Every keyboard type except number pad offer return key. By using which user can hide keyboard. When looking at the number pad, you'll notice that there is an unused
space on its bottom left. That's where we are going to plug in our
custom "return" key.
In fact every other keyboard type (except for the pretty similar
UIKeyboardTypePhonePad) does offer the possibility to be dismissed by
setting the returnKeyType property of the corresponding
UITextInputTraits implementor. When looking at the number pad, you'll notice that there is an unused
space on its bottom left. That's where we are going to plug in our
custom "return" key.
To achieve this we can create two images and like done button in number pad and set this images to a button for state
UIControlStateNormal and
UIControlStateHighlighted for iOS 3 and iOS 4. Then add this button to keyboard when keyboard shows.
Now back to coding. First we need to know when the number pad is
going to be slides up on the screen so we can put our custom button
before that happens. Luckily there’s a notification for exactly that
purpose, and registering for it is as easy as:
//Add observers for the respective notifications (depending on the os version)
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardDidShow:)
name:UIKeyboardDidShowNotification
object:nil];
}
else
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
}
Don't forget to remove the observer from the notification center in the appropriate place once you're done with the whole thing:
[[NSNotificationCenter defaultCenter] removeObserver:self];
Now we’re getting to the heart of it. All we have to do in the
keyboardWillShow method is to locate the keyboard view and add our
button to it. iOS 4 sticks the UIKeyboard inside a UIPeripheralHostView. In iOS 3 keyboard view is part of a second UIWindow of our
application as others have already figured out. So we
take a reference to that window (it will be the second window in most
cases, so objectAtIndex:1 in the code below is fine), traverse its view
hierarchy until we find the keyboard and add the button to its lower
left. So, we need to check device version first then add done button to keyboard.
- (void)keyboardWillShow: (NSNotification *)notification {
if(!addDone){
return;
}else{
if ([[[UIDevice currentDevice] systemVersion] floatValue] < 3.2) {
[self performSelector:@selector(addHideKeyboardButtonToKeyboard)
withObject:nil afterDelay:0];
}
}
}
- (void)keyboardDidShow:(NSNotification *)notification {
if(!addDone){
return;
}else{
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
[self performSelector:@selector(addHideKeyboardButtonToKeyboard) withObject:nil afterDelay:0];
}
}
}
- (void)addHideKeyboardButtonToKeyboard {
UIWindow *keyboardWindow = nil;
for (UIWindow *testWindow in [[UIApplication sharedApplication] windows]) {
if (![[testWindow class] isEqual:[UIWindow class]]) {
keyboardWindow = testWindow;
break;
}
}
if (!keyboardWindow) return;
// Locate UIKeyboard.
UIView *foundKeyboard = nil;
for (UIView *possibleKeyboard in [keyboardWindow subviews]) {
// iOS 4 sticks the UIKeyboard inside a UIPeripheralHostView.
if ([[possibleKeyboard description] hasPrefix:@"<UIPeripheralHostView"]) {
possibleKeyboard = [[possibleKeyboard subviews] objectAtIndex:0];
}
if ([[possibleKeyboard description] hasPrefix:@"<UIKeyboard"]) {
foundKeyboard = possibleKeyboard;
break;
}
}
if (foundKeyboard) {
[self addButtonToKeyboard];
}
}
-(void)addButtonToKeyboard {
// create custom button
doneButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
doneButton.frame = CGRectMake(0, 163, 106, 53);
doneButton.adjustsImageWhenHighlighted = NO;
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.0) {
[doneButton setImage:[UIImage imageNamed:@"DoneUp3.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:@"DoneDown3.png"] forState:UIControlStateHighlighted];
} else {
[doneButton setImage:[UIImage imageNamed:@"DoneUp.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:@"DoneDown.png"] forState:UIControlStateHighlighted];
}
[doneButton addTarget:self action:@selector(removeNumberKeyboardWhenDonePressed:) forControlEvents:UIControlEventTouchUpInside];
// locate keyboard view
UIView *keyboard;
UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
for(int i=0; i<[tempWindow.subviews count]; i++) {
keyboard = [tempWindow.subviews objectAtIndex:i];
// keyboard found, add the button
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
if([[keyboard description] hasPrefix:@"<UIPeripheralHost"] == YES)
[keyboard addSubview:doneButton];
} else {
if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)
[keyboard addSubview:doneButton];
}
}
buttonAdded = YES;
}
-(void)addButtonToKeyboard {
// create custom button
doneButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
doneButton.frame = CGRectMake(0, 163, 106, 53);
doneButton.adjustsImageWhenHighlighted = NO;
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.0) {
[doneButton setImage:[UIImage imageNamed:@"DoneUp3.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:@"DoneDown3.png"] forState:UIControlStateHighlighted];
} else {
[doneButton setImage:[UIImage imageNamed:@"DoneUp.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:@"DoneDown.png"] forState:UIControlStateHighlighted];
}
[doneButton addTarget:self action:@selector(removeNumberKeyboardWhenDonePressed:) forControlEvents:UIControlEventTouchUpInside];
// locate keyboard view
UIView *keyboard;
UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
for(int i=0; i<[tempWindow.subviews count]; i++) {
keyboard = [tempWindow.subviews objectAtIndex:i];
// keyboard found, add the button
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
if([[keyboard description] hasPrefix:@"<UIPeripheralHost"] == YES)
[keyboard addSubview:doneButton];
} else {
if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)
[keyboard addSubview:doneButton];
}
}
buttonAdded = YES;
}
That’s it! The empty space for our button starts at coordinate
(0, 163) and has the dimensions (106, 53).
We are done. This project can be downloaded from
here.
