[Remoting iOS] Basic viewport manipulation support

remoting/client/ios/display/gl_display_handler.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_CLIENT_IOS_DISPLAY_GL_DISPLAY_HANDLER_H_
 #define REMOTING_CLIENT_IOS_DISPLAY_GL_DISPLAY_HANDLER_H_
 
 #import <Foundation/Foundation.h>
 #import <GLKit/GLKit.h>
 
 #import "remoting/client/display/sys_opengl.h"
 
 #include "base/memory/ptr_util.h"
+#include "remoting/client/view_matrix.h"
 
 namespace remoting {
 
 class ChromotingClientRuntime;
 
 namespace protocol {
 
 class VideoRenderer;
 class CursorShapeStub;
 
 }  // namespace protocol
 }  // namespace remoting
 
+// This protocol is for receiving notifications from the renderer when its state
+// changes. Implementations can use this to reposition viewport, process
+// animations, etc.
+@protocol GlDisplayHandlerDelegate<NSObject>
+
+// Notifies the delegate that the size of the desktop image has changed.
+- (void)canvasSizeChanged:(CGSize)size;
+
+@end
+
 @interface GlDisplayHandler : NSObject {
 }
 
 - (void)stop;
 
 // Called once the GLKView created.
 - (void)onSurfaceCreated:(GLKView*)view;
 
 // Called every time the GLKView dimension is initialized or changed.
 - (void)onSurfaceChanged:(const CGRect&)frame;
 
+- (void)onPixelTransformationChanged:(const remoting::ViewMatrix&)matrix;
+
 - (std::unique_ptr<remoting::protocol::VideoRenderer>)CreateVideoRenderer;
 - (std::unique_ptr<remoting::protocol::CursorShapeStub>)CreateCursorShapeStub;
 
 - (EAGLContext*)GetEAGLContext;
 
+// This is write-only but @property doesn't support write-only modifier.
+@property id<GlDisplayHandlerDelegate> delegate;
+- (id<GlDisplayHandlerDelegate>)delegate UNAVAILABLE_ATTRIBUTE;
+
 @end
 
 #endif  // REMOTING_CLIENT_IOS_DISPLAY_GL_DISPLAY_HANDLER_H_