ash: Hide the launcher if it's pulled up from a visible state.

BUG=161352

Review URL: https://codereview.chromium.org/11413195

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@169821 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 42 insertions, 31 deletions

diff --git a/ash/wm/shelf_layout_manager.cc b/ash/wm/shelf_layout_manager.cc
index 4df054d..c8b070e 100644
--- a/ash/wm/shelf_layout_manager.cc
+++ b/ash/wm/shelf_layout_manager.cc
@@ -359,27 +359,40 @@ void ShelfLayoutManager::CompleteGestureDrag(const ui::GestureEvent& gesture) {
   bool horizontal = alignment() == SHELF_ALIGNMENT_BOTTOM;
   bool should_change = false;
   if (gesture.type() == ui::ET_GESTURE_SCROLL_END) {
-    // If the shelf was dragged X% towards the correct direction, then it is
-    // hidden/shown.
+    // The visibility of the shelf changes only if the shelf was dragged X%
+    // along the correct axis. If the shelf was already visible, then the
+    // direction of the drag does not matter.
     const float kDragHideThreshold = 0.4f;
     gfx::Rect bounds = GetIdealBounds();
-    float drag_amount = gesture_drag_auto_hide_state_ == AUTO_HIDE_SHOWN ?
-        gesture_drag_amount_ : -gesture_drag_amount_;
-    if (horizontal)
-      should_change = drag_amount > kDragHideThreshold * bounds.height();
-    else if (alignment() == SHELF_ALIGNMENT_LEFT)
-      should_change = -drag_amount > kDragHideThreshold * bounds.width();
-    else
-      should_change = drag_amount > kDragHideThreshold * bounds.width();
+    float drag_ratio = fabs(gesture_drag_amount_) /
+                       (horizontal ?  bounds.height() : bounds.width());
+    if (gesture_drag_auto_hide_state_ == AUTO_HIDE_SHOWN) {
+      should_change = drag_ratio > kDragHideThreshold;
+    } else {
+      bool correct_direction = false;
+      switch (alignment()) {
+        case SHELF_ALIGNMENT_BOTTOM:
+        case SHELF_ALIGNMENT_RIGHT:
+          correct_direction = gesture_drag_amount_ < 0;
+          break;
+        case SHELF_ALIGNMENT_LEFT:
+          correct_direction = gesture_drag_amount_ > 0;
+          break;
+      }
+      should_change = correct_direction && drag_ratio > kDragHideThreshold;
+    }
   } else if (gesture.type() == ui::ET_SCROLL_FLING_START) {
-    if (horizontal)
-      should_change = gesture.details().velocity_y() > 0;
-    else if (alignment() == SHELF_ALIGNMENT_LEFT)
-      should_change = gesture.details().velocity_x() < 0;
-    else
-      should_change = gesture.details().velocity_x() > 0;
-    if (gesture_drag_auto_hide_state_ == AUTO_HIDE_HIDDEN)
-      should_change = !should_change;
+    if (gesture_drag_auto_hide_state_ == AUTO_HIDE_SHOWN) {
+      should_change = horizontal ? fabs(gesture.details().velocity_y()) > 0 :
+                                   fabs(gesture.details().velocity_x()) > 0;
+    } else {
+      if (horizontal)
+        should_change = gesture.details().velocity_y() < 0;
+      else if (alignment() == SHELF_ALIGNMENT_LEFT)
+        should_change = gesture.details().velocity_x() > 0;
+      else
+        should_change = gesture.details().velocity_x() < 0;
+    }
   } else {
     NOTREACHED();
   }
diff --git a/ash/wm/shelf_layout_manager_unittest.cc b/ash/wm/shelf_layout_manager_unittest.cc
index 2c031d9..e0a6158 100644
--- a/ash/wm/shelf_layout_manager_unittest.cc
+++ b/ash/wm/shelf_layout_manager_unittest.cc
@@ -695,14 +695,7 @@ TEST_F(ShelfLayoutManagerTest, GestureDrag) {
   // Swipe up on the shelf. This should not change any state.
   gfx::Point start =
       shelf->launcher_widget()->GetWindowBoundsInScreen().CenterPoint();
-  gfx::Point end(start.x(), start.y() - 100);
-  generator.GestureScrollSequence(start, end,
-      base::TimeDelta::FromMilliseconds(10), 1);
-  EXPECT_EQ(ShelfLayoutManager::VISIBLE, shelf->visibility_state());
-  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_NEVER, shelf->auto_hide_behavior());
-  EXPECT_EQ(bounds_shelf.ToString(), window->bounds().ToString());
-  EXPECT_EQ(shelf_shown.ToString(),
-            shelf->launcher_widget()->GetWindowBoundsInScreen().ToString());
+  gfx::Point end(start.x(), start.y() + 100);
 
   // Swipe down on the shelf to hide it.
   end.set_y(start.y() + 100);
@@ -727,16 +720,21 @@ TEST_F(ShelfLayoutManagerTest, GestureDrag) {
   EXPECT_EQ(shelf_shown.ToString(),
             shelf->launcher_widget()->GetWindowBoundsInScreen().ToString());
 
-  // Swipe up again. This should not change any state.
+  // Swipe up again. The shelf should hide.
   end.set_y(start.y() - 100);
   generator.GestureScrollSequence(start, end,
       base::TimeDelta::FromMilliseconds(10), 1);
-  EXPECT_EQ(ShelfLayoutManager::VISIBLE, shelf->visibility_state());
-  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_NEVER, shelf->auto_hide_behavior());
-  EXPECT_EQ(bounds_shelf.ToString(), window->bounds().ToString());
-  EXPECT_EQ(shelf_shown.ToString(),
+  EXPECT_EQ(ShelfLayoutManager::AUTO_HIDE, shelf->visibility_state());
+  EXPECT_EQ(ShelfLayoutManager::AUTO_HIDE_HIDDEN, shelf->auto_hide_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS, shelf->auto_hide_behavior());
+  EXPECT_EQ(shelf_hidden.ToString(),
             shelf->launcher_widget()->GetWindowBoundsInScreen().ToString());
 
+  // Swipe up yet again to show it.
+  end.set_y(start.y() + 100);
+  generator.GestureScrollSequence(end, start,
+      base::TimeDelta::FromMilliseconds(10), 1);
+
   // Swipe down very little. It shouldn't change any state.
   end.set_y(start.y() + shelf_shown.height() * 3 / 10);
   generator.GestureScrollSequence(start, end,