How can I calculate the height of an UITableViewCell with an UITextView in it in iOS 7?
I found a lot of answers on similar questions, but sizeWithFont:
takes part in every solution and this method is deprecated!
I know I have to use - (CGFloat)tableView:heightForRowAtIndexPath:
but how do I calculate the height my TextView needs to display the whole text?
First of all, it is very important to note, that there is a big difference between UITextView and UILabel when it comes to how text is rendered. Not only does UITextView have insets on all borders, but also the text layout inside it is slightly different.
Therefore, sizeWithFont:
is a bad way to go for UITextViews.
Instead UITextView
itself has a function called sizeThatFits:
which will return the smallest size needed to display all contents of the UITextView
inside a bounding box, that you can specify.
The following will work equally for both iOS 7 and older versions and as of right now does not include any methods, that are deprecated.
- (CGFloat)textViewHeightForAttributedText: (NSAttributedString*)text andWidth: (CGFloat)width {
UITextView *calculationView = [[UITextView alloc] init];
[calculationView setAttributedText:text];
CGSize size = [calculationView sizeThatFits:CGSizeMake(width, FLT_MAX)];
return size.height;
}
This function will take a NSAttributedString
and the desired width as a CGFloat
and return the height needed
Since I have recently done something similar, I thought I would also share some solutions to the connected Issues I encountered. I hope it will help somebody.
This is far more in depth and will cover the following:
UITableViewCell
based on the size needed to display the full contents of a contained UITextView
UITextView
when resizing the UITableViewCell
while editingIf you are working with a static table view or you only have a known number of UITextView
s, you can potentially make step 2 much simpler.
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
// check here, if it is one of the cells, that needs to be resized
// to the size of the contained UITextView
if ( )
return [self textViewHeightForRowAtIndexPath:indexPath];
else
// return your normal height here:
return 100.0;
}
Add an NSMutableDictionary
(in this example called textViews
) as an instance variable to your UITableViewController
subclass.
Use this dictionary to store references to the individual UITextViews
like so:
(and yes, indexPaths are valid keys for dictionaries)
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
// Do you cell configuring ...
[textViews setObject:cell.textView forKey:indexPath];
[cell.textView setDelegate: self]; // Needed for step 3
return cell;
}
This function will now calculate the actual height:
- (CGFloat)textViewHeightForRowAtIndexPath: (NSIndexPath*)indexPath {
UITextView *calculationView = [textViews objectForKey: indexPath];
CGFloat textViewWidth = calculationView.frame.size.width;
if (!calculationView.attributedText) {
// This will be needed on load, when the text view is not inited yet
calculationView = [[UITextView alloc] init];
calculationView.attributedText = // get the text from your datasource add attributes and insert here
textViewWidth = 290.0; // Insert the width of your UITextViews or include calculations to set it accordingly
}
CGSize size = [calculationView sizeThatFits:CGSizeMake(textViewWidth, FLT_MAX)];
return size.height;
}
For the next two functions, it is important, that the delegate of the UITextViews
is set to your UITableViewController
. If you need something else as the delegate, you can work around it by making the relevant calls from there or using the appropriate NSNotificationCenter hooks.
- (void)textViewDidChange:(UITextView *)textView {
[self.tableView beginUpdates]; // This will cause an animated update of
[self.tableView endUpdates]; // the height of your UITableViewCell
// If the UITextView is not automatically resized (e.g. through autolayout
// constraints), resize it here
[self scrollToCursorForTextView:textView]; // OPTIONAL: Follow cursor
}
- (void)textViewDidBeginEditing:(UITextView *)textView {
[self scrollToCursorForTextView:textView];
}
This will make the UITableView
scroll to the position of the cursor, if it is not inside the visible Rect of the UITableView:
- (void)scrollToCursorForTextView: (UITextView*)textView {
CGRect cursorRect = [textView caretRectForPosition:textView.selectedTextRange.start];
cursorRect = [self.tableView convertRect:cursorRect fromView:textView];
if (![self rectVisible:cursorRect]) {
cursorRect.size.height += 8; // To add some space underneath the cursor
[self.tableView scrollRectToVisible:cursorRect animated:YES];
}
}
While editing, parts of your UITableView
may be covered by the Keyboard. If the tableviews insets are not adjusted, scrollToCursorForTextView:
will not be able to scroll to your cursor, if it is at the bottom of the tableview.
- (void)keyboardWillShow:(NSNotification*)aNotification {
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(self.tableView.contentInset.top, 0.0, kbSize.height, 0.0);
self.tableView.contentInset = contentInsets;
self.tableView.scrollIndicatorInsets = contentInsets;
}
- (void)keyboardWillHide:(NSNotification*)aNotification {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.35];
UIEdgeInsets contentInsets = UIEdgeInsetsMake(self.tableView.contentInset.top, 0.0, 0.0, 0.0);
self.tableView.contentInset = contentInsets;
self.tableView.scrollIndicatorInsets = contentInsets;
[UIView commitAnimations];
}
And last part:
Inside your view did load, sign up for the Notifications for Keyboard changes through NSNotificationCenter
:
- (void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}
As Dave Haupert pointed out, I forgot to include the rectVisible
function:
- (BOOL)rectVisible: (CGRect)rect {
CGRect visibleRect;
visibleRect.origin = self.tableView.contentOffset;
visibleRect.origin.y += self.tableView.contentInset.top;
visibleRect.size = self.tableView.bounds.size;
visibleRect.size.height -= self.tableView.contentInset.top + self.tableView.contentInset.bottom;
return CGRectContainsRect(visibleRect, rect);
}
Also I noticed, that scrollToCursorForTextView:
still included a direct reference to one of the TextFields in my project. If you have a problem with bodyTextView
not being found, check the updated version of the function.