drag UIView like apps in the home screen iPhone
I have a view control and inside I plan to place some controls like buttons textbox etc... I can drag my view along the x axis like:
1)
2)
with the following code:
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
if( [touch view] == ViewMain)
{
CGPoint location = [touch locationInView:self.view];
displaceX = location.x - ViewMain.center.x;
displaceY = ViewMain.center.y;
startPosX = location.x - displaceX;
}
CurrentTime = [[NSDate date] timeIntervalSince1970];
}
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
if( [touch view] == ViewMain)
{
CGPoint location = [touch locationInView:self.view];
location.x =location.x - displaceX;
location.y = displaceY;
ViewMain.center = location;
}
}
-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
double time = [[NSDate date] timeIntervalSince1970]-CurrentTime;
UITouch *touch = [[event allTouches] anyObject];
if( [touch view] == ViewMain)
{
CGPoint location = [touch locationInView:self.view];
location.x =location.x - displaceX;
location.y = displaceY;
ViewMain.center = location;
double speed = (ViewMain.center.x-startPosX)/(time*2);
NSLog(@"speed: %f", speed);
}
}
not that I have to add the global variables:
float displaceX = 0;
float displaceY = 0;
float startPosX = 0;
float startPosY = 0;
double CurrentTime;
the reason why I created those variables is so that when I start dragging the view the view moves from the point where I touch it instead of from the middle.
Anyways if I touch a button or image the view will not drag even though the images have transparency on the background. I want to be able to still be able to drag the view regardless if there is an image on top of the view. I where thinking that maybe I need to place a large transparent view on top of everything but I need to have buttons, images etc. I want to be ab开发者_如何学JAVAle to drag a view just like you can with:
note that I was able to drag the view regardless of wither I first touched an app/image or text. How could I do that?
I think your problem is that if you touch a UIButton or a UIImageView with interaction enabled, it doesn't pass the touch along.
For the images, uncheck the User Interaction Enabled
property in IB.
For the buttons that are causing touchesBegan:withEvent:, etc. to not get called, then look at the following link: Is there a way to pass touches through on the iPhone?.
You may want to consider a different approach to this problem. Rather than trying to manually manage the content scrolling yourself you would probably be better off using a UIScrollView
with the pagingEnabled
property set to YES. This is the method Apple recommends (and it's probably the method used by Springboard.app in your last screenshot). If you are a member of the iOS developer program check out the WWDC 2010 session on UIScrollView for an example of this. I think they may have also posted sample code on developer.apple.com.
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