Optionally clear PlatformCanvas instances.

skia/ext/platform_canvas_unittest.cc

 // Copyright (c) 2006-2008 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.
 
 // TODO(awalker): clean up the const/non-const reference handling in this test
 
 #include "build/build_config.h"
 
 #if defined(OS_MACOSX)
 #import <ApplicationServices/ApplicationServices.h>
@@ skipping 176 matching lines @@
 // Radius used by some tests to draw a rounded-corner rectangle.
 const SkScalar kRadius = 2.0;
 
 }
 
 // This just checks that our checking code is working properly, it just uses
 // regular skia primitives.
 TEST(PlatformCanvas, SkLayer) {
   // Create the canvas initialized to opaque white.
   PlatformCanvas canvas(16, 16, true);
+  canvas.drawARGB(0, 0, 0, 0);

[alokp, 2012/03/01 17:09:02]

eraseARGB? and everywhere else.

[Jeff Timanus, 2012/03/01 18:35:49]

I was confused by this too.

SkCanvas (& PlatformCanvas) expose drawARGB.
SkDevice exposes clear(...).
SkBitmap exposes eraseARGB(...).

All of these routines perform the same operation.

   canvas.drawColor(SK_ColorWHITE);
 
   // Make a layer and fill it completely to make sure that the bounds are
   // correct.
   {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     canvas.drawColor(SK_ColorBLACK);
   }
   EXPECT_TRUE(VerifyBlackRect(canvas, kLayerX, kLayerY, kLayerW, kLayerH));
 }
 
 // Test native clipping.
 TEST(PlatformCanvas, ClipRegion) {
   // Initialize a white canvas
   PlatformCanvas canvas(16, 16, true);
+  canvas.drawARGB(0, 0, 0, 0);
   canvas.drawColor(SK_ColorWHITE);
   EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorWHITE));
 
   // Test that initially the canvas has no clip region, by filling it
   // with a black rectangle.
   // Note: Don't use LayerSaver, since internally it sets a clip region.
   DrawNativeRect(canvas, 0, 0, 16, 16);
   EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorBLACK));
 
   // Test that intersecting disjoint clip rectangles sets an empty clip region
   canvas.drawColor(SK_ColorWHITE);
   EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorWHITE));
   {
     LayerSaver layer(canvas, 0, 0, 16, 16);
     AddClip(canvas, 2, 3, 4, 5);
     AddClip(canvas, 4, 9, 10, 10);
     DrawNativeRect(canvas, 0, 0, 16, 16);
   }
   EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorWHITE));
 }
 
 // Test the layers get filled properly by native rendering.
 TEST(PlatformCanvas, FillLayer) {
   // Create the canvas initialized to opaque white.
   PlatformCanvas canvas(16, 16, true);
+  canvas.drawARGB(0, 0, 0, 0);
 
   // Make a layer and fill it completely to make sure that the bounds are
   // correct.
   canvas.drawColor(SK_ColorWHITE);
   {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
     MakeOpaque(&canvas, 0, 0, 100, 100);
 #endif
@@ skipping 37 matching lines @@
 #endif
   }
   canvas.restore();
   EXPECT_TRUE(VerifyBlackRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH));
 }
 
 // Test that translation + make layer works properly.
 TEST(PlatformCanvas, TranslateLayer) {
   // Create the canvas initialized to opaque white.
   PlatformCanvas canvas(16, 16, true);
+  canvas.drawARGB(0, 0, 0, 0);
 
   // Make a layer and fill it completely to make sure that the bounds are
   // correct.
   canvas.drawColor(SK_ColorWHITE);
   canvas.save();
   canvas.translate(1, 1);
   {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
@@ skipping 76 matching lines @@
     MakeOpaque(&canvas, kLayerX, kLayerY, kLayerW, kLayerH);
 #endif
   }
   canvas.restore();
   EXPECT_TRUE(VerifyRoundedRect(canvas, SK_ColorWHITE, SK_ColorBLACK,
                                 kInnerX + 1, kInnerY + 1, kInnerW, kInnerH));
 #endif
 }
 
 }  // namespace skia