I am using a tap gesture on my view which also has a table view as a subview. The table does scroll but when tapped, instead of calling didSelectRowAtIndexPath it calls the selector associated with the tap gesture. I can detect the tapped view by getting tap location.
I want to access didSelectRowAtIndexPath when tapped on table instead of the tap gesture selector. How do I achieve this?
Implement the tap gesture's UIGestureRecognizerDelegate , and prevent the gesture if touch is in the tableview.
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
CGPoint p = [gestureRecognizer locationInView:view] ;
if (CGRectContainsPoint(tableview.frame, p)) {
return NO ;
}
return YES ;
}
Related
I have a table view with a pan gesture on it. When I start panning the tableview up and down the tableView selection gets disable and I can't select tableview cells.
UIPanGesture* tablePanGesture =[[UIPanGestureRecognizer alloc]initWithTarget:self action:#selector(gestureHandler:)];
tablePanGesture.delegate = self;
[tableView addGestureRecognizer:tablePanGesture];
[tablePanGesture setCancelsTouchesInView:NO];
And I using the following delegate to let my gestures and tableview gestures work together:
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
I have implemented the method for table view didSelectRowAtIndexPath but when I use panning it is not called.
Is there any conflict between pan gesture and tableview Delegate?
You are missing this line:-
[tablePanGesture setCancelsTouchesInView:NO];
This will let the UIPanGesture recognize the pan gesture and also pass the touch to the next responder means your table view select or tap.
Using UIPanGestureRecognizer & UITapGestureRecognizer on top-level UIView.
The setup in Interface Builder:
ViewController (our main view controller)
UIView (our main view and wired to our UIViewController
Our core UIView has a subview called a “Block” which is simply a UIView.
The Block view has 4 subviews (children) each being an instance of a UIButton.
The UIButton has its Touch Up Inside event wired to the the UIViewController.
The UIView (our main top-level UIView) has a UIPanGestureRecognizer and a UITapGestureRecognizer
Here is the scenario we are trying to accomplish (a.k.a.The behavior):
A user taps a button (a cell).
The button will change its stated from “normal” to “selected”. (This works fine and the code is simple)
With a selected item, a user can place their finger anywhere on the screen an move it up or down
The issue:
Need to know when panning stops.
The top UIView does not receive a gesture stated of ended.
The UIView does not receive a touchesEnded event.
How do you know when the user has lifted their finger? Suppose I start the panning when my finger is over a UIButton, while panning occurs, the UIButton eats the touches begin and end events. Therefore, you have no way of knowing when the user stopped moving their finger across the iPhone/iPad glass.
First implement UIGestureRecognizerDelegate in your view controller.
Then set the delegate on your gesture recognizers to self and implement the following method
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
Your target method should look like this:
-(void)gestureRegognized:(UIGestureRecognizer*)gestureRecognizer
{
if ([gestureRecognizer isMemberOfClass:[UIPanGestureRecognizer class]])
{
//check its state
if(gestureRecognizer.state==UIGestureRecognizerStateBegan)
{
// add your code here
}
else if(gestureRecognizer.state==UIGestureRecognizerStateEnded)
{
// pan gesture ended code goes here
}
}
else if([gestureRecognizer isMemberOfClass:[UITapGestureRecognizer class]])
{
if(gestureRecognizer.state!=UIGestureRecognizerStateFailed)
{
// tap gesture detected
}
}
}
I have a UIview that contains a table view.
I want the user to be able to select items in the table view and I want to be able to identify taps in the parent view, outside the table view.
If I add a Tab Gesture Recognizer to the UIView, the user is unable to select items in the table view.
How can accomplish this task?
In this case, You've to add gesture to your view and you can cancel gesture call back method by doing if touch happen on tableview as below.
1) set TAG to your tableview . self.tableView.tag = TAG;
2) Now cancel gesture if touch on tableview as below
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
id touchView= touch.view;
if ([touchView isKindOfClass:[UITableView class]] || [touchView isKindOfClass:[UITableViewCell class]] )
{
if ( ((UIView*)touchView).tag == TAG)
return NO;
}
return YES;
}
For those how uses #IBAction method. In Interface Builder Tap Gesture Recognizer in Attributes inspector just uncheck "Cancels touches in view".
I have a small UITableView that is hidden when the view is loaded. When i click on "SHOW" UIButton, the UITableView is made visible by myTableView.hidden=NO;
I want to hide UITableView when a user touches outside its frame. Thanks for any help!
Best Approach
Simple.Before show up the UITable View add one more grayed out/Transparent view then add tap gesture recogniser on it to hide it . That's it.
Show Overlay View first - alpha will be 0.5f and background color should be clear color.
show the table view.
NOTE: over lay view should have tap recogniser which will hide the overlay and table view
in View did load
UITapGestureRecognizer *tapRecog = [[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(overlayDidTap:)];
[myOverLayView addGestureRecognizer:tapRecog];
- (void)overlayDidTap:(UITapGestureRecognizer *)gesture
{
//hide both overlay and table view here
}
Bad Approach
We should not add tap recogniser on main view itself. Because it may have lots of
controls inside of it. so when user tap on it. it will perform its operation. So to avoid
it we can simulate the same behaviour by above approach
You can get touch position by this:
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapGestureCaptured:)];
[self.view addGestureRecognizer:singleTap];
- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
CGPoint touchPoint=[gesture locationInView:self.View];
}
Then just check if the point is in tableview frame. If not then hide the tableview. Hope this help. :)
Subclass UITableView, override pointInside:withEvent:. It is templated for this reason.
Something like:
-(BOOL)pointInside:(CGPoint) point withEvent:(UIEvent*) event
{
BOOL pointIsInsideTableView = [super pointInside:point withEvent:event];
BOOL pointIsOutsideTableView = // Some test
return pointIsInsideTableView || pointIsOutsideTableView;
}
So you can catch the touch in table view implementation, where it belongs logically in this case.
I am hoping someone will be able to help me with a problem that is doing my head in at the moment!
Given the following view hierarchy
I want to be able to detect swipe gestures on my custom UITableViewCell.
I have subclassed the UIScrollView and have a hitTest:withEvent: method that checks whether I am touching the tableview cell (or its content) or not, in which case I set the following scroll view properties:
- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView* result = [super hitTest:point withEvent:event];
if ([result.superview isKindOfClass:[UITableViewCell class]] || [result.superview tag] == SUBVIEW_TAG)
{
self.canCancelContentTouches = NO;
self.delaysContentTouches = YES;
} else {
self.canCancelContentTouches = YES;
self.delaysContentTouches = NO;
}
return result;
}
I have also implemented:
- (BOOL)touchesShouldCancelInContentView:(UIView *)view
{
if (view.tag == SUBVIEW_TAG || [[view superview] isKindOfClass:[UITableViewCell class]])
return NO;
return YES;
}
And am returning NO in case the view being touched is the table view cell.
These methods are all getting called and performing their actions as expected, but I am still unable to stop the UIScrollView from "hogging" the swipe gesture.
The interesting thing is that if I include the UIView that contains the tableview and cell on both of the methods above (the one with SUBVIEW_TAG) it works perfectly so I am guessing it must be something to do with the fact that UITableView inherits from UIScrollView.
My main goal is to be able to swipe on the cell to reveal more options for the cell. A horizontal swipe anywhere else on that view would be captured by the scroll view and shift the content horizontally as per its normal behaviour.
Any ideas would be very much appreciated!
Thanks!
Rog
I had a similar problem with a swipe detect for a component inside a scrollview and I was able to resolve it with
[scrollView.panGestureRecognizer requireGestureRecognizerToFail:swipeGesture]
Where scrollView is the scroll view object that acts like container and swipeGesture is the component swipe gesture object inside scrollview.
So, you can define a swipe for the cell object like this (for right swipe in the example, custom it as you want)
UISwipeGestureRecognizer* rightSwipeRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(yourMethod)];
[rightSwipeRecognizer setDirection:UISwipeGestureRecognizerDirectionLeft];
[cell addGestureRecognizer:rightSwipeRecognizer];
and then do
[scrollView.panGestureRecognizer requireGestureRecognizerToFail:rightSwipeRecognizer]
The documentation of requireGestureRecognizerToFail says:
This method creates a relationship with another gesture recognizer
that delays the receiver’s transition out of
UIGestureRecognizerStatePossible. The state that the receiver
transitions to depends on what happens with otherGestureRecognizer:
If otherGestureRecognizer transitions to
UIGestureRecognizerStateFailed, the receiver transitions to its normal
next state.
if otherGestureRecognizer transitions to
UIGestureRecognizerStateRecognized or UIGestureRecognizerStateBegan,
the receiver transitions to UIGestureRecognizerStateFailed.
An example where this method might be called is when you want a
single-tap gesture require that a double-tap gesture fail.
Availability Available in iOS 3.2 and later.
Hope helps!
The solution is pretty simple. All you need to do is add UIScrollView inside you UITableViewCell. It will prevent "hogging" effect during swipe gesture.