Prevent QLPreviewView from grabbing focus

Question

I have a list of files. Next to it I have a QLPreviewView which shows the currently selected file.

Unfortunately QLPreviewView loads a web view to preview bookmark files. Some web pages can grab keyboard focus. E.g. the Gmail login form places the insertion point into the user name field.

This breaks the flow of my application. I want to navigate my list using arrow keys. This is disrupted when keyboard focus is taken away from the table view.

So far the best I could come up with is to override - [NSWindow makeFirstResponder:] and not call super for instances of classes named with a QL prefix. Yuck.

Is there a more reasonable way to

Prevent unwanted changes of first responder?
or prevent user interaction on QLPreviewView and its subviews?

score 1 · Accepted Answer · answered Jul 06 '16 at 11:57

I ended up using a NSWindow subclass that allows QLPreviewViews and its private subviews to become first responder on user interaction, but prevents these views from simply stealing focus.

- (BOOL)makeFirstResponder:(NSResponder *)aResponder
{
    NSString *classname = NSStringFromClass([aResponder class]);

    // This is a hack to prevent Quick Look from stealing first responder
    if ([classname hasPrefix:@"QL"]) {
        BOOL shouldMakeFirstRespnder = NO;
        NSEvent *currentEvent = [[NSApplication sharedApplication] currentEvent] ;
        NSEventType eventType = currentEvent.type;

        if ((eventType == NSLeftMouseDown) || (eventType == NSRightMouseDown) || (eventType == NSMouseEntered)) {
            if ([aResponder isKindOfClass:[NSView class]]) {
                NSView *view = (NSView *)aResponder;
                NSPoint locationInWindow = currentEvent.locationInWindow;
                NSPoint locationInView = [view convertPoint:locationInWindow fromView:nil];
                BOOL pointInRect = NSPointInRect(locationInView, [view bounds]);

                shouldMakeFirstRespnder = pointInRect;
            }
        }

        if (!shouldMakeFirstRespnder) {
            return NO;
        }
    }

    return [super makeFirstResponder:aResponder];
}

contactritsard · Answer 2 · 2014-09-03T23:52:13.707

0

Maybe you can subclass QLPreviewView and override its becomeFirstResponder so that you can either enable or disable it when your application should allow it to accept focus.

Header @interface MyQLPreviewView : QLPreviewView

@end

Implementation @implementation

- (BOOL)becomeFirstResponder
{
    return NO;
}

@end

edited Sep 03 '14 at 23:52

answered Sep 01 '14 at 20:19

contactritsard

84
3

It's a private subview of class QLWeb2View that becomes first responder. I tried and failed to swizzle becomeFirstResponder. Also I don't know what other private subviews QLPreviewView can conjure – Pierre Bernard Sep 01 '14 at 22:17
@PierreBernard Is that how you tried to do `becomeFirstResponder` ? – contactritsard Sep 03 '14 at 23:52
NSStringFromClass(@"QLWeb2View") came up nil – Pierre Bernard Sep 04 '14 at 07:31

Prevent QLPreviewView from grabbing focus

2 Answers2