[CRD iOS] Move UI stuff into a subdirectory

remoting/client/desktop_viewport.cc

-// 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.
-
-#include "remoting/client/desktop_viewport.h"
-
-#include <algorithm>
-
-#include "base/logging.h"
-
-namespace remoting {
-
-namespace {
-
-float MAX_ZOOM_LEVEL = 100.f;
-
-}  // namespace
-
-DesktopViewport::DesktopViewport() : desktop_to_surface_transform_() {}
-
-DesktopViewport::~DesktopViewport() {}
-
-void DesktopViewport::SetDesktopSize(int desktop_width, int desktop_height) {
-  if (desktop_width == desktop_size_.x && desktop_height == desktop_size_.y) {
-    return;
-  }
-
-  desktop_size_.x = desktop_width;
-  desktop_size_.y = desktop_height;
-  ResizeToFit();
-}
-
-void DesktopViewport::SetSurfaceSize(int surface_width, int surface_height) {
-  if (surface_width == surface_size_.x && surface_height == surface_size_.y) {
-    return;
-  }
-
-  surface_size_.x = surface_width;
-  surface_size_.y = surface_height;
-  ResizeToFit();
-}
-
-void DesktopViewport::MoveDesktop(float dx, float dy) {
-  desktop_to_surface_transform_.PostTranslate({dx, dy});
-  UpdateViewport();
-}
-
-void DesktopViewport::ScaleDesktop(float px, float py, float scale) {
-  desktop_to_surface_transform_.PostScale({px, py}, scale);
-  UpdateViewport();
-}
-
-void DesktopViewport::MoveViewport(float dx, float dy) {
-  MoveViewportWithoutUpdate(dx, dy);
-  UpdateViewport();
-}
-
-void DesktopViewport::SetViewportCenter(float x, float y) {
-  ViewMatrix::Point old_center = GetViewportCenter();
-  MoveViewport(x - old_center.x, y - old_center.y);
-}
-
-void DesktopViewport::RegisterOnTransformationChangedCallback(
-    const TransformationCallback& callback,
-    bool run_immediately) {
-  on_transformation_changed_ = callback;
-  if (IsViewportReady() && run_immediately) {
-    callback.Run(desktop_to_surface_transform_);
-  }
-}
-
-const ViewMatrix& DesktopViewport::GetTransformation() const {
-  return desktop_to_surface_transform_;
-}
-
-void DesktopViewport::ResizeToFit() {
-  if (!IsViewportReady()) {
-    return;
-  }
-
-  // <---Desktop Width---->
-  // +==========+---------+
-  // |          |         |
-  // | Viewport | Desktop |
-  // |          |         |
-  // +==========+---------+
-  //
-  // +==========+ ^
-  // |          | |
-  // | Viewport | |
-  // |          | |
-  // +==========+ | Desktop
-  // |          | | Height
-  // | Desktop  | |
-  // |          | |
-  // +----------+ v
-  // resize the desktop such that it fits the viewport in one dimension.
-
-  float scale = std::max(surface_size_.x / desktop_size_.x,
-                         surface_size_.y / desktop_size_.y);
-  desktop_to_surface_transform_.SetScale(scale);
-  desktop_to_surface_transform_.SetOffset({0.f, 0.f});
-  UpdateViewport();
-}
-
-bool DesktopViewport::IsViewportReady() const {
-  return desktop_size_.x != 0 && desktop_size_.y != 0 && surface_size_.x != 0 &&
-         surface_size_.y != 0;
-}
-
-void DesktopViewport::UpdateViewport() {
-  if (!IsViewportReady()) {
-    // User may attempt to zoom and pan before the desktop image is received.
-    // This should be fine since the viewport will be reset once the image
-    // dimension is set.
-    VLOG(1) << "Viewport is not ready yet.";
-    return;
-  }
-
-  // Adjust zoom level.
-  float zoom_level = desktop_to_surface_transform_.GetScale();
-  if (zoom_level > MAX_ZOOM_LEVEL) {
-    // TODO(yuweih): This doesn't account for the effect of the pivot point,
-    //     which will shift the desktop closer to the origin.
-    desktop_to_surface_transform_.SetScale(MAX_ZOOM_LEVEL);
-  }
-
-  ViewMatrix::Vector2D desktop_size_on_surface_ =
-      desktop_to_surface_transform_.MapVector(desktop_size_);
-  if (desktop_size_on_surface_.x < surface_size_.x &&
-      desktop_size_on_surface_.y < surface_size_.y) {
-    //    +==============+
-    //    |      VP      |      +==========+
-    //    |              |      |    VP    |
-    //    | +----------+ |      +----------+
-    //    | |    DP    | |  ==> |    DP    |
-    //    | +----------+ |      +----------+
-    //    |              |      |          |
-    //    |              |      +==========+
-    //    +==============+
-    // Displayed desktop is too small in both directions, so apply the minimum
-    // zoom level needed to fit either the width or height.
-    float scale = std::min(surface_size_.x / desktop_size_.x,
-                           surface_size_.y / desktop_size_.y);
-    desktop_to_surface_transform_.SetScale(scale);
-  }
-
-  // Adjust position.
-  // Scenarios:
-  // 1. If the viewport can fully fit inside the desktop (smaller or equal width
-  //    and height) but it overlaps with the border, it will be moved in minimum
-  //    distance to be fitted inside the desktop.
-  //
-  //    +========+
-  //    | VP     |
-  //    |   +----|--------+     +========+-----+
-  //    |   |    |        |     |        |     |
-  //    +========+        |     |   VP   | DP  |
-  //        |       DP    | ==> |        |     |
-  //        |             |     +========+     |
-  //        |             |     |              |
-  //        +-------------+     +--------------+
-  //
-  // 2. If the viewport is larger than the desktop, the viewport will always
-  //    share the same center as the desktop.
-  //
-  //    +==========+------+==+     +======+------+======+
-  //    | VP       |  DP  |  | ==> | VP   |  DP  |      |
-  //    +==========+------+==+     +======+------+======+
-  //
-  // This is done on the desktop's reference frame to simplify things a bit.
-  ViewMatrix::Point old_center = GetViewportCenter();
-  ViewMatrix::Point new_center =
-      ConstrainPointToBounds(GetViewportCenterBounds(), old_center);
-  MoveViewportWithoutUpdate(new_center.x - old_center.x,
-                            new_center.y - old_center.y);
-
-  if (on_transformation_changed_) {
-    on_transformation_changed_.Run(desktop_to_surface_transform_);
-  }
-}
-
-DesktopViewport::Bounds DesktopViewport::GetViewportCenterBounds() const {
-  Bounds bounds;
-
-  // Viewport size on the desktop space.
-  ViewMatrix::Vector2D viewport_size =
-      desktop_to_surface_transform_.Invert().MapVector(surface_size_);
-
-  // Scenario 1: If VP can fully fit inside the desktop, then VP's center can be
-  // anywhere inside the desktop as long as VP doesn't overlap with the border.
-  bounds.left = viewport_size.x / 2.f;
-  bounds.right = desktop_size_.x - viewport_size.x / 2.f;
-  bounds.top = viewport_size.y / 2.f;
-  bounds.bottom = desktop_size_.y - viewport_size.y / 2.f;
-
-  // Scenario 2: If VP can't fully fit inside the desktop in dimension D, then
-  // its bounds in dimension D is tightly restricted to the center of the
-  // desktop.
-  if (bounds.left > bounds.right) {
-    float desktop_width_center = desktop_size_.x / 2.f;
-    bounds.left = desktop_width_center;
-    bounds.right = desktop_width_center;
-  }
-
-  if (bounds.top > bounds.bottom) {
-    float desktop_height_center = desktop_size_.y / 2.f;
-    bounds.top = desktop_height_center;
-    bounds.bottom = desktop_height_center;
-  }
-
-  return bounds;
-}
-
-ViewMatrix::Point DesktopViewport::GetViewportCenter() const {
-  return desktop_to_surface_transform_.Invert().MapPoint(
-      {surface_size_.x / 2.f, surface_size_.y / 2.f});
-}
-
-void DesktopViewport::MoveViewportWithoutUpdate(float dx, float dy) {
-  // <dx, dy> is defined on desktop's reference frame. Translation must be
-  // flipped and scaled.
-  desktop_to_surface_transform_.PostTranslate(
-      desktop_to_surface_transform_.MapVector({-dx, -dy}));
-}
-
-// static
-ViewMatrix::Point DesktopViewport::ConstrainPointToBounds(
-    const Bounds& bounds,
-    const ViewMatrix::Point& point) {
-  ViewMatrix::Point new_point = point;
-  if (new_point.x < bounds.left) {
-    new_point.x = bounds.left;
-  } else if (new_point.x > bounds.right) {
-    new_point.x = bounds.right;
-  }
-
-  if (new_point.y < bounds.top) {
-    new_point.y = bounds.top;
-  } else if (new_point.y > bounds.bottom) {
-    new_point.y = bounds.bottom;
-  }
-  return new_point;
-}
-
-}  // namespace remoting