I'm trying to create a simple application where you can move your UIImageView by touching him and dragging him around.
my UIImageView is called imv
-(void ) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch * touch = [touches anyObject];
if([touch view] == self.imv){
CGPoint location = [touch locationInView:self.view];
self.imv.center = location;
}
}
-(void ) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch * touch = [touches anyObject];
if([touch view] == self.imv){
CGPoint location = [touch locationInView:self.view];
self.imv.center = location;
}
}
i'am trying to solve this like whole day and i don't know what is wrong. If i disable if statement it's working else not. What can i do?
Thanks for the answers
Unless you've subclassed UIImageView (unlikely), your view is receiving the touch events.
These days it's simpler & more usual to use a UIGestureRecognizer for this kind of thing, in this case a UIPanGestureRecognizer.
e.g.
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(dragImageView:)];
[self.imv addGestureRecognizer:pan];
- (void)dragImageView:(UIPanGestureRecognizer *)dragImageView {
if(UIGestureRecognizerStateBegan == state) {
originalCenter = self.imv.center; // add CGPoint originalCenter; member
} else if(UIGestureRecognizerStateChanged == state) {
CGPoint translate = [pan translationInView:self.imv.superview];
self.imv.center = CGPointMake(originalCenter.x + translate.x, originalCenter.y + translate.y);
}
}
From a bit of experimenting, it seems that the [touch view] is returning the main UIView and not your subview, hence the problem with the if statement not working (I added the UIImageView in a storyboard xib). EDIT- it's because UIImageViews don't handle touch events by default - see here . When adding a regular UIView in the viewDidLoad seems to work as you would expect.
Anyway, this adapted version of your code works for me
-(void)moveImageForTouches:(NSSet*)touches
{
UITouch * touch = [touches anyObject];
CGPoint location = [touch locationInView:self.view];
if(CGRectContainsPoint(self.imv.frame, location))
{
self.imv.center = location;
}
}
-(void ) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[self moveImageForTouches:touches];
}
-(void ) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self moveImageForTouches:touches];
}
Related
So , i am having a problem moving some images with touchesBegan and touchesMoved here is my code for the p1 UIImageView
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView: touch.view];
NSLog(#"incepe");
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
if (touch.view == self.p1) {
CGPoint location = [touch locationInView: self.view];
self.p1.center = location;
NSLog(#"nmk");
}
}
and the way i add the pictures is this
-(void)img{
if (!self.p1) {
self.p1 =[[UIImageView alloc] initWithFrame:CGRectMake(14,20,70,50)];
}
[self.view addSubview:self.p1];
}
the touchesmoved event is not triggred when i press the p1 UIImageview
try setting p1.userInteractionEnabled = YES
Have a I look at this:
-(void)viewDidAppear:(BOOL)animated{
UIPanGestureRecognizer *pgr1 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(image1Moved:)];
[yourImageView addGestureRecognizer:pgr1];
}
-(void)image1Moved:(UIPanGestureRecognizer *)pgr{
NSLog(#"Came here");
[yourImageView setCenter:[pgr locationInView:self.view]];
}
P.S yourImageView should have userInteractionEnabled to YES
I want my UIViewImages to be movable with touch. I'm trying to use code implemented in my ViewController:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
if ([touches count]==1) {
UITouch *touch = [touches anyObject];
CGPoint p0 = [touch previousLocationInView:self.view];
CGPoint p1 = [touch locationInView:self.view];
CGPoint center = self.view.center;
center.x += p1.x - p0.x;
center.y += p1.y - p0.y;
self.view.center = center;
}
}
When I try to drag an UIImageView, I'm dragging whole screen, which is incorrect.
Need help!
Karol
You create a gesture recognizer and add it to a view like this:
UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(gestureRecognizerMethod:)];
[self.imageView addGestureRecognizer:panGestureRecognizer];
you can adjust the position of the image view
- (void)gestureRecognizerMethod:(UIPanGestureRecognizer *)recogniser
{
if (recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateChanged)
{
CGPoint touchLocation = [recognizer locationInView:self.view];
self.imageView.center = touchLocation;
}
}
read this article.
If I read your code right self.view actually IS the whole screen.
Maybe you mean self.yourImageView instead?
hey guys i was wondering if there was away to make an object like a UIImageView draggable. I am aware of the UITouch and touches i.e.
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *drag=[[event allTouches] anyObject];
player.center=[drag locationInView:self.view];
}
but in this way it is possible for the user to make the object jump across the screen to where he or she touches the screen but i want the user to have to manually drag the object across the screen.
please explain with code and let me know if i have to be more specific or clear...
You can do this:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *aTouch = [touches anyObject];
CGPoint location = [aTouch locationInView:self.view];
if(CGRectContainsPoint(self.playerView.frame,location)) {
[UIView beginAnimations:#"Dragging A DraggableView" context:nil];
self.playerView.center = location;
[UIView commitAnimations];
}
}
This should give you a smooth animation.
if you want your user to drag&drop, first you have to check if the touch is inside the imageview rect frame. To improve the user experience, you can detect the touch offset from the imageview center; a good place to do this is inside the touchesBegan:withEvent:. After that, you have to change the position of the imageview, like this:
CGPoint touchOffset; //insert this inside your interface private iVars
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *drag=[[event allTouches] anyObject];
CGPoint touchLocation = [drag locationInView:self.view];
touchOffset = CGPointMake(player.center.x-touchLocation.x,player.center.y-touchLocation.y)
if(CGRectContainsPoint(player.frame,touchLocation)
player.center = CGPointMake(touchLocation.x+touchOffset.x,touchLocation.y+touchOffset.y);
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *drag=[[event allTouches] anyObject];
CGPoint touchLocation = [drag locationInView:self.view];
if(CGRectContainsPoint(player.frame,touchLocation)
player.center = CGPointMake(touchLocation.x+touchOffset.x,touchLocation.y+touchOffset.y);
}
P.S. - Next time try to search similar questions...
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* aTouch = [touches anyObject];
UIView* aView = [aTouch view];
if (aView != self.view) {
[self.view bringSubviewToFront:aView];
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* aTouch = [touches anyObject];
UIView* aView = [aTouch view];
if (aView != self.view) {
aView.center = [aTouch locationInView:self.view];
}
}
I would like to be able to retrieve info on a tap, about all the different subviews that are placed in that tap spot. For example, if there was a background, and in front of it was a game character, I would like to be able to tap on that character, and it will retrieve the info saying that both the character and the background are in that tap spot.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//retrieve info about what other subviews lie behind at this point
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch=[touches anyObject];
CGPoint p=[touch locationInView:self.view];
NSLog(#"Coordiantes of Tap Point:(%f,%f)", p.x, p.y);
NSArray *anArrayOfSubviews = [self.view subviews];
NSMutableArray *requiredSubviewArray = [NSMutableArray array];
for (UIView *aSubView in anArrayOfSubviews){
if(CGRectContainsPoint(aSubView.frame, p)) {
//aSubView is there at point 'p'
[requiredSubviewArray addObject:aSubView];
}
}
// requiredSubviewArray contains all the Subviews at the Tap Point.
}
try this.it maybe helpful to you..
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//retrieve info about what other subviews lie behind at this point
NSLog(#"subviews--%#",[self.view subviews]); //it prints all subviews as Array
NSLog(#"superview--%#",[self.view superview]); //it prints superview of your view
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject]; // here you get all subviews on ur touchpoint
if ([touch view] == imageView) {
CGPoint location = [touch locationInView: self.view];
imageView.center = location;
}
}
/// To check both views are in one spot, use this
// CGRectContainsRect() and CGRectIntersectsRect().
You can try this one..
You can get all subviews if you use [self.view subviews]. You can compare those views frames with touch location.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint touchLocation = [touch locationInView:self.view];
startX = touchLocation.x;
startY = touchLocation.y;
for (UIView *view in [self.view subviews]){
//Here you can compare each view frame with touch location
}
}
I have implemented the drag effect on an image but during my test I see that the image is moving only on the click mouse event.
I cannot move my image with the mouse on my screen through the drag event. But when I click on a side of my screen the image take the place where I have clicked.
I followed many topics on youtube but finally, I haven't the same behavior.
This my code:
ScreenView1.h
IBOutlet UIImageView *image;
ScreenView1.m
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:touch.view];
image.center = location;
[self ifCollision];
}
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
[self touchesBegan:touches withEvent:event];
}
If you want to drag an image view, you will be so much happier using a UIPanGestureRecognizer. It makes this sort of thing trivial. Using touchesBegan is so iOS 4!
UIPanGestureRecognizer* p =
[[UIPanGestureRecognizer alloc] initWithTarget:self
action:#selector(dragging:)];
[imageView addGestureRecognizer:p];
// ...
- (void) dragging: (UIPanGestureRecognizer*) p {
UIView* vv = p.view;
if (p.state == UIGestureRecognizerStateBegan ||
p.state == UIGestureRecognizerStateChanged) {
CGPoint delta = [p translationInView: vv.superview];
CGPoint c = vv.center;
c.x += delta.x; c.y += delta.y;
vv.center = c;
[p setTranslation: CGPointZero inView: vv.superview];
}
}
You're not doing the right thing in the touchesMoved:withEvent:, which is why the drag won't work. Here's a little code that works:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:self];
[CATransaction begin];
[CATransaction setDisableActions:YES];
[image setCenter:location];
[CATransaction commit];
}
For the others, I have implemented my issue in that way:
- (IBAction)catchPanEvent:(UIPanGestureRecognizer *)recognizer{
CGPoint translation = [recognizer translationInView:self.view];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self.view];
}
thank you again Matt!