Start/End resize for attached windows during multi window resizing.

Bug: 945951
Change-Id: Ic7f983f95cff0b54ebffebea87024e524906d92d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625827
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665596}

ash/wm/workspace/multi_window_resize_controller_unittest.cc

@@ -320,14 +320,38 @@ TEST_F(MultiWindowResizeControllerTest, Three) {
   gfx::Rect bounds(resize_widget()->GetWindowBoundsInScreen());
   generator->MoveMouseTo(bounds.x() + 1, bounds.y() + 1);
   generator->PressLeftButton();
+
+  // Test that when drag starts, drag details are created for each window.
+  EXPECT_TRUE(wm::GetWindowState(w1.get())->is_dragged());
+  EXPECT_TRUE(wm::GetWindowState(w2.get())->is_dragged());
+  EXPECT_TRUE(wm::GetWindowState(w3.get())->is_dragged());
+  // Test the window components for each window.
+  EXPECT_EQ(wm::GetWindowState(w1.get())->drag_details()->window_component,
+            HTRIGHT);
+  EXPECT_EQ(wm::GetWindowState(w2.get())->drag_details()->window_component,
+            HTLEFT);
+  EXPECT_EQ(wm::GetWindowState(w3.get())->drag_details()->window_component,
+            HTLEFT);
+
   generator->MoveMouseTo(bounds.x() + 11, bounds.y() + 10);
 
+  // Drag details should exist during dragging.
+  EXPECT_TRUE(wm::GetWindowState(w1.get())->is_dragged());
+  EXPECT_TRUE(wm::GetWindowState(w2.get())->is_dragged());
+  EXPECT_TRUE(wm::GetWindowState(w3.get())->is_dragged());
+
   EXPECT_TRUE(HasTarget(w3.get()));
 
   // Release the mouse. The resizer should still be visible and a subsequent
   // press should not trigger a DCHECK.
   generator->ReleaseLeftButton();
   EXPECT_TRUE(IsShowing());
+
+  // Test that drag details are correctly deleted after dragging.
+  EXPECT_FALSE(wm::GetWindowState(w1.get())->is_dragged());
+  EXPECT_FALSE(wm::GetWindowState(w2.get())->is_dragged());
+  EXPECT_FALSE(wm::GetWindowState(w3.get())->is_dragged());
+
   generator->PressLeftButton();
 }
 

ash/wm/workspace/workspace_window_resizer.cc

@@ -487,6 +487,7 @@ void WorkspaceWindowResizer::CompleteDrag() {
   ::wm::ConvertPointToScreen(GetTarget()->parent(),
                              &last_mouse_location_in_screen);
   window_state()->OnCompleteDrag(last_mouse_location_in_screen);
+  EndDragForAttachedWindows(/*revert_drag=*/false);
 
   if (!did_move_or_resize_)
     return;
@@ -550,6 +551,7 @@ void WorkspaceWindowResizer::RevertDrag() {
   ::wm::ConvertPointToScreen(GetTarget()->parent(),
                              &last_mouse_location_in_screen);
   window_state()->OnRevertDrag(last_mouse_location_in_screen);
+  EndDragForAttachedWindows(/*revert_drag=*/true);
   window_state()->set_bounds_changed_by_user(initial_bounds_changed_by_user_);
   snap_phantom_window_controller_.reset();
 
@@ -687,6 +689,7 @@ WorkspaceWindowResizer::WorkspaceWindowResizer(
   pre_drag_window_bounds_ = window_state->window()->bounds();
 
   window_state->OnDragStarted(details().window_component);
+  StartDragForAttachedWindows();
 }
 
 void WorkspaceWindowResizer::LayoutAttachedWindows(gfx::Rect* bounds) {
@@ -1195,4 +1198,43 @@ void WorkspaceWindowResizer::SetWindowStateTypeFromGesture(
   }
 }
 
+void WorkspaceWindowResizer::StartDragForAttachedWindows() {
+  if (attached_windows_.empty())
+    return;
+
+  // The component of the attached windows is always the opposite component of
+  // the main window.
+  const int main_window_component = details().window_component;
+  DCHECK(main_window_component == HTRIGHT || main_window_component == HTBOTTOM);
+
+  int window_component = HTNOWHERE;
+  if (main_window_component == HTRIGHT)
+    window_component = HTLEFT;
+  else if (main_window_component == HTBOTTOM)
+    window_component = HTTOP;
+  DCHECK(window_component == HTLEFT || window_component == HTTOP);
+
+  for (auto* window : attached_windows_) {
+    wm::WindowState* window_state = wm::GetWindowState(window);
+    window_state->CreateDragDetails(details().initial_location_in_parent,
+                                    window_component,
+                                    ::wm::WINDOW_MOVE_SOURCE_MOUSE);
+    window_state->OnDragStarted(window_component);
+  }
+}
+
+void WorkspaceWindowResizer::EndDragForAttachedWindows(bool revert_drag) {
+  if (attached_windows_.empty())
+    return;
+
+  for (auto* window : attached_windows_) {
+    wm::WindowState* window_state = wm::GetWindowState(window);
+    if (revert_drag)
+      window_state->OnRevertDrag(last_mouse_location_);
+    else
+      window_state->OnCompleteDrag(last_mouse_location_);
+    window_state->DeleteDragDetails();
+  }
+}
+
 }  // namespace ash

ash/wm/workspace/workspace_window_resizer.h

@@ -166,6 +166,10 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   void SetWindowStateTypeFromGesture(aura::Window* window,
                                      WindowStateType new_state_type);
 
+  // Start/End drag for attached windows if there is any.
+  void StartDragForAttachedWindows();
+  void EndDragForAttachedWindows(bool revert_drag);
+
   wm::WindowState* window_state() { return window_state_; }
 
   const std::vector<aura::Window*> attached_windows_;