UIView detecting touches in only one half of the screen - objective-c

I am currently working on a 3D OpenGLES-based iPhone Game project and I want to have a view that detect touches so I can then rotate my camera according to the touch gestures.
So here I created a TouchPad class that derives from UIView to record the touch gestures.
Once done I have figured out that only half of the screen is effective. The whole left side.
Whenever i touch the right part of the screen it does not call the -[touchesBegan] method
Here is my class definition
#interface TouchPad : UIView
{
CGPoint fingerMove, originalPosition;
}
#property (nonatomic, assign) CGPoint fingerMove;
#end
And here is my class implementation
#import "TouchPad.h"
#implementation TouchPad
#synthesize fingerMove;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
fingerMove = CGPointMake(0, 0);
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
std::cout << "called";
UITouch *touch = [touches anyObject];
originalPosition = [touch locationInView:self];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPosition = [touch locationInView:self];
fingerMove = CGPointMake(currentPosition.x - originalPosition.x,
currentPosition.y - originalPosition.y);
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
{
UITouch *touch = [touches anyObject];
originalPosition = [touch locationInView:self];
fingerMove = CGPointMake(0, 0);
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
fingerMove = CGPointMake(0, 0);
}
#end
And here is how i use it inside my ViewController
- (void)prepareGame
{
game = [[MainGame alloc] init];
[self.view addSubview:game.IrrView];
[game.IrrView release];
rotationPad = [[TouchPad alloc] initWithFrame:CGRectMake(0.0, 0.0,
[[UIScreen mainScreen] bounds].size.width,
[[UIScreen mainScreen] bounds].size.height)];
[self.view addSubview:rotationPad];
[rotationPad release];
}
- (void)runGame
{
[game updateMapPattern];
[game updateCamera :rotationPad.fingerMove];
[game draw];
}
I really want to know how to make the touchPad work in the whole screen and not only the left part of the screen. Maybe there is a conflict with my game view

Related

Detect Swipe faster than UISwipeGestureRecognizer?

i was wondering how to detect a "swipe" faster than this? I'd like to call a method as soons as the user moves his finger to the left. Let's call it a "small" swipe gesture.
This would be the normal/long swipe…
UISwipeGestureRecognizer *recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipeFrom:)];
recognizer.direction = UISwipeGestureRecognizerDirectionLeft;
[scrollView addGestureRecognizer:recognizer];
[recognizer release];
[scrollView delaysContentTouches];
Now I build this:
#import "UICustomScrollView.h"
#implementation UICustomScrollView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// do stuff
}
return self;
}
// Listen for "fast" swipe
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:self];
CGPoint prevLocation = [touch previousLocationInView:self];
if (location.y - prevLocation.y > 0) {
[[NSNotificationCenter defaultCenter] postNotificationName:#"fastSwipe" object:self];
}
[super touchesMoved:touches withEvent:event];
}
#end

how to let the touchesMoved only control one view?

i create an UIButton on the view,and i want to let the touchesMoved only control the UIButton,not the whole view
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint touchMoved = [touch locationInView:self.view];
}
i want to do like this
if i touch the UIButton,and then the UIButton can be moved with my finger,if i touch other view and my finger is moving on the screen,the UIButton does nothing.
that means the function touchesMoved only has the role of the UIButton,so how can i do it? thanks
I presume the code you show takes place in your custom view controller subclass, and the UIButton is a subview of its view.
Define a simple BOOL in your class that you set to NO first. Then update it in the event handling methods.
// .h
BOOL buttonTouched;
// .m
// in the viewDidLoad
buttonTouched = NO;
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
// test wether the button is touched
UITouch *touch = [touches anyObject];
CGPoint touchBegan = [touch locationInView:self.view];
if(CGRectContainsPoint(theButton.frame, touchBegan) {
buttonTouched = YES;
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
if(buttonTouched) {
// do it here
UITouch *touch = [touches anyObject];
CGPoint touchMoved = [touch locationInView:self.view];
CGRect newFrame = CGRectMake(touchMoved.x,
touchMoved.y,
theButton.frame.width,
theButton.frame.height);
theButton.frame = newFrame;
}
}
// when the event ends, put the BOOL back to NO
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
buttonTouched = NO;
}

UIScrollview getting touch events

How can I detect touch points in my UIScrollView? The touches delegate methods are not working.
Set up a tap gesture recognizer:
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapGestureCaptured:)];
[scrollView addGestureRecognizer:singleTap];
and you will get the touches in:
- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
CGPoint touchPoint=[gesture locationInView:scrollView];
}
You can make your own UIScrollview subclass and then you can implement the following:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"DEBUG: Touches began" );
UITouch *touch = [[event allTouches] anyObject];
[super touchesBegan:touches withEvent:event];
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"DEBUG: Touches cancelled");
// Will be called if something happens - like the phone rings
UITouch *touch = [[event allTouches] anyObject];
[super touchesCancelled:touches withEvent:event];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"DEBUG: Touches moved" );
UITouch *touch = [[event allTouches] anyObject];
[super touchesMoved:touches withEvent:event];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"DEBUG: Touches ending" );
//Get all the touches.
NSSet *allTouches = [event allTouches];
//Number of touches on the screen
switch ([allTouches count])
{
case 1:
{
//Get the first touch.
UITouch *touch = [[allTouches allObjects] objectAtIndex:0];
switch([touch tapCount])
{
case 1://Single tap
break;
case 2://Double tap.
break;
}
}
break;
}
[super touchesEnded:touches withEvent:event];
}
If we're talking about the points inside the scrollview then you can hook with the delegate method:
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
and inside the method, read the property:
#property(nonatomic) CGPoint contentOffset
from the scrollView to get the coordination.
This works also on touch down event.
In the currently as correct marked answer you can get a touch point only at a "Tap" event. This event seems only to fire on "finger up" not on down.
From the comment of yuf in the same answer you can get the touch point from the underlying view also within the UIScrollView.
- (BOOL)gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer shouldReceiveTouch:(UITouch*)touch
{
CGPoint touchPoint = [touch locationInView:self.view];
return TRUE; // since we're only interested in the touchPoint
}
According to Apple's documentation the gestureRecognizer does:
Ask the delegate if a gesture recognizer should receive an object representing a touch.
which means to me that I can decide if a gestureRecognizer should recieve a touch or not.

Avoid UIView touch delay

I am using a subclass of UIView in my app. When the user touches on view I need to get the coordinates of the point; for this I am using:
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
currentPoint=[[touches anyObject]locationInView:self];
}
It has some delay. Can any one give me the solution to get the points immediately? Thank you all.
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code.
self.frame=frame;
rect=[[NSMutableArray alloc] initWithCapacity:1];
currentPointsList=[[NSMutableArray alloc]initWithCapacity:1];
}
return self;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
firstTouchedPoint = [touch locationInView:self];
NSLog(#"the firstTouched point is %");
for (int i=0; i<[rect count]; i++) {
if(CGRectContainsPoint([[rect objectAtIndex:i]CGRectValue], firstTouchedPoint)){
CGRect firstLineRect = CGRectMake(firstTouchedPoint.x,
[[rect objectAtIndex:i]CGRectValue].origin.y,
[[rect objectAtIndex:i]CGRectValue].size.width-firstTouchedPoint.x+[[rect objectAtIndex:i]CGRectValue].origin.x,
[[rect objectAtIndex:i]CGRectValue].size.height);
UIImageView *firstLine=[[UIImageView alloc]initWithFrame:firstLineRect];
firstLine.backgroundColor=[[UIColor blueColor]colorWithAlphaComponent:0.3f];
[self addSubview:firstLine];
break;
}
}
If you are using a UIScrollView there is a delay touches property (delaysContentTouches). You may want to make sure that is NO.

objective-c touch-events

I've got a set of Images and would like to know which I have touched. How could I implement that...?
To be more precise:
A "Home-Class" will instantiate a couple of Image-Classes:
Image *myImageView = [[Image alloc] initWithImage:myImage];
The image-class looks something like this:
- (id) initWithImage: (UIImage *) anImage
{
if ((self = [super initWithImage:anImage]))
{
self.userInteractionEnabled = YES;
}
return self;
}
later on, I use these touches-event-methods also in the Image-class:
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{}
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{}
My problem at the moment: the touchesBegan/Ended methods will be fired no matter where I touched the screen, but I would like to find out which of the Images has been touched.....
Whenever you get the touch, you check if that touch happen in between your image area. Here is the example code, lets suppose you have UIImage object called img.
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:self.view];
if (location.x >= img.x && location.x <= img.x && location.y >= img.y && location.y <= img.y) {
// your code here...
}
}
Inside your *.h (interface) file:
#interface MyViewController : UIViewController{
IBOutlet UIImageView *imageViewOne;
IBOutlet UIImageView *imageViewTwo;
UIImageView * alphaImage;
}
-(BOOL)isTouch:(UITouch *)touch WithinBoundsOf:(UIImageView *)imageView;
Place UIImageView components on your *.xib and bind them with 'imageViewOne' and 'imageViewTwo' using the "File's owner".
Go to the *.m (implementation) file and:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([self isTouch:touch WithinBoundsOf:imageViewOne])
{
NSLog(#"Fires first action...");
}
else if([self isTouch:touch WithinBoundsOf:imageViewTwo]){
NSLog(#"Fires second action...");
}
}
//(Optional 01) This is used to reset the transparency of the touched UIImageView
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
[alphaImage setAlpha:1.0];
}
-(BOOL)isTouch:(UITouch *)touch WithinBoundsOf:(UIImageView *)imageView{
CGRect _frameRectangle=[imageView frame];
CGFloat _imageTop=_frameRectangle.origin.y;
CGFloat _imageLeft=_frameRectangle.origin.x;
CGFloat _imageRight=_frameRectangle.size.width+_imageLeft;
CGFloat _imageBottom=_frameRectangle.size.height+_imageTop;
CGPoint _touchPoint = [touch locationInView:self.view];
/*NSLog(#"image top %f",_imageTop);
NSLog(#"image bottom %f",_imageBottom);
NSLog(#"image left %f",_imageLeft);
NSLog(#"image right %f",_imageRight);
NSLog(#"touch happens at %f-%f",_touchPoint.x,_touchPoint.y);*/
if(_touchPoint.x>=_imageLeft &&
_touchPoint.x<=_imageRight &&
_touchPoint.y>=_imageTop &&
_touchPoint.y<=_imageBottom){
[imageView setAlpha:0.5];//optional 01 -adds a transparency changing effect
alphaImage=imageView;//optional 01 -marks the UIImageView which deals with the transparency changing effect for the moment.
return YES;
}else{
return NO;
}
}
That's how I handled that. I got the idea having read the post of "itsaboutcode".