Subview of subclassed NSView re-positioned incorrectly after drawing a focus ring - macos

Question

I wanted to create a focus ring outside a subclassed NSView to identify selection. My reference comes from here: Link.
I followed the reference, overwrote the -drawRect method as:
#property (nonatomic) BOOL shouldDisplayFocus;
...
- (void)drawRect:(NSRect)dirtyRect
{
// Drawing code here.
if (_shouldDisplayFocus)
{
[self setKeyboardFocusRingNeedsDisplayInRect:[self bounds]];
}
[super drawRect:dirtyRect];
[[NSColor blackColor] set];
NSRectFill(dirtyRect);
if (_shouldDisplayFocus)
{
NSSetFocusRingStyle(NSFocusRingTypeExterior);
NSBezierPath *path = [NSBezierPath bezierPathWithRect:NSInsetRect([self bounds], -1.0, -1.0)];
[[NSColor blackColor] set];
[path stroke];
[NSGraphicsContext restoreGraphicsState];
}
}
And its -mouseDown: method also overwritten:
- (void)mouseDown:(NSEvent *)theEvent
{
[super mouseDown:theEvent];
if (_delegate && [_delegate respondsToSelector:#selector(mouseDownAtView:withEvent:)])
{
[_delegate mouseDownAtView:self withEvent:theEvent];
}
}
And after the view is clicked, its delegate would set/un-set the focus ring and which would make its -drawRect: called again.
It worked and generated the focus ring outside the view correctly. However, one problem occurred soon:
I had an image view inside the subclassed view. As the image view rectangle was auto-layout with NSLayoutConstraint objects, I create four NSLayoutConstraint outlets to adjust their values. I do not frequently change the layout constraints. Actually, as the image size remained unchanged, I would not set them.
Here is the situation when the subclassed view not clicked (seemed fine):
Then click on the image (the focus ring generated, but...):
And I tried resize the window, things got even more sadly "FUNNY":
I could not understand why the problem is or how to solve that. Could anyone help me with that? I have uploaded my sample code here: Download
Quite sad that no one answer this question.
I noticed that the subviews also layouted incorrectly when they were add to this view by -addSubview: and -setFrame method.

Answer 1

Really late answer, but here it is anyway: you didn't call [NSGraphicsContext saveGraphicsState] at the start of the if (_shouldDisplayFocus) { block.
You call [NSGraphicsContext restoreGraphicsState] to pop the graphics state off the stack, but you never put anything on the stack. Cocoa is using the graphics state stack to draw everything so you are popping off some unknown state that has something to do with the position of the image. If you want to add the focus ring style and be able to remove the focus ring style you need to first save the graphics state, set the focus ring style to whatever you want, and then restore the graphics state back to what it was.