TextView inside ScrollView stick to keyboard - ios

Question

I have a UIScrollView and content inside it. Inside content there is a UITextView. When user presses the UITextView I want the UITextView stick to the keyboard.
In the image:
Whole thing is UIScrollView
Bottom black area is the visible screen
Red area is content
Blue area is UITextView
Green distance is the dynamic margin between content and the screen bound.
I want to calculate the green distance which the user can see along with the blue are(UITextView) which the user can see. If the user half swiped UITextView, the UITextView should still stick to the keyboard.
let userInfo = notification.userInfo!
let keyboardEndFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as NSValue).CGRectValue()
let keyboardBeginFrame = (userInfo[UIKeyboardFrameBeginUserInfoKey] as NSValue).CGRectValue()
let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as UInt
let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as Double
let options = UIViewAnimationOptions(curve << 16)
UIView.animateWithDuration(duration, delay: 0, options: options,
animations: {
var visibleGreen = ???
var visibleBlue = ???
var amountToSubtract = visibleGreen + visibleBlue
var newFrame = (self.currentCardInstance?.newCommentCell.frame)!
var kbFrameEnd = self.view.convertRect(keyboardEndFrame, toView: nil)
var kbFrameBegin = self.view.convertRect(keyboardBeginFrame, toView: nil)
newFrame.origin.y -= kbFrameBegin.origin.y - kbFrameEnd.origin.y + amountToSubtract
self.currentCardInstance?.newCommentCell.frame = newFrame;
},
completion: nil
)

Answer 1

Here is how I solved it:
var keyboardModifier: CGFloat = 0
func keyboardWillAppear(notification: NSNotification) {
println("keyboardWillAppear")
keyboardResize(notification: notification)
scrollToBottom()
}
func keyboardWillDisappear(notification: NSNotification) {
println("keyboardWillDisappear")
keyboardResize(notification: notification)
}
func keyboardResize(#notification: NSNotification) {
let userInfo = notification.userInfo!
let keyboardEndFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as NSValue).CGRectValue()
let keyboardBeginFrame = (userInfo[UIKeyboardFrameBeginUserInfoKey] as NSValue).CGRectValue()
let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as UInt
let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as Double
let options = UIViewAnimationOptions(curve << 16)
var newFrame = (self. currentCardInstance?.frame)!
var kbFrameEnd = self.view.convertRect(keyboardEndFrame, toView: nil)
var kbFrameBegin = self.view.convertRect(keyboardBeginFrame, toView: nil)
keyboardModifier = kbFrameBegin.origin.y - kbFrameEnd.origin.y
scrollView.frame.size.height -= keyboardModifier
}
func scrollToBottom() {
var bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.size.height)
scrollView.setContentOffset(bottomOffset, animated: false)
}