Input & Layers: touches go through, how to avoid this?

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Input & Layers: touches go through, how to avoid this?

(10 posts) (2 voices)

Started 2 years ago by gaminghorror
Latest reply from bradparks

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gaminghorror
Member

I have a CCLayer screen with buttons on it (CCMenu with CCMenuItems). One button creates a new CCLayer, adds it as child to the current CCLayer and shows it. The new CCLayer also has buttons on it. However, while the second layer is active i can still use the buttons on the layer beneath it even though i can't see the buttons.

I think there must be some simple way to disable input for a certain layer but i haven't found it. isTouchEnabled hasn't had the desired effect, i tried to enable/disable it according to which layer should be active. I know i can just set the buttons.visible = NO but i don't want to hide the buttons if it can be avoided. I also tried receiving touch events and simply saying i've handled them to no effect.

So what do i need to do to make the input for stacking layers to only go to the top layer?

Posted 2 years ago #
bradparks
Member
For a layer, if you want to stop the touches from passing through it, just return "kEventHandled".... Here's the general idea (untested) for 0.82... there may be better ways to do it(?), but this should work...
```
-(BOOL)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
	return kEventHandled;
}
```
Posted 2 years ago #
gaminghorror
Member

Hmmm ... this is exactly what i tried at first. Should this work even when one Layer is a child of the Layer underneath it?

UPDATE: tried again, still doesn't work.

Posted 2 years ago #

gaminghorror
Member

A little bit of code might help. Here's how i create the new layer when a button is pressed. CharacterBuilderHelp derives from ScreenHelp (which does almost all of the work) which is derived from CCLayer.

-(void) onInfoButton:(id)sender
{
	if (help == nil)
	{
		help = [[CharacterBuilderHelp alloc] init];
		[self addChild:help z:9];
	}

	[help showHelp];
}

showHelp simply sets a CCFadeIn action to all the layer's nodes.

The ScreenHelp class captures all touch events but to no avail:

-(BOOL) ccTouchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
	// prevent touches from going to parent layers
	return kEventHandled;
}

-(BOOL) ccTouchesEnded:(NSSet*)touches withEvent:(UIEvent*)event
{
	// prevent touches from going to parent layers
	return kEventHandled;
}

What am i doing wrong here?

Posted 2 years ago #

bradparks
Member
Hmmm.... I just went and checked, and from my limited understanding, when I was trying to hide a layer with a menu on it in the past, I actually had to do something like this:
```
@implementation BaseMenuLayer                               

-(void) showLayer: (BOOL) shouldShow
{
  self.visible = shouldShow;
  self.isTouchEnabled = shouldShow;
  menu.isTouchEnabled = shouldShow;
}
@end
```
So I disabled isTouchEnabled for the layer and the menu and that worked to "hide" a menu for me.... I would've thought that just hiding the layer it was on would do it, but it didn't..... I kind of forgot I had to write this.... and maybe I was using something "incorrectly", but this is what I had to do to hide a layer that had a menu on it....
Posted 2 years ago #
bradparks
Member

also, this post seems to discuss similar solutions:

http://www.cocos2d-iphone.org/forum/topic/151

let us know if any of these work for you!

Posted 2 years ago #
gaminghorror
Member

Hmmm ... not sure what you're saying. But i think my problem is that the second Layer is a child of the first. Maybe instead i should put the two layers seperately into a third parent layer. I hope this will allow me to switch between the two.

Posted 2 years ago #

gaminghorror
Member

Thanks for pointing me to that thread. It works. I used the setIsEnabled approach, like this:

-(void) enableAllButtons:(bool)enable
{
	for (CCNode* node in self.children)
	{
		if (node.tag == kButtonTag)
		{
			CCMenu* menu = ((SimpleButton*)node).menu;
			for (CCMenuItem* item in [menu children])
			{
				[item setIsEnabled:enable];
			}
		}
	}
}

Posted 2 years ago #

gaminghorror
Member
I still had the problem of overlapping controls (CCMenu) stealing each other's touch events, even though they were invisible or set disabled. So as described in that thread i also had to move the layer outside of the screen to avoid any kind of touch interference.
```
-(void) moveOutsideScreen:(bool)moveOutside
{
	self.visible = !moveOutside;

	// move outside screen to ensure that no overlapping controls catch each other's touch events
	if (moveOutside)
	{
		[self setPosition:CGPointMake(-1000, -1000)];
	}
	else
	{
		[self setPosition:CGPointZero];
	}
}
```
Posted 2 years ago #
bradparks
Member

cool... glad to hear you got it! I may be misusing something, but I totally think the default behavior when hiding a menu should be to make the menu disabled.... I know there are some use cases where people want an invisible menu (kind of like hotspots in an image map), but that should be a different init function instead....

Posted 2 years ago #

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