Reuse submenu arrow images for trees (like the edit bookmark tree).

ui/views/controls/tree/tree_view.cc

 // Copyright (c) 2012 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.
 
 #include "ui/views/controls/tree/tree_view.h"
 
 #include <algorithm>
 
 #include "base/i18n/rtl.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/events/event.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/color_utils.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia_operations.h"
+#include "ui/gfx/paint_vector_icon.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/native_theme/native_theme.h"
 #include "ui/resources/grit/ui_resources.h"
 #include "ui/views/controls/focus_ring.h"
 #include "ui/views/controls/prefix_selector.h"
 #include "ui/views/controls/scroll_view.h"
 #include "ui/views/controls/textfield/textfield.h"
 #include "ui/views/controls/tree/tree_view_controller.h"
 #include "ui/views/resources/grit/views_resources.h"
 #include "ui/views/style/platform_style.h"
+#include "ui/views/vector_icons.h"
 
 using ui::TreeModel;
 using ui::TreeModelNode;
 
 namespace views {
 
 // Insets around the view.
 static const int kHorizontalInset = 2;
 static const int kVerticalInset = 2;
 // Padding before/after the image.
@@ skipping 774 matching lines @@
       text_bounds.width() - kTextHorizontalPadding * 2,
       text_bounds.height() - kTextVerticalPadding * 2);
   canvas->DrawStringRect(node->model_node()->GetTitle(), font_list_,
                          GetNativeTheme()->GetSystemColor(color_id),
                          internal_bounds);
 }
 
 void TreeView::PaintExpandControl(gfx::Canvas* canvas,
                                   const gfx::Rect& node_bounds,
                                   bool expanded) {
-  int center_x;
-  if (base::i18n::IsRTL()) {
-    center_x = node_bounds.right() - kArrowRegionSize +
-               (kArrowRegionSize - 4) / 2;
-  } else {
-    center_x = node_bounds.x() + (kArrowRegionSize - 4) / 2;
+  gfx::ImageSkia arrow = gfx::CreateVectorIcon(
+      kSubmenuArrowIcon,
+      color_utils::DeriveDefaultIconColor(
+          GetNativeTheme()->GetSystemColor(text_color_id(false, false))));

[Peter Kasting, 2017/02/15 01:05:31]

Any particular reason to move away from kColorId_TreeArrow?  If this is
equivalent or better, I'm fine with it, but in that case, this was the only user
of that color, so we should rip it out entirely.

If we keep this derivation, should we be matching the conditions on line 816
above here?

[Evan Stade, 2017/02/15 01:28:58]

Ah, forgot about that color. I think we should remove it. The derived version is
better because it will be more consistent with other ui (it will come out to
5a5a5a instead of 7a7a7a).
the selection highlight doesn't extend to the arrow, so I don't think we should
be changing its color ever. I'm ambivalent about using text_color_id() vs just
kColorId_TreeText

[Evan Stade, 2017/02/15 16:07:37]

done

+  if (expanded) {
+    arrow = gfx::ImageSkiaOperations::CreateRotatedImage(
+        arrow, base::i18n::IsRTL() ? SkBitmapOperations::ROTATION_270_CW
+                                   : SkBitmapOperations::ROTATION_90_CW);
   }
-  int center_y = node_bounds.y() + node_bounds.height() / 2;
-  const SkColor arrow_color = GetNativeTheme()->GetSystemColor(
-      ui::NativeTheme::kColorId_TreeArrow);
-  // TODO: this should come from an image.
-  if (!expanded) {
-    int delta = base::i18n::IsRTL() ? 1 : -1;
-    for (int i = 0; i < 4; ++i) {
-      canvas->FillRect(gfx::Rect(center_x + delta * (2 - i),
-                                 center_y - (3 - i), 1, (3 - i) * 2 + 1),
-                       arrow_color);
-    }
-  } else {
-    center_y -= 2;
-    for (int i = 0; i < 4; ++i) {
-      canvas->FillRect(gfx::Rect(center_x - (3 - i), center_y + i,
-                                 (3 - i) * 2 + 1, 1), arrow_color);
-    }
-  }
+  gfx::Rect arrow_bounds = node_bounds;
+  arrow_bounds.Inset(gfx::Insets((node_bounds.height() - arrow.height()) / 2,
+                                 (kArrowRegionSize - arrow.width()) / 2));
+  canvas->DrawImageInt(arrow, base::i18n::IsRTL()
+                                  ? arrow_bounds.right() - arrow.width()
+                                  : arrow_bounds.x(),
+                       arrow_bounds.y());

[Peter Kasting, 2017/02/15 01:05:31]

Nit: I think this is equivalent, and seems shorter and more readable:

  gfx::Rect arrow_bounds(kArrowRegionSize, node_bounds.height());
  arrow_bounds.ClampToCenteredSize(arrow.size());
  canvas->DrawImageInt(arrow, node_bounds.GetMirroredXForRect(arrow_bounds),
                       node_bounds.y() + arrow_bounds.y());

[Evan Stade, 2017/02/15 01:28:58]

the arrow square isn't centered in the node bounds.

[Peter Kasting, 2017/02/15 02:05:28]

I know.  The code I wrote won't center it in the node bounds.  It will center it
vertically within the node height, and horizontally within a
kArrowRegionSize-width space pinned to the leading edge of the control (mirrored
for RTL).

 }
 
 TreeView::InternalNode* TreeView::GetInternalNodeForModelNode(
     ui::TreeModelNode* model_node,
     GetInternalNodeCreateType create_type) {
   if (model_node == root_.model_node())
     return &root_;
   InternalNode* parent_internal_node =
       GetInternalNodeForModelNode(model_->GetParent(model_node), create_type);
   if (!parent_internal_node)
@@ skipping 250 matching lines @@
   if (!is_expanded_)
     return max_width;
   for (int i = 0; i < child_count(); ++i) {
     max_width = std::max(max_width,
                          GetChild(i)->GetMaxWidth(indent, depth + 1));
   }
   return max_width;
 }
 
 }  // namespace views