Disallow toggling of shelf auto-hide with touch when there are no windows open.

When there are no windows opened, do not change the auto_hide status when
swiping down (or swiping up and then releasing) on the shelf.

BUG=310322

Review-Url: https://codereview.chromium.org/2824233003
Cr-Commit-Position: refs/heads/master@{#468156}

ash/shelf/shelf_layout_manager.cc

@@ -864,6 +864,22 @@ gfx::Rect ShelfLayoutManager::GetAutoHideShowShelfRegionInScreen() const {
   return show_shelf_region_in_screen;
 }
 
+bool ShelfLayoutManager::HasVisibleWindow() const {
+  WmWindow* root =
+      WmWindow::Get(shelf_widget_->GetNativeWindow())->GetRootWindow();
+  const std::vector<WmWindow*> windows =
+      Shell::Get()->mru_window_tracker()->BuildWindowListIgnoreModal();
+  // Process the window list and check if there are any visible windows.
+  // Ignore app list windows that may be animating to hide after dismissal.
+  for (auto* window : windows) {
+    if (window->IsVisible() && !IsAppListWindow(window) &&
+        root->Contains(window)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 ShelfAutoHideState ShelfLayoutManager::CalculateAutoHideState(
     ShelfVisibilityState visibility_state) const {
   if (visibility_state != SHELF_AUTO_HIDE || !wm_shelf_->IsShelfInitialized())
@@ -887,25 +903,8 @@ ShelfAutoHideState ShelfLayoutManager::CalculateAutoHideState(
        shelf_widget_->status_area_widget()->IsActive()))
     return SHELF_AUTO_HIDE_SHOWN;
 
-  const int64_t shelf_display_id =
-      WmWindow::Get(shelf_widget_->GetNativeWindow())
-          ->GetDisplayNearestWindow()
-          .id();
-  const std::vector<WmWindow*> windows =
-      Shell::Get()->mru_window_tracker()->BuildWindowListIgnoreModal();
-  // Process the window list and check if there are any visible windows.
-  // Ignore app list windows that may be animating to hide after dismissal.
-  bool visible_window = false;
-  for (size_t i = 0; i < windows.size(); ++i) {
-    if (windows[i] && windows[i]->IsVisible() && !IsAppListWindow(windows[i]) &&
-        !windows[i]->GetWindowState()->IsMinimized() &&
-        windows[i]->GetDisplayNearestWindow().id() == shelf_display_id) {
-      visible_window = true;
-      break;
-    }
-  }
   // If there are no visible windows do not hide the shelf.
-  if (!visible_window)
+  if (!HasVisibleWindow())
     return SHELF_AUTO_HIDE_SHOWN;
 
   if (gesture_drag_status_ == GESTURE_DRAG_COMPLETE_IN_PROGRESS)
@@ -1128,12 +1127,15 @@ void ShelfLayoutManager::CompleteGestureDrag(const ui::GestureEvent& gesture) {
   // When in fullscreen and the shelf is forced to be auto hidden, the auto hide
   // behavior affects neither the visibility state nor the auto hide state. Set
   // |gesture_drag_status_| to GESTURE_DRAG_COMPLETE_IN_PROGRESS to set the auto
-  // hide state to |gesture_drag_auto_hide_state_|.
+  // hide state to |gesture_drag_auto_hide_state_|. Only change the auto-hide
+  // behavior if there is at least one window visible.
   gesture_drag_status_ = GESTURE_DRAG_COMPLETE_IN_PROGRESS;
-  if (wm_shelf_->auto_hide_behavior() != new_auto_hide_behavior)
+  if (wm_shelf_->auto_hide_behavior() != new_auto_hide_behavior &&
+      HasVisibleWindow()) {
     wm_shelf_->SetAutoHideBehavior(new_auto_hide_behavior);
-  else
+  } else {
     UpdateVisibilityState();
+  }
   gesture_drag_status_ = GESTURE_DRAG_NONE;
 }
 

ash/shelf/shelf_layout_manager.h

@@ -261,6 +261,9 @@ class ASH_EXPORT ShelfLayoutManager
   // two displays.
   gfx::Rect GetAutoHideShowShelfRegionInScreen() const;
 
+  // Returns true if at least one window is visible.
+  bool HasVisibleWindow() const;
+
   // Returns the AutoHideState. This value is determined from the shelf and
   // tray.
   ShelfAutoHideState CalculateAutoHideState(

ash/shelf/shelf_layout_manager_unittest.cc

@@ -550,10 +550,11 @@ void ShelfLayoutManagerTest::RunGestureDragTests(gfx::Vector2d delta) {
   EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
   EXPECT_EQ(bounds_fullscreen.ToString(), window->bounds().ToString());
 
-  // Close actually, otherwise further event may be affected since widget
+  // Minimize actually, otherwise further event may be affected since widget
   // is fullscreen status.
-  widget->Close();
+  widget->Minimize();
   RunAllPendingInMessageLoop();
+  EXPECT_FALSE(layout_manager->HasVisibleWindow());
 
   // The shelf should be shown because there are no more visible windows.
   EXPECT_EQ(SHELF_AUTO_HIDE, shelf->GetVisibilityState());
@@ -570,6 +571,62 @@ void ShelfLayoutManagerTest::RunGestureDragTests(gfx::Vector2d delta) {
   EXPECT_EQ(SHELF_AUTO_HIDE, shelf->GetVisibilityState());
   EXPECT_EQ(SHELF_AUTO_HIDE_SHOWN, shelf->GetAutoHideState());
   EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
+  EXPECT_EQ(shelf_shown.ToString(),
+            GetShelfWidget()->GetWindowBoundsInScreen().ToString());
+
+  // Swipe-down to hide. This should have no effect because there are no visible
+  // windows.
+  end = start + delta;
+  generator.GestureScrollSequenceWithCallback(
+      start, end, kTimeDelta, kNumScrollSteps,
+      base::Bind(&ShelfDragCallback::ProcessScroll,
+                 base::Unretained(&handler)));
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_SHOWN, shelf->GetAutoHideState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
+  EXPECT_EQ(shelf_shown.ToString(),
+            GetShelfWidget()->GetWindowBoundsInScreen().ToString());
+
+  widget->Restore();
+  RunAllPendingInMessageLoop();
+  EXPECT_TRUE(layout_manager->HasVisibleWindow());
+
+  // Swipe up on the shelf. This should show the shelf and disable auto-hide
+  // since there is one visible window.
+  end = below_start - delta;
+  generator.GestureScrollSequenceWithCallback(
+      below_start, end, kTimeDelta, kNumScrollSteps,
+      base::Bind(&ShelfDragCallback::ProcessScroll,
+                 base::Unretained(&handler)));
+  EXPECT_EQ(SHELF_VISIBLE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_NEVER, shelf->auto_hide_behavior());
+
+  widget->Close();
+  RunAllPendingInMessageLoop();
+  EXPECT_FALSE(layout_manager->HasVisibleWindow());
+
+  // Swipe-up to hide. This should have no effect because there are no visible
+  // windows.
+  generator.GestureScrollSequenceWithCallback(
+      below_start, end, kTimeDelta, kNumScrollSteps,
+      base::Bind(&ShelfDragCallback::ProcessScroll,
+                 base::Unretained(&handler)));
+  EXPECT_EQ(SHELF_VISIBLE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_NEVER, shelf->auto_hide_behavior());
+  EXPECT_EQ(shelf_shown.ToString(),
+            GetShelfWidget()->GetWindowBoundsInScreen().ToString());
+
+  // Swipe-down to hide. This should have no effect because there are no visible
+  // windows.
+  end = start + delta;
+  generator.GestureScrollSequenceWithCallback(
+      start, end, kTimeDelta, kNumScrollSteps,
+      base::Bind(&ShelfDragCallback::ProcessScroll,
+                 base::Unretained(&handler)));
+  EXPECT_EQ(SHELF_VISIBLE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_NEVER, shelf->auto_hide_behavior());
+  EXPECT_EQ(shelf_shown.ToString(),
+            GetShelfWidget()->GetWindowBoundsInScreen().ToString());
 }
 
 // Makes sure SetVisible updates work area and widget appropriately.