I am working on the pdf based application where I am trying to implement UIPinchGestureRecognizer.I want to limit the pinch off functionality when user reaches to the default view size with 640,960.
In my current implementation user is able to pinch in/out infinite.
- (void)pinchZoom:(UIPinchGestureRecognizer *)gestureRecognizer
{
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
if (!zoomActive) {
zoomActive = YES;
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panMove:)];
[panGesture setMaximumNumberOfTouches:2];
[panGesture setDelegate:self];
[self addGestureRecognizer:panGesture];
[panGesture release];
}
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);
[delegate leavesView:self zoomingCurrentView:[gestureRecognizer scale]];
[gestureRecognizer setScale:1];
}
}
// This method will handle the PAN / MOVE gesture
- (void)panMove:(UIPanGestureRecognizer *)gestureRecognizer
{
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
CGPoint translation = [gestureRecognizer translationInView:[[gestureRecognizer view] superview]];
[[gestureRecognizer view] setCenter:CGPointMake([[gestureRecognizer view] center].x + translation.x, [[gestureRecognizer view] center].y + translation.y)];
[gestureRecognizer setTranslation:CGPointZero inView:[[gestureRecognizer view] superview]];
}
}
this is default view size/scale I am talking about:
and this is what I don't want or I want to limit in pinch out:
Any suggestion?
What about handling yourself the lower limit in your handler function? Something like this:
- (void)pinchZoom:(UIPinchGestureRecognizer *)gestureRecognizer {
....
if ( [gestureRecognizer scale] > MIN_SCALE )
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);
...
Inside of your gestureRecognizer, you are going to have to test and understand the current scale / size of you PDF view, and NOT zoom smaller when you are taking up the full screen.
Related
So I'm making a simple iPhone app that lets you move / scale images that have been imported in a view. I'm using UIGestureRecognizers with #paulsolt 's code below to accomplish this. It works great. The only problem I'm having is when I go to move an object after not having touched the screen or performed any other actions for a while, there is a slight hiccup before it starts moving smoothly.
Does anyone know how to fix this problem?
- (void)addGestureRecognizersToView:(UIView *)theView {
theView.userInteractionEnabled = YES; // Enable user interaction
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePanGesture:)];
[panGesture setMaximumNumberOfTouches:2];
[panGesture setDelegate:self];
[theView addGestureRecognizer:panGesture];
[panGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(handlePinchGesture:)];
[theView addGestureRecognizer:pinchGesture];
[pinchGesture release];
}
- (void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer {
if([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
// Reset the last scale, necessary if there are multiple objects with different scales
lastScale = [gestureRecognizer scale];
}
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan ||
[gestureRecognizer state] == UIGestureRecognizerStateChanged) {
CGFloat currentScale = [[[gestureRecognizer view].layer valueForKeyPath:#"transform.scale"] floatValue];
// Constants to adjust the max/min values of zoom
const CGFloat kMaxScale = 1.5;
const CGFloat kMinScale = 1.0;
const CGFloat kSpeed = 0.75;
CGFloat newScale = 1 - (lastScale - [gestureRecognizer scale]) * (kSpeed);
newScale = MIN(newScale, kMaxScale / currentScale);
newScale = MAX(newScale, kMinScale / currentScale);
CGAffineTransform transform = CGAffineTransformScale([[gestureRecognizer view] transform], newScale, newScale);
[gestureRecognizer view].transform = transform;
lastScale = [gestureRecognizer scale]; // Store the previous scale factor for the next pinch gesture call
}
}
- (void)handlePanGesture:(UIPanGestureRecognizer *)gestureRecognizer {
UIView *myView = [gestureRecognizer view];
CGPoint translate = [gestureRecognizer translationInView:[myView superview]];
if ([gestureRecognizer state] == UIGestureRecognizerStateChanged || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[myView setCenter:CGPointMake(myView.center.x + translate.x, myView.center.y + translate.y)];
[gestureRecognizer setTranslation:CGPointZero inView:[myView superview]];
}
}
Maybe because you do this [panGesture setMaximumNumberOfTouches:2];, it has to ensure that the current action is not pinching before moving your view?
This is happening when the imagepicker selects a photo taken by the iPhone camera. For other images it seems to work fine. Not sure how to fix this.
Thanks in advance.
I want to apply pinch, rotation and pan gesture effect on an image view.like this
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:#selector(scalePiece:)];
[imgView addGestureRecognizer:pinchGesture];
[pinchGesture release];
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:#selector(rotatePiece:)];
[imgView addGestureRecognizer:rotationGesture];
[rotationGesture release];
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc]initWithTarget:self action:#selector(panPiece:)];
[imgView addGestureRecognizer:panGesture];
[panGesture release];
// Method implementation
- (void)adjustAnchorPointForGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {
UIView *piece = gestureRecognizer.view;
CGPoint locationInView = [gestureRecognizer locationInView:piece];
CGPoint locationInSuperview = [gestureRecognizer locationInView:piece.superview];
piece.layer.anchorPoint = CGPointMake(locationInView.x / piece.bounds.size.width, locationInView.y / piece.bounds.size.height);
piece.center = locationInSuperview;
}
}
- (void)rotatePiece:(UIRotationGestureRecognizer *)gestureRecognizer
{
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[gestureRecognizer view].transform = CGAffineTransformRotate([[gestureRecognizer view] transform], [gestureRecognizer rotation]);
NSLog(#"Rotate : %f",[gestureRecognizer rotation]);
[gestureRecognizer setRotation:0];
}
}
- (void)panPiece:(UIPanGestureRecognizer *)gestureRecognizer
{
UIView *piece = [gestureRecognizer view];
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
CGPoint translation = [gestureRecognizer translationInView:[piece superview]];
[piece setCenter:CGPointMake([piece center].x + translation.x, [piece center].y + translation.y)];
[gestureRecognizer setTranslation:CGPointZero inView:[piece superview]];
}
}
- (void)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer
{
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer velocity], [gestureRecognizer velocity]);
[gestureRecognizer setScale:1];
}
}
In this rotation and swipe(pan) working fine but pinch is not good. I have seen one app i.e.,http://itunes.apple.com/us/app/image-mask-costume-hd/id443821357?mt=8 in this the touch events are very nice . I want to implement like this is it possible by using gesture or we need to follow touch events. Do any one have idea please help me to do it.
Try this code: http://dl.dropbox.com/u/9397784/Image%20multitouch.txt
Replace currentlyEditing with your view. Just copy the code into the implementation of the view or view controller you want to use it in. The code handles zoom, rotate and pan. To reset the view back to the default position, call yourView.transform = CGAffineTransformIdentity;.
The Apple Touches example suggests to use [gestureRecognizer scale] and not [gestureRecognizer velocity]:
- (IBAction)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer
{
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);
[gestureRecognizer setScale:1];
}
}
i was just searching for an appropriate event that i can catch. the pinch works well. and following line works only if there was no pinch before
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent*)event
{
NSLog(#"---> event");
}
it seems that the pinch eats up the following touch up.
anyhow in this code the touch up is recognized
- (void)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer
{
//[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
NSLog(#"scalePiece");
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);
[gestureRecognizer setScale:1];
}
}
how can i recognize the touch up of the last/second finger after pinching the view? or better said, how can i differentiate between pinch move and pinch end?
cheers
You can use:
if ([gestureRecognizer state] == UIGestureRecognizerStateEnded)
in your pinch function
I'm working on an iPad app that will use UIGestureRecognizers to allow the user to pan, scale and rotate objects (subclass of UIView) on the screen.
I understand that the [UIView frame] property isn't valid after a transform is done, so I'm trying to take the values of my UIGestureRecognizers and keep the "frame" myself.
Here's the code I'm using to attempt this (you may recognize a lot of code from Apple's sample project, SimpleGestureRecognizers):
// Shape.h (partial)
#interface Shape : UIView <UIGestureRecognizerDelegate> {
CGFloat centerX;
CGFloat centerY;
CGFloat rotatation;
CGFloat xScale;
CGFloat yScale;
}
// Shape.m (partial)
- (void)panPiece:(UIPanGestureRecognizer *)gestureRecognizer
{
UIView *piece = [gestureRecognizer view];
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
CGPoint translation = [gestureRecognizer translationInView:[piece superview]];
self.centerX += translation.x;
self.centerY += translation.y;
[piece setCenter:CGPointMake([piece center].x + translation.x, [piece center].y + translation.y)];
for ( HandleView *h in [self handles] ) {
[h setCenter:CGPointMake([h center].x + translation.x, [h center].y + translation.y)];
[h setNeedsDisplay];
}
[gestureRecognizer setTranslation:CGPointZero inView:[piece superview]];
NSLog(#"(%.0f, %.0f, %.0f, %.0f) %.2f˚, (%.2fx, %.2fx)", [self frame].origin.x, [self frame].origin.y, [self frame].size.width, [self frame].size.height, [self rotation], [self xScale], [self yScale]);
}
}
// rotate the piece by the current rotation
// reset the gesture recognizer's rotation to 0 after applying so the next callback is a delta from the current rotation
- (void)rotatePiece:(UIRotationGestureRecognizer *)gestureRecognizer
{
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
CGFloat rot = [self normalizeRotation:[gestureRecognizer rotation]];
self.rotation += rot * 180.0 / M_PI;
NSLog(#"Rotation: %.12f", [gestureRecognizer rotation]);
[gestureRecognizer view].transform = CGAffineTransformRotate([[gestureRecognizer view] transform], [gestureRecognizer rotation]);
[gestureRecognizer setRotation:0];
NSLog(#"(%.0f, %.0f, %.0f, %.0f) %.2f˚, (%.2fx, %.2fx)", [self frame].origin.x, [self frame].origin.y, [self frame].size.width, [self frame].size.height, [self rotation], [self xScale], [self yScale]);
}
}
// scale the piece by the current scale
// reset the gesture recognizer's rotation to 0 after applying so the next callback is a delta from the current scale
- (void)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer
{
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
self.xScale *= [gestureRecognizer scale];
self.yScale *= [gestureRecognizer scale];
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);
[gestureRecognizer setScale:1];
NSLog(#"(%.0f, %.0f, %.0f, %.0f) %.2f˚, (%.2fx, %.2fx)", [self frame].origin.x, [self frame].origin.y, [self frame].size.width, [self frame].size.height, [self rotation], [self xScale], [self yScale]);
}
}
Because of some weirdness I noticed with the rotations, I implemented the following method to help keep an accurate rotation value:
- (CGFloat) normalizeRotation:(CGFloat)rot
{
if (abs(rot) > 0.05) {
if (rot > 0) {
rot -= M_PI;
} else {
rot += M_PI;
}
return [self normalizeRotation:rot];
} else {
return rot;
}
}
Anyway, the shape on-screen pans, scales and rotates fine. All is as you would expect and the performance is good.
The problem is that, after a user moves, resizes and rotates a UIView, I want to let them tap it and give them "handles" that allow for resizing other than the "square" resizing that pinching gives (i.e., when you use the pinch gesture, you upsize or downsize in the same ratio for both x and y). Now, even with the code above, the values that are stored aren't ever quite accurate.
The "handles" I'm using are simply 10x10 dots that are supposed to go at each corner and halfway down each "side" of the UIView's frame/rectangle. When I first place a square and tap it to get the handles before doing anything else, the handles appear in the appropriate place. When I move, resize and rotate an object, then tap it, the handles are all shifted off of the shape some amount. It generally seems to be about 20 pixels.
Are the values in the UIGestureRecognizer objects just not accurate enough? That doesn't seem to be the case, because those values are used to change the object on-screen, and that is accurate.
I'm pretty sure there's no way for me to get a real representation of the UIView's frame after messing with it so much, but where's the flaw in my custom code that's giving me bad values? Am I losing precision when converting between degrees and radians?
On a related note: Apple obviously has internal code that keeps track of how to draw a view that's been translated/transformed. The box of solid color that I'm currently using is moved, zoomed and rotated correctly. So, is there any way to access the values that they use for displayed a translated/transformed UIView?
Thanks!
I would like to make 2 operations to an UIImageView zoom, rotate, I have 2 problems:
A. I make an operation for zoom for ex. and when I try to make rotation the UIImageView is set to initial size, I would like to know how to keep the zoomed UIImageView and make the rotation from the zoomed image.
B. I would like to combine the zoom operation with rotation and I don't know ho to implement this:
- (void)viewDidLoad
{
foo = [[UIImageView alloc]initWithFrame:CGRectMake(100.0, 100.0, 600, 800.0)];
foo.userInteractionEnabled = YES;
foo.multipleTouchEnabled = YES;
foo.image = [UIImage imageNamed:#"earth.jpg"];
foo.contentMode = UIViewContentModeScaleAspectFit;
foo.clipsToBounds = YES;
[self.view addSubview:foo];
}
//---pinch gesture---
UIPinchGestureRecognizer *pinchGesture =
[[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(handlePinchGesture:)];
[foo addGestureRecognizer:pinchGesture];
[pinchGesture release];
//---rotate gesture---
UIRotationGestureRecognizer *rotateGesture =
[[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(handleRotateGesture:)];
[foo addGestureRecognizer:rotateGesture];
[rotateGesture release];
//---handle pinch gesture---
-(IBAction) handlePinchGesture:(UIGestureRecognizer *) sender {
NSLog(#"Pinch");
CGFloat factor = [(UIPinchGestureRecognizer *) sender scale];
if (factor > 1) {
//---zooming in---
sender.view.transform = CGAffineTransformMakeScale(
lastScaleFactor + (factor-1),
lastScaleFactor + (factor-1));
}
else {
//---zooming out---
sender.view.transform = CGAffineTransformMakeScale(lastScaleFactor * factor, lastScaleFactor * factor);
}
if (sender.state == UIGestureRecognizerStateEnded) {
if (factor > 1) {
lastScaleFactor += (factor-1);
} else {
lastScaleFactor *= factor;
}
}
}
//---handle rotate gesture---
-(IBAction) handleRotateGesture:(UIGestureRecognizer *) sender {
CGFloat rotation = [(UIRotationGestureRecognizer *) sender rotation];
CGAffineTransform transform = CGAffineTransformMakeRotation(rotation + netRotation);
sender.view.transform = transform;
if (sender.state == UIGestureRecognizerStateEnded) {
netRotation += rotation;
}
}
Thanks
Hope this can be helpful to you, that's how I usually implement gesture recognizers:
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotatePiece:)];
[piece addGestureRecognizer:rotationGesture];
[rotationGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(scalePiece:)];
[pinchGesture setDelegate:self];
[piece addGestureRecognizer:pinchGesture];
[pinchGesture release];
Rotate method: Reset the gesture recognizer's rotation to 0 after applying so the next callback is a delta from the current rotation
- (void)rotatePiece:(UIRotationGestureRecognizer *)gestureRecognizer {
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[gestureRecognizer view].transform = CGAffineTransformRotate([[gestureRecognizer view] transform], [gestureRecognizer rotation]);
[gestureRecognizer setRotation:0];
}
}
Scale Method, at the end reset the gesture recognizer's scale to 1 after applying so the next callback is a delta from the current scale
- (void)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer {
[self adjustAnchorPointForGestureRecognizer:gestureRecognizer];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
[gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);
[gestureRecognizer setScale:1];
}
}
Than ensure that the pinch, pan and rotate gesture recognizers on a particular view can all recognize simultaneously prevent other gesture recognizers from recognizing simultaneously
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
// if the gesture recognizers are on different views, don't allow simultaneous recognition
if (gestureRecognizer.view != otherGestureRecognizer.view)
return NO;
// if either of the gesture recognizers is the long press, don't allow simultaneous recognition
if ([gestureRecognizer isKindOfClass:[UILongPressGestureRecognizer class]] || [otherGestureRecognizer isKindOfClass:[UILongPressGestureRecognizer class]])
return NO;
return YES;
}
Scale and rotation transforms are applied relative to the layer's anchor point this method moves a gesture recognizer's view's anchor point between the user's fingers
- (void)adjustAnchorPointForGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {
UIView *piece = gestureRecognizer.view;
CGPoint locationInView = [gestureRecognizer locationInView:piece];
CGPoint locationInSuperview = [gestureRecognizer locationInView:piece.superview];
piece.layer.anchorPoint = CGPointMake(locationInView.x / piece.bounds.size.width, locationInView.y / piece.bounds.size.height);
piece.center = locationInSuperview;
}
}
Just implement gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer: in your delegate.
I have a UIPinchGestureRecognizer, a UIPanGestureRecognizer and a UIRotationGestureRecognizer set up and I want them all to work at the same time. I also have a UITapGestureRecognizer which I do not want to be recognized simultaneously. All I did was this:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
if (![gestureRecognizer isKindOfClass:[UITapGestureRecognizer class]] && ![otherGestureRecognizer isKindOfClass:[UITapGestureRecognizer class]]) {
return YES;
}
return NO;
}
I found something that may interest you on the stanford university website:
http://www.stanford.edu/class/cs193p/cgi-bin/drupal/downloads-2010-winter
on this site you will need to scroll down until you see the number 14: "Title: Lecture #14 - MultiTouch"
Download the: "14_MultiTouchDemo.zip"
In this example you can scale and rotate every image at the same time.
hope i helped :)
When you use CGAffineTransformMakeScale, you are resetting the transformation of Identity every time you use it and you lose the previous transformation information.
Try using CGAffineTransformScale(view.transform,scale, scale) for the pinch zooming. You will need to retain the original frame size to keep the zooming under control though.
see: How can I use pinch zoom(UIPinchGestureRecognizer) to change width of a UITextView?
For rotation similarly:
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
view.transform = CGAffineTransformRotate([view transform], [gestureRecognizer rotation]);
[gestureRecognizer setRotation:0];
}
I know this is a pretty old thread, I came across this imageview subclass, which works nice for zoom, rotate and pan. It uses gesture recognizer on an imageview. I am using this for one of my app.
ZoomRotatePanImageView