Getting row of UITableView cell on button press - objective-c

I have a tableview controller that displays a row of cells. Each cell has 3 buttons. I have numbered the tags for each cell to be 1,2,3. The problem is I don't know how to find on which cell a button is being pressed. I'm currently only getting the sender's tag when one of the buttons has been pressed. Is there a way to get the cell row number as well when a button is pressed?

You should really be using this method instead:
CGPoint buttonPosition = [sender convertPoint:CGPointZero toView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:buttonPosition];
Swift version:
let buttonPosition = sender.convert(CGPoint(), to:tableView)
let indexPath = tableView.indexPathForRow(at:buttonPosition)
That will give you the indexPath based on the position of the button that was pressed. Then you'd just call cellForRowAtIndexPath if you need the cell or indexPath.row if you need the row number.
If you're paranoid, you can check for if (indexPath) ... before using it just in case the indexPath isn't found for that point on the table view.
All of the other answers are likely to break if Apple decides to change the view structure.

Edit: This answer is outdated. Please use this method instead
Try this:
-(void)button1Tapped:(id)sender
{
UIButton *senderButton = (UIButton *)sender;
UITableViewCell *buttonCell = (UITableViewCell *)[senderButton superview];
UITableView* table = (UITableView *)[buttonCell superview];
NSIndexPath* pathOfTheCell = [table indexPathForCell:buttonCell];
NSInteger rowOfTheCell = [pathOfTheCell row];
NSLog(#"rowofthecell %d", rowOfTheCell);
}
Edit: If you are using contentView, use this for buttonCell instead:
UITableViewCell *buttonCell = (UITableViewCell *)senderButton.superview.superview;

I would recommend this way to fetch indexPath of cell which has any custom subview - (compatible with iOS 7 as well as all previous versions)
-(void)button1Tapped:(id)sender {
//- (void)cellSubviewTapped:(UIGestureRecognizer *)gestureRecognizer {
// UIView *parentCell = gestureRecognizer.view.superview;
UIView *parentCell = sender.superview;
while (![parentCell isKindOfClass:[UITableViewCell class]]) { // iOS 7 onwards the table cell hierachy has changed.
parentCell = parentCell.superview;
}
UIView *parentView = parentCell.superview;
while (![parentView isKindOfClass:[UITableView class]]) { // iOS 7 onwards the table cell hierachy has changed.
parentView = parentView.superview;
}
UITableView *tableView = (UITableView *)parentView;
NSIndexPath *indexPath = [tableView indexPathForCell:(UITableViewCell *)parentCell];
NSLog(#"indexPath = %#", indexPath);
}
This doesn't require self.tablview either.
Also, notice the commented code which is useful if you want the same through a #selector of UIGestureRecognizer added to your custom subview.

There are two ways:
#H2CO3 is right. You can do what #user523234 suggested, but with a small change, to respect the UITableViewCellContentView that should come in between the UIButton and the UITableViewCell. So to modify his code:
- (IBAction)button1Tapped:(id)sender
{
UIButton *senderButton = (UIButton *)sender;
UITableViewCellContentView *cellContentView = (UITableViewCellContentView *)senderButton.superview;
UITableViewCell *tableViewCell = (UITableViewCell *)cellContentView.superview;
UITableView* tableView = (UITableView *)tableViewCell.superview;
NSIndexPath* pathOfTheCell = [tableView indexPathForCell:tableViewCell];
NSInteger rowOfTheCell = pathOfTheCell.row;
NSLog(#"rowofthecell %d", rowOfTheCell);
}
If you create a custom UITableViewCell (your own subclass), then you can simply call self in the IBAction. You can link the IBAction function to your button by using storyboard or programmatically when you set up the cell.
- (IBAction)button1Tapped:(id)sender
{
UITableView* tableView = (UITableView *)self.superview;
NSIndexPath* pathOfTheCell = [tableView indexPathForCell:self];
NSInteger rowOfTheCell = pathOfTheCell.row;
NSLog(#"rowofthecell %d", rowOfTheCell);
}

I assume you add buttons to cell in cellForRowAtIndexPath, then what I would do is to create a custom class subclass UIButton, add a tag called rowNumber, and append that data while you adding button to cell.

Another simple way:
Get the point of touch in tableView
Then get index path of cell at point
The index path contains row index
The code is:
- (void)buttonTapped:(id)sender {
UITapGestureRecognizer *tap = (UITapGestureRecognizer *)sender;
CGPoint point = [tap locationInView:theTableView];
NSIndexPath *theIndexPath = [theTableView indexPathForRowAtPoint:point];
NSInteger theRowIndex = theIndexPath.row;
// do your stuff here
// ...
}

Swift 3
Note: This should really go in the accepted answer above, except that meta frowns upon such edits.
#IBAction func doSomething(_ sender: UIButton) {
let buttonPosition = sender.convert(CGPoint(), to: tableView)
let index = tableView.indexPathForRow(at: buttonPosition)
}
Two minor comments:
The default function has sender type as Any, which doesn't have convert.
CGPointZero can be replaced by CGPoint()

One solution could be to check the tag of the button's superview or even higher in the view hierarchy (if the button is in the cell's content view).

I would like to share code in swift -
extension UITableView
{
func indexPathForCellContainingView(view1:UIView?)->NSIndexPath?
{
var view = view1;
while view != nil {
if (view?.isKindOfClass(UITableViewCell) == true)
{
return self.indexPathForCell(view as! UITableViewCell)!
}
else
{
view = view?.superview;
}
}
return nil
}
}

In swift:
#IBAction func buttonAction(_ sender: UIButton) {
guard let indexPath = tableView.indexPathForRow(at: sender.convert(CGPoint(), to: tableView)) else {
return
}
// do something
}

Related

UITableView is lagging a cell containing a UITextView is displayed the first time

I'm running into issues with a UITableView that lags while scrolling when specific cells will move to superview.
I've written my own IPFormKit for an easy way to create beautiful input forms with different kind of inputViews without having to re-code everything manually for each form field / cell.
I've got a UITableViewController that initializes my IPFormKit and its fields.
The - (UITableViewCell *) cellForRowAtIndexPath:(NSIndexPath)indexPath; loads the dequeued custom cells (called IPFormTableViewCell) and assigns the IPFormField to each cell.
The custom UITableViewCell (IPFormTableViewCell) creates all (possibly) required inputViews (UITextField, UITextView, CustomUILabel) with a CGRectZero on initialization.
The matching inputView depending on the IPFormField's type (that was already inited as an iVar of the cell) is resized and added as a subview to the cell.contentView within.
- (UITableViewCell *)cellForRowAtIndexPath:(NSIndexPath)indexPath
For UITextField and CustomUILabel this works flawlessly, but when the inputView is a UITextView, the scrolling of the UITableView lags (slightly) noticable when this cell will be displayed for the first time.
When the cell will be displayed again later after scrolling a bit (even if the cell was reused and thus the UITextView removed and readded), there is no lag and scrolling is super smooth for those cells.
I'm running out of ideas what the reason for this lag could be.
Any idea is appreciated.
PS: The lag is noticable on both, iPhone 4 and iPhone 4S and is of almost exactly the same duration (so it should not be CPU related)
UITableViewController.m:
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"IPFormFieldCell";
// Get Form Field for indexPath
IPFormField *formField = [self.form fieldAtIndexPath:indexPath];
IPTableViewCell *cell = (IPTableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[IPTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.backgroundView = nil;
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"background.png"]];
cell.selectedBackgroundView = nil;
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
[cell assignFormField:formField];
return cell;
}
IPFormTableViewCell.m:
- (void) assignFormField:(IPFormField *)field:
- (void) assignFormField:(IPFormField *)field {
if (formField != nil) {
formField.inputView = nil; // unlink old field
}
self.formField = field;
// Change Field Label
[fieldLabel setText:[field label]];
// Add an Input View to the Field
UIView *labelView = nil;
UIView *inputView = nil;
switch (formField.type) {
case IPFormFieldTypeTextField:
{
labelView = fieldLabel;
UITextField *textField = inputTextField;
textField.delegate = (IPFormTextField *)formField;
textField.inputAccessoryView = [formField.form inputAccessoryView];
textField.placeholder = [self.formField stringFromValue:self.formField.defaultValue];
textField.keyboardType = [(IPFormTextField *)formField keyboardType];
if (self.formField.value == nil || [[self.formField stringFromValue:self.formField.value] isEqualToString:[self.formField stringFromValue:self.formField.defaultValue]]) {
textField.clearsOnBeginEditing = YES;
} else {
textField.text = [self.formField stringFromValue:self.formField.value];
textField.clearsOnBeginEditing = NO;
}
inputView = textField;
break;
}
case IPFormFieldTypeTextArea:
{
UITextView *textView = inputTextView;
textView.delegate = (IPFormTextArea *)formField;
textView.inputAccessoryView = [formField.form inputAccessoryView];
if (self.formField.value == nil || ![[self.formField stringFromValue:self.formField.value] length] > 0) {
textView.text = [self.formField stringFromValue:self.formField.defaultValue];
} else {
textView.text = [self.formField stringFromValue:self.formField.value];
}
inputView = textView;
break;
}
default:
break;
}
self.leftItem = labelView;
self.rightItem = inputView;
if (leftItem != nil) {
[self.contentView addSubview:leftItem];
}
if (rightItem != nil) {
[self.contentView addSubview:rightItem];
}
formField.inputView = rightItem;
}
Apparently, cellForRowAtIndexPath: of my dataSource made use of a field's property, that was set as #property (nonatomic, copy) instead of #property (nonatomic, readonly).
Now that I've fixed it, the scrolling isn't lagging anymore.
As I guessed, your problem here is with your custom controls. Yes, you are reusing the cell, but this doesn't give anything in your case, as every time you request for the cell, you are creating new custom control for each cell. My advise, you can create and keep your custom controls as an instance variables, and when required return them without many if-elses, or, you could create custom cells for your two cases, and keep them dequeued with different cell identifiers and reuse them. Good Luck!

Multiple UITextFields in a custom UITableViewCell

I have a UITableView that has 2 different customcell definitions. One is a single UITextField and the other has 4 UITextFields
userInteractionEnabled is manually set to enable cell level touch navigation, and I handle the UI interaction within didSelectRowAtIndexPath to the first responder to the relevant cell
This all worked fine when I was using just the one customcell (EditableCustomCell) with one UITextField (editableTextField), but now I have a customcell (LatLonCustomCell) with 4 UITextFields (degrees, minutes, seconds, cartesian), I cannot determine which field has been touched in order to set becomeFirstResponder
(currently I'm defaulting in the first textfield called degrees during debug)
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[prevField resignFirstResponder];
prevField.userInteractionEnabled = NO;
if(indexPath.section == kFirstSection && (indexPath.row == kLatitudeRow || indexPath.row == kLongitudeRow)) {
LatLonCustomCell *customCell = (LatLonCustomCell *)[MyTableView cellForRowAtIndexPath:indexPath];
currField = customCell.degrees; // need to set correct field here
} else {
EditableCustomCell *customCell = (EditableCustomCell *)[MyTableView cellForRowAtIndexPath:indexPath];
currField = customCell.editableTextField;
}
currFieldIndexPath = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section];
currField.userInteractionEnabled = YES;
[currField becomeFirstResponder];
}
OK, so for those that come across this with the same or similar problem, I have finally made a breakthrough
I decided that I was going to need to capture the X/Y coordinates of the touch prior to the didSelectRowAtIndexPath being called. This way I could then determine which UITextField the touch occurred in by checking the touch against the "bounds" of the textfield
After some random searching, I found that a VERY easy way of capturing ANY touch event in the viewcontroller (as touchesBegan only occurred in the custom overridden UITableViewCell class and I knew not how to pass this back up the chain Cell > TableView > Scroll View > Controller)
By adding this to the viewDidLoad method:
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTapGesture:)];
tapGesture.numberOfTapsRequired = 1;
// Pass the tap through to the UITableView
tapGesture.cancelsTouchesInView = NO;
[self.view addGestureRecognizer:tapGesture];
This captures all touches, calling the handleTapGesture method
Then within this method it was simply a case of checking if the touch was within the bounds of the tableview, and if so, determine the indexPath for the point touched and then check against the bounds of the object required, below is a simplified version of what I came up with
-(void)handleTapGesture:(UITapGestureRecognizer *)tapGesture {
CGPoint tapLoc = [tapGesture locationInView:self.tableView];
if([MyTableView indexPathForRowAtPoint:tapLoc]) {
// Tap still handled by the UITableView delegate method
NSIndexPath *indexPath = [MyTableView indexPathForRowAtPoint:tapLoc];
if(indexPath.section == 0 && (indexPath.row == kLatitudeRow || indexPath.row == kLongitudeRow)) {
LatLonCustomCell *customCell = (LatLonCustomCell *)[MyTableView cellForRowAtIndexPath:indexPath];
UIScrollView *scrollView = (UIScrollView *)self.view;
CGRect rc;
// Degrees
rc = [customCell.degrees convertRect:[customCell.degrees bounds] toView:scrollView];
if (tapLoc.x >= rc.origin.x && tapLoc.y >= rc.origin.y && tapLoc.x <= (rc.origin.x + rc.size.width) && tapLoc.y <= (rc.origin.y + rc.size.height)) {
NSLog(#"touch within bounds for DEGREES");
touchField = customCell.degrees;
}
// Repeat for other textfields here ....
....
In my code I save the field within touchField, as within the didSelectRowAtIndexPath code, I am already handling prevField/currField values to control the enabling/disabling of userInteractionEnabled and to set the currField as becomeFirstReponder
Hope this proves helpful to someone :)
In the past when I have needed to check if a text box has been touched I checked if YourTextField.text.length > 0. If it is you can set becomeFirstResponder. Hope this helps.
Have you thought about using NSNotificationCenter to request notifications for UITextFieldTextDidBeginEditingNotification?
in viewDidLoad
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(textFieldBeganEditing)
name:UITextFieldTextDidBeginEditingNotification object:nil];
and then something like
-(void) textFieldBegainEditing: (NSNotification*) notification {
// [notification object] will be the UITextField
// do what you need to do with it (resign, become first responder)
}

Cell selection issue with EasyTableView

I have what must be a simple problem with EasyTableView (https://github.com/alekseyn/EasyTableView)
I have a number of horizontally scrolling tables that function properly.
I am able to select a cell and perform a segue, however, once the new view controller is dismissed, I am no longer able to select that cell and perform the same action until I have selected another cell in the same table.
My question is: How can I deselect previously selected the cell programmatically to renable this particular action.
Thanks in advance!
The selectedIndexPath is intentionally persistent in case a user scrolls the selected tableview cell offscreen and then back again. If you don't want this persistence please add the line shown below, after the delegate method (in EasyTableView.m):
- (void)setSelectedIndexPath:(NSIndexPath *)indexPath {
if (![_selectedIndexPath isEqual:indexPath]) {
NSIndexPath *oldIndexPath = [_selectedIndexPath copy];
_selectedIndexPath = indexPath;
UITableViewCell *deselectedCell = (UITableViewCell *)[self.tableView cellForRowAtIndexPath:oldIndexPath];
UITableViewCell *selectedCell = (UITableViewCell *)[self.tableView cellForRowAtIndexPath:_selectedIndexPath];
if ([delegate respondsToSelector:#selector(easyTableView:selectedView:atIndexPath:deselectedView:)]) {
UIView *selectedView = [selectedCell viewWithTag:CELL_CONTENT_TAG];
UIView *deselectedView = [deselectedCell viewWithTag:CELL_CONTENT_TAG];
[delegate easyTableView:self
selectedView:selectedView
atIndexPath:_selectedIndexPath
deselectedView:deselectedView];
// Add this line here!
_selectedIndexPath = nil;
}
}
}

UITextField subview of UITableViewCell, get indexPath of cell

I have added a UITextField as a subview of a UITableViewCell. Then I have added a target and selector so that I can know when UIControlEventEditingChanged. This works great, but I would like you know the indexPath of the cell that the UITextField is in, as it could be added to any number of cells.
Is this possible? Basically I want to find the parent view which is a UITableViewCell.
Call [UIView superview] on the field to get the cell that it's in, then call [UITableView indexPathForCell:] on the cell to get the index path.
UPDATE: on iOS 7 you need to call superview on that view too (extra layer of views); here's a category on UITableView that should work independent of iOS version:
#interface UITableView (MyCoolExtension)
- (NSIndexPath *)indexPathForCellContainingView:(UIView *)view;
#end
#implementation UITableView (MyCoolExtension)
- (NSIndexPath *)indexPathForCellContainingView:(UIView *)view {
while (view != nil) {
if ([view isKindOfClass:[UITableViewCell class]]) {
return [self indexPathForCell:(UITableViewCell *)view];
} else {
view = [view superview];
}
}
return nil;
}
#end
Instead of recursively trying to find the superview, there's a simpler solution:
Swift
func indexPathForCellContainingView(view: UIView, inTableView tableView:UITableView) -> NSIndexPath? {
let viewCenterRelativeToTableview = tableView.convertPoint(CGPointMake(CGRectGetMidX(view.bounds), CGRectGetMidY(view.bounds)), fromView:view)
return tableView.indexPathForRowAtPoint(viewCenterRelativeToTableview)
}
Objective-C
- (NSIndexPath *)indexPathForCellContainingView:(UIView *)view inTableView:(UITableView *)tableView {
CGPoint viewCenterRelativeToTableview = [tableView convertPoint:CGPointMake(CGRectGetMidX(view.bounds), CGRectGetMidY(view.bounds)) fromView:view];
NSIndexPath *cellIndexPath = [tableView indexPathForRowAtPoint:viewCenterRelativeToTableview];
return cellIndexPath
}
I made this into a Gist for the Swift hearted
Try this solution. It worked for me
#pragma mark - Get textfield indexpath
- (NSIndexPath *)TextFieldIndexpath:(UITextField *)textField
{
CGPoint origin = textField.frame.origin;
CGPoint point = [textField.superview convertPoint:origin toView:self.TblView];
NSIndexPath * indexPath = [self.TblView indexPathForRowAtPoint:point];
NSLog(#"Indexpath = %#", indexPath);
return indexPath;
}
I would like to share #Ertebolle code in swift -
extension UITableView
{
func indexPathForCellContainingView(view1:UIView?)->NSIndexPath?
{
var view = view1;
while view != nil {
if (view?.isKindOfClass(UITableViewCell) == true)
{
return self.indexPathForCell(view as! UITableViewCell)!
}
else
{
view = view?.superview;
}
}
return nil
}
}
Swift 4/5
func indexPathForCellContainingView(view: UIView,
inTableView tableView:UITableView) -> IndexPath? {
let viewCenterRelativeToTableview =
tableView.convert(CGPoint(x: view.bounds.midX, y: view.bounds.midY), to: view)
return tableView.indexPathForRow(at: viewCenterRelativeToTableview)
}

NSIndexPath of UITableViewCell subview?

Is there any was to get the NSIndexPath of a UITableViewCell's contentView subview?
In my case, I have a table view in which each row is split into 3 buttons. I can use the button tag to keep track of which column it is but I also need to know what row of the table view it is a subview of (when the user taps the button).
Because the button blocks the entire actual table view row, didSelectRowAtIndexPath is never called (which is expected), so I can't get it that way.
I have tried just [thisButton superview] but that doesn't seem to work. Any thoughts?
I assume the button is sending its UIControlEventTouchUpInside event message to your view controller? Then you could do something like:
- (void)buttonPressed:(UIButton *)button
{
CGPoint location = [button.superview convertPoint:button.center toView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:location];
[self doSomethingWithRowAtIndexPath:indexPath];
}
One possible option is when making the cell for index path you can assign the tag to be 3 * row_number + <the tag number>. then just divide the tag by 3 to get the row and %3 to get the button.
You don't need to call button.superview. You can go straight from any subview in the tree right to the table view
Objective-C
- (NSIndexPath *)indexPathForCellContainingView:(UIView *)view inTableView:(UITableView *)tableView {
CGPoint viewCenterRelativeToTableview = [tableView convertPoint:CGPointMake(CGRectGetMidX(view.bounds), CGRectGetMidY(view.bounds)) fromView:view];
NSIndexPath *cellIndexPath = [tableView indexPathForRowAtPoint:viewCenterRelativeToTableview];
return cellIndexPath
}
Swift
func indexPathForCellContainingView(view: UIView, inTableView tableView:UITableView) -> NSIndexPath? {
let viewCenterRelativeToTableview = tableView.convertPoint(CGPointMake(CGRectGetMidX(view.bounds), CGRectGetMidY(view.bounds)), fromView:view)
return tableView.indexPathForRowAtPoint(viewCenterRelativeToTableview)
}