How to get UIMenuController work for a custom view?

Question

I'm trying to get the following code work:

UIMenuController * menu = [UIMenuController sharedMenuController];
[menu setTargetRect: CGRectMake(100, 100, 100, 100) inView: self.view];
[menu setMenuVisible: YES animated: YES];

The menu instance is ready but it doesn't show - the width is always zero.

Or is there some sample code on this UIPasteboard/UIMenuController topic?

Answer 1

I was not able to get it working even when I read all of your answers. I'm presenting ready code that will work for everyone.

Let's say we have a controller class named Controller. You can simply paste the following code to this controller to have the menu working on its view:

- (void)loadView {
    [super loadView];

    UILongPressGestureRecognizer *gr = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
    [self.view addGestureRecognizer:gr];    
}

- (void) longPress:(UILongPressGestureRecognizer *) gestureRecognizer {
    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
        CGPoint location = [gestureRecognizer locationInView:[gestureRecognizer view]];
        UIMenuController *menuController = [UIMenuController sharedMenuController];
        UIMenuItem *resetMenuItem = [[UIMenuItem alloc] initWithTitle:@"Item" action:@selector(menuItemClicked:)];

        NSAssert([self becomeFirstResponder], @"Sorry, UIMenuController will not work with %@ since it cannot become first responder", self);
        [menuController setMenuItems:[NSArray arrayWithObject:resetMenuItem]];
        [menuController setTargetRect:CGRectMake(location.x, location.y, 0.0f, 0.0f) inView:[gestureRecognizer view]];
        [menuController setMenuVisible:YES animated:YES];
    }
}

- (void) copy:(id) sender {
    // called when copy clicked in menu
}

- (void) menuItemClicked:(id) sender {
    // called when Item clicked in menu
}

- (BOOL) canPerformAction:(SEL)selector withSender:(id) sender {
    if (selector == @selector(menuItemClicked:) || selector == @selector(copy:)) {
        return YES;
    }
    return NO;
}

- (BOOL) canBecomeFirstResponder {
    return YES;
}

What has to be done in order for menu to work is that the firstResponder(in our case our controller - see line with [self becomeFirstResponder]) has to be able to become first responder (override method canBecomeFirstResponder cause default implementation returns NO) as well as - (BOOL) canPerformAction:(SEL)selector withSender:(id) sender which should return YES to any action that can be performed by firstResponder

Answer 2

In case somebody still has problems: My menu used to work and some day stopped working miraculously. Everything else in my app still worked. Now I had removed the [window makeKeyAndVisible] method from application:didFinishLaunchingWithOptions: method, and while everything else still worked, this breaks UIMenuController!

Stupid error on my side, difficult to find the culprit...

Answer 3

If you're implementing a custom view and that view is supposed to be the responder (as opposed to some other view, like a UITextField), you need to override the canBecomeFirstResponder function in your view and return YES:

- (BOOL)canBecomeFirstResponder {
    return YES;
}

then, when you're displaying the menu, you should do something like the following:

- (void)myMenuFunc {
    if (![self becomeFirstResponder]) {
        NSLog(@"couldn't become first responder");
        return;
    }

    UIMenuController *theMenu = [UIMenuController sharedMenuController];
    CGRect selectionRect = CGRectMake(0, 0, 0, 0);
    [theMenu setTargetRect:selectionRect inView:self];
    [theMenu setMenuVisible:YES animated:YES];
}