[CRD iOS] Move UI stuff into a subdirectory

remoting/client/desktop_viewport.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_DESKTOP_VIEWPORT_H_
-#define REMOTING_CLIENT_DESKTOP_VIEWPORT_H_
-
-#include "base/callback.h"
-#include "remoting/client/view_matrix.h"
-
-namespace remoting {
-
-// The viewport is a sliding window on the desktop image. This class defines
-// the viewport's position and size, provides methods to manipulate it, and
-// outputs a desktop space -> surface space transformation matrix for drawing
-// the desktop onto the client's view surface on the screen.
-//
-// Desktop space: Coordinates to locate a point on the host's desktop image in
-//     pixels, similar to the mouse's cursor position.
-// Surface space: Coordinates to locate a point on the client device's view
-//     surface (e.g. GLKView/SurfaceView) for rendering the desktop, this is
-//     often the coordinate system to locate a point on the user's phone
-//     screen (if the surface expands to the whole screen).
-//
-// Viewport: Projection of the user surface view on the desktop space.
-// Desktop: Projection of the host's desktop on the surface space.
-//
-// You may either manipulate the desktop on the surface coordinate or manipulate
-// the viewport on the desktop coordinate, depending on your choice of the
-// reference frame.
-class DesktopViewport {
- public:
-  using TransformationCallback = base::Callback<void(const ViewMatrix&)>;
-
-  DesktopViewport();
-  ~DesktopViewport();
-
-  // Sets the |desktop_size_| and initializes the viewport when necessary.
-  void SetDesktopSize(int desktop_width, int desktop_height);
-
-  // Sets the |surface_size_| and initializes the viewport when necessary.
-  void SetSurfaceSize(int surface_width, int surface_height);
-
-  // Translates the desktop on the surface's reference frame by <dx, dy>.
-  void MoveDesktop(float dx, float dy);
-
-  // Scales the desktop on the surface's reference frame at pivot point (px, py)
-  // by |scale|.
-  void ScaleDesktop(float px, float py, float scale);
-
-  // Moves the viewport center by <x, y> on the desktop's coordinate.
-  void MoveViewport(float dx, float dy);
-
-  // Sets the viewport center to (x, y) on the desktop's coordinate.
-  void SetViewportCenter(float x, float y);
-
-  // Registers the callback to be called once the transformation has changed.
-  // run_immediately: If true and the viewport is ready to be used, the callback
-  //     will be called immedately with the transformation matrix.
-  void RegisterOnTransformationChangedCallback(
-      const TransformationCallback& callback,
-      bool run_immediately);
-
-  // Returns the reference to the desktop-to-surface transformation.
-  const ViewMatrix& GetTransformation() const;
-
- private:
-  struct Bounds {
-    float left;
-    float right;
-    float top;
-    float bottom;
-  };
-
-  // Resizes the desktop such that the image is displayed without borders in
-  // minimum possible zoom-level. This will be called once both the desktop
-  // and the surface size are set.
-  void ResizeToFit();
-
-  // True if desktop size and surface size are set.
-  bool IsViewportReady() const;
-
-  // Adjusts the size and position of the viewport so that the constrains always
-  // hold, then feed the matrix to |on_transformation_changed_|.
-  void UpdateViewport();
-
-  // Gets a rectangle of all possible positions where the viewport's center can
-  // locate.
-  Bounds GetViewportCenterBounds() const;
-
-  // Returns the current center of the viewport on the desktop's coordinate.
-  ViewMatrix::Point GetViewportCenter() const;
-
-  // Translates the viewport on the desktop's reference frame by <dx, dy>,
-  // without calling UpdateViewport().
-  void MoveViewportWithoutUpdate(float dx, float dy);
-
-  // Moves the point inside the bounds with minimum displacement if it is out of
-  // the bounds.
-  static ViewMatrix::Point ConstrainPointToBounds(
-      const Bounds& bounds,
-      const ViewMatrix::Point& point);
-
-  ViewMatrix::Vector2D desktop_size_{0.f, 0.f};
-  ViewMatrix::Vector2D surface_size_{0.f, 0.f};
-
-  ViewMatrix desktop_to_surface_transform_;
-
-  TransformationCallback on_transformation_changed_;
-
-  // DesktopViewport is neither copyable nor movable.
-  DesktopViewport(const DesktopViewport&) = delete;
-  DesktopViewport& operator=(const DesktopViewport&) = delete;
-};
-
-}  // namespace remoting
-#endif  // REMOTING_CLIENT_DESKTOP_VIEWPORT_H_