How can I get touch offset when using UITouch? I am doing a project like a remote control. I have a view set to multi-touched and I want the view to act like a touch pad for Mac, so I need the touch offsets when people move to control the mouse. Any ideas?
This can be accomplished with a UIPanGestureRecognizer by measuring the diagonal distance from the center of the screen to the current touch location.
#import <QuartzCore/QuartzCore.h>
Declare the gesture and hook it to self.view so that the entire screen responds to touch events.
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(myPanRecognizerMethod:)];
[pan setDelegate:self];
[pan setMaximumNumberOfTouches:2];
[pan setMinimumNumberOfTouches:1];
[self.view setUserInteractionEnabled:YES];
[self.view addGestureRecognizer:pan];
Then in this method, we use the gesture recognizers state: UIGestureRecognizerStateChanged to update and integer that measures the diagonal distance between touch location and screen center as the touch location changes.
-(void)myPanRecognizerMethod:(id)sender
{
[[[(UITapGestureRecognizer*)sender view] layer] removeAllAnimations];
if ([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateChanged) {
CGPoint touchLocation = [sender locationOfTouch:0 inView:self.view];
NSNumber *distanceToTouchLocation = #(sqrtf(fabsf(powf(self.view.center.x - touchLocation.x, 2) + powf(self.view.center.y - touchLocation.y, 2))));
NSLog(#"Distance from center screen to touch location is == %#",distanceToTouchLocation);
}
}
Related
I am working on Scroll View with gestures. I added a UIView in Scroll View whose size is equal to the ScrollView content size. I want to apply the pinch gesture and rotate gesture on the View which is subview of ScrollView. I have done the work of the pinch gesture by using zoom property and delegate of the ScrollView which give me same effect which I want. But Rotation Gesture is creating Problem. When I add rotation gesture on the view then zooming of the scroll view also get disturb.
So how can i apply the pinch gesture and Rotate gesture on the Scroll View's subview whose size must be equal to the content size of the ScrollView initially.
Can anybody give me the way to do this!
This is the code of .m file, when we rotate the view it become invisible
#import "ViewController.h"
#interface ViewController ()
{
UIView *backgroundView;
UIScrollView *scrollView;
CGFloat lastRotation;
}
#end
#implementation ViewController
-(void)loadView
{
[super loadView];
//Scroll View
scrollView = [[UIScrollView alloc] initWithFrame:self.view.frame];
scrollView.contentSize = self.view.frame.size;
scrollView.delegate = self;
scrollView.backgroundColor = [UIColor grayColor];
//Zooming factors of the Scroll View
scrollView.minimumZoomScale = 1.0;
scrollView.maximumZoomScale = 5.0f;
scrollView.zoomScale = 1.0;
[self.view addSubview:scrollView];
//Scroll View's subview
backgroundView = [[UIView alloc] initWithFrame:scrollView.frame];
[backgroundView setBackgroundColor:[UIColor orangeColor]];
[scrollView addSubview:backgroundView];
UIRotationGestureRecognizer *bgRotationGstr = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotateBackgroundView:)];
bgRotationGstr.delegate = self;
bgRotationGstr.cancelsTouchesInView = NO;
[backgroundView addGestureRecognizer:bgRotationGstr];
//Child of background view
UIView *childView = [[UIView alloc] initWithFrame:CGRectMake(20, 50, 100, 100)];
childView.backgroundColor = [UIColor grayColor];
[backgroundView addSubview:childView];
}
//Rotation of the background view
-(void)rotateBackgroundView:(UIRotationGestureRecognizer*)gesture
{
CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)gesture rotation]);
CGAffineTransform currentTransform = backgroundView.transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);
[backgroundView setTransform:newTransform];
lastRotation = [(UIRotationGestureRecognizer*)gesture rotation];
if (gesture.state == UIGestureRecognizerStateBegan || gesture.state == UIGestureRecognizerStateChanged)
{
scrollView.scrollEnabled = NO;
}
else if (gesture.state == UIGestureRecognizerStateEnded)
{
lastRotation = 0.0;
scrollView.scrollEnabled = YES;
return;
}
}
#pragma mark<UIScrollViewDelegate>
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return backgroundView;
}
#pragma mark<UIGetsureRecognizer>
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
return YES;
}
#end
After many days of struggling I found a definitive solution in order to use UIScrollView integrated zoom behavior together with UIRotationGestureRecognizer working like a charm. You have to add a container dummy view as subview of the scroll view, and put the UIImageView as subview of the container view. Afterthat, return the container view in the viewForZoomingInScrollView method and add the UIRotationGestureRecognizer to the scrollview, applying CGAffineTransformRotate to the UIImageView. Finally, return true in the shouldRecognizeSimultaneouslyWithGestureRecognizer method. In this way the scrollView will capture both the two fingers rotation gesture and the pinch to zoom gesture: the zoom will be applied to the dummy view and rotation to the uiimageview, without conflicts between transformations.
In code: let's think to have a UIViewController presenting a UIScrollView. We want to use scrollview's zoom behaviour out of the box together with UIImageView rotation.
1) The controller (or any other object) containing UIScrollView must conforms to UIGestureRecognizerDelegate protocol.
In myViewController.h
#interface myViewController : UIViewController < UIGestureRecognizerDelegate> {
}
2) Create a UIScrollView, add a dummy view as subview and finally add a UIImageView as subview of the dummy view.
In myViewController.m
//Scrollview
myScrollView=[[UIScrollView alloc] initWithFrame:CGRectMake(0,0, view.frame.size.width, view.frame.size.height)];
myScrollView.delegate=self;
[view addSubview:myScrollView];
//Dummy View
UIView *dummyView=[[UIView alloc] initWithFrame:CGRectMake(0, 0, myScrollView.frame.size.width, myScrollView.frame.size.height)];
[self addSubview:dummyView];
//ImageView
imageView=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, dummyView.frame.size.width, dummyView.frame.size.height)];
imageView.contentMode=UIViewContentModeScaleAspectFit;
[dummyView addSubview:imageView];
//Add rotation gesture to the scrollView
rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(handleRotate:)];
[myScrollView addGestureRecognizer:_rotationGestureRecognizer];
//Set the controller as delegate of the recognizer
rotationGestureRecognizer.delegate=self;
[...]
#pragma UIScrollViewDelegate
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
//Set the dummy view (imageview's superview) as view for zooming
return imageView.superview;
}
[...]
#pragma Mark - UIGestureRecognizerDelegate
- (BOOL) gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
//Make it possibile to recognize simultaneously pinch and rotation gestures
return TRUE;
}
[...]
- (IBAction) handleRotate:(UIRotationGestureRecognizer*)recognizer {
//Apply the rotation to imageView
imageView.transform = CGAffineTransformRotate(imageView.transform, recognizer.rotation);
recognizer.rotation = 0;
}
For simplyfing purposes, I wrote everything in the same controller. You are free to subclass the UIScrollView. Remember that the tricks are:
1) returning the container dummy view as viewForZoomingInScrollView so zoom will affect the container view and rotation will affect the uiimageview.
2) set the viewcontroller containing the scrollview as delegate of the rotation gesture recognizer and return TRUE for shouldRecognizeSimultaneouslyWithGestureRecognizer.
Add this to your .m
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
Also make sure you dont have exclusive touch enabled on any gesture recognizers.
Try to put you scalable/rotatable content in a subview of your content view. ( Maybe you must set the "clip content" property of your content view to true - not sure )
This way the scrollview is not concerned anymore by transformations, since its content view stays still.
If you have to display the clipped content ( if you rotate a square, for example, the corners go out the initial area), recompute your content view and update the scrollview.
Since you gave the code, I suggest to try:
//Scroll View's subview
backgroundViewHolder = [[UIView alloc] initWithFrame:scrollView.frame];
[backgroundViewHolder setBackgroundColor:[UIColor orangeColor]];
[scrollView backgroundViewHolder];
//Holder View's subview
backgroundView = [[UIView alloc] initWithFrame:backgroundViewHolder.bounds];
[backgroundViewHolder addSubview:backgroundView];
Everything else should remain the same. This is just an idea... Not sure it is the right answer.
Add this to your implement file, make it a UIGestureRecognizerDelegate.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
rotationGeustureRecognozier.delegate = self;// (the implement file)
I'm new to Cocoa development on the Mac, and I'm having issues creating a draggable NSView subclass, despite having followed many different guides, including the main Apple docs on custom views.
The code I've implemented so far is:
-(void)mouseDown:(NSEvent *) e {
[[NSCursor closedHandCursor] push];
self.lastDragLocation = [e locationInWindow];
}
-(void)mouseDragged:(NSEvent *)event {
NSView* superView = [self superview];
NSPoint currentOrigin = self.lastDragLocation;
NSRect currentFrame = [self frame];
NSPoint nextOrigin = NSMakePoint(currentOrigin.x + [event deltaX],
currentOrigin.y + ([event deltaY] *
([superView isFlipped] ? 1 : -1))
);
[self setFrameOrigin:nextOrigin];
[self autoscroll:event];
[superView setNeedsDisplayInRect:NSUnionRect(currentFrame, [self frame])];
self.lastDragLocation = nextOrigin;
}
-(void)mouseUp:(NSEvent*)event {
[NSCursor pop];
[[self window] invalidateCursorRectsForView:self];
}
Everything seems to work when I drag the view, but when I stop moving or release the mouse, the view snaps back to the original origin. When this happens during a drag, subsequent drag events set the view back to the right place, only to repeat the issue.
Incidentally, this is XCode 5.0 running on Mountain Lion.
I am having issues adding an image across a view while moving finger across the screen.
Currently it is adding the image multiple times but squeezing them too close together and not really following my touch.
EDIT:
What I want:
After taking or choosing an image, the user can then select another image from a list. I want the user to touch and move their finger across the view and the selected image will appear where they drag their finger, without overlapping, in each location.
This works:
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
currentTouch = [touch locationInView:self.view];
CGRect myImageRect = CGRectMake(currentTouch.x, currentTouch.y, 80.0f, 80.0f);
myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:#"dot.png"]];
[self.view addSubview:myImage];
[myImage release];
}
New Question: How do I add spaces in this so that the image isn't so snug when drawing it on the view?
You might want to explain your question more, what exactly are you trying to achieve! If you dont want the images to overlap than you can try this!
UITouch * touch = [touches anyObject];
touchPoint = [touch locationInView:imageView];
prev_touchPoint = [touch previousLocationInView:imageView];
if (ABS(touchPoint.x - prev_touchPoint.x) > 80
|| ABS(touchPoint.y - prev_touchPoint.y) > 80) {
_aImageView = [[UIImageView alloc] initWithImage:aImage];
_aImageView.multipleTouchEnabled = YES;
_aImageView.userInteractionEnabled = YES;
[_aImageView setFrame:CGRectMake(touchPoint.x, touchPoint.y, 80.0, 80.0)];
[imageView addSubview:_aImageView];
[_aImageView release];
}
I'm sorry because I'm in company and I can't post too big data(the code). The squeezing is because you have not checked the touch point's distance with last touch point. Check a point whether it's in a view:bool CGRectContainsPoint (CGRect rect,CGPoint point);I mean remember a touch point in touchesBegan:. Update it if the new touches in touchesMomved: is bigger than image's width or left. And put the add image view in a method and call it use - (void)performSelectorInBackground:(SEL)aSelector withObject:(id)arg.
you can also use UISwipeGestureRecognizer as below instead of touchesMoved method,while swiping across the screen.in viewDidload:method,
UISwipeGestureRecognizer *swipeup = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:#selector(swipedone:)];
swipeup.direction = UISwipeGestureRecognizerDirectionUp;
swipeup.numberOfTouchesRequired=1;
[self.view addGestureRecognizer:swipeup];
method definition:
-(IBAction)swipedone:(UISwipeGestureRecognizer*)recognizer
{
NSLog(#"swiped");
UIImageView* _aImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"1.png"]];
_aImageView.frame = CGRectMake(10, 10, 100, 100);
_aImageView.multipleTouchEnabled = YES;
_aImageView.userInteractionEnabled = YES;
CGPoint point = [recognizer locationInView:recognizer.view];
[_aImageView setFrame:CGRectMake(point.x, point.y, 80.0, 80.0)];
[self.view addSubview:_aImageView];
[_aImageView release];
}
currently i am using this code for swipe up.i think it will works fine.once try it.
I have this code that retrieves the coordinates of an object when it is panned:
UITapGestureRecognizer *moveBuildingTap = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(moveobject:)];
Method moveobject contents:
CGPoint tapPoint=[recognizer locationOfTouch:0 inView:self.view];
I use this to change the frame of - move it -an imageview using these coordinates.
However, upon dragging the image around - triggering the uipangesturerecognizer action, I found that when I drag it to the absolute bottom, I get an error that -[UIPanGestureRecognizer locationOfTouch:inView:]: index (0) beyond bounds (0).
How can I solve this exception and prevent the user from dragging past this point?
Thanks
It's weird that your moveobject: method gets called even though the private touches array of the gesture recognizer seems to be empty.
Anyway, in general, if you don't handle multitouch gestures within gesture recognizer, I would suggest to use [recognizer locationInView:] rather then locationOfTouch:inView:.
Btw:
Your talking about a UIPanGestureRecognizer while in the code you're using a UITapGestureRecognizer.
The code I would recommend to handle dragging of a particular view looks like this:
//...
UIPanGestureRecognizer *panGR = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
[someView addGestureRecognizer:panGR];
//...
- (void)handlePan:(UIPanGestureRecognizer *)gr
{
CGPoint translation = [gr translationInView:gr.view];
gr.view.frame = CGRectOffset(gr.view.frame, translation.x, translation.y);
[gr setTranslation:CGPointZero inView:gr.view];
}
You should check the numberOfTouches in your UIGestureRecognizer like:
if (recognizer.numberOfTouches) {
CGPoint tapPoint = [recognizer locationOfTouch:0 inView:self.view];
}
I have an MKMapView with a single subview:
MKMapView *mapView = [[MKMapView alloc] initWithFrame:[UIScreen mainScreen].bounds];
UIView *subView = [[UIView alloc] initWithFrame:CGRectMake(0, 200, 200, 200)];
subView.backgroundColor = [UIColor grayColor];
[mapView addSubview:subView];
I would expect that because the subview does not handle any touch events, all touch events would be passed along to the parent map view (via the responder chain). I would then expect that panning and pinching in the subview would pan and pinch the map.
This, unfortunately, does not appear to be the case. Does anyone know of a way to get the map view in to the responder chain?
I realize overriding hitTest in my subview can achieve what I'm expecting here, but I can't use that approach because I have other gestures I need to respond to in the subview.
How about handling all gestures with UIGestureRecognizers (properly setup to ignore other gesture recognizer or to fire simultanously with them) added to your mapView and disabling userInteractionEnabled of your subview?
I use the following code to listen to Taps on the mapView without interfering with the standard gestures:
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(mtd_handleMapTap:)];
// we require all gesture recognizer except other single-tap gesture recognizers to fail
for (UIGestureRecognizer *gesture in self.gestureRecognizers) {
if ([gesture isKindOfClass:[UITapGestureRecognizer class]]) {
UITapGestureRecognizer *systemTap = (UITapGestureRecognizer *)gesture;
if (systemTap.numberOfTapsRequired > 1) {
[tap requireGestureRecognizerToFail:systemTap];
}
} else {
[tap requireGestureRecognizerToFail:gesture];
}
}
- (void)mtd_handleMapTap:(UITapGestureRecognizer *)tap {
if ((tap.state & UIGestureRecognizerStateRecognized) == UIGestureRecognizerStateRecognized) {
// Get view frame rect in the mapView's coordinate system
CGRect viewFrameInMapView = [self.mySubview.superview convertRect:self.mySubview.frame toView:self.mapView];
// Get touch point in the mapView's coordinate system
CGPoint point = [tap locationInView:self.mapView];
// Check if the touch is within the view bounds
if (CGRectContainsPoint(viewFrameInMapView, point)) {
// tap was on mySubview
}
}
}