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