Use vector icon for Ash shelf launcher

ash/shelf/app_list_button.cc

 // Copyright 2014 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 "ash/shelf/app_list_button.h"
 
 #include "ash/ash_constants.h"
 #include "ash/shelf/shelf_item_types.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_view.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "base/command_line.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_switches_util.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/paint_vector_icon.h"
+#include "ui/gfx/vector_icons_public.h"
 #include "ui/views/painter.h"
 
+namespace {
+// Width and height of the launcher icon, which includes 2px of internal
+// padding at each side.
+const int kLauncherIconSize = 18;

[tdanderson, 2016/05/23 21:18:24]

So if I remember our conversation correctly, the vectorization process bakes
some padding into the .icon, and there is no easy way to strip this out or add
to it. In this case, I wanted the search icon to appear as 14px (length from one
side of the magnifying glass to the other without any padding) so I had to play
around with sizes to determine that using 18 would give me a 14px magnifying
glass + 2px baked-in padding to the left + 2px of baked-in padding to the right.
Does this sound like what your workflow would be, or am I missing something?

[Evan Stade, 2016/05/23 22:11:57]

Overall, yes. One way to add to the padding would be to set an empty border on a
views::ImageView. In this case, the centering code you have looks reasonable.

+
+// Color of the launcher icon.
+// TODO(tdanderson): Move Ash color constants to a common location.
+const SkColor kLauncherIconColor = SK_ColorWHITE;
+}  // namespace
+
 namespace ash {
 
 AppListButton::AppListButton(ShelfView* shelf_view)
     : views::ImageButton(shelf_view),
       draw_background_as_active_(false),
       shelf_view_(shelf_view) {
   SetAccessibleName(
       app_list::switches::IsExperimentalAppListEnabled()
           ? l10n_util::GetStringUTF16(IDS_ASH_SHELF_APP_LIST_LAUNCHER_TITLE)
           : l10n_util::GetStringUTF16(IDS_ASH_SHELF_APP_LIST_TITLE));
@@ skipping 68 matching lines @@
   int background_image_id = 0;
   if (Shell::GetInstance()->GetAppListTargetVisibility() ||
       draw_background_as_active_) {
     background_image_id = IDR_AURA_NOTIFICATION_BACKGROUND_PRESSED;
   } else {
     if (shelf_view_->shelf()->shelf_widget()->GetDimsShelf())
       background_image_id = IDR_AURA_NOTIFICATION_BACKGROUND_ON_BLACK;
     else
       background_image_id = IDR_AURA_NOTIFICATION_BACKGROUND_NORMAL;
   }
+
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   const gfx::ImageSkia* background_image =
       rb.GetImageNamed(background_image_id).ToImageSkia();
-  // TODO(mgiuca): When the "classic" app list is removed, also remove this
-  // resource and its icon file.
-  int foreground_image_id = app_list::switches::IsExperimentalAppListEnabled()
-                                ? IDR_ASH_SHELF_ICON_APPLIST
-                                : IDR_ASH_SHELF_ICON_APPLIST_CLASSIC;
-  const gfx::ImageSkia* forground_image =
-      rb.GetImageNamed(foreground_image_id).ToImageSkia();
+
+  const gfx::ImageSkia& foreground_image =
+      gfx::CreateVectorIcon(gfx::VectorIconId::SEARCH,
+                            kLauncherIconSize, kLauncherIconColor);
 
   gfx::Rect contents_bounds = GetContentsBounds();
-  gfx::Rect background_bounds, forground_bounds;
+  gfx::Rect background_bounds, foreground_bounds;
 
   wm::ShelfAlignment alignment = shelf_view_->shelf()->alignment();
   background_bounds.set_size(background_image->size());
   if (alignment == wm::SHELF_ALIGNMENT_LEFT) {
     background_bounds.set_x(contents_bounds.width() -
         ShelfLayoutManager::kShelfItemInset - background_image->width());
     background_bounds.set_y(contents_bounds.y() +
         (contents_bounds.height() - background_image->height()) / 2);
   } else if (alignment == wm::SHELF_ALIGNMENT_RIGHT) {
     background_bounds.set_x(ShelfLayoutManager::kShelfItemInset);
     background_bounds.set_y(contents_bounds.y() +
         (contents_bounds.height() - background_image->height()) / 2);
   } else {
     background_bounds.set_y(ShelfLayoutManager::kShelfItemInset);
     background_bounds.set_x(contents_bounds.x() +
         (contents_bounds.width() - background_image->width()) / 2);
   }
 
-  forground_bounds.set_size(forground_image->size());
-  forground_bounds.set_x(background_bounds.x() +
+  foreground_bounds.set_size(foreground_image.size());
+  foreground_bounds.set_x(background_bounds.x() +
       std::max(0,
-          (background_bounds.width() - forground_bounds.width()) / 2));
-  forground_bounds.set_y(background_bounds.y() +
+          (background_bounds.width() - foreground_bounds.width()) / 2));
+  foreground_bounds.set_y(background_bounds.y() +
       std::max(0,
-          (background_bounds.height() - forground_bounds.height()) / 2));
+          (background_bounds.height() - foreground_bounds.height()) / 2));
 
   canvas->DrawImageInt(*background_image,
                        background_bounds.x(),
                        background_bounds.y());
-  canvas->DrawImageInt(*forground_image,
-                       forground_bounds.x(),
-                       forground_bounds.y());
+  canvas->DrawImageInt(foreground_image,
+                       foreground_bounds.x(),
+                       foreground_bounds.y());
 
   views::Painter::PaintFocusPainter(this, canvas, focus_painter());
 }
 
 void AppListButton::GetAccessibleState(ui::AXViewState* state) {
   state->role = ui::AX_ROLE_BUTTON;
   state->name = shelf_view_->GetTitleForView(this);
 }
 
 void AppListButton::SetDrawBackgroundAsActive(
     bool draw_background_as_active) {
   if (draw_background_as_active_ == draw_background_as_active)
     return;
   draw_background_as_active_ = draw_background_as_active;
   SchedulePaint();
 }
 
 }  // namespace ash