ChromeOS MD: Fix cannot drag tab onto immersive fullscreen window

chrome/browser/ui/views/tabs/tab_drag_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/tabs/tab_drag_controller.h"
 
 #include <math.h>
 #include <set>
 
 #include "base/auto_reset.h"
@@ skipping 93 matching lines @@
 gfx::NativeWindow GetModalTransient(gfx::NativeWindow window) {
   return wm::GetModalTransient(window);
 }
 #else
 gfx::NativeWindow GetModalTransient(gfx::NativeWindow window) {
   NOTIMPLEMENTED();
   return NULL;
 }
 #endif
 
+// Get tabstrip bounds from non-client view coordinates where tabstrip should be

[sky, 2017/01/18 16:40:46]

I think you mean, "Returns the bounds of the tabstrip in screen coordinates in
|rect|." I'm a bit confused on how this fails, comments below.

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

changed to GetBoundsForTabStripInBrowserView, so change the comments.

+// laid when revealed, then convert to screen coordinates. Return false if the
+// corresponding browser view doesn't exist.
+bool GetBoundsForTabStripInScreen(TabStrip* tabstrip, gfx::Rect* rect) {
+  if (!tabstrip)
+    return false;

[sky, 2017/01/18 16:40:46]

I think callers should check for this case.

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

caller will make sure it

+  gfx::NativeWindow window = tabstrip->GetWidget()->GetNativeWindow();
+  if (!window)

[sky, 2017/01/18 16:40:46]

Can this case really happen?

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

seems cannot happen. remove it.

+    return false;
+  BrowserView* browser_view =
+      BrowserView::GetBrowserViewForNativeWindow(window);
+  if (!browser_view)

[sky, 2017/01/18 16:40:46]

Same comment here. Can this case really happen?

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

Done.

+    return false;
+  *rect = browser_view->frame()->GetBoundsForTabStrip(tabstrip);

[sky, 2017/01/18 16:40:46]

Why do you need to use GetBoundsForTabStrip rather than the actual bounds?

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

the actual bounds will return (0, 0, 0x0) for this case.

+  aura::Window::ConvertRectToTarget(window, window->GetRootWindow(), rect);
+  return true;
+}
+
 // Returns true if |bounds| contains the y-coordinate |y|. The y-coordinate
 // of |bounds| is adjusted by |vertical_adjustment|.
 bool DoesRectContainVerticalPointExpanded(
     const gfx::Rect& bounds,
     int vertical_adjustment,
     int y) {
   int upper_threshold = bounds.bottom() + vertical_adjustment;
   int lower_threshold = bounds.y() - vertical_adjustment;
   return y >= lower_threshold && y <= upper_threshold;
 }
@@ skipping 438 matching lines @@
     TabStrip* target_tabstrip,
     const gfx::Point& point_in_screen) {
   TRACE_EVENT1("views", "TabDragController::DragBrowserToNewTabStrip",
                "point_in_screen", point_in_screen.ToString());
 
   if (!target_tabstrip) {
     DetachIntoNewBrowserAndRunMoveLoop(point_in_screen);
     return DRAG_BROWSER_RESULT_STOP;
   }
 
+  // If tabstrip is invisible, it is not eligible to determine the tab insertion
+  // position, so show the tabstrip here.
+  gfx::Rect tabstrip_bounds;
+  if (!target_tabstrip->visible() &&
+      GetBoundsForTabStripInScreen(target_tabstrip, &tabstrip_bounds)) {
+    target_tabstrip->SetVisible(true);
+    target_tabstrip->SetBoundsRect(tabstrip_bounds);
+  }
+
 #if defined(USE_AURA)
   // Only Aura windows are gesture consumers.
   ui::GestureRecognizer::Get()->TransferEventsTo(
       GetAttachedBrowserWidget()->GetNativeView(),
       target_tabstrip->GetWidget()->GetNativeView(),
       ui::GestureRecognizer::ShouldCancelTouches::DontCancel);
 #endif
 
   if (is_dragging_window_) {
     // ReleaseCapture() is going to result in calling back to us (because it
@@ skipping 267 matching lines @@
       attached_tabstrip_ ? attached_tabstrip_ : source_tabstrip_;
   DCHECK(tab_strip);
 
   return other_tabstrip->controller()->IsCompatibleWith(tab_strip) ?
       other_tabstrip : NULL;
 }
 
 bool TabDragController::DoesTabStripContain(
     TabStrip* tabstrip,
     const gfx::Point& point_in_screen) const {
-  // Make sure the specified screen point is actually within the bounds of the
-  // specified tabstrip...
-  gfx::Rect tabstrip_bounds = GetViewScreenBounds(tabstrip);
+  // Make sure the specified screen point is within the bounds of the specified
+  // tabstrip where it should be laid when revealed.
+  gfx::Rect tabstrip_bounds;
+  DCHECK(GetBoundsForTabStripInScreen(tabstrip, &tabstrip_bounds));
+
   return point_in_screen.x() < tabstrip_bounds.right() &&
-      point_in_screen.x() >= tabstrip_bounds.x() &&
-      DoesRectContainVerticalPointExpanded(tabstrip_bounds,
-                                           kVerticalDetachMagnetism,
-                                           point_in_screen.y());
+         point_in_screen.x() >= tabstrip_bounds.x() &&
+         DoesRectContainVerticalPointExpanded(
+             tabstrip_bounds, kVerticalDetachMagnetism, point_in_screen.y());
 }
 
 void TabDragController::Attach(TabStrip* attached_tabstrip,
                                const gfx::Point& point_in_screen) {
   TRACE_EVENT1("views", "TabDragController::Attach",
                "point_in_screen", point_in_screen.ToString());
 
   DCHECK(!attached_tabstrip_);  // We should already have detached by the time
                                 // we get here.
 
@@ skipping 918 matching lines @@
   // TODO(pkotwicz): Fix this properly (crbug.com/358482)
   for (auto* browser : *BrowserList::GetInstance()) {
     if (browser->tab_strip_model()->empty())
       exclude.insert(browser->window()->GetNativeWindow());
   }
 #endif
   base::WeakPtr<TabDragController> ref(weak_factory_.GetWeakPtr());
   *window = window_finder_->GetLocalProcessWindowAtPoint(screen_point, exclude);
   return ref ? Liveness::ALIVE : Liveness::DELETED;
 }