Support moving the cursor and dragging windows to 3+ displays.

ash/display/extended_mouse_warp_controller.h

Index: ash/display/extended_mouse_warp_controller.h
diff --git a/ash/display/extended_mouse_warp_controller.h b/ash/display/extended_mouse_warp_controller.h
index 162afa684e0ed521ae016bf3b27c508bb2f0e8f3..d1502064f7b99b9cf7f13eb45c9f1fef864b66cf 100644
--- a/ash/display/extended_mouse_warp_controller.h
+++ b/ash/display/extended_mouse_warp_controller.h
@@ -7,6 +7,9 @@
 
 #include "ash/display/mouse_warp_controller.h"
 
+#include <vector>
+
+#include "ash/display/display_layout.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
@@ -18,6 +21,7 @@ class Window;
 
 namespace gfx {
 class Point;
+class Display;
 }
 
 namespace ash {
@@ -44,6 +48,47 @@ class ASH_EXPORT ExtendedMouseWarpController : public MouseWarpController {
                            IndicatorBoundsTestOnLeft);
   FRIEND_TEST_ALL_PREFIXES(ExtendedMouseWarpControllerTest,
                            IndicatorBoundsTestOnTopBottom);
+  FRIEND_TEST_ALL_PREFIXES(ExtendedMouseWarpControllerTest,
+                           IndicatorBoundsTestThreeDisplays);
+
+  // Defined in header file because tests need access.
+  struct WarpRegion {
+   public:
+    WarpRegion(int64_t a_display_id,
+               int64_t b_display_id,
+               const gfx::Rect& a_indicator_bounds,
+               const gfx::Rect& b_indicator_bounds);
+    ~WarpRegion();
+
+    // If the mouse cursor is in |a_edge_bounds_in_native|, then it will be
+    // moved to |b_display_id|. Similarily, if the cursor is in
+    // |b_edge_bounds_in_native|, then it will be moved to |a_display_id|.
+
+    // The id for the displays. Used for warping the cursor.
+    int64_t a_display_id;
+    int64_t b_display_id;
+
+    gfx::Rect a_edge_bounds_in_native;
+    gfx::Rect b_edge_bounds_in_native;
+
+    // The bounds for warp hole windows. These are kept in the instance for
+    // testing.
+    gfx::Rect a_indicator_bounds;
+    gfx::Rect b_indicator_bounds;
+
+    // Shows the area where a window can be dragged in to/out from another
+    // display.
+    scoped_ptr<SharedDisplayEdgeIndicator> shared_display_edge_indicator;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(WarpRegion);
+  };
+
+  std::vector<scoped_ptr<WarpRegion>> warp_regions_;
+
+  // Registers the WarpRegion; also displays a drag indicator on the screen if
+  // |drag_source| is true.
+  void AddWarpRegion(scoped_ptr<WarpRegion> region, bool drag_source);
 
   // Warps the mouse cursor to an alternate root window when the
   // mouse location in |event|, hits the edge of the event target's root and
@@ -56,35 +101,22 @@ class ASH_EXPORT ExtendedMouseWarpController : public MouseWarpController {
 
   // Update the edge/indicator bounds based on the current
   // display configuration.
-  void UpdateHorizontalEdgeBounds();
-  void UpdateVerticalEdgeBounds();
-
-  // Returns the source and destination window. When |src_window| is
-  // |drag_soruce_root_| when it is set. Otherwise, the |src_window|
-  // is always the primary root window, because there is no difference
-  // between moving src to dst and moving dst to src.
-  void GetSrcAndDstRootWindows(aura::Window** src_window,
-                               aura::Window** dst_window);
+  scoped_ptr<WarpRegion> CreateHorizontalEdgeBounds(
+      const gfx::Display& a,
+      const gfx::Display& b,
+      DisplayLayout::Position position);
+  scoped_ptr<WarpRegion> CreateVerticalEdgeBounds(
+      const gfx::Display& a,
+      const gfx::Display& b,
+      DisplayLayout::Position position);
 
   void allow_non_native_event_for_test() { allow_non_native_event_ = true; }
 
-  // The bounds for warp hole windows. |dst_indicator_bounds_| is kept
-  // in the instance for testing.
-  gfx::Rect src_indicator_bounds_;
-  gfx::Rect dst_indicator_bounds_;
-
-  gfx::Rect src_edge_bounds_in_native_;
-  gfx::Rect dst_edge_bounds_in_native_;
-
   // The root window in which the dragging started.
   aura::Window* drag_source_root_;
 
   bool enabled_;
 
-  // Shows the area where a window can be dragged in to/out from
-  // another display.
-  scoped_ptr<SharedDisplayEdgeIndicator> shared_display_edge_indicator_;
-
   bool allow_non_native_event_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtendedMouseWarpController);