ash/display/root_window_transformers.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ash/display/root_window_transformers.h"
   6
   7 #include <cmath>
   8
   9 #include "ash/ash_switches.h"
  10 #include "ash/display/display_info.h"
  11 #include "ash/display/display_manager.h"
  12 #include "ash/host/root_window_transformer.h"
  13 #include "ash/magnifier/magnification_controller.h"
  14 #include "ash/shell.h"
  15 #include "base/basictypes.h"
  16 #include "base/command_line.h"
  17 #include "base/memory/scoped_ptr.h"
  18 #include "third_party/skia/include/utils/SkMatrix44.h"
  19 #include "ui/aura/window_event_dispatcher.h"
  20 #include "ui/aura/window_property.h"
  21 #include "ui/compositor/dip_util.h"
  22 #include "ui/gfx/display.h"
  23 #include "ui/gfx/geometry/insets.h"
  24 #include "ui/gfx/geometry/size_conversions.h"
  25 #include "ui/gfx/transform.h"
  26 #include "ui/gfx/transform.h"
  27
  28 DECLARE_WINDOW_PROPERTY_TYPE(gfx::Display::Rotation);
  29
  30 namespace ash {
  31 namespace {
  32
  33 #if defined(OS_WIN)
  34 DEFINE_WINDOW_PROPERTY_KEY(gfx::Display::Rotation, kRotationPropertyKey,
  35                            gfx::Display::ROTATE_0);
  36 #endif
  37
  38 // Round near zero value to zero.
  39 void RoundNearZero(gfx::Transform* transform) {
  40   const float kEpsilon = 0.001f;
  41   SkMatrix44& matrix = transform->matrix();
  42   for (int x = 0; x < 4; ++x) {
  43     for (int y = 0; y < 4; ++y) {
  44       if (std::abs(SkMScalarToFloat(matrix.get(x, y))) < kEpsilon)
  45         matrix.set(x, y, SkFloatToMScalar(0.0f));
  46     }
  47   }
  48 }
  49
  50 // TODO(oshima): Transformers should be able to adjust itself
  51 // when the device scale factor is changed, instead of
  52 // precalculating the transform using fixed value.
  53
  54 gfx::Transform CreateRotationTransform(aura::Window* root_window,
  55                                        const gfx::Display& display) {
  56   DisplayInfo info =
  57       Shell::GetInstance()->display_manager()->GetDisplayInfo(display.id());
  58
  59   // TODO(oshima): Add animation. (crossfade+rotation, or just cross-fade)
  60 #if defined(OS_WIN)
  61   // Windows 8 bots refused to resize the host window, and
  62   // updating the transform results in incorrectly resizing
  63   // the root window. Don't apply the transform unless
  64   // necessary so that unit tests pass on win8 bots.
  65   if (info.rotation() == root_window->GetProperty(kRotationPropertyKey))
  66     return gfx::Transform();
  67   root_window->SetProperty(kRotationPropertyKey, info.rotation());
  68 #endif
  69
  70   gfx::Transform rotate;
  71   // The origin is (0, 0), so the translate width/height must be reduced by
  72   // 1 pixel.
  73   float one_pixel = 1.0f / display.device_scale_factor();
  74   switch (info.rotation()) {
  75     case gfx::Display::ROTATE_0:
  76       break;
  77     case gfx::Display::ROTATE_90:
  78       rotate.Translate(display.bounds().height() - one_pixel, 0);
  79       rotate.Rotate(90);
  80       break;
  81     case gfx::Display::ROTATE_270:
  82       rotate.Translate(0, display.bounds().width() - one_pixel);
  83       rotate.Rotate(270);
  84       break;
  85     case gfx::Display::ROTATE_180:
  86       rotate.Translate(display.bounds().width() - one_pixel,
  87                        display.bounds().height() - one_pixel);
  88       rotate.Rotate(180);
  89       break;
  90   }
  91
  92   RoundNearZero(&rotate);
  93   return rotate;
  94 }
  95
  96 gfx::Transform CreateMagnifierTransform(aura::Window* root_window) {
  97   MagnificationController* magnifier =
  98       Shell::GetInstance()->magnification_controller();
  99   float magnifier_scale = 1.f;
 100   gfx::Point magnifier_offset;
 101   if (magnifier && magnifier->IsEnabled()) {
 102     magnifier_scale = magnifier->GetScale();
 103     magnifier_offset = magnifier->GetWindowPosition();
 104   }
 105   gfx::Transform transform;
 106   if (magnifier_scale != 1.f) {
 107     transform.Scale(magnifier_scale, magnifier_scale);
 108     transform.Translate(-magnifier_offset.x(), -magnifier_offset.y());
 109   }
 110   return transform;
 111 }
 112
 113 gfx::Transform CreateInsetsAndScaleTransform(const gfx::Insets& insets,
 114                                              float device_scale_factor,
 115                                              float ui_scale) {
 116   gfx::Transform transform;
 117   if (insets.top() != 0 || insets.left() != 0) {
 118     float x_offset = insets.left() / device_scale_factor;
 119     float y_offset = insets.top() / device_scale_factor;
 120     transform.Translate(x_offset, y_offset);
 121   }
 122   float inverted_scale = 1.0f / ui_scale;
 123   transform.Scale(inverted_scale, inverted_scale);
 124   return transform;
 125 }
 126
 127 gfx::Transform CreateMirrorTransform(const gfx::Display& display) {
 128   gfx::Transform transform;
 129   transform.matrix().set3x3(-1, 0, 0,
 130                             0, 1, 0,
 131                             0, 0, 1);
 132   transform.Translate(-display.size().width(), 0);
 133   return transform;
 134 }
 135
 136 // RootWindowTransformer for ash environment.
 137 class AshRootWindowTransformer : public RootWindowTransformer {
 138  public:
 139   AshRootWindowTransformer(aura::Window* root,
 140                            const gfx::Display& display)
 141       : root_window_(root) {
 142     DisplayInfo info = Shell::GetInstance()->display_manager()->
 143         GetDisplayInfo(display.id());
 144     host_insets_ = info.GetOverscanInsetsInPixel();
 145     root_window_ui_scale_ = info.GetEffectiveUIScale();
 146     root_window_bounds_transform_ =
 147         CreateInsetsAndScaleTransform(host_insets_,
 148                                       display.device_scale_factor(),
 149                                       root_window_ui_scale_) *
 150         CreateRotationTransform(root, display);
 151     if (base::CommandLine::ForCurrentProcess()->HasSwitch(
 152             switches::kAshEnableMirroredScreen)) {
 153       // Apply the tranform that flips the screen image horizontally so that
 154       // the screen looks normal when reflected on a mirror.
 155       root_window_bounds_transform_ =
 156           root_window_bounds_transform_ * CreateMirrorTransform(display);
 157     }
 158     transform_ = root_window_bounds_transform_ * CreateMagnifierTransform(root);
 159
 160     CHECK(transform_.GetInverse(&invert_transform_));
 161   }
 162
 163   // aura::RootWindowTransformer overrides:
 164   gfx::Transform GetTransform() const override { return transform_; }
 165   gfx::Transform GetInverseTransform() const override {
 166     return invert_transform_;
 167   }
 168   gfx::Rect GetRootWindowBounds(const gfx::Size& host_size) const override {
 169     gfx::Rect bounds(host_size);
 170     bounds.Inset(host_insets_);
 171     bounds = ui::ConvertRectToDIP(root_window_->layer(), bounds);
 172     gfx::RectF new_bounds(bounds);
 173     root_window_bounds_transform_.TransformRect(&new_bounds);
 174     // Apply |root_window_scale_| twice as the downscaling
 175     // is already applied once in |SetTransformInternal()|.
 176     // TODO(oshima): This is a bit ugly. Consider specifying
 177     // the pseudo host resolution instead.
 178     new_bounds.Scale(root_window_ui_scale_ * root_window_ui_scale_);
 179     // Ignore the origin because RootWindow's insets are handled by
 180     // the transform.
 181     // Floor the size because the bounds is no longer aligned to
 182     // backing pixel when |root_window_scale_| is specified
 183     // (850 height at 1.25 scale becomes 1062.5 for example.)
 184     return gfx::Rect(gfx::ToFlooredSize(new_bounds.size()));
 185   }
 186
 187   gfx::Insets GetHostInsets() const override { return host_insets_; }
 188
 189  private:
 190   ~AshRootWindowTransformer() override {}
 191
 192   aura::Window* root_window_;
 193   gfx::Transform transform_;
 194
 195   // The accurate representation of the inverse of the |transform_|.
 196   // This is used to avoid computation error caused by
 197   // |gfx::Transform::GetInverse|.
 198   gfx::Transform invert_transform_;
 199
 200   // The transform of the root window bounds. This is used to calculate
 201   // the size of root window.
 202   gfx::Transform root_window_bounds_transform_;
 203
 204   // The scale of the root window. See |display_info::ui_scale_|
 205   // for more info.
 206   float root_window_ui_scale_;
 207
 208   gfx::Insets host_insets_;
 209
 210   DISALLOW_COPY_AND_ASSIGN(AshRootWindowTransformer);
 211 };
 212
 213 // RootWindowTransformer for mirror root window. We simply copy the
 214 // texture (bitmap) of the source display into the mirror window, so
 215 // the root window bounds is the same as the source display's
 216 // pixel size (excluding overscan insets).
 217 class MirrorRootWindowTransformer : public RootWindowTransformer {
 218  public:
 219   MirrorRootWindowTransformer(const DisplayInfo& source_display_info,
 220                               const DisplayInfo& mirror_display_info) {
 221     root_bounds_ = gfx::Rect(source_display_info.bounds_in_native().size());
 222     gfx::Rect mirror_display_rect =
 223         gfx::Rect(mirror_display_info.bounds_in_native().size());
 224
 225     bool letterbox = root_bounds_.width() * mirror_display_rect.height() >
 226         root_bounds_.height() * mirror_display_rect.width();
 227     if (letterbox) {
 228       float mirror_scale_ratio =
 229           (static_cast<float>(root_bounds_.width()) /
 230            static_cast<float>(mirror_display_rect.width()));
 231       float inverted_scale = 1.0f / mirror_scale_ratio;
 232       int margin = static_cast<int>(
 233           (mirror_display_rect.height() -
 234            root_bounds_.height() * inverted_scale) / 2);
 235       insets_.Set(0, margin, 0, margin);
 236
 237       transform_.Translate(0,  margin);
 238       transform_.Scale(inverted_scale, inverted_scale);
 239     } else {
 240       float mirror_scale_ratio =
 241           (static_cast<float>(root_bounds_.height()) /
 242            static_cast<float>(mirror_display_rect.height()));
 243       float inverted_scale = 1.0f / mirror_scale_ratio;
 244       int margin = static_cast<int>(
 245           (mirror_display_rect.width() -
 246            root_bounds_.width() * inverted_scale) / 2);
 247       insets_.Set(margin, 0, margin, 0);
 248
 249       transform_.Translate(margin, 0);
 250       transform_.Scale(inverted_scale, inverted_scale);
 251     }
 252   }
 253
 254   // aura::RootWindowTransformer overrides:
 255   gfx::Transform GetTransform() const override { return transform_; }
 256   gfx::Transform GetInverseTransform() const override {
 257     gfx::Transform invert;
 258     CHECK(transform_.GetInverse(&invert));
 259     return invert;
 260   }
 261   gfx::Rect GetRootWindowBounds(const gfx::Size& host_size) const override {
 262     return root_bounds_;
 263   }
 264   gfx::Insets GetHostInsets() const override { return insets_; }
 265
 266  private:
 267   ~MirrorRootWindowTransformer() override {}
 268
 269   gfx::Transform transform_;
 270   gfx::Rect root_bounds_;
 271   gfx::Insets insets_;
 272
 273   DISALLOW_COPY_AND_ASSIGN(MirrorRootWindowTransformer);
 274 };
 275
 276 }  // namespace
 277
 278 RootWindowTransformer* CreateRootWindowTransformerForDisplay(
 279     aura::Window* root,
 280     const gfx::Display& display) {
 281   return new AshRootWindowTransformer(root, display);
 282 }
 283
 284 RootWindowTransformer* CreateRootWindowTransformerForMirroredDisplay(
 285     const DisplayInfo& source_display_info,
 286     const DisplayInfo& mirror_display_info) {
 287   return new MirrorRootWindowTransformer(source_display_info,
 288                                          mirror_display_info);
 289 }
 290
 291 }  // namespace ash