ambient: Add photo attribution (part 2).

Please see screenshot in the linked bug.

Bug: b/161481195
Test: manually.
Change-Id: Ie276b743b122d447cc658dfff6e72476122aef3f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2336493
Commit-Queue: Meilin Wang <meilinw@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797418}

ash/ambient/model/ambient_backend_model.cc

@@ -92,7 +92,7 @@ void AmbientBackendModel::Clear() {
   next_image_.Clear();
 }
 
-PhotoWithDetails AmbientBackendModel::GetNextImage() const {
+const PhotoWithDetails& AmbientBackendModel::GetNextImage() const {
   if (!next_image_.IsNull())
     return next_image_;
 

ash/ambient/model/ambient_backend_model.h

@@ -67,7 +67,7 @@ class ASH_EXPORT AmbientBackendModel {
   void Clear();
 
   // Get images from local storage. Could be null image.
-  PhotoWithDetails GetNextImage() const;
+  const PhotoWithDetails& GetNextImage() const;
 
   // Updates the weather information and notifies observers if the icon image is
   // not null.

ash/ambient/ui/ambient_background_image_view.cc

@@ -4,18 +4,39 @@
 
 #include "ash/ambient/ui/ambient_background_image_view.h"
 
+#include <memory>
+
+#include "ash/ambient/util/ambient_util.h"
 #include "ash/assistant/ui/assistant_view_ids.h"
 #include "ui/events/event.h"
+#include "ui/gfx/geometry/insets.h"
 #include "ui/views/controls/image_view.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/box_layout.h"
+#include "ui/views/layout/fill_layout.h"
 #include "ui/views/metadata/metadata_impl_macros.h"
 
 namespace ash {
 
+namespace {
+
+// Appearance.
+constexpr int kHorizontalMarginDip = 16;
+constexpr int kVerticalMarginDip = 43;
+
+// Typography.
+constexpr SkColor kTextColor = SK_ColorWHITE;
+constexpr int kDefaultFontSizeDip = 64;
+constexpr int kDetailsFontSizeDip = 13;
+
+}  // namespace
+
 AmbientBackgroundImageView::AmbientBackgroundImageView(
     AmbientViewDelegate* delegate)
     : delegate_(delegate) {
   DCHECK(delegate_);
   SetID(AssistantViewID::kAmbientBackgroundImageView);
+  InitLayout();
 }
 
 AmbientBackgroundImageView::~AmbientBackgroundImageView() = default;
@@ -34,6 +55,52 @@ void AmbientBackgroundImageView::OnGestureEvent(ui::GestureEvent* event) {
   }
 }
 
+void AmbientBackgroundImageView::UpdateImage(const gfx::ImageSkia& img) {
+  image_view_->SetImage(img);
+}
+
+void AmbientBackgroundImageView::UpdateImageDetails(
+    const base::string16& details) {
+  details_label_->SetText(details);
+}
+
+const gfx::ImageSkia& AmbientBackgroundImageView::GetCurrentImage() {
+  return image_view_->GetImage();
+}
+
+gfx::Rect AmbientBackgroundImageView::GetCurrentImageBoundsForTesting() const {
+  return image_view_->GetImageBounds();
+}
+
+void AmbientBackgroundImageView::InitLayout() {
+  SetLayoutManager(std::make_unique<views::FillLayout>());
+
+  // Inits the image view. This view should have the same size of the screen.
+  image_view_ = AddChildView(std::make_unique<views::ImageView>());
+
+  // Inits the attribution view. It also has a full-screen size and is
+  // responsible for layout the details label at its bottom left corner.
+  views::View* attribution_view = AddChildView(std::make_unique<views::View>());
+  views::BoxLayout* attribution_layout =
+      attribution_view->SetLayoutManager(std::make_unique<views::BoxLayout>(
+          views::BoxLayout::Orientation::kHorizontal));
+  attribution_layout->set_main_axis_alignment(
+      views::BoxLayout::MainAxisAlignment::kStart);
+  attribution_layout->set_inside_border_insets(
+      gfx::Insets(0, kHorizontalMarginDip, kVerticalMarginDip, 0));
+
+  // Inits the details label.
+  details_label_ =
+      attribution_view->AddChildView(std::make_unique<views::Label>());
+  details_label_->SetAutoColorReadabilityEnabled(false);
+  details_label_->SetEnabledColor(kTextColor);
+  details_label_->SetFontList(
+      ambient::util::GetDefaultFontlist().DeriveWithSizeDelta(
+          kDetailsFontSizeDip - kDefaultFontSizeDip));
+  details_label_->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
+  details_label_->SetVerticalAlignment(gfx::VerticalAlignment::ALIGN_BOTTOM);
+}
+
 BEGIN_METADATA(AmbientBackgroundImageView)
 METADATA_PARENT_CLASS(views::ImageView)
 END_METADATA()

ash/ambient/ui/ambient_background_image_view.h

@@ -5,18 +5,25 @@
 #ifndef ASH_AMBIENT_UI_AMBIENT_BACKGROUND_IMAGE_VIEW_H_
 #define ASH_AMBIENT_UI_AMBIENT_BACKGROUND_IMAGE_VIEW_H_
 
+#include <string>
+
 #include "ash/ambient/ui/ambient_view_delegate.h"
 #include "ash/ash_export.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/metadata/metadata_header_macros.h"
 #include "ui/views/view.h"
 
+namespace views {
+class Label;
+}  // namespace views
+
 namespace ash {
 
 // AmbientBackgroundImageView--------------------------------------------------
-// A custom ImageView for ambient mode to handle specific mouse/gesture events
-// when the user interacts with the background photos.
-class ASH_EXPORT AmbientBackgroundImageView : public views::ImageView {
+// A custom ImageView to display photo image and details information on ambient.
+// It also handles specific mouse/gesture events to dismiss ambient when user
+// interacts with the background photos.
+class ASH_EXPORT AmbientBackgroundImageView : public views::View {
  public:
   METADATA_HEADER(AmbientBackgroundImageView);
 
@@ -29,9 +36,28 @@ class ASH_EXPORT AmbientBackgroundImageView : public views::ImageView {
   bool OnMousePressed(const ui::MouseEvent& event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
 
+  // Updates the display image.
+  void UpdateImage(const gfx::ImageSkia& img);
+
+  // Updates the details for the currently displayed image.
+  void UpdateImageDetails(const base::string16& details);
+
+  const gfx::ImageSkia& GetCurrentImage();
+
+  gfx::Rect GetCurrentImageBoundsForTesting() const;
+
  private:
+  void InitLayout();
+
   // Owned by |AmbientController| and should always outlive |this|.
   AmbientViewDelegate* delegate_ = nullptr;
+
+  // View to display the current image on ambient. Owned by the view hierarchy.
+  views::ImageView* image_view_ = nullptr;
+
+  // Label to show details text, i.e. attribution, to be displayed for the
+  // current image. Owned by the view hierarchy.
+  views::Label* details_label_ = nullptr;
 };
 }  // namespace ash
 

ash/ambient/ui/photo_view.cc

@@ -5,6 +5,7 @@
 #include "ash/ambient/ui/photo_view.h"
 
 #include <algorithm>
+#include <iterator>
 #include <memory>
 
 #include "ash/ambient/ambient_constants.h"
@@ -14,6 +15,7 @@
 #include "ash/assistant/ui/assistant_view_ids.h"
 #include "ash/public/cpp/metrics_util.h"
 #include "base/metrics/histogram_functions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/animation_metrics_reporter.h"
 #include "ui/compositor/animation_throughput_reporter.h"
@@ -82,7 +84,7 @@ void PhotoView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   for (const int index : {0, 1}) {
     auto image = images_unscaled_[index];
     auto image_resized = ResizeImage(image, size());
-    image_views_[index]->SetImage(image_resized);
+    image_views_[index]->UpdateImage(image_resized);
   }
 }
 
@@ -103,14 +105,16 @@ void PhotoView::Init() {
   layer()->SetFillsBoundsOpaquely(false);
   SetLayoutManager(std::make_unique<views::FillLayout>());
 
-  image_views_[0] =
-      AddChildView(std::make_unique<AmbientBackgroundImageView>(delegate_));
-  image_views_[1] =
-      AddChildView(std::make_unique<AmbientBackgroundImageView>(delegate_));
-  image_views_[0]->SetPaintToLayer();
-  image_views_[0]->layer()->SetFillsBoundsOpaquely(false);
-  image_views_[1]->SetPaintToLayer();
-  image_views_[1]->layer()->SetFillsBoundsOpaquely(false);
+  for (auto*& image_view : image_views_) {
+    // Creates image views.
+    image_view =
+        AddChildView(std::make_unique<AmbientBackgroundImageView>(delegate_));
+    // Each image view will be animated on its own layer.
+    image_view->SetPaintToLayer();
+    image_view->layer()->SetFillsBoundsOpaquely(false);
+  }
+
+  // Hides one image view initially for fade in animation.
   image_views_[1]->layer()->SetOpacity(0.0f);
 
   delegate_->GetAmbientBackendModel()->AddObserver(this);
@@ -118,12 +122,15 @@ void PhotoView::Init() {
 
 void PhotoView::UpdateImages() {
   auto* model = delegate_->GetAmbientBackendModel();
-  images_unscaled_[image_index_] = model->GetNextImage().photo;
+  auto& next_image = model->GetNextImage();
+  images_unscaled_[image_index_] = next_image.photo;
   if (images_unscaled_[image_index_].isNull())
     return;
 
   auto next_resized = ResizeImage(images_unscaled_[image_index_], size());
-  image_views_[image_index_]->SetImage(next_resized);
+  image_views_[image_index_]->UpdateImage(next_resized);
+  image_views_[image_index_]->UpdateImageDetails(
+      base::UTF8ToUTF16(next_image.details));
   image_index_ = 1 - image_index_;
 }
 
@@ -175,7 +182,7 @@ bool PhotoView::NeedToAnimateTransition() const {
 }
 
 const gfx::ImageSkia& PhotoView::GetCurrentImagesForTesting() {
-  return image_views_[image_index_]->GetImage();
+  return image_views_[image_index_]->GetCurrentImage();
 }
 
 }  // namespace ash

ash/ambient/ui/photo_view_unittest.cc

@@ -32,7 +32,7 @@ TEST_F(AmbientPhotoViewTest, ShouldResizePortraitImageForPortraitScreen) {
 
   // Image should be full width. Image height should extend above and below the
   // visible part of the screen.
-  ASSERT_EQ(image_view->GetImageBounds(),
+  ASSERT_EQ(image_view->GetCurrentImageBoundsForTesting(),
             gfx::Rect(/*x=*/0, /*y=*/-200, /*width=*/600, /*height=*/1200));
 }
 
@@ -52,7 +52,7 @@ TEST_F(AmbientPhotoViewTest, ShouldResizeLandscapeImageForPortraitScreen) {
 
   // Image should be full width. Image should have equal empty space top and
   // bottom.
-  ASSERT_EQ(image_view->GetImageBounds(),
+  ASSERT_EQ(image_view->GetCurrentImageBoundsForTesting(),
             gfx::Rect(/*x=*/0, /*y=*/200, /*width=*/600, /*height=*/400));
 }
 
@@ -72,7 +72,7 @@ TEST_F(AmbientPhotoViewTest, ShouldResizePortraitImageForLandscapeScreen) {
 
   // Image should be full height. Image width should have equal empty space on
   // left and right.
-  ASSERT_EQ(image_view->GetImageBounds(),
+  ASSERT_EQ(image_view->GetCurrentImageBoundsForTesting(),
             gfx::Rect(/*x=*/250, /*y=*/0, /*width=*/300, /*height=*/600));
 }
 
@@ -93,7 +93,7 @@ TEST_F(AmbientPhotoViewTest, ShouldResizeLandscapeImageForFillLandscapeScreen) {
 
   // Image should be full height. Image width should extend equally to the left
   // and right of the visible part of the screen.
-  ASSERT_EQ(image_view->GetImageBounds(),
+  ASSERT_EQ(image_view->GetCurrentImageBoundsForTesting(),
             gfx::Rect(/*x=*/-50, /*y=*/0, /*width=*/900, /*height=*/600));
 }