Proper way to determine if NSView is drawn

Question

Is there a proper way to determine if a NSView is actually drawn in the current view hierarchy or not, considering cases like:

The view is completely offscreen (not mandatory)
The view is not on top of the view hierarchy

The -isHidden and -isHiddenOrHasHiddenAncestor are unfortunately not set when e.g. a view disappears because a tab view switches to another tab.

The reason for this is that I have an attached child window and I would like to be able to hide it as well when the view that it is attached to is not drawn.

score 3 · Accepted Answer · 2015-01-07T14:20:40.130

3

I have found a trick to tell if it is visible, but it requires subclassing. It works by toggling an ivar on 2 events.

- (void)discardCursorRects {
  isDrawn_ = NO;
  [super discardCursorRects];
}

- (void)resetCursorRects {
  isDrawn_ = YES;
  [super resetCursorRects];
}

edited Jan 07 '15 at 14:20

answered Mar 23 '11 at 17:33

score 0 · Answer 2 · answered Mar 23 '11 at 16:10

0

Whether (or when) it's drawn is supposed to be "none of your business" and really have nothing to do with whether or not it's on-screen. Use NSView's -viewDidMoveToSuperview or -viewDidMoveToWindow to manage this.

answered Mar 23 '11 at 16:10

Joshua Nozzi

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Of course it has something todo if it's drawn (on screen) or not. `-viewDidMoveToSuperview` renders itself useless when the view is e.g. in another Tab that is not active - and therefore not visible. – Mar 23 '11 at 17:17

Proper way to determine if NSView is drawn

2 Answers2

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