Use nine image painter to draw tray background

ash/system/tray/tray_background_view.cc

Index: ash/system/tray/tray_background_view.cc
diff --git a/ash/system/tray/tray_background_view.cc b/ash/system/tray/tray_background_view.cc
index e8b0f2fafe035b6f43f0a13f16798aa05605c4a0..c20a6ae7bbe27f366069475e7280c3d8b5ebd6b4 100644
--- a/ash/system/tray/tray_background_view.cc
+++ b/ash/system/tray/tray_background_view.cc
@@ -21,7 +21,7 @@
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
-#include "ui/base/resource/resource_bundle.h"
+#include "ui/base/nine_image_painter_factory.h"
 #include "ui/base/ui_base_switches_util.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_element.h"
@@ -31,6 +31,7 @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_operations.h"
+#include "ui/gfx/nine_image_painter.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/skia_util.h"
@@ -100,53 +101,6 @@ class TrayBackground : public views::Background {
   explicit TrayBackground(TrayBackgroundView* tray_background_view) :
       tray_background_view_(tray_background_view) {
     set_alpha(kTrayBackgroundAlpha);
-    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-    leading_images_[kImageHorizontal][kImageTypeDefault] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_LEFT).ToImageSkia();
-    middle_images_[kImageHorizontal][kImageTypeDefault] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_CENTER).ToImageSkia();
-    trailing_images_[kImageHorizontal][kImageTypeDefault] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_RIGHT).ToImageSkia();
-
-    leading_images_[kImageHorizontal][kImageTypeOnBlack] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_LEFT_ONBLACK).ToImageSkia();
-    middle_images_[kImageHorizontal][kImageTypeOnBlack] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_CENTER_ONBLACK).ToImageSkia();
-    trailing_images_[kImageHorizontal][kImageTypeOnBlack] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_RIGHT_ONBLACK).ToImageSkia();
-
-    leading_images_[kImageHorizontal][kImageTypePressed] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_LEFT_PRESSED).ToImageSkia();
-    middle_images_[kImageHorizontal][kImageTypePressed] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_CENTER_PRESSED).ToImageSkia();
-    trailing_images_[kImageHorizontal][kImageTypePressed] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_HORIZ_RIGHT_PRESSED).ToImageSkia();
-
-    leading_images_[kImageVertical][kImageTypeDefault] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_VERTICAL_TOP).ToImageSkia();
-    middle_images_[kImageVertical][kImageTypeDefault] =
-        rb.GetImageNamed(
-            IDR_AURA_TRAY_BG_VERTICAL_CENTER).ToImageSkia();
-    trailing_images_[kImageVertical][kImageTypeDefault] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_VERTICAL_BOTTOM).ToImageSkia();
-
-    leading_images_[kImageVertical][kImageTypeOnBlack] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_VERTICAL_TOP_ONBLACK).ToImageSkia();
-    middle_images_[kImageVertical][kImageTypeOnBlack] =
-        rb.GetImageNamed(
-            IDR_AURA_TRAY_BG_VERTICAL_CENTER_ONBLACK).ToImageSkia();
-    trailing_images_[kImageVertical][kImageTypeOnBlack] =
-        rb.GetImageNamed(
-            IDR_AURA_TRAY_BG_VERTICAL_BOTTOM_ONBLACK).ToImageSkia();
-
-    leading_images_[kImageVertical][kImageTypePressed] =
-        rb.GetImageNamed(IDR_AURA_TRAY_BG_VERTICAL_TOP_PRESSED).ToImageSkia();
-    middle_images_[kImageVertical][kImageTypePressed] =
-        rb.GetImageNamed(
-            IDR_AURA_TRAY_BG_VERTICAL_CENTER_PRESSED).ToImageSkia();
-    trailing_images_[kImageVertical][kImageTypePressed] =
-        rb.GetImageNamed(
-            IDR_AURA_TRAY_BG_VERTICAL_BOTTOM_PRESSED).ToImageSkia();
   }
 
   ~TrayBackground() override {}
@@ -163,6 +117,19 @@ class TrayBackground : public views::Background {
 
   // Overridden from views::Background.
   void Paint(gfx::Canvas* canvas, views::View* view) const override {
+    const int kImages[kNumOrientations][kNumStates][9] = {

[stevenjb, 2014/12/15 17:19:10]

nit: 9 should be a const defined with the macro, otheriwse one has to look at
the macro definition to understand what is going on here.

[sadrul, 2014/12/15 19:45:56]

Someone using a NineImagePainter should be aware of what it does, and where this
9 comes from, no?

[stevenjb, 2014/12/15 20:03:23]

Just saying that, even with the diff right here in the CL it took me an extra
moment to puzzle out where the 9 came from. Besides, we're supposed to avoid
"magic numbers" like this anyway :P

[sadrul, 2014/12/15 20:55:41]

Consider the alternative: we would have a constant kNineImageGridSize = 9
(because kImageGridNum is too generic), and that wouldn't be nice.

If we were to make it easier to read, we should define a const int locally here:

  const int kGridSizeForPainter = 9;
  const int kImages[...][kGridSizeForPainter] = { ... };

+      { // Horizontal
+        IMAGE_GRID_HORIZONTAL(IDR_AURA_TRAY_BG_HORIZ),
+        IMAGE_GRID_HORIZONTAL(IDR_AURA_TRAY_BG_HORIZ_ONBLACK),
+        IMAGE_GRID_HORIZONTAL(IDR_AURA_TRAY_BG_HORIZ_PRESSED),
+      },
+      { // Vertical
+        IMAGE_GRID_VERTICAL(IDR_AURA_TRAY_BG_VERTICAL),
+        IMAGE_GRID_VERTICAL(IDR_AURA_TRAY_BG_VERTICAL_ONBLACK),
+        IMAGE_GRID_VERTICAL(IDR_AURA_TRAY_BG_VERTICAL_PRESSED),
+      }
+    };
+
     int orientation = kImageHorizontal;
     ShelfWidget* shelf_widget = GetShelfWidget();
     if (shelf_widget &&
@@ -177,57 +144,14 @@ class TrayBackground : public views::Background {
     else
       state = kImageTypeDefault;
 
-    const gfx::ImageSkia* leading = leading_images_[orientation][state];
-    const gfx::ImageSkia* middle = middle_images_[orientation][state];
-    const gfx::ImageSkia* trailing = trailing_images_[orientation][state];
-
-    gfx::Rect bounds(view->GetLocalBounds());
-    gfx::Point leading_location, trailing_location;
-    gfx::Rect middle_bounds;
-
-    if (orientation == kImageHorizontal) {
-      leading_location = gfx::Point(0, 0);
-      trailing_location = gfx::Point(bounds.width() - trailing->width(), 0);
-      middle_bounds = gfx::Rect(
-          leading->width(),
-          0,
-          bounds.width() - (leading->width() + trailing->width()),
-          bounds.height());
-    } else {
-      leading_location = gfx::Point(0, 0);
-      trailing_location = gfx::Point(0, bounds.height() - trailing->height());
-      middle_bounds = gfx::Rect(
-          0,
-          leading->height(),
-          bounds.width(),
-          bounds.height() - (leading->height() + trailing->height()));
-    }
-
-    canvas->DrawImageInt(*leading,
-                         leading_location.x(),
-                         leading_location.y());
-
-    canvas->DrawImageInt(*trailing,
-                         trailing_location.x(),
-                         trailing_location.y());
-
-    canvas->TileImageInt(*middle,
-                         middle_bounds.x(),
-                         middle_bounds.y(),
-                         middle_bounds.width(),
-                         middle_bounds.height());
+    ui::CreateNineImagePainter(kImages[orientation][state])
+        ->Paint(canvas, view->GetLocalBounds());
   }
 
   SkColor color_;
   // Reference to the TrayBackgroundView for which this is a background.
   TrayBackgroundView* tray_background_view_;
 
-  // References to the images used as backgrounds, they are owned by the
-  // resource bundle class.
-  const gfx::ImageSkia* leading_images_[kNumOrientations][kNumStates];
-  const gfx::ImageSkia* middle_images_[kNumOrientations][kNumStates];
-  const gfx::ImageSkia* trailing_images_[kNumOrientations][kNumStates];
-
   DISALLOW_COPY_AND_ASSIGN(TrayBackground);
 };