Draw multi window resize controls programmatically

ash/wm/workspace/multi_window_resize_controller.cc

Index: ash/wm/workspace/multi_window_resize_controller.cc
diff --git a/ash/wm/workspace/multi_window_resize_controller.cc b/ash/wm/workspace/multi_window_resize_controller.cc
index dc02e31d3c97c5cc4ce55658b2ef68ed012480d9..f402a546cefe16303fe9228ded734c179f1e2d09 100644
--- a/ash/wm/workspace/multi_window_resize_controller.cc
+++ b/ash/wm/workspace/multi_window_resize_controller.cc
@@ -5,13 +5,11 @@
 #include "ash/wm/workspace/multi_window_resize_controller.h"
 
 #include "ash/public/cpp/shell_window_ids.h"
-#include "ash/resources/grit/ash_resources.h"
 #include "ash/root_window_controller.h"
 #include "ash/wm/workspace/workspace_window_resizer.h"
 #include "ash/wm_window.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/hit_test.h"
-#include "ui/base/resource/resource_bundle.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image.h"
@@ -64,45 +62,80 @@ class MultiWindowResizeController::ResizeView : public views::View {
  public:
   explicit ResizeView(MultiWindowResizeController* controller,
                       Direction direction)
-      : controller_(controller), direction_(direction), image_(NULL) {
-    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-    int image_id = direction == TOP_BOTTOM ? IDR_AURA_MULTI_WINDOW_RESIZE_H
-                                           : IDR_AURA_MULTI_WINDOW_RESIZE_V;
-    image_ = rb.GetImageNamed(image_id).ToImageSkia();
-  }
+      : controller_(controller), direction_(direction) {}
 
   // views::View overrides:
   gfx::Size GetPreferredSize() const override {
-    return gfx::Size(image_->width(), image_->height());
+    const bool vert = direction_ == LEFT_RIGHT;
+    return gfx::Size(vert ? kShortSide : kLongSide,
+                     vert ? kLongSide : kShortSide);
   }
   void OnPaint(gfx::Canvas* canvas) override {
-    canvas->DrawImageInt(*image_, 0, 0);
+    cc::PaintFlags flags;
+    flags.setColor(SkColorSetA(SK_ColorBLACK, 0x7F));
+    flags.setAntiAlias(true);
+    canvas->DrawRoundRect(gfx::RectF(GetLocalBounds()), 2, flags);

[varkha, 2017/04/27 03:04:29]

s/2/kButtonCornerRadius ?

[Evan Stade, 2017/04/27 17:36:29]

I prefer not to used named constants for values that are only used once. They
add verbosity and not a whole lot of clarity and create the false implication
that it is used somewhere else as well.

+
+    // Craft the left arrow.
+    SkRect arrow = SkRect::MakeXYWH(4, 28, 4, 8);

[varkha, 2017/04/27 03:04:29]

How about arrow_rect?

[varkha, 2017/04/27 03:04:29]

I can see that XYWH makes it less ambiguous but I would still prefer named
constants here.

[Evan Stade, 2017/04/27 17:36:29]

changed to kArrowRect

[Evan Stade, 2017/04/27 17:36:29]

Indeed, the XYHW serve as names. The only difference I see is that these are all
on the same line and the code is documenting itself (variable names can be self
documenting but they aren't actually enforced by anything, whereas there's
greater assuredness a library function called XYWH really means XYWH).

+    SkPath path;
+    path.moveTo(arrow.right(), arrow.y());
+    path.lineTo(arrow.x(), arrow.centerY());
+    path.lineTo(arrow.right(), arrow.bottom());
+    path.close();
+
+    // Do the same for the right arrow.
+    arrow = arrow.makeOffset(kShortSide - arrow.width() - arrow.x() * 2, 0);
+    path.moveTo(arrow.x(), arrow.y());
+    path.lineTo(arrow.right(), arrow.centerY());
+    path.lineTo(arrow.x(), arrow.bottom());
+    path.close();
+
+    // The arrows are drawn for the vertical orientation; flip if need be.
+    if (direction_ == TOP_BOTTOM) {
+      SkMatrix transform;
+      constexpr int kHalfShort = kShortSide / 2;
+      constexpr int kHalfLong = kLongSide / 2;
+      transform.setRotate(90, kHalfShort, kHalfLong);
+      transform.postTranslate(kHalfLong - kHalfShort, kHalfShort - kHalfLong);
+      path.transform(transform);
+    }
+
+    flags.setColor(SK_ColorWHITE);
+    canvas->DrawPath(path, flags);
   }
+
   bool OnMousePressed(const ui::MouseEvent& event) override {
     gfx::Point location(event.location());
     views::View::ConvertPointToScreen(this, &location);
     controller_->StartResize(location);
     return true;
   }
+
   bool OnMouseDragged(const ui::MouseEvent& event) override {
     gfx::Point location(event.location());
     views::View::ConvertPointToScreen(this, &location);
     controller_->Resize(location, event.flags());
     return true;
   }
+
   void OnMouseReleased(const ui::MouseEvent& event) override {
     controller_->CompleteResize();
   }
+
   void OnMouseCaptureLost() override { controller_->CancelResize(); }
+
   gfx::NativeCursor GetCursor(const ui::MouseEvent& event) override {
     int component = (direction_ == LEFT_RIGHT) ? HTRIGHT : HTBOTTOM;
     return ::wm::CompoundEventFilter::CursorForWindowComponent(component);
   }
 
  private:
+  static constexpr int kLongSide = 64;
+  static constexpr int kShortSide = 28;
+
   MultiWindowResizeController* controller_;
   const Direction direction_;
-  const gfx::ImageSkia* image_;
 
   DISALLOW_COPY_AND_ASSIGN(ResizeView);
 };