I have multiple Views inside a ViewController and I want to know when a view is tapped on and I'm not sure how to go about it
In order to check whether certain view inside another view was touched you can use hitTest.
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event;
In your custom implementation of touchesBegan check every touch in touches set. The point for hitTest method can be obtained using
- (CGPoint)locationInView:(UIView *)view;
method, where the view is your superView (the one that contains other views).
EDIT: Here's a fast custom implementation:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint locationPoint = [[touches anyObject] locationInView:self];
UIView* viewYouWishToObtain = [self hitTest:locationPoint withEvent:event];
}
I hope this was helpful, Paul
Sources : Detect if certain UIView was touched amongst other UIViews
Related
I have 3 UIViews of the same size stacked on top of each other. The topmost is transparent and only used for detecting touches. The type of touch detected will determine which of the other two underlying views I want to receive the touch events. Once the topmost view is finished with the touch, I need to forward the touch events to the correct underlying view. How can I do that?
EDIT - I am adding my touch detection code. This is within MainViewController, whose view contains all 3 subviews.
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
for (UITouch *touch in touches)
{
if (touch.view == self.touchOverlay) {
CGPoint touchLocation = [touch locationInView:touch.view];
//do a bunch of math to determine which view should get the touches.
if (viewAshouldGetTouches) //forward to viewA
if (viewBshouldGetTouches) //forward to viewB
}
}
}
Make your two subviews setUserInteractionEnabled:NO and handle all touches in the parent. Then, depending on touch type, send the correct view a programatic touch event. Then you don't need your clear view on the top. Basically you will be coordinating touch events from the bottom up instead of going top->bottom->middle.
You'll have to do this by creating a UIView subclass for your top view and overriding the following method :
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
// UIView will be "transparent" for touch events if we return NO
return (point.y < MIDDLE_Y1 || point.y > MIDDLE_Y2);
}
I'm working on iPad app. My UIViewController contains only a custom UIView with a size of 500wx500h.
I implemented the touches methods both in the UIViewController and the custom UIView in order to call the UIViewController touches methods when we touch all around the custom UIView and call the custom UIView touches methods when we touch inside it.
UIViewController touchesMoved :
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:self.view];
NSLog(#"TEST"); // Added during edition
if (!CGRectContainsPoint(self.drawingView.frame, point)) {
NSLog(#"UIVIEWCONTROLLER");
}
}
Custom UIView touches Moved :
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"CUSTOM VIEW");
}
When I'm touching the custom UIView moving my finger, CUSTOM VIEW is logged until I removed the finger on the screen. On the other hand, when I'm touching outside of the custom UIView, the UIVIEWCONTROLLER is called only one time in the touchesMoved method.
Am I missing something wrong ?
EDIT : I added a log in my UIViewController touchesMoved method. When I touch inside the custom view, it logs the TEST during all the touching phase. But when I touch outside, I get the same behaviour.
add exclusiveTouch property to your view to disable multi touches
your view.exclusiveTouch=YES;
There is some likeliness that your self.view is intercepting touches and handling them, so they will not make it through to the view controller. You could try doing either of 2 things (or both) and see if it works:
self.view.exclusiveTouch = NO;
self.view.userInteractionEnabled = NO;
I would also try to call [super touchesMoved: touches withEvent: event];
Hope it helps.
I have a static UITableView that contains a number of UITextFields. When the user taps outside of any of the text fields I'd like to I'd like to dismiss the keyboard.
At the top level of my UIViewController is a UITableView and a UITabBarItem. I believe I'll also have to handle taps on the status bar.
I am unsure as how I should register for touches on them (so that I can force any of the text fields to call resignFirstResponder.
I thought I might have to handle UIResponder's
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
for the table view and tab bar item but neither of them are UIControls so I can't use
- (void)addTarget:(id)target action:(SEL)action forControlEvents:(UIControlEvents)controlEvents
UIWindow is also a UIResponder but again, I can't seem to get touch events for it.
Any help would be much appreciated,
CS
If you had one text field I'd add touches began into the UIViewController it belongs to and do it like this...
- (void)touchesBegan ... cant remember full name
{
if ([touches count] > 1) {
return;
}
UITouch *touch = [touches anyObject];
CGPoint touchPoint = [touch locationInView self.view];
if (!CGRectContainsPoint(self.textField.frame, touchPoint)) {
//touch originated outside textField.
[textField resignFirstResponder];
}
}
If you have more than one text field then just do the CGRectContainsPoint check for each of them inside the if.
When you have a static UITableView it "eats" the touch events. So what I did was by subclassing UITableView and then added a delegate which reports touch events.
I'm trying to distinguish between horizontal swiping / panning and
vertical scrolling in a UITableView. The behavior I'm looking to
imitate (in a sense) is that of the Twitter iPad app, that has
multiple UITableView that can be moved horizontally on the screen. If
I slide my finger left or right on one of these UITableView, the view
itself moves horizontally. If I swipe vertically, the view scrolls as
expected.
I'm having trouble figuring out the correct way to implement this
behavior. I've seen some tutorials on this which involve adding touch
event handlers in the UITableViewCells, and overriding hitTest in the
UITableViewto appropriately route events depending on which direction
the gesture is moving. I've implemented some of these techniques, but
none of them work particularly well.
Does anyone know the correct way to implement this sort of behavior?
Conditionally performing actions on a UITableViewdependent on the
direction of the user's finger movement?
Thanks.
I've been struggling with a similar problem for days, and I've went through several potential solutions. I've found the best way and also the simplest solution to be subclassing UIGestureRecognizer to handle horizontal movement and attach it to your UITableViews.
The way it works is that it intercepts any touch events before they go to the UITableView (also UIScrollView). The UITableView, being a subclass of UIScrollView, has a custom UIPanGestureRecognizer built in which detects dragging and scrolls it's view accordingly. By adding your own subclass of UIGestureRecognizer, you can get the touches before the UIScrollView's gesture recognizer does. If your recognizer sees that the user is dragging horizontally, it should change it's state in an overridden touchesMoved: method to UIGestureRecognizerStateBegan. Otherwise, it sets it's state to UIGestureRecognizerCancelled, which lets the underlying UIScrollView handle the touches instead.
Here's what my UIGestureRecognizer subclass looks like:
#import <UIKit/UIGestureRecognizerSubclass.h>
#interface TableViewCellPanGestureRecognizer : UIGestureRecognizer
{
CGPoint startTouchPoint;
CGPoint currentTouchPoint;
BOOL isPanningHorizontally;
}
- (void)reset;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;
#end
#implementation TableViewCellPanGestureRecognizer
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
startTouchPoint = [[touches anyObject] locationInView:nil];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesMoved:touches withEvent:event];
currentTouchPoint = [[touches anyObject] locationInView:nil];
if ( !isPanningHorizontally ) {
float touchSlope = fabsf((currentTouchPoint.y - startTouchPoint.y) / (currentTouchPoint.x - startTouchPoint.x));
if ( touchSlope < 1 ) {
self.state = UIGestureRecognizerStateBegan;
isPanningHorizontally = YES;
[self.view touchesCancelled:touches withEvent:event];
} else {
self.state = UIGestureRecognizerStateCancelled;
[self.view touchesCancelled:touches withEvent:event];
}
} else {
self.state = UIGestureRecognizerStateChanged;
}
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesCancelled:touches withEvent:event];
self.state = UIGestureRecognizerStateCancelled;
[self.view touchesCancelled:touches withEvent:event];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesEnded:touches withEvent:event];
self.state = UIGestureRecognizerStateCancelled;
}
-(void)reset
{
[super reset];
startTouchPoint = CGPointZero;
currentTouchPoint = CGPointZero;
isPanningHorizontally = NO;
}
#end
Then I have a subclassed UITableView that attaches the recognizer to itself and implements an action method to trigger horizontal movement of individual rows:
In my UITableView init:
horizontalPanGesture = [[TableViewCellPanGestureRecognizer alloc] initWithTarget:self action:#selector(handleHorizontalDrag:)];
[self addGestureRecognizer:horizontalPanGesture];
[horizontalPanGesture release];
And the action method:
-(void)handleHorizontalDrag:(UIGestureRecognizer *)gesture
{
UIGestureRecognizerState state = gesture.state;
// Set the touched cell
if (!touchedCell){
NSIndexPath *indexPathAtHitPoint = [self indexPathForRowAtPoint:[gesture locationInView:self]];
id cell = [self cellForRowAtIndexPath:indexPathAtHitPoint];
touchedCell = cell;
startTouchPoint = [gesture locationInView:touchedCell];
}
if ( state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged ) {
// move your views horizontally
} else if ( state == UIGestureRecognizerStateEnded || state == UIGestureRecognizerStateCancelled ) {
touchedCell = nil;
}
}
The above gets the current cell being touched within the table view, and then applies horizontal movements to it as the user drags left or right. However, if my gesture recognizer determines that the touches are meant to scroll vertically, it just cancels itself and the following touches are sent on to the UITableView to initiate vertical scrolling automatically.
This setup seems to be much simpler than overriding hitTest and doing all sorts of touch event trickery within the UITableView itself. It simply makes an immediate determination about the direction of the touch movement. You'll want to read up on UIGestureRecognizers - specifically about how it should be subclassed. You need to make sure to forward on certain touch events like touchesCancelled to the UITableView, as the UITableView's built in panGestureRecognizer won't be handling these events as it normally does. Obviously, you'll want to move entire table views and not individual cells, but it should be pretty straightforward.
This solution, as simple as it is, took me awhile to get exactly right for my exact needs. I am pretty new to IOS development, so I had to spend a lot of time reading about and tinkering with gesture recognizers and scroll views to figure this out.
I have never done this myself, but as a UITableView is a subclass of UIScrollView, the delegates of UITableView are also UIScrollViewDelegates. So in your UITableViewController subclass, you should be able to use UIScrollView delegates, and intercept the scrolls - making sure to also call the super method.
If you want the UITableViews to be placed "side by side" and when you swipe horizontally you expect them to all move together horizontally at the same time, (like a photo gallery with UITableViews instead of images) you can do the following:
Use a UIScrollView and add the UITableViews as the UIScrollView's subviews. You should set the scrollview's contentSize like this:
CGRect bounds = scrollView.bounds;
scrollView.contentSize=CGSizeMake(bounds.size.width * kNumOfTableViews, bounds.size.height);
so that the UIScrollview scrolls horizontally and not vertically.
You may also want to use
scrollView.pagingEnabled=YES;
depending on the desirable behaviour.
The UITableviews will respond the normal way if you slide your finger vertically and you will be able to change between UITableViews by sliding your finger horizontally.
For more details about how to do this efficiently, you can look at the WWDC 2010 video Session 104 - Designing Apps with Scroll Views and check out the source code from here: http://developer.apple.com/library/ios/#samplecode/PhotoScroller/ . This session describes how to slide between images. Instead of images you will use UITableViews
However, if you want each UITableView to be able to move horizontally independently and maybe overlap with another one as in the twitter app for iPad, this solution will not work for you, at least not out of the box.
Does anyone have any sample code for detecting touches on a dynamically created UIView? I have found some references to touchesBegan but cannot figure out how to implement it...
A very general way to get touches is to override these methods in a custom UIView subclass:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
The official docs for these methods is under Responding to Touch Events in the UIResponder class docs (UIView inherits those methods since it's a subclass of UIResponder). Longer and more introductory docs can be found in the Event Handling Guide for iOS.
If you just want to detect a tap (touch-down, then touch-up within your view), it's easiest to add a UIButton as a subview of your view, and add your own custom method as a target/action pair for that button. Custom buttons are invisible by default, so it wouldn't affect the look of your view.
If you're looking for more advanced interactions, it's also good to know about the UIGestureRecognizer class.
Create touch event with UIAnimation on UIView , you can manage touches on UIView anywhere .
Following Code : here self.finalScore is a UIView , and cup is a UIImageView . I handle
the touch event on UIImageView , it present inside the UIView .
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch1 = [touches anyObject];
CGPoint touchLocation = [touch1 locationInView:self.finalScore];
CGRect startRect = [[[cup layer] presentationLayer] frame];
CGRectContainsPoint(startRect, touchLocation);
[UIView animateWithDuration:0.7
delay:0.0
options:UIViewAnimationCurveEaseOut
animations:^{cup.transform = CGAffineTransformMakeScale(1.25, 0.75);}
completion:^(BOOL finished) {
[UIView animateWithDuration:2.0
delay:2.0
options:0
animations:^{cup.alpha = 0.0;}
completion:^(BOOL finished) {
[cup removeFromSuperview];
cup = nil;}];
}];
}
Like UITapGestureRecognizer is another way of handle the touch events on UIView ....
UITapGestureRecognizer *touchOnView = [[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(releaseButAction)] autorelease];
// Set required taps and number of touches
[touchOnView setNumberOfTapsRequired:1];
[touchOnView setNumberOfTouchesRequired:1];
// Add the gesture to the view
[[self view] addGestureRecognizer:touchOnView];
Create your own custom UIView from a subclass you created by inheriting UIView and override the following method inside the sub-class,
(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
}
With gesture recognizer, it is much easy to catch touch events.
Find one guested from component library in storyboard:
For example, drag Tap Gesture Recognizer to your view. It is not shown in the view UI. You can find it from Document outline in the left panel in Storyboard:
The final step is to link it (by control-drag) to the view as delegate where touch is monitored, and control-drag to your view controller class as an action. Here is the picture of link connections.
and action code:
#IBAction func tapAction(_ sender: Any) {
// touch is captured here.
}
Instead of capturing touch using gesture, I would suggest to change UIView parent class to UIControl, so that it can handle touchUpInside event
From:
#interface MyView : UIView
To:
#interface MyView : UIControl
and then add this line for view-
[self addTarget:self action:#selector(viewTapped:) forControlEvents:UIControlEventTouchUpInside];
Because gesture may create problem while scrolling.
My method is simply change the UIView to UIControl class in InterfaceBuilder IdentityInspector, then the ConnectionsInspector will instantly have the touch event ready for hook.
zero code changes.