Prep for content forward holding space tray icon.

This CL pulls the holding space tray icon out into a separate class.
Moving forward, the new HoldingSpaceTrayIcon will be modified to add
support for a content forward UI and accompanying motion spec. Changes
will be gated by a new feature flag (or param to the existing flag).

No changes should be visible to the user as a result of this CL.

Bug: 1142572
Change-Id: I21f85f37eeb595f7aa9ac3c79a171634b22e939b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2499376Reviewed-by: Toni Baržić <tbarzic@chromium.org>
Commit-Queue: David Black <dmblack@google.com>
Cr-Commit-Position: refs/heads/master@{#821343}

ash/BUILD.gn

@@ -970,6 +970,8 @@ component("ash") {
     "system/holding_space/holding_space_tray.h",
     "system/holding_space/holding_space_tray_bubble.cc",
     "system/holding_space/holding_space_tray_bubble.h",
+    "system/holding_space/holding_space_tray_icon.cc",
+    "system/holding_space/holding_space_tray_icon.h",
     "system/holding_space/pinned_files_container.cc",
     "system/holding_space/pinned_files_container.h",
     "system/holding_space/recent_files_container.cc",

ash/public/cpp/holding_space/holding_space_constants.h

@@ -36,7 +36,8 @@ constexpr int kHoldingSpaceScreenCaptureSpacing = 8;
 constexpr gfx::Size kHoldingSpaceScreenCaptureSize(104, 80);
 constexpr gfx::Insets kHoldingSpaceScreenCapturesContainerPadding(8, 0);
 constexpr float kHoldingSpaceSelectedOverlayOpacity = 0.24f;
-constexpr int kHoldingSpaceTrayMainAxisMargin = 6;
+constexpr int kHoldingSpaceTrayIconMainAxisMargin = 6;
+constexpr int kHoldingSpaceTrayIconSize = 20;
 
 // Context menu commands.
 enum HoldingSpaceCommandId {

ash/system/holding_space/holding_space_tray.cc

@@ -6,24 +6,17 @@
 #include <memory>
 
 #include "ash/accessibility/accessibility_controller_impl.h"
-#include "ash/public/cpp/holding_space/holding_space_constants.h"
 #include "ash/public/cpp/holding_space/holding_space_metrics.h"
 #include "ash/public/cpp/holding_space/holding_space_prefs.h"
-#include "ash/public/cpp/shelf_config.h"
 #include "ash/public/cpp/system_tray_client.h"
-#include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/session/session_controller_impl.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shell.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "ash/system/holding_space/holding_space_tray_bubble.h"
+#include "ash/system/holding_space/holding_space_tray_icon.h"
 #include "ash/system/tray/tray_container.h"
 #include "ui/base/l10n/l10n_util.h"
-#include "ui/gfx/paint_vector_icon.h"
-#include "ui/views/controls/image_view.h"
-#include "ui/views/controls/label.h"
-#include "ui/views/layout/fill_layout.h"
-#include "ui/views/vector_icons.h"
 
 namespace ash {
 
@@ -31,14 +24,10 @@ HoldingSpaceTray::HoldingSpaceTray(Shelf* shelf) : TrayBackgroundView(shelf) {
   controller_observer_.Add(HoldingSpaceController::Get());
   SetVisible(false);
 
-  SetLayoutManager(std::make_unique<views::FillLayout>());
-
-  icon_ = tray_container()->AddChildView(std::make_unique<views::ImageView>());
-  icon_->SetTooltipText(l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_TITLE));
-  icon_->SetImage(CreateVectorIcon(kHoldingSpaceIcon,
-                                   ShelfConfig::Get()->shelf_icon_color()));
-
-  tray_container()->SetMargin(kHoldingSpaceTrayMainAxisMargin, 0);
+  // Icon.
+  auto* container = tray_container();
+  icon_ = container->AddChildView(std::make_unique<HoldingSpaceTrayIcon>());
+  container->SetMargin(icon_->GetPreferredMainAxisMargin(), 0);
 }
 
 HoldingSpaceTray::~HoldingSpaceTray() = default;
@@ -52,7 +41,7 @@ base::string16 HoldingSpaceTray::GetAccessibleNameForTray() {
 }
 
 void HoldingSpaceTray::HandleLocaleChange() {
-  icon_->SetTooltipText(l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_TITLE));
+  icon_->OnLocaleChanged();
 }
 
 void HoldingSpaceTray::HideBubbleWithView(const TrayBubbleView* bubble_view) {}

ash/system/holding_space/holding_space_tray.h

@@ -18,11 +18,10 @@
 #include "base/scoped_observer.h"
 #include "ui/views/widget/widget_observer.h"
 
-namespace views {
-class ImageView;
-}  // namespace views
-
 namespace ash {
+
+class HoldingSpaceTrayIcon;
+
 // The HoldingSpaceTray shows the tray button in the bottom area of the screen.
 // This class also controls the lifetime for all of the tools available in the
 // palette. HoldingSpaceTray has one instance per-display.
@@ -69,11 +68,9 @@ class ASH_EXPORT HoldingSpaceTray : public TrayBackgroundView,
   void OnWidgetDragWillStart(views::Widget* widget) override;
   void OnWidgetDestroying(views::Widget* widget) override;
 
+  HoldingSpaceTrayIcon* icon_ = nullptr;  // Owned by `TrayContainer`.
   std::unique_ptr<HoldingSpaceTrayBubble> bubble_;
 
-  // Weak pointer, will be parented by TrayContainer for its lifetime.
-  views::ImageView* icon_ = nullptr;
-
   ScopedObserver<HoldingSpaceController, HoldingSpaceControllerObserver>
       controller_observer_{this};
   ScopedObserver<HoldingSpaceModel, HoldingSpaceModelObserver> model_observer_{

ash/system/holding_space/holding_space_tray_icon.cc

+// Copyright 2020 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/system/holding_space/holding_space_tray_icon.h"
+
+#include "ash/public/cpp/holding_space/holding_space_constants.h"
+#include "ash/public/cpp/shelf_config.h"
+#include "ash/resources/vector_icons/vector_icons.h"
+#include "ash/strings/grit/ash_strings.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/paint_vector_icon.h"
+#include "ui/views/controls/image_view.h"
+#include "ui/views/layout/fill_layout.h"
+#include "ui/views/metadata/metadata_impl_macros.h"
+
+namespace ash {
+
+HoldingSpaceTrayIcon::HoldingSpaceTrayIcon() {
+  InitLayout();
+}
+
+HoldingSpaceTrayIcon::~HoldingSpaceTrayIcon() = default;
+
+int HoldingSpaceTrayIcon::GetPreferredMainAxisMargin() const {
+  return kHoldingSpaceTrayIconMainAxisMargin;
+}
+
+void HoldingSpaceTrayIcon::OnLocaleChanged() {
+  TooltipTextChanged();
+}
+
+base::string16 HoldingSpaceTrayIcon::GetTooltipText(
+    const gfx::Point& point) const {
+  return l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_TITLE);
+}
+
+void HoldingSpaceTrayIcon::InitLayout() {
+  SetLayoutManager(std::make_unique<views::FillLayout>());
+
+  // Image.
+  auto* image_view = AddChildView(std::make_unique<views::ImageView>());
+  image_view->SetImage(
+      gfx::CreateVectorIcon(kHoldingSpaceIcon, kHoldingSpaceTrayIconSize,
+                            ShelfConfig::Get()->shelf_icon_color()));
+
+  // Disallow events on `image_view` so that tooltips will be retrieved from
+  // `this`. Moving forward, `image_view` will not exist as we transition to a
+  // more content forward tray icon.
+  image_view->SetCanProcessEventsWithinSubtree(false);
+}
+
+BEGIN_METADATA(HoldingSpaceTrayIcon, views::View)
+END_METADATA
+
+}  // namespace ash

ash/system/holding_space/holding_space_tray_icon.h

+// Copyright 2020 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.
+
+#ifndef ASH_SYSTEM_HOLDING_SPACE_HOLDING_SPACE_TRAY_ICON_H_
+#define ASH_SYSTEM_HOLDING_SPACE_HOLDING_SPACE_TRAY_ICON_H_
+
+#include "ash/ash_export.h"
+#include "ui/views/metadata/metadata_header_macros.h"
+#include "ui/views/view.h"
+
+namespace ash {
+
+// TODO(crbug.com/1142572): Implement content forward icon w/ motion spec.
+// The icon used to represent holding space in its tray in the shelf.
+class ASH_EXPORT HoldingSpaceTrayIcon : public views::View {
+ public:
+  METADATA_HEADER(HoldingSpaceTrayIcon);
+
+  HoldingSpaceTrayIcon();
+  HoldingSpaceTrayIcon(const HoldingSpaceTrayIcon&) = delete;
+  HoldingSpaceTrayIcon& operator=(const HoldingSpaceTrayIcon&) = delete;
+  ~HoldingSpaceTrayIcon() override;
+
+  // Returns the preferred main axis margin for this view.
+  int GetPreferredMainAxisMargin() const;
+
+  // Invoked when the system locale has changed.
+  void OnLocaleChanged();
+
+ private:
+  // views::View:
+  base::string16 GetTooltipText(const gfx::Point& point) const override;
+
+  void InitLayout();
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_HOLDING_SPACE_HOLDING_SPACE_TRAY_ICON_H_