I want a pretty simple thing - in my top controller (which is navigation controller) to set up a tap gesture recognizer which will catch all the taps everywhere on the view. Currently when I tap on a button the system is not even thinking to bother my recognizer (except the gestureRecognizer:shouldReceiveTouch: delegate method, where I return YES). Instead, it just executes a button click. So I want to install "the strongest" recognizer on a view hierarchy no matter what.
You might try putting an empty UIView on top of all other views and add the UITapGestureRecognizer to it. We do something similar with help overlays. The biggest issue is figuring out how and when to ignore the touches so the underlying buttons get them when needed.
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
UIButton *b = [UIButton buttonWithType:UIButtonTypeInfoDark];
b.frame = CGRectMake(50,50, b.bounds.size.width, b.bounds.size.height );
[self.view addSubview:b];
UIView *invisibleView = [[UIView alloc] initWithFrame:self.view.bounds];
invisibleView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[invisibleView addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapHit:)]];
[self.view addSubview:invisibleView];
}
-(void)tapHit:(UITapGestureRecognizer*)tap {
NSLog( #"tapHit" );
}
#end
Related
When tapping a specific button in my app I want an image to show, I did this using an UIImageView. Then I want to hide that image by tapping it, but I don't understand how to do this?
I tried the following code, but it doesn't work.
#implementation ViewController
-(IBAction)pic {
UIImage *img = [UIImage imageNamed:#"test.png"];
[ImageView setImage:img];
imageView.userInteractionEnabled = YES;
UITapGestureRecognizer *tapRecognize = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(handleTap:)];
tapRecognizer.delegate = self;
[imageView addGestureRecognizer:tapRecognizer];
}
- (void)handleTap:(UITapGestureRecognizer *)tapGestureRecognizer {
//handle tap
}
Its pretty simple.
Use an UIImageView instead and check that userInteractionEnabled is YES on the UIImageView. Then you can then add a gesture recognizer.
Your .h file should have atleast something like below:
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController<UIGestureRecognizerDelegate>
#property (weak, nonatomic) IBOutlet UIImageView *touchImageView;
#end
Dont forget to connect UIImageView from your storyboard to property declared above.
in your .m file:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.touchImageView.userInteractionEnabled = YES;
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(handleTap:)];
tapRecognizer.delegate = self;
[self.touchImageView addGestureRecognizer:tapRecognizer];
}
- (void)handleTap:(UITapGestureRecognizer *)tapGestureRecognizer {
//handle tap
self.touchImageView.alpha = 0.0f;
}
You could put an image on a button instead. I think using a UIImageView is the right decision though. You need to hook up a gesture to it programmatically. You can do this using something similar to below:
let singleFingerTap = UITapGestureRecognizer(target: self, action: "viewTapped:")
imageView.addGestureRecognizer(singleFingerTap)
You can add a tap gesture recognizer to the UIImageView that contains the image.
var tapGesture = UITapGestureRecognizer(target: <#AnyObject#>, action: <#Selector#>)
In the method you assign as the action, just set myImageView.alpha = 0. This should essentially "hide" your image view. You could also set the height of the image view to 0 if you wanted to hide it in that sense.
An alternative could be to import an open-sourced project, such as the AKImageViewer, to get posts to appear full screen (giving the user a better full view) and allowing them to swipe or cancel to get away from the image (similar to viewing images in the Twitter app.
I have a view controller that have a label, and I want to perform panning to the right on that label.
So what I did so far is:
*add a pan gesture to the label in the nib file
*created a didPan method:
- (IBAction)didPan:(UIScreenEdgePanGestureRecognizer *)sender;
and the implementation:
- (IBAction)didPan:(UIScreenEdgePanGestureRecognizer *)sender {
CGPoint newTranslation = [sender translationInView:self.homeLabel];
self.homeLabel.transform = CGAffineTransformMakeTranslation(newTranslation.x, 0);
}
and changed the screen edge pan gesture recogniser to right.
I thought it should pan now but its now, what am I doing wrong?
tnx
So I had some time to try it out myself.
Here's what the Interface Builder looks like with -didPan IBAction connected.
However that didn't work for me. I did some searching and found this also on StackOverflow.
Possible bug with UIScreenEdgePanGestureRecognizer in Interface Builder
So, I would suggest you try implementing it the old fashion way in code.
Try this:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIScreenEdgePanGestureRecognizer *swipeFromLeft = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:#selector(didPan:)];
swipeFromLeft.edges = UIRectEdgeLeft;
[self.view addGestureRecognizer:swipeFromLeft];
UIScreenEdgePanGestureRecognizer *swipeFromRight = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:#selector(didPan:)];
swipeFromRight.edges = UIRectEdgeRight;
[self.view addGestureRecognizer:swipeFromRight];
}
I have a UIView called myView on myViewController. I have a UIGestureRecognizer called swipeLeft (code below) that detects when a user swipes left on it.
The problem is: myViewController recognises the same gesture on the whole screen and performs another action. So I would like my app to perform myMethod when you swipeLeft in this particular area of myViewController, the area being myView.
UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self
action:#selector(myMethod:)];
swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
swipeLeft.delaysTouchesBegan = YES;
[self.myView addGestureRecognizer:swipeLeft];
More details: I am using RESideMenu and myViewController is the right menu, so when it is visible, the whole view of myViewController recognises swipes in all directions. I would like to change the recogniser in this particular UIView myView.
Thanks!
First you will need to add the swipe gesture to your view controllers header file.
#property (strong, nonatomic) UISwipeGestureRecognizer *swipeLeft;
If you look in DEMORootViewController.m, you will see this call:
self.rightMenuViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"rightMenuViewController"];
This will call your awakeFromNib, and it's your first chance to do something. In here you will create that swipe gesture. You can not add it to your view yet though, because your outlets are not set at this point. The first time they are set is in viewDidLoad, so that's where you will add the gesture to your view. So add this to your view controllers implementation file
- (void)awakeFromNib
{
self.swipeLeft = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:#selector(myMethod:)];
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self.swipeView addGestureRecognizer:self.swipeLeft];
}
- (void)myMethod:(UISwipeGestureRecognizer *)swipe
{
NSLog(#"Did swipe") ;
}
Finally you will need to tell the pan gesture in RESideMenu.m to fail whenever our swipeLeft gesture occurs. The way to do that is to add the following code to RESideMenu.m at line 220. That's at the end of the viewDidLoad method.
if ([self.rightMenuViewController isKindOfClass:[DEMOVC class]]) {
DEMOVC *rightVC = (DEMOVC *)self.rightMenuViewController;
if (rightVC.swipeLeft) {
[panGestureRecognizer requireGestureRecognizerToFail:rightVC.swipeGesture];
} } }
This is assuming your custom VC is called DEMOVC. You will also need to import your custom VC to RESideMenu.m like this:
#import "DEMOVC.h"
Please let me know if this worked out for you, and if there's something else I can help you with.
I recently got into trouble with a View Controller which has a UIWebView in it and a subview which I would like to add to the View Controller.
That's the View with the UIWebView:
http://cl.ly/image/03473l0e3a2L
My target is, to add a Share Menu which does work without problems:
http://cl.ly/image/3b273t2o3P00
But now I have the problem, that I set gesture recognizers for the social icons + labels (twitter,facebook,mail) - but these gesture recognizers don't do anything.
The ShareView is a UIView Subclass and I add the Gesture Recognizers this way:
UITapGestureRecognizer *fbTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(fbTapped:)];
fbTap.numberOfTapsRequired = 1;
fbTap.numberOfTouchesRequired = 1;
fbTap.delegate = self;
[fbImage addGestureRecognizer:fbTap];
[fbLabel addGestureRecognizer:fbTap];
UITapGestureRecognizer *twTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(twTapped:)];
twTap.numberOfTapsRequired = 1;
twTap.numberOfTouchesRequired = 1;
twTap.delegate = self;
[twImage addGestureRecognizer:twTap];
[twLabel addGestureRecognizer:twTap];
UITapGestureRecognizer *mailTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(mailTapped:)];
mailTap.numberOfTapsRequired = 1;
mailTap.numberOfTouchesRequired = 1;
mailTap.delegate = self;
[mailImage addGestureRecognizer:mailTap];
[mailLabel addGestureRecognizer:mailTap];
I think the Label and the UIImageView names do explain themselves. Every Label and ImageView has set userInteractionEnabled to YES. The ShareView is also enabled for Userinteractions and I did set UIGestureRecognizerDelegate to it.
The fbTapped,mailTapped and twTapped functions do send a Notification to the Main View (the view which has the webview and the ShareView in it).
But now when I click on the labels or imageviews, nothing happendes.
I did read on stackoverflow that the UIWebView in the MainView could interrupt the recognization? But I don't know how to solve this problem.
Would be really happy If you could help me or point me into the right direction to solve this problem.
I hope this piece of code will point you to the right direction:
1.Add a gesture recognizer delegate :
#interface myclass <UIGestureRecognizerDelegate>
{
//Whatever you are doing with gestures
}
2.Implement the delegate method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
//Do your stuff
return YES;
}
check if the control reaches this delegate
I know this is really basic stuff but i need to understand whether my understanding of this is correct.
So what i want to do is this. I want an view with a label on which when double tapped flips and loads another view. On the second view i want a UIPickerView and above i have a button saying back. Both views will be of same size as an UIPickerView which is 320px x 216px.
What i am thinking of to do is create two UIViewclasses named labelView and pickerView. I would then create a viewController which on loadView loads labelView then when user double taps the labelView i get an event in labelView class which is sent to my viewController that then can unload loadView and load the pickerView.
Does this sound as the best way to do this ? Is there a simpler way ? I am also unsure how i route the event from the labelView class to the viewControllerclass.
I dont exactly know the most efficient way to do it(as i am also now to this language),but it is for sure that i have solved ur problem. I made a simple program for that.Three classes involved here in my eg are BaseViewController (which will show two views),LabelView and PickerView (according to ur requirement).
In LabelView.h
#protocol LabelViewDelegate
-(void)didTapTwiceLabelView;
#end
#interface LabelView : UIView {
id <LabelViewDelegate> delegate;
}
#property(nonatomic,retain)id <LabelViewDelegate> delegate;
-(void)didTouch;
#end
In LabelView.m
#synthesize delegate;
-(id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self)
{
UILabel* labl = [[UILabel alloc] initWithFrame:CGRectMake(10, 5, frame.size.width-20,20)];
labl.text = #"Some Text";
[self addSubview:labl];
[labl release]; labl = nil;
self.backgroundColor = [UIColor grayColor];
UITapGestureRecognizer* ges = [[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(didTouch)] autorelease];
ges.numberOfTapsRequired = 2;
[self addGestureRecognizer:ges];
}
return self;
}
-(void)didTouch
{
[delegate didTapTwiceLabelView];
}
//=============================================================
In Pickerview.h
#protocol PickerViewDelegate
-(void)didTapBackButton;
#end
#interface PickerView : UIView <UIPickerViewDelegate,UIPickerViewDataSource>{
id <PickerViewDelegate> delegate;
}
#property(nonatomic,retain)id <PickerViewDelegate> delegate;
#end
In Pickerview.m
#implementation PickerView
#synthesize delegate;
-(id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self)
{
UIPickerView* picker = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 30, 320, 216)];
picker.delegate = self;
picker.dataSource = self;
[self addSubview:picker];
[picker release]; picker = nil;
self.frame = CGRectMake(frame.origin.x, frame.origin.y, 320, 250);
UIButton* btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setFrame:CGRectMake(10, 1, 50, 27)];
[btn setTitle:#"Back" forState:UIControlStateNormal];
[btn addTarget:self action:#selector(backButton) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:btn];
}
return self;
}
-(void)backButton
{
[delegate didTapBackButton];
}
//====================================================================
in BaseViewController.h
#import "LabelView.h"
#import "PickerView.h"
#interface VarticalLabel : UIViewController<UITextFieldDelegate,PickerViewDelegate,LabelViewDelegate> {
PickerView* myPickerView;
LabelView* myLabelView;
}
#end
In BaseViewController.m
-(void)viewDidLoad
{
[super viewDidLoad];
myPickerView= [[PickerView alloc] initWithFrame:CGRectMake(0, 50, 320, 250)];
[self.view addSubview:myPickerView];
myPickerView.delegate = self;
myLabelView= [[LabelView alloc] initWithFrame:CGRectMake(0, 50, 320, 250)];
[self.view addSubview:myLabelView];
myLabelView.delegate = self;
myPickerView.hidden = YES;
}
#pragma mark PickerViewDelgate
-(void)didTapBackButton
{
myPickerView.hidden = YES;
myLabelView.hidden = NO;
}
#pragma mark LabelViewDelegate
-(void)didTapTwiceLabelView
{
myPickerView.hidden = NO;
myLabelView.hidden = YES;
}
To get events from a button to the view controller, just hook up the button's event, e.g. touch up inside, to a method in the view controller, using interface builder. (Double tapping is probably more complicated though.)
When you say 'flips', do you mean it actually shows an animation of flipping over a view to show a 'reverse' side? Like in the weather app when you hit the 'i' button? I'm assuming this is what you mean.
Perhaps check TheElements sample example on the iPhone Reference Library, it has an example of flip animation.
Btw, it's not strictly necessary to unload the loadView that is being 'hidden' when you flip -- it saves you having to construct it again when you flip back -- but it may be pertinent if you have memory use concerns, and/or the system warns you about memory being low.
Also, what do you mean by "create a UIView"? Do you mean subclass UIView, or just instantiate a UIVIew and add children view objects to it? The latter is the usual strategy. Don't subclass UIView just because you want to add some things to a UIView.
If you've got one screen of information that gives way to another screen of information, you'd normally make them separate view controllers. So in your case you'd have one view controller with the label and upon receiving the input you want, you'd switch to the view controller composed of the UIPickerView and the button.
Supposing you use Interface Builder, you would probably have a top level XIB (which the normal project templates will have provided) that defines the app delegate and contains a reference to the initial view controller in a separate XIB (also supplied). In the separate XIB you'd probably want to add another view controller by reference (so, put it in, give it the class name but indicate that its description is contained in another file) and in that view controller put in the picker view and the button.
The point of loadView, as separate from the normal class init, is to facilitate naming and linking to an instance in one XIB while having the layout defined in another. View controllers are alloced and inited when something that has a reference to them is alloced and inited. But the view is only loaded when it is going to be presented, and may be unloaded and reloaded while the app is running (though not while it is showing). Generally speaking, views will be loaded when needed and unnecessary views will be unloaded upon a low memory warning. That's all automatic, even if you don't put anything in the XIBs and just create a view programmatically within loadView or as a result of viewDidLoad.
I've made that all sound more complicated than your solution, but it's actually simpler because of the amount you can do in Interface Builder, once you're past the curve of learning it. It may actually be worth jumping straight to the Xcode 4 beta, as it shakes things up quite a lot in this area and sites have reported that a gold master was seeded at one point, so is likely to become the official thing very soon.
With respect to catching the double tap, the easiest thing is a UITapGestureRecognizer (see here). You'd do something like:
// create a tap gesture recogniser, tell it to send events to this instance
// of this class, and to send them via the 'handleGesture:' message, which
// we'll implement below...
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(handleGesture:)];
// we want double taps
tapGestureRecognizer.numberOfTapsRequired = 2;
// attach the gesture recogniser to the view we want to catch taps on
[labelView addGestureRecognizer:tapGestureRecognizer];
// we have an owning reference to the recogniser but have now given it to
// the label. We don't intend to talk to it again without being prompted,
// so should relinquish ownership
[tapGestureRecognizer release];
/* ... elsewhere ... */
// the method we've nominated to receive gesture events
- (void)handleGesture:(UIGestureRecognizer *)gestureRecognizer
{
// could check 'gestureRecognizer' against tapGestureRecognizer above if
// we set the same message for multiple recognisers
// just make sure we're getting this because the gesture occurred
if(gestureRecognizer.state == UIGestureRecognizerStateRecognized)
{
// do something to present the other view
}
}
Gesture recognisers are available as of iOS 3.2 (which was for iPad only; so iOS 4.0 on iPhone and iPod Touch).