxX(windowFrame) > NSMaxX(screen.visibleFrame))
{
windowFrame.origin.x = NSWidth(screen.visibleFrame) - NSWidth(windowFrame);
}
If you do override -constrainFrameRect:toScreen:, then you should call through to super. You can either do it after you've made your adjustments and let it constrain further, or call it first and then make your adjustments to what it returned.