I have a horizontal scrolling UICollectionView with UICollectionViewCells that contain a UITextView. Is there any way to pass gestures on the textview to the cells, so that didSelectItemAtIndexPath gets called?.
I tried it with subclassing UITextView and passing touchesbegin/end to the cell, but that didn't worked.
You can make the view non-interactive, which will cause touches to get passed through:
textView.userInteractionEnabled = NO;
If you need it to be interactive, you can try this:
textView.editable = NO;
UITapGestureRecognizer* tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapped)];
[textView addGestureRecognizer:tap];
... and then add this function to your UICollectionViewCell subclass:
-(void) tapped {
UICollectionView *collectionView = (UICollectionView*)self.superview;
NSIndexPath *indexPath = [collectionView indexPathForCell:self];
[collectionView.delegate collectionView:collectionView didSelectItemAtIndexPath:indexPath];
}
I haven't tested it though...
Well, if your cell is the superview of the text view, you could implement something like this in the UITextViewDelegate method textViewDidBeginEditing:.
- (void)textViewDidBeginEditing:(UITextView *)textView {
NSIndexPath *indexPath = [self.collectionView indexPathForCell:(UICollectionViewCell *)textView.superview];
[self.collectionView selectItemAtIndexPath:indexPath animated:YES scrollPosition:UICollectionViewScrollPositionTop];
}
This doesn't seem to work in iOS6.x: the all view in a UICollectionViewCell seem to be embedded in a UIView that is the first child of the cell. In order to get the actual cell that is the UITextView is in you will need to dereference a second time. In other words the order is (from bottom to top):
UITextView->enclosingUIView->UICollectionViewCell
Related
I have a collection view, and inside the collection view cell, I have a scrollView in which I want to display some pictures.
I placed a ScrollView inside my collectionviewcell in the storyboard and initialised the ScrollView inside my -collectionView:cellForItemAtIndexPath method as follows:
UIScrollView *scrollView = [cell viewWithTag:20];
scrollView.delegate = self;
[scrollView setContentSize:CGSizeMake((cell.frame.size.width*images.count), scrollView.frame.size.height)];
scrollView.userInteractionEnabled = NO;
[cell addGestureRecognizer:imagesScrollView.panGestureRecognizer];
Only the first image from the images array should be loaded when the view is first loaded and the rest of the images need to be loaded dynamically when the user scrolls the scrollview, in the -scrollViewDidScroll method. However, these images depend on the index of the collectionviewcell that my scrollView is lying in.
How can I access the index of the collectionviewcell from the -scrollViewDidScroll method?
Also, does this seem like a viable method to achieve what I'm trying to do, or will I need to subclass UICollectionViewCell?
Subclassing can be one of the solutions but you can get the indexPath of a UICollectionViewCell from its subviews too. The following code would hopefully serve your needs. Use it in your scrollViewDidScroll: method.
UIView *superview = scrollView;
while (![superview isKindOfClass:[UICollectionViewCell class]]) {
superview = superview.superview;
}
UICollectionViewCell *cell = (UICollectionViewCell *)superview;
NSIndexPath *indexPath = [self.collectionView indexPathForCell:cell];
NSLog(#"IndexPath: %#", indexPath);
Make sure you are not using a scrollView elsewhere in this viewController.
I have taken the UIScrollView inside that
i have taken one UIView with fixed
position and just below it taken UICollectionView which is horizontal scrolling,
then i have again UIView and then again i have taken
UICollectionView with fixed cell 1.
So, on select of item of both collection view's didSelectItemAtIndexPath method not getting called.I have found some solution here but not found exact one.
By using above solution, i am facing problem is on tap anywhere(ex. image gallary) tap of UIScrollview call the tap method but every time didSelectItemAtIndexPath called wheather i click on collection view or not default zero indexpath is called.
UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(gestureAction:)];
[recognizer setNumberOfTapsRequired:1];
self.scrollViu.userInteractionEnabled = YES;
[self.scrollViu addGestureRecognizer:recognizer];
-(void)gestureAction:(UITapGestureRecognizer *) sender
{
CGPoint touchLocation = [sender locationOfTouch:0 inView:self.YourCollectionViewName];
NSIndexPath *indexPath = [self.YourCollectionViewName indexPathForRowAtPoint:touchLocation];
NSLog(#"%d", indexPath.item);
}
I need to change the value inside a UITableViewCell when the user taps on it.
I need to modify the value trough an animation of a value inside a UITableViewCell.
Right now, I've implemented a UITapGestureRecognizer when the user taps on the UILabel, like so:
UITapGestureRecognizer *tapOnAmount = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapOnBalance)];
[cell.amountLabel setUserInteractionEnabled:YES];
[cell.amountLabel addGestureRecognizer:tapOnAmount];
Changing the values in a method didTapOnBalance will crash the app, like so:
-(void)tapOnBalance{
NSString *headerIdentifier = #"HeaderCell";
HeaderTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:headerIdentifier];
cell.amountLabel.text = #"new Value"; // this will crash because at runtime
// the compiler won't recognize cell.amountLabel...
}
Implementing this in the UITableViewCell will cause me to send the values of the HeaderTableViewCell to the subclass and I don't know how to do that either.
You can't just deque a new cell, that will not give you the cell that the user tapped - it will make a new one. But, if you change your tap handler just a little, you can get the index path of the cell tapped from the gesture.
You need a slight change to the initialization of the gesture (look at the selector):
UITapGestureRecognizer *tapOnAmount = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapOnBalance:)];
[cell.amountLabel setUserInteractionEnabled:YES];
[cell.amountLabel addGestureRecognizer:tapOnAmount];
and then another slight change to your handler:
- (void)tapOnBalance:(UITapGestureRecognizer *)sender
{
CGPoint location = [sender locationInView:self.view];
CGPoint locationInTableview = [self.tableView convertPoint:location fromView:self.view];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:locationInTableview];
// then you can either use the index path to call something like configureCell or send a didSelectRowAtIndexPath like this:
[self tableView:self.tableView didSelectRowAtIndexPath:indexPath];
}
Your code is totally wrong.
You're creating a new cell when the user taps on an existing cell, and trying to change the value displayed in that new cell. Don't do that.
Instead, change the data in your table view's data model, then tell your table view to reload that cell (as explained in ZAZ's answer.) If you've changed the data model to reflect new info for your cell, reloading it will cause it to be displayed with the new settings.
you must implement didSelecRowAtIndexPath and write in it the following line of code after the changing the value to animate the tapped row
[self.myTableView reloadRowsAtIndexPaths:indexPath] withRowAnimation:UITableViewRowAnimationNone];
Hope it helps!
What's the best method for efficiently adding a tap gesture to a subview of a UICollectionViewCell returned from dequeueReusableCellWithReuseIdentifier that already has a bunch of default gesture recognizers attached to it (such as a UIScrollView). Do I need to check and see if my one custom gesture is already attached (scrollView.gestureRecognizers) and if not then add it? I need my app's scrolling to be as smooth as possible so performance of the check and efficient reuse of already created resources is key. This code all takes place inside cellForItemAtIndexPath. Thanks.
I figured out a way to do it that requires only a single, shared, tap gesture recognizer object and moves the setup code from cellForItemAtIndexPath (which gets called very frequently as a user scrolls) to viewDidLoad (which gets called once when the view is loaded). Here's the code:
- (void)myCollectionViewWasTapped:(UITapGestureRecognizer *)tap
{
CGPoint tapLocation = [tap locationInView:self.collectionView];
NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:tapLocation];
if (indexPath)
{
MyCollectionViewCell *cell = (MyCollectionViewCell *)[self.collectionView cellForItemAtIndexPath:indexPath];
CGRect mySubviewRectInCollectionViewCoorSys = [self.collectionView convertRect:cell.mySubview.frame fromView:cell];
if (CGRectContainsPoint(mySubviewRectInCollectionViewCoorSys, tapLocation))
{
// Yay! My subview was tapped!
}
}
}
- (void)viewDidLoad
{
// Invoke super
[super viewDidLoad];
// Add tap handler to collection view
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(myCollectionViewWasTapped:)];
[self.collectionView addGestureRecognizer:tap];
}
Here's a rough, very simple outline of a possible design solution: you could subclass UICollectionViewCell and override its initialization methods to add the gesture recognizer to its subviews. Furthermore, if you don't want the cell to "know" about the gesture recognizer, you could create a protocol that the data source object would conform to. The cell object would call a "setup" protocol method at the appropriate time.
Hope this helps!
I have a tableview in my View. The cells are created using custom Cells. I need to display a large string in the table view cells So I had added the text Label in a Scrollview. Also I need to execute some code when the user taps on table view cell. Please see the below code:
[cell.textLabelLine2 setFrame:CGRectMake(cell.textLabelLine2.frame.origin.x, cell.textLabelLine2.frame.origin.y, 500, cell.textLabelLine2.frame.size.height)];
cell.scrollView.contentSize = CGSizeMake(cell.textLabelLine2.text.length*10 , 10);
cell.scrollView.pagingEnabled = NO;
The problem is when the user touches above the Scroll View, the Tableview did select method will not be called. The solution I found for this problem is to add a gesture recogniser to the scroll view. But in this solution, we have no ways to check which cell(or which gesture recogniser) was selected. Could anyone help me to find a solution for this problem?
You can get to know the cell by the following code
if(gestureRecognizer.state == UIGestureRecognizerStateBegan) {
CGPoint p = [gestureRecognizer locationInView:[self tableView]];
NSIndexPath *indexPath = [[self tableView] indexPathForRowAtPoint:p];
if(indexPath != nil) {
UITableViewCell *cell = [[self tableView] cellForRowAtIndexPath:indexPath];
...
}
}
It's generally a bad idea putting scroll views inside scroll views. UITableView is also just a UIScrollView. That only kind of works if they are scrolling on different axis, i.e. the outer scroll view scrolling vertically and the inner scrolling horizontally.
For your specific scenario you would have to trigger the selection yourself. Once you have a reference to the cell you can ask the table view for the indexPath of it. Then you would call the delegate method for didSelectRow... yourself.
In the solution with the scrollview you are not able to scroll in the scrollview because the gestureRecognizer 'gets' the touch. Therefor I would not use the scrollview at all.
Make the label resize to its content like:
CGSize customTextLabelSize = [cell.customTextLabel.text sizeWithFont:cell.customTextLabel.font constrainedToSize:CGSizeMake(cell.customTextLabel.frame.size.width, 999999)];
cell.customTextLabel.frame = CGRectMake(cell.customTextLabel.frame.origin.x, cell.customTextLabel.frame.origin.y, cell.customTextLabel.frame.size.width, customTextLabelSize.height);
You also need to implement this in the heightForRowAtIndexPath
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
CGSize cellSize = [bigTextString sizeWithFont:customTextLabel.font constrainedToSize:CGSizeMake(generalCellWidth, 999999)];
return cellSize.height;
}
This way you can just use the didSelectRowAtIndex method.
If you really want to use the scrollview, add a button to your cell in the cellForRowAtIndexPath: method. Make the button just as big as the cell and add a button tag like this:
UIButton *cellButton = [UIButton buttonWithType:UIButtonTypeCustom];
cellButton.frame = CGRectMake(0, 0, cell.frame.size.width, cell.frame.size.height);
cellButton.tag = indexPath.row;
[cellButton addTarget:self action:#selector(cellButtonAction:) forControlEvents:UIControlEventTouchUpInside];
[cell.contentView addSubview:cellButton];
Then add:
-(void)cellButtonAction:(UIButton*)sender
{
//do something with sender.tag
}