iPhone: Combining MKMapView with another UITapGestureRecognizer - iphone

i am trying to implement my own gesture recognizer in addition to the one already used by the MKMapView. Right now i can tap on the map and set a pin. This behavior is realized by my UITapGestureRecognizer. When i tap on a pin that already exists, my gesture recognizer does nothing, but instead the callout bubble of this pin is shown. The UIGestureRecognizerDelegate looks like this:
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if (gestureRecognizer == self.tapRecognizer)
{
bool hitAnnotation = false;
int count = [self.mapView.annotations count];
int counter = 0;
while (counter < count && hitAnnotation == false )
{
if (touch.view == [self.mapView viewForAnnotation:[self.mapView.annotations objectAtIndex:counter]])
{
hitAnnotation = true;
}
counter++;
}
if (hitAnnotation)
{
return NO;
}
}
return YES;
}
This works fine. My only problem are the callout bubbles of the pins and the double tap. Normally the double tap is used for zooming in. This still works but in addition to this, i also get a new pin. Is there any way to avoid this?
The other problem occurs with the callout bubble of a pin. I can open the bubble by tapping on the pin without setting a new pin at this place (see code above) but when i want to close the bubble by tapping on it, another pin is set. My problem is, that i cannot check with touch.view , if the user tapped on a callout bubble, because it is not a regular UIView as far as i know. Any ideas or workarounds for this problem?
Thanks

I had the same problem as your first problem: distinguishing double taps from single taps in an MKMapView. What I did was the following:
[doubleTapper release];
doubleTapper = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(mapDoubleTapped:)];
doubleTapper.numberOfTapsRequired = 2;
doubleTapper.delaysTouchesBegan = NO;
doubleTapper.delaysTouchesEnded = NO;
doubleTapper.cancelsTouchesInView = NO;
doubleTapper.delegate = self;
[mapTapper release];
mapTapper = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(mapTapped:)];
mapTapper.numberOfTapsRequired = 1;
mapTapper.delaysTouchesBegan = NO;
mapTapper.delaysTouchesEnded = NO;
mapTapper.cancelsTouchesInView = NO;
[mapTapper requireGestureRecognizerToFail:doubleTapper];
and then implemented the following delegate method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
Using requireGestureRecognizerToFail: allows the app to distinguish single taps from double taps and implementing gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer: ensures that double taps are still forwarded to the MKMapView so that it continues zooming normally. Note that doubleTapper doesn't actually do anything (in my case, except log debug messages). It's simply a dummy UIGestureRecognizer that's used to help separate single taps from double taps.

Related

Tap Gesture + Long Press Gesture both not working Together

I want use tap gesture and long press gesture together in a view. But my problem is that I can't able to run tap gesture action on tap. But Long press gesture is working fine.
Here is code snippet.
UILongPressGestureRecognizer *longPressGesture=[[UILongPressGestureRecognizer alloc]initWithTarget:self action:#selector(ontappLongPressGesture:)];
longPressGesture.minimumPressDuration=0.6;
longPressGesture.delegate=self;
[cell.view addGestureRecognizer:longPressGesture];
UITapGestureRecognizer *gesture=[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(cellSelected:)];
//[gesture requireGestureRecognizerToFail:longPressGesture]; //I have tried with this line also but not working
gesture.delegate=self;
[cell.view addGestureRecognizer:gesture];
Also I have set delegate method also
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
This method is getting called on long press
- (void)ontappLongPressGesture:(id)sender{
//Long press code here
}
But this method is not getting called on tap
-(void)cellSelected:(id)sender {
//Single tap code here
}
You haven't specified what type of view your putting these gestureRecognizer's on, however since you are calling it "cell", I'm assuming its on a UITableView?
You need to make sure you set the cancelsTouchesInView flag if so:
gesture.cancelsTouchesInView=NO;
You either need to use one of these two ways.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
// test if our control subview is on-screen
if (cell.view.superview != nil) {
if ([touch.view isDescendantOfView:cell.view]) {
// we touched our control surface
return YES; // handle the touch
}
}
return NO; // ignore the touch
}
Here you need to specify the view for which you want the gestureRecognizer.
Or you can also use these lines of code
gesture.cancelsTouchesInView = NO;
longPressGesture.cancelsTouchesInView = NO;
Hope it will help you.

Stopping a UIGestureRecognizer from calling selector

I'm adding in a few UIGestureRecognizers with a target and selector. I'll just talk about one since the other will be the same i'm sure.
I've added a UIPinchGestureRecognizer
UIPinchGestureRecognizer *pinch = [UIPinchGestureRecognizer new];
[pinch addTarget:self action:#selector(pinchGestureDetected:)];
[self.view setMultipleTouchEnabled:YES];
[self.view addGestureRecognizer:pinch];
Now my goal here is to simply call this method once when I receive a pinch gesture. But obvoiusly it continues to call it as the person pinches. I'm using it as part of a page navigation and will be updating the view when a pinch in is detected.
So in my -(void)pinchGestureDetected:(UIPinchGestureRecognizer)pinch method I'll be calling another method. Kinda like ... and this is a little sudo
-(void)pinchGestureDetected:(UIPinchGestureRecognizer)pinch
{
if (pinch.scale > 1) layoutViewWithMoreDetail;
else layoutViewWithLessDetail;
}
So I don't want it to keep calling this method or the layout method will continue to be called. I want one layout / pinch gesture.
Is there a way I can stop detecting the pinch once it has determined the scale?? Something along the way of ...
-(void)pinchGestureDetected:(UIPinchGestureRecognizer)pinch
{
if (pinch.scale > 1)
{
layoutViewWithMoreDetail;
stop receiving pinch gestures till this.gesture is finished;
}
Would I impliment the GestureDelegate??
-(void)pinchGestureDetected:(UIPinchGestureRecognizer)pinch
{
if (pinch.scale > 1 && pinching == NO )
{
layoutViewWithMoreDetail;
pinching = YES;
}
and then in the delegate for Gesture ended ... pinching = NO;
Thanks for any help
UPinchGestureRecognizer is a continuous gesture - use if(pinch.state == UIGestureRecognizerStateBegan) to detect whether or not the event is just now starting.
However, this results in a low threshold for triggering the event. An alternate method is to quicky disable and enable a gesture when it has been triggered to your satisfaction, like so:
-(void)pinchGestureDetected:(UIPinchGestureRecognizer)pinch
{
if (pinch.scale > 1)
{
//do your stuff here
pinch.enabled = NO;
pinch.enabled = YES;
}
}
This is because if you look at the documentation, it states:
enabled
A Boolean property that indicates whether the gesture recognizer is enabled.
#property(nonatomic, getter=isEnabled) BOOL enabled
Discussion
Disables a gesture recognizers so it does not receive touches. The default value is YES. If you change this property to NO while a gesture recognizer is currently recognizing a gesture, the gesture recognizer transitions to a cancelled state.

handle taps in two different points at a same time via UIGestureRecognizer

I have two labels in two different positions, when both labels are tapped at the same time i want another label to show a success message.
How do I accomplish this? I can recognize a single tap or double tap with one or more finger touches but this is a different scenario. Please help. I tried this, but it does not work.
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
tapRecognizer.numberOfTapsRequired = 1;
tapRecognizer.numberOfTouchesRequired = 2;
tapRecognizer.delegate = self;
[self.view addGestureRecognizer:tapRecognizer];
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if (touch.view == tap2 && touch.view == tap1)
{
result.text = #"success";
}
return YES;
}
Thanks in advance.
What you're trying to detect isn't really a single gesture.
I'd suggest adding a tap gesture recogniser to each button. The handler would:
Store the time of the tap (at the moment that the handler is called)
Compare this time with the time that the other button was last
tapped. If the times are very similar (perhaps 0.25 secs apart),
consider that they've both been tapped simultaneously and react
accordingly.
Play with the time interval on a real device to find the ideal amount.
UPDATE:
A code snippet that obviously hasn't been tested in any way:
- (void)handleButton1Tap:(UITapGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateEnded)
{
self.button1TapTime = CACurrentMediaTime();
[self testForSimultaneousTap];
}
}
- (void)handleButton2Tap:(UITapGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateEnded)
{
self.button2TapTime = CACurrentMediaTime();
[self testForSimultaneousTap];
}
}
- (void)testForSimultaneousTap
{
if (fabs(self.button1TapTime - self.button2TapTime) <= 0.2)
{
// Do stuff
}
}
where self.button1TapTime and self.button2TapTime are member variables (doubles).
Tim
Formally I had accepted termes's answer first and that worked too, but I have found a more simpler solution to this process. There is no need for two gesture recognizers, it is achievable with a simple tap gesture recognizer with number of touches count to two. Here is the code:
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
tapRecognizer.numberOfTapsRequired = 1;
tapRecognizer.numberOfTouchesRequired = 2;
tapRecognizer.delegate = self;
[self addGestureRecognizer:tapRecognizer];
Now, in the handle tap method we can easily get the two touch points by "locationOfTouch:inView:", a instance method of UIGestureRecognizer class. So in the handleTap: method we need to check if the two touch points are in the desired location. Here is the code:
-(void)handleTap:(UITapGestureRecognizer*)recognizer
{
if (recognizer.state == UIGestureRecognizerStateEnded)
{
CGPoint point1 = [recognizer locationOfTouch:0 self];
CGPoint point2 = [recognizer locationOfTouch:1 self];
if ([self validateTapIn:point1 and:point2])
{
resultLabel.text = #"success";
}
}
}
-(BOOL)validateTapIn:(CGPoint)point1 and:(CGPoint)point2
{
return
(CGRectContainsPoint(label1.frame, point1) && CGRectContainsPoint(label2.frame,:point2)) ||
(CGRectContainsPoint(label1.frame, point2) && CGRectContainsPoint(label2.frame, point1));
}

How to intercept long press on UITextView?

Total Objective-C / Cocoa Touch noob here, beware.
I'm trying to intercept when a user long presses on a UITextView (a magnifying glass then appears with the caret positioner) and then releases the touch, i.e. when normally the "Select" and "Select All" Options appear, after the magnifying glass. I want to replace this with my own custom action that is then performed.
Is this possible?
You can try something like this:
Disable the built-in long press recognizer
for (UIGestureRecognizer *recognizer in textView.gestureRecognizers) {
if ([recognizer isKindOfClass:[UILongPressGestureRecognizer class]]){
recognizer.enabled = NO;
}
}
Then add your own
UILongPressGestureRecognizer *myLongPressRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:<your target> action:#selector(<your custom handler>)];
[textView addGestureRecognizer:myLongPressRecognizer];
[myLongPressRecognizer release];
Swift version of #Altealice's code to disable the built-in long press recognizer:
if let actualRecognizers = self.sourcesTextView.gestureRecognizers {
for recognizer in actualRecognizers {
if recognizer.isKindOfClass(UILongPressGestureRecognizer) {
recognizer.enabled = false
}
}
}
This solution works but beware that it's gonna disable the textView interactions, so the links won't be highlighted when pressed and the text won't be selectable.
if you remove the [LongPressgesture setMinimumPressDuration:2.0]; it will work .. since the tab gesture will be called to start edit the textField ... or just implement this gesture delegate function
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}

How to disable multitouch?

My app has several buttons which trigger different events. The user should NOT be able to hold down several buttons. Anyhow, holding down several buttons crashes the app.
And so, I'm trying to disable multi-touch in my app.
I've unchecked 'Multiple Touch' in all the xib files, and as far as I can work out, the properties 'multipleTouchEnabled' and 'exclusiveTouch' control whether the view uses multitouch. So in my applicationDidFinishLaunching I've put this:
self.mainViewController.view.multipleTouchEnabled = NO;
self.mainViewController.view.exclusiveTouch = YES;
And in each of my view controllers I've put this in the viewDidLoad
self.view.multipleTouchEnabled = NO;
self.view.exclusiveTouch = YES;
However, it still accepts multiple touches. I could do something like disable other buttons after getting a touch down event, but this would be an ugly hack. Surely there is a way to properly disable multi-touch?
If you want only one button to respond to touches at a time, you need to set exclusiveTouch for that button, rather than for the parent view. Alternatively, you could disable the other buttons when a button gets the "Touch Down" event.
Here's an example of the latter, which worked better in my testing. Setting exclusiveTouch for the buttons kind-of worked, but led to some interesting problems when you moved your finger off the edge of a button, rather than just clicking it.
You need to have outlets in your controller hooked up to each button, and have the "Touch Down", "Touch Up Inside", and "Touch Up Outside" events hooked to the proper methods in your controller.
#import "multibuttonsViewController.h"
#implementation multibuttonsViewController
// hook this up to "Touch Down" for each button
- (IBAction) pressed: (id) sender
{
if (sender == one)
{
two.enabled = false;
three.enabled = false;
[label setText: #"One"]; // or whatever you want to do
}
else if (sender == two)
{
one.enabled = false;
three.enabled = false;
[label setText: #"Two"]; // or whatever you want to do
}
else
{
one.enabled = false;
two.enabled = false;
[label setText: #"Three"]; // or whatever you want to do
}
}
// hook this up to "Touch Up Inside" and "Touch Up Outside"
- (IBAction) released: (id) sender
{
one.enabled = true;
two.enabled = true;
three.enabled = true;
}
#end
- (void)viewDidLoad {
[super viewDidLoad];
for(UIView* v in self.view.subviews)
{
if([v isKindOfClass:[UIButton class]])
{
UIButton* btn = (UIButton*)v;
[btn setExclusiveTouch:YES];
}
}
}
- (void)viewDidLoad {
[super viewDidLoad];
for(UIView* v in self.view.subviews)
{
if([v isKindOfClass:[UIButton class]])
{
UIButton* btn = (UIButton*)v;
[btn setExclusiveTouch:YES];
}
}
}
This code is tested and working perfectly for me.there is no app crash when pressing more than one button at a time.
Your app crashes for a reason. Investigate further, use the debugger, see what's wrong instead of trying to hide the bug.
Edit:
OK, ok, I have to admit I was a bit harsh. You have to set the exclusiveTouch property on each button. That's all. The multipleTouchEnabled property is irrelevant.
To disable multitouch in SWIFT:
You need first to have an outlet of every button and afterwards just set the exclusive touch to true.Therefore in you viewDidLoad() would have:
yourButton.exclusiveTouch = true.
// not really necessary but you could also add:
self.view.multipleTouchEnabled = false
If you want to disable multi touch throughout the application and don't want to write code for each button then you can simply use Appearance of button. Write below line in didFinishLaunchingWithOptions.
UIButton.appearance().isExclusiveTouch = true
Thats great!! UIAppearance
You can even use it for any of UIView class so if you want to disable multi touch for few buttons. Make a CustomClass of button and then
CustomButton.appearance().isExclusiveTouch = true
There is one more advantage which can help you. In case you want to disable multi touch of buttons in a particular ViewController
UIButton.appearance(whenContainedInInstancesOf: [ViewController2.self]).isExclusiveTouch = true
Based on neoevoke's answer, only improving it a bit so that it also checks subviews' children, I created this function and added it to my utils file:
// Set exclusive touch to all children
+ (void)setExclusiveTouchToChildrenOf:(NSArray *)subviews
{
for (UIView *v in subviews) {
[self setExclusiveTouchToChildrenOf:v.subviews];
if ([v isKindOfClass:[UIButton class]]) {
UIButton *btn = (UIButton *)v;
[btn setExclusiveTouch:YES];
}
}
}
Then, a simple call to:
[Utils setExclusiveTouchToChildrenOf:self.view.subviews];
... will do the trick.
This is quite often issue being reported by our testers. One of the approach that I'm using sometimes, although it should be used consciously, is to create category for UIView, like this one:
#implementation UIView (ExclusiveTouch)
- (BOOL)isExclusiveTouch
{
return YES;
}
Pretty much simple you can use make use of ExclusiveTouch property in this case
[youBtn setExclusiveTouch:YES];
This is a Boolean value that indicates whether the receiver handles touch events exclusively.
Setting this property to YES causes the receiver to block the delivery of touch events to other views in the same window. The default value of this property is NO.
For disabling global multitouch in Xamarin.iOS
Copy&Paste the code below:
[DllImport(ObjCRuntime.Constants.ObjectiveCLibrary, EntryPoint = "objc_msgSend")]
internal extern static IntPtr IntPtr_objc_msgSend(IntPtr receiver, IntPtr selector, bool isExclusiveTouch);
static void SetExclusiveTouch(bool isExclusiveTouch)
{
var selector = new ObjCRuntime.Selector("setExclusiveTouch:");
IntPtr_objc_msgSend(UIView.Appearance.Handle, selector.Handle, isExclusiveTouch);
}
And set it on AppDelegate:
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
...
SetExclusiveTouch(true); // setting exlusive to true disables the multitouch
...
}
My experience is that, by default, a new project doesn't even allow multitouch, you have to turn it on. But I suppose that depends on how you got started. Did you use a mutlitouch example as a template?
First of all, are you absolutely sure multitouch is on? It's possible to generate single touches in sequence pretty quickly. Multitouch is more about what you do with two or more fingers once they are on the surface. Perhaps you have single touch on but aren't correctly dealing with what happens if two buttons are pressed at nearly the same time.
I've just had exactly this problem.
The solution we came up with was simply to inherit a new class from UIButton that overrides the initWithCoder method, and use that where we needed one button push at a time (ie. everywhere):
#implementation ExclusiveButton
(id)initWithCoder: (NSCoder*)decoder
{
[self setExclusiveTouch:YES];
return [super initWithCoder:decoder]
}
#end
Note that this only works with buttons loaded from nib files.
I created UIView Class Extension and added this two functions. and when i want to disable view touch i just call [view makeExclusiveTouch];
- (void) makeExclusiveTouchForViews:(NSArray*)views {
for (UIView * view in views) {
[view makeExclusiveTouch];
}
}
- (void) makeExclusiveTouch {
self.multipleTouchEnabled = NO;
self.exclusiveTouch = YES;
[self makeExclusiveTouchForViews:self.subviews];
}
If you want to disable multitouch programmatically, or if you are using cocos2d (no multipleTouchEnabled option), you can use the following code on your ccTouches delegate:
- (BOOL)ccTouchesBegan:(NSSet *)touches
withEvent:(UIEvent *)event {
NSSet *multiTouch = [event allTouches];
if( [multiTouch count] > 1) {
return;
}
else {
//else your rest of the code
}
Disable all the buttons on view in "Touch Down" event and enable them in "Touch Up Inside" event.
for example
- (void) handleTouchDown {
for (UIButton *btn in views) {
btn.enable = NO;
}
}
- (void) handleTouchUpInside {
for (UIButton *btn in views) {
btn.enable = Yes;
}
------
------
}
I decided this problem by this way:
NSTimeInterval intervalButtonPressed;
- (IBAction)buttonPicturePressed:(id)sender{
if (([[NSDate date] timeIntervalSince1970] - intervalButtonPressed) > 0.1f) {
intervalButtonPressed = [[NSDate date] timeIntervalSince1970];
//your code for button
}
}
I had struggled with some odd cases when dragging objects around a view, where if you touched another object at the same time it would fire the touchesBegan method. My work-around was to disable user interaction for the parent view until touchesEnded or touchesCancelled is called.
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
// whatever setup you need
self.view.userInteractionEnabled = false
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
// whatever setup you need
self.view.userInteractionEnabled = true
}
override func touchesCancelled(touches: Set<UITouch>?, withEvent event: UIEvent?) {
// whatever setup you need
self.view.userInteractionEnabled = true
}
A Gotcha:
If you are using isExclusiveTouch, be aware that overriding point(inside:) on the button can interfere, effectively making isExclusiveTouch useless.
(Sometimes you need to override point(inside:) for handling the "button not responsive at bottom of iPhone screen" bug/misfeature (which is caused by Apple installing swipe GestureRecognizers at the bottom of the screen, interfering with button highlighting.)
See: UIButton fails to properly register touch in bottom region of iPhone screen
Just set all relevant UIView's property exclusiveTouch to false do the trick.