How do I create a UITextView that exactly fits above the keyboard?

Question

I want to create a view, like the Facebook or Twitter app's share dialog, for example, where there is just a UITextView and a permanent keyboard. I can see how to start with the keyboard visible from this answer, but I'm not sure how to size the UITextView to fit exactly above the keyboard. If I don't, text can get hidden under the keyboard which is awkward.

Answer 1

I found a helpful code sample in the Apple documentation for this: https://developer.apple.com/library/ios/#samplecode/KeyboardAccessory/Introduction/Intro.html

Here's the code I ended up with. I'm not worrying about the keyboard hiding, since in my view, the keyboard should never hide.

- (void)viewWillAppear:(BOOL)flag
{
    [super viewWillAppear:flag];

    // Listen for the keyboard to show up so we can get its height
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];

    // Set focus on the text view to display the keyboard immediately
    [self.textView becomeFirstResponder];
}
- (void)keyboardWillShow:(NSNotification *)notification
{
    /*
     Reduce the size of the text view so that it's not obscured by the keyboard.
     */

    NSDictionary *userInfo = [notification userInfo];

    // Get the origin of the keyboard when it's displayed.
    NSValue* keyboardFrame = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];

    // Get the top of the keyboard as the y coordinate of its origin in self's view's
    // coordinate system. The bottom of the text view's frame should align with the
    // top of the keyboard's final position.
    CGRect keyboardRect = [keyboardFrame CGRectValue];
    keyboardRect = [self.view convertRect:keyboardRect fromView:nil];

    // Set the text view's frame height as the distance from the top of the view bounds
    // to the top of the keyboard
    CGFloat keyboardTop = keyboardRect.origin.y;
    CGRect newTextViewFrame = self.view.bounds;
    newTextViewFrame.size.height = keyboardTop - self.view.bounds.origin.y;
    self.textView.frame = newTextViewFrame;
}