NSWindow's top position is jumping during resize (auto layout)

2
votes

I do heavily use auto layout in my new project, but I've got one issue related to NSWindow during resizing ...

  • NSWindow is borderless window,
  • during initial setup, frame of this window is set based on status item position and initial content view size (intrinsicContentSize of contentView),
  • vertical anchor attribute is set to NSLayoutAttributeTop,
  • horizontal anchor attribute is set to NSLayoutAttributeCenterX

... so far, so good. NSWindow is placed correctly, size is correct and everything looks good.

Whenever contentView is resized automatically because of auto layout, etc. final window position is correct, size is correct, ..., so again, so far so good.

What's the problem? When animation is in progress (window is vertically resizing), top of my window is jumping +- 1 pixel down/up/down/up/down/up/down/up/... until animation is finished. It looks pretty ugly ...

It behaves like this pseudo code ...

NSRect frameRect = window.frame;
while ( frameRect.size.height != desiredHeight ) {
  frame.origin.y -= 1; // Move window down by 1px
  [self setFrame:frame display:YES animate:YES];
  frame.size.height += 1; // Increase window height
  [self setFrame:frame display:YES animated:YES];
}

... it looks like auto layout changes origin of window and then auto layout realizes that the height should be changed as well, ...

Anyone did see this behavior?

1
objective-ccocoanswindowautolayout

1 Answers

1
votes

Mea culpa, how can I missed it, it's because I do use NSLayoutConstraint for height of one of my views and I'm animating it via animator and it produces non integer values - so the height sometimes does contain real numbers and this is the cause for jumping top of NSWindow. Problem solved.