Question

I’ve make a custom keyboard for a UITextField, consisting of 18 UIButtons. It’s a UIView which is set as the text field’s inputView.

The buttons are created in the initWithFrame: method of the UIView using the code

UIImage* buttonImage =[[UIImage imageNamed:@"keyboard-button-background.png"] stretchableImageWithLeftCapWidth:1.0 topCapHeight:79.0];
UIImage* buttonPressedImage =[[UIImage imageNamed:@"keyboard-button-pressed-background.png"] stretchableImageWithLeftCapWidth:1.0 topCapHeight:79.0];

UIButton* button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:title forState:UIControlStateNormal];
[button setBackgroundImage:buttonImage forState:UIControlStateNormal];
[button setBackgroundImage:buttonPressedImage forState:UIControlStateHighlighted];

button.frame = CGRectMake(xPosition, yPosition, buttonWidth, buttonHeight);

Once the button has been pressed, that button is then set as enabled = NO. The background stretches perfectly while at least one of the buttons is enabled. If all the buttons are disabled, and the UITextfield resignsFirstResponder and then the UITextField becomes First Responder again, the buttons appear but the background image no longer seems to stretch (at least not in the vertical direction, horizontal seems fine).

I’m not really sure where to start looking for the solution. My guess is that’s in the way the custom keyboard is drawing the subviews, but I’m not sure.

Could this be fixed by setting the background image in layoutSubviews, or drawRect: or something like that? The fact that the horizontal stretch works fine makes me wonder if the frame of the UIButton isn’t right as it’s being drawn.

EDIT
The cells on the far left are just labels, the cells on the right with numbers are UITextfields and have the custom keyboard

How the keyboard should look:

How the keyboard actually looks once resigned first responder on cell 3, then gave 1 first responder (all keys disabled), then gave 4 first responder:

Answer 1

To handle different iOS APIs I did a category for
UIImage.

@implementation UIImage (SPResizableImage)

- (UIImage *)spResizableImageWithCapInsets:(UIEdgeInsets)edge
{
    UIImage * resizableImage = nil;

    if ([self respondsToSelector:@selector(resizableImageWithCapInsets:)]) // iOS 5
    {
        resizableImage = [self resizableImageWithCapInsets:edge];
    }
    else
    {
        resizableImage = [self stretchableImageWithLeftCapWidth:edge.left
                                                   topCapHeight:edge.top];
    }

    return resizableImage;
}

@end