Implement empty state for holding space pinned files container.

Pinned files container should show a prompt to the user when empty,
otherwise the pinned files.

This CL also:
- Updates a few styles.
- Fixes a bug in which downloads were not restored due to the time of
  first enabling holding space not being stored to prefs.

Bug: 1131253
Change-Id: Ife26c626e633c4263fea80610b4948c7971ba09e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2434465
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811426}

ash/ash_strings.grd

@@ -976,6 +976,9 @@ This file contains the strings for ash.
       <message name="IDS_ASH_HOLDING_SPACE_PINNED_TITLE" desc="Title of the pinned files area in the holding space bubble.">
         Pinned
       </message>
+      <message name="IDS_ASH_HOLDING_SPACE_PINNED_EMPTY_PROMPT" desc="Prompt shown in the pinned files area of the holding space bubble if the user has no pinned files.">
+        Quickly access your important files. Right-click or touch &amp; hold a file to pin it.
+      </message>
       <message name="IDS_ASH_HOLDING_SPACE_DOWNLOADS_TITLE" desc="Title of the downloads area in the holding space bubble.">
         Downloads
       </message>

ash/ash_strings_grd/IDS_ASH_HOLDING_SPACE_PINNED_EMPTY_PROMPT.png.sha1

+0ad404e14ac69a7254a868558f7ca5c89489c141
\ No newline at end of file

ash/system/holding_space/holding_space_item_chip_view.cc

@@ -39,8 +39,8 @@ HoldingSpaceItemChipView::HoldingSpaceItemChipView(
   label_->SetElideBehavior(gfx::ELIDE_MIDDLE);
   layout->SetFlexForView(label_, 1);
 
-  TrayPopupItemStyle style(TrayPopupItemStyle::FontStyle::HOLDING_SPACE_TITLE);
-  style.SetupLabel(label_);
+  TrayPopupItemStyle(TrayPopupItemStyle::FontStyle::DETAILED_VIEW_LABEL)
+      .SetupLabel(label_);
 
   const auto* color_provider = AshColorProvider::Get();
   SetBackground(views::CreateRoundedRectBackground(

ash/system/holding_space/pinned_files_container.cc

@@ -28,6 +28,9 @@
 namespace ash {
 
 namespace {
+
+// HoldingSpaceScrollView ------------------------------------------------------
+
 class HoldingSpaceScrollView : public views::ScrollView,
                                public views::ViewObserver {
  public:
@@ -44,6 +47,13 @@ class HoldingSpaceScrollView : public views::ScrollView,
     PreferredSizeChanged();
   }
 
+  void OnViewVisibilityChanged(views::View* observed_view,
+                               views::View* starting_view) override {
+    // Sync scroll view visibility with contents visibility.
+    if (GetVisible() != observed_view->GetVisible())
+      SetVisible(observed_view->GetVisible());
+  }
+
   void OnViewIsDeleting(View* observed_view) override {
     view_observer_.Remove(observed_view);
   }
@@ -51,8 +61,11 @@ class HoldingSpaceScrollView : public views::ScrollView,
  private:
   ScopedObserver<views::View, views::ViewObserver> view_observer_{this};
 };
+
 }  // namespace
 
+// PinnedFilesContainer --------------------------------------------------------
+
 PinnedFilesContainer::PinnedFilesContainer(
     HoldingSpaceItemViewDelegate* delegate)
     : delegate_(delegate) {
@@ -64,19 +77,33 @@ PinnedFilesContainer::PinnedFilesContainer(
 
   auto* title_label = AddChildView(std::make_unique<views::Label>(
       l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_PINNED_TITLE)));
-  TrayPopupItemStyle style(TrayPopupItemStyle::FontStyle::HOLDING_SPACE_TITLE,
-                           true /* use_unified_theme */);
-  style.SetupLabel(title_label);
+  title_label->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
   title_label->SetPaintToLayer();
   title_label->layer()->SetFillsBoundsOpaquely(false);
 
-  auto* scroller = AddChildView(std::make_unique<HoldingSpaceScrollView>());
-  scroller->SetBackgroundColor(base::nullopt);
-  scroller->SetDrawOverflowIndicator(false);
-  scroller->ClipHeightTo(0, INT_MAX);
+  TrayPopupItemStyle(TrayPopupItemStyle::FontStyle::SUB_HEADER)
+      .SetupLabel(title_label);
+
+  empty_prompt_label_ = AddChildView(std::make_unique<views::Label>(
+      l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_PINNED_EMPTY_PROMPT)));
+  empty_prompt_label_->SetHorizontalAlignment(
+      gfx::HorizontalAlignment::ALIGN_LEFT);
+  empty_prompt_label_->SetMultiLine(true);
+  empty_prompt_label_->SetPaintToLayer();
+  empty_prompt_label_->layer()->SetFillsBoundsOpaquely(false);
+
+  TrayPopupItemStyle(TrayPopupItemStyle::FontStyle::DETAILED_VIEW_LABEL)
+      .SetupLabel(empty_prompt_label_);
 
-  item_chips_container_ =
-      scroller->SetContents(std::make_unique<HoldingSpaceItemChipsContainer>());
+  auto* scroll_view = AddChildView(std::make_unique<HoldingSpaceScrollView>());
+  scroll_view->SetBackgroundColor(base::nullopt);
+  scroll_view->SetDrawOverflowIndicator(false);
+  scroll_view->SetVisible(false);
+  scroll_view->ClipHeightTo(0, INT_MAX);
+
+  item_chips_container_ = scroll_view->SetContents(
+      std::make_unique<HoldingSpaceItemChipsContainer>());
+  item_chips_container_->SetVisible(false);
 
   if (HoldingSpaceController::Get()->model())
     OnHoldingSpaceModelAttached(HoldingSpaceController::Get()->model());
@@ -84,6 +111,28 @@ PinnedFilesContainer::PinnedFilesContainer(
 
 PinnedFilesContainer::~PinnedFilesContainer() = default;
 
+void PinnedFilesContainer::ChildVisibilityChanged(views::View* child) {
+  PreferredSizeChanged();
+}
+
+void PinnedFilesContainer::ViewHierarchyChanged(
+    const views::ViewHierarchyChangedDetails& details) {
+  // We only care about `item_chips_container_` becoming empty and non-empty.
+  if (details.parent != item_chips_container_ ||
+      item_chips_container_->children().size() != 1u) {
+    return;
+  }
+  if (details.is_add) {
+    // `item_chips_container_` is becoming non-empty.
+    empty_prompt_label_->SetVisible(false);
+    item_chips_container_->SetVisible(true);
+  } else {
+    // `item_chips_container_` is becoming empty.
+    item_chips_container_->SetVisible(false);
+    empty_prompt_label_->SetVisible(true);
+  }
+}
+
 void PinnedFilesContainer::AddHoldingSpaceItemView(
     const HoldingSpaceItem* item) {
   DCHECK(!base::Contains(views_by_item_id_, item->id()));

ash/system/holding_space/pinned_files_container.h

@@ -9,6 +9,10 @@
 
 #include "ash/system/holding_space/holding_space_item_views_container.h"
 
+namespace views {
+class Label;
+}  // namespace views
+
 namespace ash {
 
 class HoldingSpaceItemChipsContainer;
@@ -23,6 +27,8 @@ class PinnedFilesContainer : public HoldingSpaceItemViewsContainer {
   ~PinnedFilesContainer() override;
 
   // HoldingSpaceItemViewsContainer:
+  void ChildVisibilityChanged(views::View* child) override;
+  void ViewHierarchyChanged(const views::ViewHierarchyChangedDetails&) override;
   void AddHoldingSpaceItemView(const HoldingSpaceItem* item) override;
   void RemoveAllHoldingSpaceItemViews() override;
   void RemoveHoldingSpaceItemView(const HoldingSpaceItem* item) override;
@@ -30,6 +36,7 @@ class PinnedFilesContainer : public HoldingSpaceItemViewsContainer {
  private:
   HoldingSpaceItemViewDelegate* const delegate_;
 
+  views::Label* empty_prompt_label_ = nullptr;
   HoldingSpaceItemChipsContainer* item_chips_container_ = nullptr;
 
   std::map<std::string, views::View*> views_by_item_id_;

ash/system/holding_space/recent_files_container.cc

@@ -34,17 +34,18 @@ RecentFilesContainer::RecentFilesContainer(
       views::BoxLayout::Orientation::kVertical, kHoldingSpaceContainerPadding,
       kHoldingSpaceContainerChildSpacing));
 
-  auto setup_layered_child = [](views::View* child) {
-    child->SetPaintToLayer();
-    child->layer()->SetFillsBoundsOpaquely(false);
+  auto setup_label = [](views::Label* label) {
+    TrayPopupItemStyle(TrayPopupItemStyle::FontStyle::SUB_HEADER)
+        .SetupLabel(label);
+
+    label->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
+    label->SetPaintToLayer();
+    label->layer()->SetFillsBoundsOpaquely(false);
   };
 
   auto* screenshots_label = AddChildView(std::make_unique<views::Label>(
       l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_SCREENSHOTS_TITLE)));
-  setup_layered_child(screenshots_label);
-  TrayPopupItemStyle style(TrayPopupItemStyle::FontStyle::HOLDING_SPACE_TITLE,
-                           true /* use_unified_theme */);
-  style.SetupLabel(screenshots_label);
+  setup_label(screenshots_label);
 
   screenshots_container_ = AddChildView(std::make_unique<views::View>());
   screenshots_container_
@@ -57,8 +58,7 @@ RecentFilesContainer::RecentFilesContainer(
 
   auto* downloads_label = AddChildView(std::make_unique<views::Label>(
       l10n_util::GetStringUTF16(IDS_ASH_HOLDING_SPACE_DOWNLOADS_TITLE)));
-  setup_layered_child(downloads_label);
-  style.SetupLabel(downloads_label);
+  setup_label(downloads_label);
 
   downloads_container_ =
       AddChildView(std::make_unique<HoldingSpaceItemChipsContainer>());

ash/system/tray/tray_popup_item_style.cc

@@ -116,11 +116,6 @@ void TrayPopupItemStyle::SetupLabel(views::Label* label) const {
       label->SetFontList(base_font_list.Derive(0, gfx::Font::NORMAL,
                                                gfx::Font::Weight::NORMAL));
       break;
-    case FontStyle::HOLDING_SPACE_TITLE:
-      label->SetFontList(base_font_list.Derive(3, gfx::Font::NORMAL,
-                                               gfx::Font::Weight::NORMAL));
-      label->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
-      break;
   }
 }
 

ash/system/tray/tray_popup_item_style.h

@@ -49,8 +49,6 @@ class TrayPopupItemStyle {
     CLICKABLE_SYSTEM_INFO,
     // Sub text within a row (e.g. user name in user row).
     CAPTION,
-    // Labels in holding space bubble
-    HOLDING_SPACE_TITLE,
   };
 
   static constexpr double kInactiveIconAlpha = 0.54;

chrome/browser/ui/ash/holding_space/holding_space_keyed_service.cc

@@ -43,6 +43,11 @@ HoldingSpaceKeyedService::HoldingSpaceKeyedService(Profile* profile,
       account_id_(account_id),
       holding_space_client_(profile),
       thumbnail_loader_(profile) {
+  // If true, store this as the first time holding space has been enabled.
+  PrefService* const prefs = profile_->GetPrefs();
+  if (prefs->FindPreference(kPrefPathFirstEnabledTime)->IsDefaultValue())
+    prefs->SetTime(kPrefPathFirstEnabledTime, base::Time::Now());
+
   // Model restoration is a multi-step process, currently consisting of a
   // restoration from persistence followed by a restoration of downloads. Once
   // all steps have indicated completion, `OnModelFullyRestored()` is invoked.