[Sharesheet] Update bubble position with anchor movement

This CL adds a SharesheetParentWidgetObserver which
observes changes in the parent widget and updates the
position of the bubble to remain anchored to it.

Bug: 1159674
Change-Id: I9bc7d180b249fda54bc387b83501063be72ab37f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2596899Reviewed-by: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Melissa Zhang <melzhang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#840469}

chrome/browser/ui/ash/sharesheet/sharesheet_bubble_view.cc

@@ -10,6 +10,7 @@
 #include "ash/public/cpp/ash_typography.h"
 #include "ash/public/cpp/tablet_mode.h"
 #include "base/i18n/rtl.h"
+#include "base/scoped_observation.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "chrome/app/vector_icons/vector_icons.h"
@@ -49,6 +50,7 @@
 #include "ui/views/metadata/metadata_impl_macros.h"
 #include "ui/views/view_class_properties.h"
 #include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
 
 namespace {
 
@@ -106,11 +108,33 @@ bool IsKeyboardCodeArrow(ui::KeyboardCode key_code) {
 
 }  // namespace
 
+class SharesheetBubbleView::SharesheetParentWidgetObserver
+    : public views::WidgetObserver {
+ public:
+  SharesheetParentWidgetObserver(SharesheetBubbleView* owner,
+                                 views::Widget* widget)
+      : owner_(owner) {
+    observer_.Observe(widget);
+  }
+  ~SharesheetParentWidgetObserver() override = default;
+
+  void OnWidgetBoundsChanged(views::Widget* widget,
+                             const gfx::Rect& bounds) override {
+    owner_->OnWidgetBoundsChanged(widget, bounds);
+  }
+
+ private:
+  SharesheetBubbleView* owner_;
+  base::ScopedObservation<views::Widget, views::WidgetObserver> observer_{this};
+};
+
 SharesheetBubbleView::SharesheetBubbleView(
     gfx::NativeWindow native_window,
     sharesheet::SharesheetServiceDelegate* delegate)
     : delegate_(delegate) {
   set_parent_window(native_window);
+  parent_widget_observer_ = std::make_unique<SharesheetParentWidgetObserver>(
+      this, views::Widget::GetWidgetForNativeWindow(native_window));
   parent_view_ =
       views::Widget::GetWidgetForNativeWindow(native_window)->GetRootView();
   UpdateAnchorPosition();
@@ -464,6 +488,11 @@ void SharesheetBubbleView::OnWidgetActivationChanged(views::Widget* widget,
   }
 }
 
+void SharesheetBubbleView::OnWidgetBoundsChanged(views::Widget* widget,
+                                                 const gfx::Rect& new_bounds) {
+  UpdateAnchorPosition();
+}
+
 void SharesheetBubbleView::CreateBubble() {
   set_close_on_deactivate(false);
   SetButtons(ui::DIALOG_BUTTON_NONE);

chrome/browser/ui/ash/sharesheet/sharesheet_bubble_view.h

@@ -44,7 +44,13 @@ class SharesheetBubbleView : public views::BubbleDialogDelegateView {
   void ResizeBubble(const int& width, const int& height);
   void CloseBubble();
 
+  // views::BubbleDialogDelegateView:
+  void OnWidgetBoundsChanged(views::Widget* widget,
+                             const gfx::Rect& new_bounds) override;
+
  private:
+  class SharesheetParentWidgetObserver;
+
   // ui::EventHandler:
   void OnKeyEvent(ui::KeyEvent* event) override;
 
@@ -98,6 +104,8 @@ class SharesheetBubbleView : public views::BubbleDialogDelegateView {
   views::Separator* expanded_view_separator_ = nullptr;
   views::View* parent_view_ = nullptr;
   SharesheetExpandButton* expand_button_ = nullptr;
+
+  std::unique_ptr<SharesheetParentWidgetObserver> parent_widget_observer_;
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_SHARESHEET_SHARESHEET_BUBBLE_VIEW_H_