-[NSResponder swipeWithEvent:] not called

Question

I am writing an application targeting OS X Lion and Snow Leopard. I have a view that I want to have respond to swipe events. My understanding is that three-finger swipes will call -[NSResponder swipeWithEvent:] if that method is implemented in my custom view. I have already looked at this question and corresponding answers, and tried the following modified stub implementation of Oscar Del Ben's code:

@implementation TestView

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
    }

    return self;
}

- (void)drawRect:(NSRect)dirtyRect
{
    [[NSColor redColor] set];
    NSRectFillUsingOperation(dirtyRect, NSCompositeSourceOver);
}

- (void)swipeWithEvent:(NSEvent *)event {
    NSLog(@"Swipe event detected!");
}

- (void)beginGestureWithEvent:(NSEvent *)event {
    NSLog(@"Gesture detected!");
}

- (void)endGestureWithEvent:(NSEvent *)event {
    NSLog(@"Gesture end detected!");
}

- (void)mouseDown:(NSEvent *)theEvent {
    NSLog(@"mouseDown event detected!");
}

@end

This compiles and runs fine, and the view renders as expected. The mouseDown: event is properly registered. However, none of the other events are triggered. Neither the begin/endGestureWithEvent: methods, nor the swipeWithEvent: method. Which makes me wonder: do I need to set a project/application setting somewhere to properly receive and/or interpret gestures? Thanks in advance for the help.

As a side note, it is possible to get scrolling gestures from `-[NSResponder scrollWheel:]`, but this I wanted to specifically use three-fingered gestures. — nomothetis, Sep 15 '11 at 16:48

score 12 · Accepted Answer · answered Dec 08 '11 at 07:59

To receive swipeWithEvent: messages, you have to ensure that the 3 finger swipe gesture is not mapped to anything that might cause a conflict. Go to System preferences -> Trackpad -> More Gestures, and set these preferences to one of the following:

Swipe between pages:
1. Swipe with two or three fingers, or
2. Swipe with three fingers

Swipe between full-screen apps:
1. Swipe left or right with four fingers

Specifically, the swipe between full-screen apps should not be set to three fingers, otherwise you will not get swipeWithEvent: messages.

Together, these two preference settings cause swipeWithEvent: messages to be sent to the first responder.

Of course, you still have to implement the actual swipe logic. And if you want to perform a fluid scroll-swipe à la iOS, then you will need to do a little more work. There is an example of how to do this in the Lion App Kit release notes under the section "Fluid Swipe Tracking."

See http://developer.apple.com/library/mac/#releasenotes/Cocoa/AppKit.html

Sorry for taking to long to respond; I assumed SO would send me emails when someone responded. I use BetterTouchTool, so it's very possible that this is the reason things haven't worked as I would have liked. I'll take a look at it; meanwhile, I think this answer gives the necessary information, so I'm tagging it as correct. — nomothetis, Dec 28 '11 at 19:55

score 2 · Answer 2 · edited Jul 14 '15 at 23:08

2

try with [self setAcceptsTouchEvents:YES]; where it says // Initialization code here.

edited Jul 14 '15 at 23:08

zpasternack

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answered Apr 10 '12 at 21:00

Jonas

21
2

I believe you meant [self setAcceptTouchEvents: YES]; – Jason Fuerstenberg Feb 15 '13 at 07:14
Or simply override acceptsTouchEvents to return YES for your view. – uchuugaka Jul 05 '13 at 01:17

score 1 · Answer 3 · answered Sep 15 '11 at 22:11

1

Not sure if it's the problem, but only the key window receives Gestures. Is your window key?

answered Sep 15 '11 at 22:11

Ken Aspeslagh

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It should be; it's the only window in the application, and it receives scrolling events. Is there something that might make it not key other than me actively not setting it to be key? – nomothetis Sep 16 '11 at 13:30
Non-key windows do still receive scrollwheel events (that's why you can two-finger drag on background windows.) – Ken Aspeslagh Sep 16 '11 at 17:11
I checked; it's key. I'll see if I can create a tiny project to reproduce the behavior (this is currently happening in a moderately sized app). – nomothetis Sep 16 '11 at 20:08

Oscar Del Ben · Answer 4 · 2011-09-15T20:22:45.263

0

Is your view accepting first responders?

- (BOOL) acceptsFirstResponder
{
  return YES;
}

edited Sep 15 '11 at 20:22

answered Sep 15 '11 at 16:54

Oscar Del Ben

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I assume you meant `-(BOOL)acceptsFirstResponder`; I didn't have it, but I just tried it with it and it didn't work. – nomothetis Sep 15 '11 at 19:07
Yes, I edited the answer. Are you sure you're swiping your fingers above your view? – Oscar Del Ben Sep 15 '11 at 20:27
Yes; I implemented other functionality that responds the scroll gesture and it works as expected, as does the `mouseUp:` callback. – nomothetis Sep 15 '11 at 20:43

-[NSResponder swipeWithEvent:] not called

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