ui/wm/core/image_grid.cc

   1 // Copyright (c) 2012 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 "ui/wm/core/image_grid.h"
   6
   7 #include <algorithm>
   8
   9 #include "third_party/skia/include/core/SkColor.h"
  10 #include "third_party/skia/include/core/SkXfermode.h"
  11 #include "ui/compositor/dip_util.h"
  12 #include "ui/compositor/paint_recorder.h"
  13 #include "ui/gfx/canvas.h"
  14 #include "ui/gfx/geometry/rect.h"
  15 #include "ui/gfx/geometry/rect_conversions.h"
  16 #include "ui/gfx/geometry/size.h"
  17 #include "ui/gfx/geometry/size_conversions.h"
  18 #include "ui/gfx/image/image.h"
  19 #include "ui/gfx/image/image_skia_operations.h"
  20 #include "ui/gfx/transform.h"
  21
  22 using std::max;
  23 using std::min;
  24
  25 namespace wm {
  26 namespace {
  27
  28 // Sets the scaling for the transform applied to a layer.  The left, top,
  29 // right and bottom layers are stretched to the height or width of the
  30 // center image.
  31
  32 void ScaleWidth(gfx::Size center, ui::Layer* layer, gfx::Transform& transform) {
  33   float layer_width = layer->bounds().width() * layer->device_scale_factor();
  34   float scale = static_cast<float>(center.width()) / layer_width;
  35   transform.Scale(scale, 1.0);
  36 }
  37
  38 void ScaleHeight(gfx::Size center,
  39                  ui::Layer* layer,
  40                  gfx::Transform& transform) {
  41   float layer_height = layer->bounds().height() * layer->device_scale_factor();
  42   float scale = static_cast<float>(center.height()) / layer_height;
  43   transform.Scale(1.0, scale);
  44 }
  45
  46 // Returns the dimensions of |image| if non-NULL or gfx::Size(0, 0) otherwise.
  47 gfx::Size GetImageSize(const gfx::Image* image) {
  48   return image ? gfx::Size(image->ToImageSkia()->width(),
  49                            image->ToImageSkia()->height())
  50                : gfx::Size();
  51 }
  52
  53 // Returns true if |layer|'s bounds don't fit within |size|.
  54 bool LayerExceedsSize(const ui::Layer* layer, const gfx::Size& size) {
  55   return layer->bounds().width() > size.width() ||
  56          layer->bounds().height() > size.height();
  57 }
  58
  59 }  // namespace
  60
  61 gfx::RectF ImageGrid::TestAPI::GetTransformedLayerBounds(
  62     const ui::Layer& layer) {
  63   gfx::RectF bounds = gfx::RectF(layer.bounds());
  64   layer.transform().TransformRect(&bounds);
  65   return bounds;
  66 }
  67
  68 ImageGrid::ImageGrid()
  69     : layer_(new ui::Layer(ui::LAYER_NOT_DRAWN)),
  70       top_image_height_(0),
  71       bottom_image_height_(0),
  72       left_image_width_(0),
  73       right_image_width_(0),
  74       base_top_row_height_(0),
  75       base_bottom_row_height_(0),
  76       base_left_column_width_(0),
  77       base_right_column_width_(0) {
  78 }
  79
  80 ImageGrid::~ImageGrid() {
  81 }
  82
  83 void ImageGrid::SetImages(const gfx::Image* top_left_image,
  84                           const gfx::Image* top_image,
  85                           const gfx::Image* top_right_image,
  86                           const gfx::Image* left_image,
  87                           const gfx::Image* center_image,
  88                           const gfx::Image* right_image,
  89                           const gfx::Image* bottom_left_image,
  90                           const gfx::Image* bottom_image,
  91                           const gfx::Image* bottom_right_image) {
  92   SetImage(top_left_image, &top_left_layer_, &top_left_painter_, NONE);
  93   SetImage(top_image, &top_layer_, &top_painter_, HORIZONTAL);
  94   SetImage(top_right_image, &top_right_layer_, &top_right_painter_, NONE);
  95   SetImage(left_image, &left_layer_, &left_painter_, VERTICAL);
  96   SetImage(center_image, &center_layer_, &center_painter_, NONE);
  97   SetImage(right_image, &right_layer_, &right_painter_, VERTICAL);
  98   SetImage(bottom_left_image, &bottom_left_layer_, &bottom_left_painter_, NONE);
  99   SetImage(bottom_image, &bottom_layer_, &bottom_painter_, HORIZONTAL);
 100   SetImage(
 101       bottom_right_image, &bottom_right_layer_, &bottom_right_painter_, NONE);
 102
 103   top_image_height_ = GetImageSize(top_image).height();
 104   bottom_image_height_ = GetImageSize(bottom_image).height();
 105   left_image_width_ = GetImageSize(left_image).width();
 106   right_image_width_ = GetImageSize(right_image).width();
 107
 108   base_top_row_height_ = max(GetImageSize(top_left_image).height(),
 109                              max(GetImageSize(top_image).height(),
 110                                  GetImageSize(top_right_image).height()));
 111   base_bottom_row_height_ = max(GetImageSize(bottom_left_image).height(),
 112                                 max(GetImageSize(bottom_image).height(),
 113                                     GetImageSize(bottom_right_image).height()));
 114   base_left_column_width_ = max(GetImageSize(top_left_image).width(),
 115                                 max(GetImageSize(left_image).width(),
 116                                     GetImageSize(bottom_left_image).width()));
 117   base_right_column_width_ = max(GetImageSize(top_right_image).width(),
 118                                  max(GetImageSize(right_image).width(),
 119                                      GetImageSize(bottom_right_image).width()));
 120
 121   // Invalidate previous |size_| so calls to SetSize() will recompute it.
 122   size_.SetSize(0, 0);
 123 }
 124
 125 void ImageGrid::SetSize(const gfx::Size& size) {
 126   if (size_ == size)
 127     return;
 128
 129   size_ = size;
 130
 131   gfx::Rect updated_bounds = layer_->bounds();
 132   updated_bounds.set_size(size);
 133   layer_->SetBounds(updated_bounds);
 134
 135   // Calculate the available amount of space for corner images on all sides of
 136   // the grid.  If the images don't fit, we need to clip them.
 137   const int left = min(base_left_column_width_, size_.width() / 2);
 138   const int right = min(base_right_column_width_, size_.width() - left);
 139   const int top = min(base_top_row_height_, size_.height() / 2);
 140   const int bottom = min(base_bottom_row_height_, size_.height() - top);
 141
 142   // The remaining space goes to the center image.
 143   int center_width = std::max(size.width() - left - right, 0);
 144   int center_height = std::max(size.height() - top - bottom, 0);
 145
 146   // At non-integer scale factors, the ratio of dimensions in DIP is not
 147   // necessarily the same as the ratio in physical pixels due to rounding.  Set
 148   // the transform on each of the layers based on dimensions in pixels.
 149   gfx::Size center_size_in_pixels = gfx::ToFlooredSize(gfx::ScaleSize(
 150       gfx::Size(center_width, center_height), layer_->device_scale_factor()));
 151
 152   if (top_layer_.get()) {
 153     if (center_width > 0) {
 154       gfx::Transform transform;
 155       transform.Translate(left, 0);
 156       ScaleWidth(center_size_in_pixels, top_layer_.get(), transform);
 157       top_layer_->SetTransform(transform);
 158     }
 159     top_layer_->SetVisible(center_width > 0);
 160   }
 161   if (bottom_layer_.get()) {
 162     if (center_width > 0) {
 163       gfx::Transform transform;
 164       transform.Translate(
 165           left, size.height() - bottom_layer_->bounds().height());
 166       ScaleWidth(center_size_in_pixels, bottom_layer_.get(), transform);
 167       bottom_layer_->SetTransform(transform);
 168     }
 169     bottom_layer_->SetVisible(center_width > 0);
 170   }
 171   if (left_layer_.get()) {
 172     if (center_height > 0) {
 173       gfx::Transform transform;
 174       transform.Translate(0, top);
 175       ScaleHeight(center_size_in_pixels, left_layer_.get(), transform);
 176       left_layer_->SetTransform(transform);
 177     }
 178     left_layer_->SetVisible(center_height > 0);
 179   }
 180   if (right_layer_.get()) {
 181     if (center_height > 0) {
 182       gfx::Transform transform;
 183       transform.Translate(
 184           size.width() - right_layer_->bounds().width(), top);
 185       ScaleHeight(center_size_in_pixels, right_layer_.get(), transform);
 186       right_layer_->SetTransform(transform);
 187     }
 188     right_layer_->SetVisible(center_height > 0);
 189   }
 190
 191   if (top_left_layer_.get()) {
 192     // No transformation needed; it should be at (0, 0) and unscaled.
 193     top_left_painter_->SetClipRect(
 194         LayerExceedsSize(top_left_layer_.get(), gfx::Size(left, top)) ?
 195             gfx::Rect(gfx::Rect(0, 0, left, top)) :
 196             gfx::Rect(),
 197         top_left_layer_.get());
 198   }
 199   if (top_right_layer_.get()) {
 200     gfx::Transform transform;
 201     transform.Translate(size.width() - top_right_layer_->bounds().width(), 0.0);
 202     top_right_layer_->SetTransform(transform);
 203     top_right_painter_->SetClipRect(
 204         LayerExceedsSize(top_right_layer_.get(), gfx::Size(right, top)) ?
 205             gfx::Rect(top_right_layer_->bounds().width() - right, 0,
 206                       right, top) :
 207             gfx::Rect(),
 208         top_right_layer_.get());
 209   }
 210   if (bottom_left_layer_.get()) {
 211     gfx::Transform transform;
 212     transform.Translate(
 213         0.0, size.height() - bottom_left_layer_->bounds().height());
 214     bottom_left_layer_->SetTransform(transform);
 215     bottom_left_painter_->SetClipRect(
 216         LayerExceedsSize(bottom_left_layer_.get(), gfx::Size(left, bottom)) ?
 217             gfx::Rect(0, bottom_left_layer_->bounds().height() - bottom,
 218                       left, bottom) :
 219             gfx::Rect(),
 220         bottom_left_layer_.get());
 221   }
 222   if (bottom_right_layer_.get()) {
 223     gfx::Transform transform;
 224     transform.Translate(
 225         size.width() - bottom_right_layer_->bounds().width(),
 226         size.height() - bottom_right_layer_->bounds().height());
 227     bottom_right_layer_->SetTransform(transform);
 228     bottom_right_painter_->SetClipRect(
 229         LayerExceedsSize(bottom_right_layer_.get(), gfx::Size(right, bottom)) ?
 230             gfx::Rect(bottom_right_layer_->bounds().width() - right,
 231                       bottom_right_layer_->bounds().height() - bottom,
 232                       right, bottom) :
 233             gfx::Rect(),
 234         bottom_right_layer_.get());
 235   }
 236
 237   if (center_layer_.get()) {
 238     if (center_width > 0 && center_height > 0) {
 239       gfx::Transform transform;
 240       transform.Translate(left, top);
 241       transform.Scale(center_width / center_layer_->bounds().width(),
 242                       center_height / center_layer_->bounds().height());
 243       center_layer_->SetTransform(transform);
 244     }
 245     center_layer_->SetVisible(center_width > 0 && center_height > 0);
 246   }
 247 }
 248
 249 void ImageGrid::SetContentBounds(const gfx::Rect& content_bounds) {
 250
 251   SetSize(gfx::Size(
 252       content_bounds.width() + left_image_width_ + right_image_width_,
 253       content_bounds.height() + top_image_height_ +
 254       bottom_image_height_));
 255   layer_->SetBounds(
 256       gfx::Rect(content_bounds.x() - left_image_width_,
 257                 content_bounds.y() - top_image_height_,
 258                 layer_->bounds().width(),
 259                 layer_->bounds().height()));
 260 }
 261
 262 void ImageGrid::ImagePainter::SetClipRect(const gfx::Rect& clip_rect,
 263                                           ui::Layer* layer) {
 264   if (clip_rect != clip_rect_) {
 265     clip_rect_ = clip_rect;
 266     layer->SchedulePaint(layer->bounds());
 267   }
 268 }
 269
 270 void ImageGrid::ImagePainter::OnPaintLayer(const ui::PaintContext& context) {
 271   gfx::Size bounding_size(clip_rect_.right(), clip_rect_.bottom());
 272   ui::PaintRecorder recorder(context, bounding_size);
 273   if (!clip_rect_.IsEmpty())
 274     recorder.canvas()->ClipRect(clip_rect_);
 275   recorder.canvas()->DrawImageInt(image_, 0, 0);
 276 }
 277
 278 void ImageGrid::ImagePainter::OnDelegatedFrameDamage(
 279     const gfx::Rect& damage_rect_in_dip) {
 280 }
 281
 282 void ImageGrid::ImagePainter::OnDeviceScaleFactorChanged(
 283     float device_scale_factor) {
 284   // Redrawing will take care of scale factor change.
 285 }
 286
 287 base::Closure ImageGrid::ImagePainter::PrepareForLayerBoundsChange() {
 288   return base::Closure();
 289 }
 290
 291 void ImageGrid::SetImage(const gfx::Image* image,
 292                          scoped_ptr<ui::Layer>* layer_ptr,
 293                          scoped_ptr<ImagePainter>* painter_ptr,
 294                          ImageType type) {
 295   // Minimum width (for HORIZONTAL) or height (for VERTICAL) of the
 296   // |image| so that layers are scaled property if the device scale
 297   // factor is non integral.
 298   const int kMinimumSize = 20;
 299
 300   // Clean out old layers and painters.
 301   if (layer_ptr->get())
 302     layer_->Remove(layer_ptr->get());
 303   layer_ptr->reset();
 304   painter_ptr->reset();
 305
 306   // If we're not using an image, we're done.
 307   if (!image)
 308     return;
 309
 310   gfx::ImageSkia image_skia = image->AsImageSkia();
 311   switch (type) {
 312     case HORIZONTAL:
 313       if (image_skia.width() < kMinimumSize) {
 314         image_skia = gfx::ImageSkiaOperations::CreateResizedImage(
 315             image_skia,
 316             skia::ImageOperations::RESIZE_GOOD,
 317             gfx::Size(kMinimumSize, image_skia.height()));
 318       }
 319       break;
 320     case VERTICAL:
 321       if (image_skia.height() < kMinimumSize) {
 322         image_skia = gfx::ImageSkiaOperations::CreateResizedImage(
 323             image_skia,
 324             skia::ImageOperations::RESIZE_GOOD,
 325             gfx::Size(image_skia.width(), kMinimumSize));
 326       }
 327       break;
 328     case NONE:
 329       break;
 330   }
 331
 332   // Set up the new layer and painter.
 333   layer_ptr->reset(new ui::Layer(ui::LAYER_TEXTURED));
 334
 335   const gfx::Size size = image_skia.size();
 336   layer_ptr->get()->SetBounds(gfx::Rect(0, 0, size.width(), size.height()));
 337
 338   painter_ptr->reset(new ImagePainter(image_skia));
 339   layer_ptr->get()->set_delegate(painter_ptr->get());
 340   layer_ptr->get()->SetFillsBoundsOpaquely(false);
 341   layer_ptr->get()->SetVisible(true);
 342   layer_->Add(layer_ptr->get());
 343 }
 344
 345 }  // namespace wm