Rework app list item drag zones.

ui/app_list/views/apps_grid_view_unittest.cc

Index: ui/app_list/views/apps_grid_view_unittest.cc
diff --git a/ui/app_list/views/apps_grid_view_unittest.cc b/ui/app_list/views/apps_grid_view_unittest.cc
index c6fd60b50d2e303a10d854db12167a69d69d1738..febc17cc1fa5eb59854760a1cd36b2274761e4ed 100644
--- a/ui/app_list/views/apps_grid_view_unittest.cc
+++ b/ui/app_list/views/apps_grid_view_unittest.cc
@@ -420,25 +420,59 @@ TEST_F(AppsGridViewTest, MouseDragItemReorder) {
   // This test assumes Folders are enabled.
   EnsureFoldersEnabled();
 
-  size_t kTotalItems = 2;
-  model_->PopulateApps(kTotalItems);
-  EXPECT_EQ(2u, model_->top_level_item_list()->item_count());
-  EXPECT_EQ(std::string("Item 0,Item 1"), model_->GetModelContent());
+  model_->PopulateApps(4);
+  EXPECT_EQ(4u, model_->top_level_item_list()->item_count());
+  EXPECT_EQ(std::string("Item 0,Item 1,Item 2,Item 3"),
+            model_->GetModelContent());
 
-  gfx::Point from = GetItemTileRectAt(0, 1).CenterPoint();
-  int reorder_offset = (GetItemTileRectAt(0, 1).CenterPoint() -
-                        GetItemTileRectAt(0, 0).CenterPoint()).Length() -
-                       kReorderDroppingCircleRadius - kGridIconDimension / 2 +
-                       5;
-  gfx::Point to = gfx::Point(from.x() - reorder_offset, from.y());
+  // Dragging an item towards its neighbours should not reorder until the drag
+  // is past the folder drop point.
+  gfx::Point top_right = GetItemTileRectAt(0, 1).CenterPoint();
+  gfx::Vector2d drag_vector;
+  int half_tile_width =
+      (GetItemTileRectAt(0, 1).x() - GetItemTileRectAt(0, 0).x()) / 2;
+  int tile_height = GetItemTileRectAt(1, 0).y() - GetItemTileRectAt(0, 0).y();
+
+  // Drag left but stop before the folder dropping circle.
+  drag_vector.set_x(-half_tile_width - 5);
+  SimulateDrag(AppsGridView::MOUSE, top_right, top_right + drag_vector);
+  apps_grid_view_->EndDrag(false);
+  EXPECT_EQ(std::string("Item 0,Item 1,Item 2,Item 3"),
+            model_->GetModelContent());
 
-  // Dragging item_1 closing to item_0 should leads to re-ordering these two
-  // items.
-  SimulateDrag(AppsGridView::MOUSE, from, to);
+  // Drag left, past the folder dropping circle.
+  drag_vector.set_x(-3 * half_tile_width + 5);
+  SimulateDrag(AppsGridView::MOUSE, top_right, top_right + drag_vector);
   apps_grid_view_->EndDrag(false);
-  EXPECT_EQ(2u, model_->top_level_item_list()->item_count());
-  EXPECT_EQ(std::string("Item 1,Item 0"), model_->GetModelContent());
-  test_api_->LayoutToIdealBounds();
+  EXPECT_EQ(std::string("Item 1,Item 0,Item 2,Item 3"),
+            model_->GetModelContent());
+
+  // Drag down, between apps 2 and 3. The gap should open up, making space for
+  // app 0 in the bottom left.
+  drag_vector.set_x(-half_tile_width);
+  drag_vector.set_y(tile_height);
+  SimulateDrag(AppsGridView::MOUSE, top_right, top_right + drag_vector);
+  apps_grid_view_->EndDrag(false);
+  EXPECT_EQ(std::string("Item 1,Item 2,Item 0,Item 3"),
+            model_->GetModelContent());
+
+  // Drag up, between apps 1 and 2. The gap should open up, making space for app
+  // 0 in the top right.
+  gfx::Point bottom_left = GetItemTileRectAt(1, 0).CenterPoint();
+  drag_vector.set_x(half_tile_width);
+  drag_vector.set_y(-tile_height);
+  SimulateDrag(AppsGridView::MOUSE, bottom_left, bottom_left + drag_vector);
+  apps_grid_view_->EndDrag(false);
+  EXPECT_EQ(std::string("Item 1,Item 0,Item 2,Item 3"),
+            model_->GetModelContent());
+
+  // Dragging down past the last app should reorder to the last position.
+  drag_vector.set_x(half_tile_width);
+  drag_vector.set_y(2 * tile_height);
+  SimulateDrag(AppsGridView::MOUSE, top_right, top_right + drag_vector);
+  apps_grid_view_->EndDrag(false);
+  EXPECT_EQ(std::string("Item 1,Item 2,Item 3,Item 0"),
+            model_->GetModelContent());
 }
 
 TEST_F(AppsGridViewTest, MouseDragFolderReorder) {