Class: Motion::KeyboardAvoiding

Inherits:
Object
  • Object
show all
Defined in:
lib/project/motion-keyboard-avoiding.rb

Constant Summary collapse

KEYBOARD_ANIMATION_DURATION = 
0.3
MINIMUM_SCROLL_FRACTION = 
0.2
MAXIMUM_SCROLL_FRACTION = 
0.8
PORTRAIT_KEYBOARD_HEIGHT = 
216.0
LANDSCAPE_KEYBOARD_HEIGHT = 
162.0

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(view) ⇒ KeyboardAvoiding

Returns a new instance of KeyboardAvoiding.



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# File 'lib/project/motion-keyboard-avoiding.rb', line 11

def initialize(view)
  self.view = view

  listen

  view.instance_eval do
    def willMoveToWindow(window)
      NSNotificationCenter.defaultCenter.postNotificationName('WillMoveToWindow', object: self)
    end
  end

  add_tap_recognizer
end

Instance Attribute Details

#active_text_field ⇒ Object

Returns the value of attribute active_text_field.



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# File 'lib/project/motion-keyboard-avoiding.rb', line 9

def active_text_field
  @active_text_field
end

#animated_distance ⇒ Object

Returns the value of attribute animated_distance.



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# File 'lib/project/motion-keyboard-avoiding.rb', line 9

def animated_distance
  @animated_distance
end

#view ⇒ Object

Returns the value of attribute view.



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# File 'lib/project/motion-keyboard-avoiding.rb', line 9

def view
  @view
end

Instance Method Details

#add_tap_recognizer ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 33

def add_tap_recognizer
  view.addGestureRecognizer(tap_recognizer)
end

#dismiss_keyboard ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 41

def dismiss_keyboard
  active_text_field.resignFirstResponder if active_text_field
end

#listen ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 25

def listen
  NSNotificationCenter.defaultCenter.addObserver(self, selector: 'reset:', name: 'WillMoveToWindow', object: view)
end

#reset(notification) ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 29

def reset(notification)
  active_text_field.resignFirstResponder if active_text_field
end

#set_frame(frame) ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 81

def set_frame(frame)
  UIView.beginAnimations(nil, context: nil)
  UIView.setAnimationBeginsFromCurrentState(true)
  UIView.setAnimationDuration(KEYBOARD_ANIMATION_DURATION)

  view.setFrame(frame)

  UIView.commitAnimations
end

#tap_recognizer ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 37

def tap_recognizer
  UITapGestureRecognizer.alloc.initWithTarget(self, action: 'dismiss_keyboard')
end

#textFieldDidBeginEditing(text_field) ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 45

def textFieldDidBeginEditing(text_field)
  self.active_text_field = text_field

  text_field_rect = view.window.convertRect(text_field.bounds, fromView: text_field)
  view_rect       = view.window.convertRect(view.bounds, fromView: view)
  midline         = text_field_rect.origin.y + 0.5 * text_field_rect.size.height
  numerator       = midline - view_rect.origin.y - MINIMUM_SCROLL_FRACTION * view_rect.size.height
  denominator     = (MAXIMUM_SCROLL_FRACTION - MINIMUM_SCROLL_FRACTION) * view_rect.size.height
  height_fraction = numerator / denominator

  if height_fraction < 0.0
    height_fraction = 0.0
  elsif height_fraction > 1.0
    height_fraction = 1.0
  end

  orientation = UIApplication.sharedApplication.statusBarOrientation
  if orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown
    self.animated_distance = (PORTRAIT_KEYBOARD_HEIGHT * height_fraction).floor
  else
    self.animated_distance = (LANDSCAPE_KEYBOARD_HEIGHT * height_fraction).floor
  end

  view_frame = view.frame
  view_frame.origin.y -= animated_distance

  set_frame(view_frame)
end

#textFieldDidEndEditing(text_field) ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 74

def textFieldDidEndEditing(text_field)
  view_frame = view.frame
  view_frame.origin.y += animated_distance || 0.0

  set_frame(view_frame)
end

#textFieldShouldReturn(text_field) ⇒ Object 



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# File 'lib/project/motion-keyboard-avoiding.rb', line 91

def textFieldShouldReturn(text_field)
  text_field.resignFirstResponder

  true
end