ui/gfx/canvas.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/gfx/canvas.h"
   6
   7 #include <limits>
   8
   9 #include "base/i18n/rtl.h"
  10 #include "base/logging.h"
  11 #include "third_party/skia/include/core/SkBitmap.h"
  12 #include "third_party/skia/include/effects/SkGradientShader.h"
  13 #include "ui/gfx/canvas.h"
  14 #include "ui/gfx/font.h"
  15 #include "ui/gfx/rect.h"
  16 #include "ui/gfx/size_conversions.h"
  17 #include "ui/gfx/skia_util.h"
  18 #include "ui/gfx/transform.h"
  19
  20 #if defined(OS_WIN)
  21 #include "ui/gfx/canvas_skia_paint.h"
  22 #endif
  23
  24 namespace gfx {
  25
  26 Canvas::Canvas(const gfx::Size& size,
  27                ui::ScaleFactor scale_factor,
  28                bool is_opaque)
  29       : scale_factor_(scale_factor),
  30         canvas_(NULL) {
  31   gfx::Size pixel_size = gfx::ToCeiledSize(
  32       gfx::ScaleSize(size, ui::GetScaleFactorScale(scale_factor)));
  33   owned_canvas_ = skia::AdoptRef(skia::CreatePlatformCanvas(pixel_size.width(),
  34                                                             pixel_size.height(),
  35                                                             is_opaque));
  36   canvas_ = owned_canvas_.get();
  37 #if defined(OS_WIN) || defined(OS_MACOSX)
  38   // skia::PlatformCanvas instances are initialized to 0 by Cairo on Linux, but
  39   // uninitialized on Win and Mac.
  40   if (!is_opaque)
  41     owned_canvas_->clear(SkColorSetARGB(0, 0, 0, 0));
  42 #endif
  43
  44   SkScalar scale = SkFloatToScalar(ui::GetScaleFactorScale(scale_factor));
  45   canvas_->scale(scale, scale);
  46 }
  47
  48 Canvas::Canvas(const gfx::ImageSkiaRep& image_rep, bool is_opaque)
  49     : scale_factor_(image_rep.scale_factor()),
  50       owned_canvas_(skia::AdoptRef(
  51           skia::CreatePlatformCanvas(image_rep.pixel_width(),
  52                                      image_rep.pixel_height(),
  53                                      is_opaque))),
  54       canvas_(owned_canvas_.get()) {
  55   SkScalar scale = SkFloatToScalar(ui::GetScaleFactorScale(scale_factor_));
  56   canvas_->scale(scale, scale);
  57   DrawImageInt(gfx::ImageSkia(image_rep), 0, 0);
  58 }
  59
  60 Canvas::Canvas()
  61     : scale_factor_(ui::SCALE_FACTOR_100P),
  62       owned_canvas_(skia::AdoptRef(skia::CreatePlatformCanvas(0, 0, false))),
  63       canvas_(owned_canvas_.get()) {
  64 }
  65
  66 Canvas::~Canvas() {
  67 }
  68
  69 // static
  70 Canvas* Canvas::CreateCanvasWithoutScaling(SkCanvas* canvas,
  71                                            ui::ScaleFactor scale_factor) {
  72   return new Canvas(canvas, scale_factor);
  73 }
  74
  75 void Canvas::RecreateBackingCanvas(const gfx::Size& size,
  76                                    ui::ScaleFactor scale_factor,
  77                                    bool is_opaque) {
  78   scale_factor_ = scale_factor;
  79   gfx::Size pixel_size = gfx::ToFlooredSize(
  80       gfx::ScaleSize(size, ui::GetScaleFactorScale(scale_factor)));
  81   owned_canvas_ = skia::AdoptRef(skia::CreatePlatformCanvas(pixel_size.width(),
  82                                                             pixel_size.height(),
  83                                                             is_opaque));
  84   canvas_ = owned_canvas_.get();
  85   SkScalar scale = SkFloatToScalar(ui::GetScaleFactorScale(scale_factor_));
  86   canvas_->scale(scale, scale);
  87 }
  88
  89 // static
  90 int Canvas::GetStringWidth(const string16& text, const gfx::Font& font) {
  91   int width = 0, height = 0;
  92   Canvas::SizeStringInt(text, font, &width, &height, 0, NO_ELLIPSIS);
  93   return width;
  94 }
  95
  96 // static
  97 int Canvas::DefaultCanvasTextAlignment() {
  98   return base::i18n::IsRTL() ? TEXT_ALIGN_RIGHT : TEXT_ALIGN_LEFT;
  99 }
 100
 101 gfx::ImageSkiaRep Canvas::ExtractImageRep() const {
 102   const SkBitmap& device_bitmap = canvas_->getDevice()->accessBitmap(false);
 103
 104   // Make a bitmap to return, and a canvas to draw into it. We don't just want
 105   // to call extractSubset or the copy constructor, since we want an actual copy
 106   // of the bitmap.
 107   SkBitmap result;
 108   device_bitmap.copyTo(&result, SkBitmap::kARGB_8888_Config);
 109
 110   return gfx::ImageSkiaRep(result, scale_factor_);
 111 }
 112
 113 void Canvas::DrawDashedRect(const gfx::Rect& rect, SkColor color) {
 114   // Create a 2D bitmap containing alternating on/off pixels - we do this
 115   // so that you never get two pixels of the same color around the edges
 116   // of the focus rect (this may mean that opposing edges of the rect may
 117   // have a dot pattern out of phase to each other).
 118   static SkColor last_color;
 119   static SkBitmap* dots = NULL;
 120   if (!dots || last_color != color) {
 121     int col_pixels = 32;
 122     int row_pixels = 32;
 123
 124     delete dots;
 125     last_color = color;
 126     dots = new SkBitmap;
 127     dots->setConfig(SkBitmap::kARGB_8888_Config, col_pixels, row_pixels);
 128     dots->allocPixels();
 129     dots->eraseARGB(0, 0, 0, 0);
 130
 131     uint32_t* dot = dots->getAddr32(0, 0);
 132     for (int i = 0; i < row_pixels; i++) {
 133       for (int u = 0; u < col_pixels; u++) {
 134         if ((u % 2 + i % 2) % 2 != 0) {
 135           dot[i * row_pixels + u] = color;
 136         }
 137       }
 138     }
 139   }
 140
 141   // Make a shader for the bitmap with an origin of the box we'll draw. This
 142   // shader is refcounted and will have an initial refcount of 1.
 143   skia::RefPtr<SkShader> shader = skia::AdoptRef(
 144       SkShader::CreateBitmapShader(
 145           *dots, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode));
 146   // Assign the shader to the paint & release our reference. The paint will
 147   // now own the shader and the shader will be destroyed when the paint goes
 148   // out of scope.
 149   SkPaint paint;
 150   paint.setShader(shader.get());
 151
 152   DrawRect(gfx::Rect(rect.x(), rect.y(), rect.width(), 1), paint);
 153   DrawRect(gfx::Rect(rect.x(), rect.y() + rect.height() - 1, rect.width(), 1),
 154            paint);
 155   DrawRect(gfx::Rect(rect.x(), rect.y(), 1, rect.height()), paint);
 156   DrawRect(gfx::Rect(rect.x() + rect.width() - 1, rect.y(), 1, rect.height()),
 157            paint);
 158 }
 159
 160 void Canvas::Save() {
 161   canvas_->save();
 162 }
 163
 164 void Canvas::SaveLayerAlpha(uint8 alpha) {
 165   canvas_->saveLayerAlpha(NULL, alpha);
 166 }
 167
 168
 169 void Canvas::SaveLayerAlpha(uint8 alpha, const gfx::Rect& layer_bounds) {
 170   SkRect bounds(gfx::RectToSkRect(layer_bounds));
 171   canvas_->saveLayerAlpha(&bounds, alpha);
 172 }
 173
 174 void Canvas::Restore() {
 175   canvas_->restore();
 176 }
 177
 178 bool Canvas::ClipRect(const gfx::Rect& rect) {
 179   return canvas_->clipRect(gfx::RectToSkRect(rect));
 180 }
 181
 182 bool Canvas::ClipPath(const SkPath& path) {
 183   return canvas_->clipPath(path);
 184 }
 185
 186 bool Canvas::GetClipBounds(gfx::Rect* bounds) {
 187   SkRect out;
 188   bool has_non_empty_clip = canvas_->getClipBounds(&out);
 189   bounds->SetRect(out.left(), out.top(), out.width(), out.height());
 190   return has_non_empty_clip;
 191 }
 192
 193 void Canvas::Translate(const gfx::Vector2d& offset) {
 194   canvas_->translate(SkIntToScalar(offset.x()), SkIntToScalar(offset.y()));
 195 }
 196
 197 void Canvas::Scale(int x_scale, int y_scale) {
 198   canvas_->scale(SkIntToScalar(x_scale), SkIntToScalar(y_scale));
 199 }
 200
 201 void Canvas::DrawColor(SkColor color) {
 202   DrawColor(color, SkXfermode::kSrcOver_Mode);
 203 }
 204
 205 void Canvas::DrawColor(SkColor color, SkXfermode::Mode mode) {
 206   canvas_->drawColor(color, mode);
 207 }
 208
 209 void Canvas::FillRect(const gfx::Rect& rect, SkColor color) {
 210   FillRect(rect, color, SkXfermode::kSrcOver_Mode);
 211 }
 212
 213 void Canvas::FillRect(const gfx::Rect& rect,
 214                       SkColor color,
 215                       SkXfermode::Mode mode) {
 216   SkPaint paint;
 217   paint.setColor(color);
 218   paint.setStyle(SkPaint::kFill_Style);
 219   paint.setXfermodeMode(mode);
 220   DrawRect(rect, paint);
 221 }
 222
 223 void Canvas::DrawRect(const gfx::Rect& rect, SkColor color) {
 224   DrawRect(rect, color, SkXfermode::kSrcOver_Mode);
 225 }
 226
 227 void Canvas::DrawRect(const gfx::Rect& rect,
 228                       SkColor color,
 229                       SkXfermode::Mode mode) {
 230   SkPaint paint;
 231   paint.setColor(color);
 232   paint.setStyle(SkPaint::kStroke_Style);
 233   // Set a stroke width of 0, which will put us down the stroke rect path.  If
 234   // we set a stroke width of 1, for example, this will internally create a
 235   // path and fill it, which causes problems near the edge of the canvas.
 236   paint.setStrokeWidth(SkIntToScalar(0));
 237   paint.setXfermodeMode(mode);
 238
 239   DrawRect(rect, paint);
 240 }
 241
 242 void Canvas::DrawRect(const gfx::Rect& rect, const SkPaint& paint) {
 243   canvas_->drawIRect(RectToSkIRect(rect), paint);
 244 }
 245
 246 void Canvas::DrawPoint(const gfx::Point& p1, const SkPaint& paint) {
 247   canvas_->drawPoint(SkIntToScalar(p1.x()), SkIntToScalar(p1.y()), paint);
 248 }
 249
 250 void Canvas::DrawLine(const gfx::Point& p1,
 251                       const gfx::Point& p2,
 252                       SkColor color) {
 253   SkPaint paint;
 254   paint.setColor(color);
 255   paint.setStrokeWidth(SkIntToScalar(1));
 256   DrawLine(p1, p2, paint);
 257 }
 258
 259 void Canvas::DrawLine(const gfx::Point& p1,
 260                       const gfx::Point& p2,
 261                       const SkPaint& paint) {
 262   canvas_->drawLine(SkIntToScalar(p1.x()), SkIntToScalar(p1.y()),
 263                     SkIntToScalar(p2.x()), SkIntToScalar(p2.y()), paint);
 264 }
 265
 266 void Canvas::DrawCircle(const gfx::Point& center_point,
 267                         int radius,
 268                         const SkPaint& paint) {
 269   canvas_->drawCircle(SkIntToScalar(center_point.x()),
 270       SkIntToScalar(center_point.y()), SkIntToScalar(radius), paint);
 271 }
 272
 273 void Canvas::DrawRoundRect(const gfx::Rect& rect,
 274                            int radius,
 275                            const SkPaint& paint) {
 276   canvas_->drawRoundRect(RectToSkRect(rect), SkIntToScalar(radius),
 277                          SkIntToScalar(radius), paint);
 278 }
 279
 280 void Canvas::DrawPath(const SkPath& path, const SkPaint& paint) {
 281   canvas_->drawPath(path, paint);
 282 }
 283
 284 void Canvas::DrawFocusRect(const gfx::Rect& rect) {
 285   DrawDashedRect(rect, SK_ColorGRAY);
 286 }
 287
 288 void Canvas::DrawImageInt(const gfx::ImageSkia& image, int x, int y) {
 289   SkPaint paint;
 290   DrawImageInt(image, x, y, paint);
 291 }
 292
 293 void Canvas::DrawImageInt(const gfx::ImageSkia& image, int x, int y, uint8 a) {
 294   SkPaint paint;
 295   paint.setAlpha(a);
 296   DrawImageInt(image, x, y, paint);
 297 }
 298
 299 void Canvas::DrawImageInt(const gfx::ImageSkia& image,
 300                           int x, int y,
 301                           const SkPaint& paint) {
 302   const gfx::ImageSkiaRep& image_rep = GetImageRepToPaint(image);
 303   if (image_rep.is_null())
 304     return;
 305   const SkBitmap& bitmap = image_rep.sk_bitmap();
 306   float bitmap_scale = image_rep.GetScale();
 307
 308   canvas_->save();
 309   canvas_->scale(SkFloatToScalar(1.0f / bitmap_scale),
 310                  SkFloatToScalar(1.0f / bitmap_scale));
 311   canvas_->drawBitmap(bitmap,
 312                       SkFloatToScalar(x * bitmap_scale),
 313                       SkFloatToScalar(y * bitmap_scale),
 314                       &paint);
 315   canvas_->restore();
 316 }
 317
 318 void Canvas::DrawImageInt(const gfx::ImageSkia& image,
 319                           int src_x, int src_y, int src_w, int src_h,
 320                           int dest_x, int dest_y, int dest_w, int dest_h,
 321                           bool filter) {
 322   SkPaint p;
 323   DrawImageInt(image, src_x, src_y, src_w, src_h, dest_x, dest_y,
 324                dest_w, dest_h, filter, p);
 325 }
 326
 327 void Canvas::DrawImageInt(const gfx::ImageSkia& image,
 328                           int src_x, int src_y, int src_w, int src_h,
 329                           int dest_x, int dest_y, int dest_w, int dest_h,
 330                           bool filter,
 331                           const SkPaint& paint) {
 332   DLOG_ASSERT(src_x + src_w < std::numeric_limits<int16_t>::max() &&
 333               src_y + src_h < std::numeric_limits<int16_t>::max());
 334   if (src_w <= 0 || src_h <= 0) {
 335     NOTREACHED() << "Attempting to draw bitmap from an empty rect!";
 336     return;
 337   }
 338
 339   if (!IntersectsClipRectInt(dest_x, dest_y, dest_w, dest_h))
 340     return;
 341
 342   float user_scale_x = static_cast<float>(dest_w) / src_w;
 343   float user_scale_y = static_cast<float>(dest_h) / src_h;
 344
 345   const gfx::ImageSkiaRep& image_rep = GetImageRepToPaint(image,
 346       user_scale_x, user_scale_y);
 347   if (image_rep.is_null())
 348     return;
 349
 350   SkRect dest_rect = { SkIntToScalar(dest_x),
 351                        SkIntToScalar(dest_y),
 352                        SkIntToScalar(dest_x + dest_w),
 353                        SkIntToScalar(dest_y + dest_h) };
 354
 355   if (src_w == dest_w && src_h == dest_h &&
 356       user_scale_x == 1.0f && user_scale_y == 1.0f &&
 357       image_rep.scale_factor() == ui::SCALE_FACTOR_100P) {
 358     // Workaround for apparent bug in Skia that causes image to occasionally
 359     // shift.
 360     SkIRect src_rect = { src_x, src_y, src_x + src_w, src_y + src_h };
 361     const SkBitmap& bitmap = image_rep.sk_bitmap();
 362     canvas_->drawBitmapRect(bitmap, &src_rect, dest_rect, &paint);
 363     return;
 364   }
 365
 366   // Make a bitmap shader that contains the bitmap we want to draw. This is
 367   // basically what SkCanvas.drawBitmap does internally, but it gives us
 368   // more control over quality and will use the mipmap in the source image if
 369   // it has one, whereas drawBitmap won't.
 370   SkMatrix shader_scale;
 371   shader_scale.setScale(SkFloatToScalar(user_scale_x),
 372                         SkFloatToScalar(user_scale_y));
 373   shader_scale.preTranslate(SkIntToScalar(-src_x), SkIntToScalar(-src_y));
 374   shader_scale.postTranslate(SkIntToScalar(dest_x), SkIntToScalar(dest_y));
 375
 376   skia::RefPtr<SkShader> shader = gfx::CreateImageRepShader(
 377       image_rep,
 378       SkShader::kRepeat_TileMode,
 379       shader_scale);
 380
 381   // Set up our paint to use the shader & release our reference (now just owned
 382   // by the paint).
 383   SkPaint p(paint);
 384   p.setFilterBitmap(filter);
 385   p.setShader(shader.get());
 386
 387   // The rect will be filled by the bitmap.
 388   canvas_->drawRect(dest_rect, p);
 389 }
 390
 391 void Canvas::DrawImageInPath(const gfx::ImageSkia& image,
 392                              int x,
 393                              int y,
 394                              const SkPath& path,
 395                              const SkPaint& paint) {
 396   const gfx::ImageSkiaRep& image_rep = GetImageRepToPaint(image);
 397   if (image_rep.is_null())
 398     return;
 399
 400   SkMatrix matrix;
 401   matrix.setTranslate(SkIntToScalar(x), SkIntToScalar(y));
 402   skia::RefPtr<SkShader> shader = gfx::CreateImageRepShader(
 403       image_rep,
 404       SkShader::kRepeat_TileMode,
 405       matrix);
 406
 407   SkPaint p(paint);
 408   p.setShader(shader.get());
 409   canvas_->drawPath(path, p);
 410 }
 411
 412 void Canvas::DrawStringInt(const string16& text,
 413                            const gfx::Font& font,
 414                            SkColor color,
 415                            int x, int y, int w, int h) {
 416   DrawStringInt(text, font, color, x, y, w, h, DefaultCanvasTextAlignment());
 417 }
 418
 419 void Canvas::DrawStringInt(const string16& text,
 420                            const gfx::Font& font,
 421                            SkColor color,
 422                            const gfx::Rect& display_rect) {
 423   DrawStringInt(text, font, color, display_rect.x(), display_rect.y(),
 424                 display_rect.width(), display_rect.height());
 425 }
 426
 427 void Canvas::DrawStringInt(const string16& text,
 428                            const gfx::Font& font,
 429                            SkColor color,
 430                            int x, int y, int w, int h,
 431                            int flags) {
 432   DrawStringWithShadows(text,
 433                         font,
 434                         color,
 435                         gfx::Rect(x, y, w, h),
 436                         0,
 437                         flags,
 438                         ShadowValues());
 439 }
 440
 441 void Canvas::TileImageInt(const gfx::ImageSkia& image,
 442                           int x, int y, int w, int h) {
 443   TileImageInt(image, 0, 0, x, y, w, h);
 444 }
 445
 446 void Canvas::TileImageInt(const gfx::ImageSkia& image,
 447                           int src_x, int src_y,
 448                           int dest_x, int dest_y, int w, int h) {
 449   TileImageInt(image, src_x, src_y, 1.0f, 1.0f, dest_x, dest_y, w, h);
 450 }
 451
 452 void Canvas::TileImageInt(const gfx::ImageSkia& image,
 453                           int src_x, int src_y,
 454                           float tile_scale_x, float tile_scale_y,
 455                           int dest_x, int dest_y, int w, int h) {
 456   if (!IntersectsClipRectInt(dest_x, dest_y, w, h))
 457     return;
 458
 459   const gfx::ImageSkiaRep& image_rep = GetImageRepToPaint(image,
 460       tile_scale_x, tile_scale_y);
 461   if (image_rep.is_null())
 462     return;
 463
 464   SkMatrix shader_scale;
 465   shader_scale.setScale(SkFloatToScalar(tile_scale_x),
 466                         SkFloatToScalar(tile_scale_y));
 467   shader_scale.preTranslate(SkIntToScalar(-src_x), SkIntToScalar(-src_y));
 468   shader_scale.postTranslate(SkIntToScalar(dest_x), SkIntToScalar(dest_y));
 469
 470   skia::RefPtr<SkShader> shader = gfx::CreateImageRepShader(
 471       image_rep,
 472       SkShader::kRepeat_TileMode,
 473       shader_scale);
 474
 475   SkPaint paint;
 476   paint.setShader(shader.get());
 477   paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
 478
 479   SkRect dest_rect = { SkIntToScalar(dest_x),
 480                        SkIntToScalar(dest_y),
 481                        SkIntToScalar(dest_x + w),
 482                        SkIntToScalar(dest_y + h) };
 483   canvas_->drawRect(dest_rect, paint);
 484 }
 485
 486 gfx::NativeDrawingContext Canvas::BeginPlatformPaint() {
 487   return skia::BeginPlatformPaint(canvas_);
 488 }
 489
 490 void Canvas::EndPlatformPaint() {
 491   skia::EndPlatformPaint(canvas_);
 492 }
 493
 494 void Canvas::Transform(const gfx::Transform& transform) {
 495   canvas_->concat(transform.matrix());
 496 }
 497
 498 Canvas::Canvas(SkCanvas* canvas, ui::ScaleFactor scale_factor)
 499     : scale_factor_(scale_factor),
 500       owned_canvas_(),
 501       canvas_(canvas) {
 502   DCHECK(canvas);
 503 }
 504
 505 bool Canvas::IntersectsClipRectInt(int x, int y, int w, int h) {
 506   SkRect clip;
 507   return canvas_->getClipBounds(&clip) &&
 508       clip.intersect(SkIntToScalar(x), SkIntToScalar(y), SkIntToScalar(x + w),
 509                      SkIntToScalar(y + h));
 510 }
 511
 512 bool Canvas::IntersectsClipRect(const gfx::Rect& rect) {
 513   return IntersectsClipRectInt(rect.x(), rect.y(),
 514                                rect.width(), rect.height());
 515 }
 516
 517 const gfx::ImageSkiaRep& Canvas::GetImageRepToPaint(
 518     const gfx::ImageSkia& image) const {
 519   return GetImageRepToPaint(image, 1.0f, 1.0f);
 520 }
 521
 522 const gfx::ImageSkiaRep& Canvas::GetImageRepToPaint(
 523     const gfx::ImageSkia& image,
 524     float user_additional_scale_x,
 525     float user_additional_scale_y) const {
 526   const gfx::ImageSkiaRep& image_rep = image.GetRepresentation(scale_factor_);
 527
 528   if (!image_rep.is_null()) {
 529     SkMatrix m = canvas_->getTotalMatrix();
 530     float scale_x = SkScalarToFloat(SkScalarAbs(m.getScaleX())) *
 531         user_additional_scale_x;
 532     float scale_y = SkScalarToFloat(SkScalarAbs(m.getScaleY())) *
 533         user_additional_scale_y;
 534
 535     float bitmap_scale = image_rep.GetScale();
 536     if (scale_x < bitmap_scale || scale_y < bitmap_scale)
 537       const_cast<SkBitmap&>(image_rep.sk_bitmap()).buildMipMap();
 538   }
 539
 540   return image_rep;
 541 }
 542
 543 }  // namespace gfx