Class: Motion::ImageEditorController

Inherits:
UIViewController
  • Object
show all
Defined in:
lib/project/controllers/image_editor_controller.rb

Constant Summary collapse

ANIMATION_DURATION = 
0.2
MINIMUM_SCALE = 
1
MAXIMUM_SCALE = 
3

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#crop_rect ⇒ Object

Returns the value of attribute crop_rect.



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# File 'lib/project/controllers/image_editor_controller.rb', line 6

def crop_rect
  @crop_rect
end

#enforce_bounds=(value) ⇒ Object (writeonly)

Sets the attribute enforce_bounds

Parameters:

  • value —

    the value to set the attribute enforce_bounds to.



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# File 'lib/project/controllers/image_editor_controller.rb', line 7

def enforce_bounds=(value)
  @enforce_bounds = value
end

#output_width ⇒ Object (readonly)

Returns the value of attribute output_width.



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# File 'lib/project/controllers/image_editor_controller.rb', line 6

def output_width
  @output_width
end

#rotation_enabled=(value) ⇒ Object (writeonly)

Sets the attribute rotation_enabled

Parameters:

  • value —

    the value to set the attribute rotation_enabled to.



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# File 'lib/project/controllers/image_editor_controller.rb', line 7

def rotation_enabled=(value)
  @rotation_enabled = value
end

#source_image ⇒ Object

Returns the value of attribute source_image.



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# File 'lib/project/controllers/image_editor_controller.rb', line 6

def source_image
  @source_image
end

Instance Method Details

#add_gesture_recognizers ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 39

def add_gesture_recognizers
  crop_view.addGestureRecognizer(pan_recognizer)
  crop_view.addGestureRecognizer(pinch_recognizer)
  crop_view.addGestureRecognizer(rotation_recognizer)
  crop_view.addGestureRecognizer(tap_recognizer)
end

#add_subviews ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 34

def add_subviews
  view.addSubview(crop_view)
  view.insertSubview(image_view, belowSubview: crop_view)
end

#bounded_scale(scale) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 358

def bounded_scale(scale)
  return scale if (MINIMUM_SCALE..MAXIMUM_SCALE).include? scale

  scale < MINIMUM_SCALE ? MINIMUM_SCALE : MAXIMUM_SCALE
end

#check_bounds ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 229

def check_bounds
  y_offset = 0
  x_offset = 0

  if image_view.frame.origin.x > crop_rect.origin.x
    x_offset    = -(image_view.frame.origin.x - crop_rect.origin.x)
    new_right_x = CGRectGetMaxX(image_view.frame) + x_offset

    if new_right_x < CGRectGetMaxX(crop_rect)
      x_offset = CGRectGetMaxX(crop_rect) - CGRectGetMaxX(image_view.frame)
    end
  elsif CGRectGetMaxX(image_view.frame) < CGRectGetMaxX(crop_rect)
    x_offset = CGRectGetMaxX(crop_rect) - CGRectGetMaxX(image_view.frame)
    new_left_x = image_view.frame.origin.x + x_offset

    if new_left_x > crop_rect.origin.x
      x_offset = crop_rect.origin.x - image_view.frame.origin.x
    end
  end

  if image_view.frame.origin.y > crop_rect.origin.y
    y_offset = -(image_view.frame.origin.y - crop_rect.origin.y)
    new_bottom_y = CGRectGetMaxY(image_view.frame) + y_offset

    if new_bottom_y < CGRectGetMaxY(crop_rect)
      y_offset = CGRectGetMaxY(crop_rect) - CGRectGetMaxY(image_view.frame)
    end
  elsif CGRectGetMaxY(image_view.frame) < CGRectGetMaxY(crop_rect)
    y_offset = CGRectGetMaxY(crop_rect) - CGRectGetMaxY(image_view.frame)
    new_top_y = image_view.frame.origin.y + y_offset

    if new_top_y > crop_rect.origin.y
      y_offset = crop_rect.origin.y - image_view.frame.origin.y
    end
  end

  if x_offset || y_offset
    view.userInteractionEnabled = false
    transform = CGAffineTransformTranslate(image_view.transform, x_offset / scale, y_offset / scale)
    UIView.animateWithDuration(
      ANIMATION_DURATION,
      delay:      0,
      options:    UIViewAnimationOptionCurveEaseOut,
      animations: -> { image_view.transform = transform },
      completion: -> (finished) { view.userInteractionEnabled = true })
  end
end

#crop_view ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 408

def crop_view
  @crop_view ||= Motion::ImageEditorView.alloc.init.tap do |view|
    view.translatesAutoresizingMaskIntoConstraints = false
  end
end

#enforce_bounds? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/project/controllers/image_editor_controller.rb', line 434

def enforce_bounds?
  !!@enforce_bounds
end

#handle_gesture_state?(state) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/project/controllers/image_editor_controller.rb', line 73

def handle_gesture_state?(state)
  case state
  when UIGestureRecognizerStateEnded || UIGestureRecognizerStateCancelled
    new_scale = bounded_scale(scale)

    delta_x = scale_center.x - image_view.bounds.size.width / 2.0
    delta_y = scale_center.y - image_view.bounds.size.height / 2.0

    transform = CGAffineTransformTranslate(image_view.transform, delta_x, delta_y)

    transform = CGAffineTransformScale(transform, new_scale / scale , new_scale / scale)

    transform = CGAffineTransformTranslate(transform, -delta_x, -delta_y)

    view.userInteractionEnabled = false

    UIView.animateWithDuration(
      ANIMATION_DURATION,
      delay: 0,
      options: UIViewAnimationOptionCurveEaseOut,
      animations: -> { image_view.transform = transform },
      completion: -> (finished) {
        view.userInteractionEnabled = true
        @scale = new_scale
    })

    check_bounds if enforce_bounds?

    false
  else
    true
  end
end

#handle_pan(recognizer) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 307

def handle_pan(recognizer)
  if handle_gesture_state? recognizer.state
    translation = recognizer.translationInView(image_view)
    transform   = CGAffineTransformTranslate(image_view.transform, translation.x, translation.y)

    image_view.transform = transform

    recognizer.setTranslation(CGPointZero, inView: crop_view)
  end
end

#handle_pinch(recognizer) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 318

def handle_pinch(recognizer)
  if handle_gesture_state? recognizer.state
    if recognizer.state == UIGestureRecognizerStateBegan
      @scale_center = @touch_center
    end

    delta_x = scale_center.x - image_view.bounds.size.width / 2.0
    delta_y = scale_center.y - image_view.bounds.size.height / 2.0

    transform = CGAffineTransformTranslate(image_view.transform, delta_x, delta_y)
    transform = CGAffineTransformScale(transform, recognizer.scale, recognizer.scale)
    transform = CGAffineTransformTranslate(transform, -delta_x, -delta_y)

    @scale *= recognizer.scale

    image_view.transform = transform

    recognizer.scale = 1
  end
end

#handle_rotation(recognizer) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 339

def handle_rotation(recognizer)
  if rotation_enabled? && handle_gesture_state?(recognizer.state)
    delta_x = touch_center.x - image_view.bounds.size.width / 2
    delta_y = touch_center.y - image_view.bounds.size.height / 2

    transform = CGAffineTransformTranslate(image_view.transform, delta_x, delta_y)
    transform = CGAffineTransformRotate(transform, recognizer.rotation)
    transform = CGAffineTransformTranslate(transform, -delta_x, -delta_y)

    image_view.transform = transform

    recognizer.rotation = 0
  end
end

#handle_tap(recognizer) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 354

def handle_tap(recognizer)
  reset(animated: true)
end

#handle_touches(touches) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 293

def handle_touches(touches)
  @touch_center = CGPointZero

  if touches.count >= 2
    touches.each do |touch|
      touch_location = touch.locationInView(image_view)

      @touch_center = CGPointMake(touch_center.x + touch_location.x, touch_center.y + touch_location.y)
    end

    @touch_center = CGPointMake(touch_center.x / touches.count, touch_center.y / touches.count)
  end
end

#image_view ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 402

def image_view
  @image_view ||= UIImageView.alloc.init.tap do |view|
    view.translatesAutoresizingMaskIntoConstraints = false
  end
end

#initWithNibName(nib, bundle: bundle) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 9

def initWithNibName(nib, bundle: bundle)
  super.tap do |controller|
    controller.rotation_enabled = true
    controller.enforce_bounds   = false
  end
end

#pan_recognizer ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 371

def pan_recognizer
  @pan_recognizer ||= UIPanGestureRecognizer.alloc.initWithTarget(self, action: 'handle_pan:').tap do |recognizer|
    recognizer.cancelsTouchesInView = false
    recognizer.delegate             = self
  end
end

#pinch_recognizer ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 391

def pinch_recognizer
  @pinch_recognizer ||= UIPinchGestureRecognizer.alloc.initWithTarget(self, action: 'handle_pinch:').tap do |recognizer|
    recognizer.cancelsTouchesInView = false
    recognizer.delegate             = self
  end
end

#prefersStatusBarHidden ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 426

def prefersStatusBarHidden
  true
end

#preview_image ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 398

def preview_image
  @preview_image ||= source_image.resizedImageToFitInSize(view.bounds.size, scaleIfSmaller: false)
end

#process(&block) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 107

def process(&block)
  view.userInteractionEnabled = false

  Dispatch::Queue.concurrent.async do
    @result_ref = transform_image(
      image_view.transform,
      source_image:       source_image.CGImage,
      source_size:        source_image.size,
      source_orientation: source_image.imageOrientation,
      output_width:       output_width || source_image.size.width,
      crop_rect:          crop_rect,
      image_view_size:    image_view.bounds.size)

    Dispatch::Queue.main.async do
      transformed_image = UIImage.imageWithCGImage(
        @result_ref,
        scale: 1.0,
        orientation: UIImageOrientationUp)

      @result_ref = nil

      view.userInteractionEnabled = true

      block.call(transformed_image)
    end
  end
end

#reset(options = {}) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 193

def reset(options = {})
  animated = options.fetch(:animated, false)

  w = 0.0
  h = 0.0

  source_aspect = source_image.size.height / source_image.size.width
  crop_aspect   = crop_rect.size.height    / crop_rect.size.width

  if source_aspect > crop_aspect
    w = crop_rect.size.width
    h = source_aspect * w
  else
    h = crop_rect.size.height
    w = h / source_aspect
  end

  @scale = 1

  reset_block = -> {
    image_view.transform = CGAffineTransformIdentity
    image_view.frame     = CGRectMake(CGRectGetMidX(crop_rect) - w / 2, CGRectGetMidY(crop_rect) - h / 2, w, h)
    image_view.transform = CGAffineTransformMakeScale(scale, scale)
  }

  if animated
    view.userInteractionEnabled = false

    UIView.animateWithDuration(ANIMATION_DURATION, animations: reset_block, completion: -> (finished) {
        view.userInteractionEnabled = true
    })
  else
    reset_block.call
  end
end

#rotation_enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/project/controllers/image_editor_controller.rb', line 430

def rotation_enabled?
  !!@rotation_enabled
end

#rotation_recognizer ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 384

def rotation_recognizer
  @rotation_recognizer ||= UIRotationGestureRecognizer.alloc.initWithTarget(self, action: 'handle_rotation:').tap do |recognizer|
    recognizer.cancelsTouchesInView = false
    recognizer.delegate             = self
  end
end

#scale ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 414

def scale
  @scale ||= 1
end

#scale_center ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 422

def scale_center
  @scale_center ||= CGPointZero
end

#scale_reset_orientations ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 364

def scale_reset_orientations
  [ UIImageOrientationUpMirrored,
    UIImageOrientationDownMirrored,
    UIImageOrientationLeftMirrored,
    UIImageOrientationRightMirrored ]
end

#setup_constraints ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 46

def setup_constraints
  view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat(
    'H:|[crop]|',
    options: 0,
    metrics: nil,
    views:   { 'crop' => crop_view }))

  view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat(
    'V:|[crop]|',
    options: 0,
    metrics: nil,
    views:   { 'crop' => crop_view }))
end

#tap_recognizer ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 378

def tap_recognizer
  @tap_recognizer ||= UITapGestureRecognizer.alloc.initWithTarget(self, action: 'handle_tap:').tap do |recognizer|
    recognizer.numberOfTapsRequired = 2
  end
end

#touch_center ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 418

def touch_center
  @touch_center ||= CGPointZero
end

#touchesBegan(touches, withEvent: event) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 277

def touchesBegan(touches, withEvent: event)
  handle_touches(event.allTouches)
end

#touchesCancelled(touches, withEvent: event) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 289

def touchesCancelled(touches, withEvent: event)
  handle_touches(event.allTouches)
end

#touchesEnded(touches, withEvent: event) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 285

def touchesEnded(touches, withEvent: event)
  handle_touches(event.allTouches)
end

#touchesMoved(touches, withEvent: event) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 281

def touchesMoved(touches, withEvent: event)
  handle_touches(event.allTouches)
end

#transform_image(transform, source_image: source_image, source_size: source_size, source_orientation: source_orientation, output_width: output_width, crop_rect: crop_rect, image_view_size: image_view_size) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 135

def transform_image(transform, source_image: source_image, source_size: source_size, source_orientation: source_orientation, output_width: output_width, crop_rect: crop_rect, image_view_size: image_view_size)
  aspect = crop_rect.size.height / crop_rect.size.width
  output_size = CGSizeMake(output_width, output_width * aspect)

  transpose = false
  orientation_transform = CGAffineTransformIdentity

  case source_orientation
  when UIImageOrientationDown || UIImageOrientationDownMirrored
    orientation_transform = CGAffineTransformMakeRotation(Math::PI)
  when UIImageOrientationLeft || UIImageOrientationLeftMirrored
    orientation_transform = CGAffineTransformMakeRotation(Math::PI / 2.0)
    transpose             = true
  when UIImageOrientationRight || UIImageOrientationRightMirrored
    orientation_transform = CGAffineTransformMakeRotation(-(Math::PI / 2.0))
    transpose             = true
  end

  if scale_reset_orientations.include? source_orientation
    orientation_transform = CGAffineTransformScale(transform, -1, 1)
  end

  if transpose
    image_view_size = CGSizeMake(image_view_size.height, image_view_size.width)
  end

  context = CGBitmapContextCreate(
    nil,                                      # data
    output_size.width,                        # width
    output_size.height,                       # height
    CGImageGetBitsPerComponent(source_image), # bits per component
    0,                                        # bytes per row
    CGImageGetColorSpace(source_image),       # color space
    CGImageGetBitmapInfo(source_image))       # bitmap info

  CGContextSetFillColorWithColor(context,  UIColor.clearColor.CGColor)
  CGContextFillRect(context, CGRectMake(0, 0, output_size.width, output_size.height))

  ui_coords = CGAffineTransformMakeScale(output_size.width / crop_rect.size.width,
                                         output_size.height / crop_rect.size.height)

  ui_coords = CGAffineTransformTranslate(ui_coords, crop_rect.size.width / 2.0,
                                         crop_rect.size.height / 2.0)

  ui_coords = CGAffineTransformScale(ui_coords, 1.0, -1.0)
  CGContextConcatCTM(context, ui_coords)

  CGContextConcatCTM(context, transform)
  CGContextScaleCTM(context, 1.0, -1.0)
  CGContextConcatCTM(context, orientation_transform)

  drawing_rect = CGRectMake(-image_view_size.width / 2.0, -image_view_size.height / 2.0, image_view_size.width, image_view_size.height)

  CGContextDrawImage(context, drawing_rect, source_image)

  CGBitmapContextCreateImage(context)
end

#viewDidAppear(animated) ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 26

def viewDidAppear(animated)
  super

  image_view.image = preview_image

  reset
end

#viewDidLoad ⇒ Object 



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# File 'lib/project/controllers/image_editor_controller.rb', line 16

def viewDidLoad
  super

  add_subviews

  add_gesture_recognizers

  setup_constraints
end