Implements core logic for Pixel Canvas

ui/views/view.h

Index: ui/views/view.h
diff --git a/ui/views/view.h b/ui/views/view.h
index 7a8a7b327ebb5627de5a291fa7d0c06d35e3162e..33487f5391469e2d9bb3e2b89263b68e951944b7 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -37,6 +37,7 @@
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/path.h"
+#include "ui/views/paint_info.h"
 #include "ui/views/view_targeter.h"
 #include "ui/views/views_export.h"
 
@@ -543,7 +544,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // for View coordinates and language direction as required, allows the View
   // to paint itself via the various OnPaint*() event handlers and then paints
   // the hierarchy beneath it.
-  void Paint(const ui::PaintContext& parent_context);
+  void Paint(const PaintInfo& parent_paint_info);
 
   // The background object may be null.
   void SetBackground(std::unique_ptr<Background> b);
@@ -1152,7 +1153,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
 
   // Responsible for calling Paint() on child Views. Override to control the
   // order child Views are painted.
-  virtual void PaintChildren(const ui::PaintContext& context);
+  virtual void PaintChildren(const PaintInfo& info);
 
   // Override to provide rendering in any part of the View's bounds. Typically
   // this is the "contents" of the view. If you override this method you will
@@ -1271,6 +1272,12 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // hierarchy).
   virtual void OnNativeThemeChanged(const ui::NativeTheme* theme) {}
 
+  // Pixel Canvas --------------------------------------------------------------
+
+  // Returns the type of scaling to be done for this View. Values should be from
+  // PaintInfo::ScaleType.

[sky, 2017/07/26 22:12:12]

Remove second sentence as this is obvious given the return type.

[malaykeshav, 2017/07/28 01:24:38]

Done

+  virtual PaintInfo::ScaleType GetPaintScaleType() const;

[sky, 2017/07/26 22:12:12]

Move this up with the other painting functions. Say line 1170.

[sky, 2017/07/26 22:12:12]

Are we really going to have different scale types for different views? Wouldn't
we do the same scale type for all views?

[malaykeshav, 2017/07/28 01:24:38]

All except the ones that don't want any distortion in scaling. Specifically the
images and icons. There may be other cases as well where we do not want any
distorted scaling.

[malaykeshav, 2017/07/28 01:24:38]

Done.

+
   // Debugging -----------------------------------------------------------------
 
 #if !defined(NDEBUG)
@@ -1296,6 +1303,10 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   friend class ViewLayerTest;
   friend class Widget;
 
+  FRIEND_TEST_ALL_PREFIXES(ViewTest, PaintWithMovedViewUsesCache);
+  FRIEND_TEST_ALL_PREFIXES(ViewTest, PaintWithMovedViewUsesCacheInRTL);
+  FRIEND_TEST_ALL_PREFIXES(ViewTest, PaintWithUnknownInvalidation);
+
   // Painting  -----------------------------------------------------------------
 
   enum SchedulePaintType {
@@ -1319,17 +1330,19 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // during painting.
   bool ShouldPaint() const;
 
-  // Returns the offset that should be used when constructing the paint context
+  // Returns the bounds that should be used when constructing the |PaintInfo|
   // for this view.
-  gfx::Vector2d GetPaintContextOffset() const;
+  gfx::Rect GetPaintRecordingBounds() const;
 
   // Adjusts the transform of |recorder| in advance of painting.
-  void SetupTransformRecorderForPainting(ui::TransformRecorder* recorder) const;
+  void SetupTransformRecorderForPainting(
+      ui::TransformRecorder* recorder,
+      const gfx::Vector2d& offset_from_parent) const;
 
   // Recursively calls the painting method |func| on all non-layered children,
   // in Z order.
-  void RecursivePaintHelper(void (View::*func)(const ui::PaintContext&),
-                            const ui::PaintContext& context);
+  void RecursivePaintHelper(void (View::*func)(const PaintInfo&),
+                            const PaintInfo& info);
 
   // Invokes Paint() and, if necessary, PaintDebugRects().  Should be called
   // only on the root of a widget/layer.  PaintDebugRects() is invoked as a
@@ -1340,7 +1353,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // Draws a semitransparent rect to indicate the bounds of this view.
   // Recursively does the same for all children.  Invoked only with
   // --draw-view-bounds-rects.
-  void PaintDebugRects(const ui::PaintContext& parent_context);
+  void PaintDebugRects(const PaintInfo& paint_info);
 
   // Tree operations -----------------------------------------------------------