CODEWITHSUNDEEP
iosswiftuser-interface
DatForis
DatForis

Reputation: 1341

how can I properly implement a shrinking and expanding view according to keyboard size?

I'm attempting to create a chat interface for iOS that expands and shrinks according to the presence of the keyboard.

I have implemented it using observers for the keyboard will show and will disappear notifications and its working.

func keyboardWillDisappear(notification: NSNotification){
    var userInfo:NSDictionary = notification.userInfo!
    var keyboardSize = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)!.CGRectValue().size
    var oldViewFrame : CGRect = self.view.frame
    self.view.frame = CGRectMake (0, 0, oldViewFrame.width, oldViewFrame.height + keyboardSize.height)
}
func keyboardWillAppear(notification: NSNotification){

    var keyboardSize = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)!.CGRectValue().size
    var oldViewFrame : CGRect = self.view.frame
    self.view.frame = CGRectMake (0, 0, oldViewFrame.width, oldViewFrame.height - keyboardSize.height)      
}

Now to some extent this works however if the user attempts to activate or deactivate predictive typing suggestions the thing blows up. keyboardWillAppear gets called but keyboardWillDisappear doesn't and so the view shrinks again and again every time predictions are enabled

There must be simpler and safer way in doing this, and if there are other things I should watch out for please tell me. Thanks

Upvotes: 0

Views: 83

Answers (2)

DatForis
DatForis

Reputation: 1341

func keyboardFrameWillChange(notification : NSNotification){
    var userInfo:NSDictionary = notification.userInfo!
    var oldKeyboardHeight : CGSize = userInfo.objectForKey(UIKeyboardFrameBeginUserInfoKey)!.CGRectValue().size
    var newKeyboardHeight : CGSize = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)!.CGRectValue().size
    var oldViewFrame : CGRect = self.view.frame
    var difference = newKeyboardHeight.height - oldKeyboardHeight.height
    self.view.frame = CGRectMake (0, 0, oldViewFrame.width, oldViewFrame.height - difference)
    scrollToBottom()
}

This is the piece of code that used to fix my problem.

Upvotes: 0

Nurep
Nurep

Reputation: 61

You need to also observe 

UIKeyboardWillChangeFrameNotification

and/or

UIKeyboardDidChangeFrameNotification

Upvotes: 1

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