Merge three implementations for getting the topmost x11 window at a point

chrome/browser/ui/views/tabs/window_finder_x11.cc

 // Copyright 2014 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/window_finder.h"
 
-#include "base/debug/trace_event.h"
-#include "chrome/browser/ui/host_desktop.h"
-#include "ui/aura/window.h"
-#include "ui/aura/window_tree_host.h"
-#include "ui/base/x/x11_util.h"
-#include "ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h"
+#include "ui/views/widget/desktop_aura/x11_topmost_window_finder.h"
 
 #if defined(USE_ASH)
 aura::Window* GetLocalProcessWindowAtPointAsh(
     const gfx::Point& screen_point,
     const std::set<aura::Window*>& ignore);
 #endif
 
-namespace {
-
-////////////////////////////////////////////////////////////////////////////////
-// BaseWindowFinder
-//
-// Base class used to locate a window. A subclass need only override
-// ShouldStopIterating to determine when iteration should stop.
-class BaseWindowFinder : public ui::EnumerateWindowsDelegate {
- public:
-  explicit BaseWindowFinder(const std::set<aura::Window*>& ignore) {
-    std::set<aura::Window*>::iterator iter;
-    for (iter = ignore.begin(); iter != ignore.end(); iter++) {
-      XID xid = (*iter)->GetHost()->GetAcceleratedWidget();
-      ignore_.insert(xid);
-    }
-  }
-
-  virtual ~BaseWindowFinder() {}
-
- protected:
-  // Returns true if |window| is in the ignore list.
-  bool ShouldIgnoreWindow(XID window) {
-    return (ignore_.find(window) != ignore_.end());
-  }
-
-  // Returns true if iteration should stop, false otherwise.
-  virtual bool ShouldStopIterating(XID window) OVERRIDE {
-    return false;
-  }
-
- private:
-  std::set<XID> ignore_;
-
-  DISALLOW_COPY_AND_ASSIGN(BaseWindowFinder);
-};
-
-////////////////////////////////////////////////////////////////////////////////
-// TopMostFinder
-//
-// Helper class to determine if a particular point of a window is not obscured
-// by another window.
-class TopMostFinder : public BaseWindowFinder {
- public:
-  // Returns true if |window| is not obscured by another window at the
-  // location |screen_loc|, not including the windows in |ignore|.
-  static bool IsTopMostWindowAtPoint(XID window,
-                                     const gfx::Point& screen_loc,
-                                     const std::set<aura::Window*>& ignore) {
-    TopMostFinder finder(window, screen_loc, ignore);
-    return finder.is_top_most_;
-  }
-
- protected:
-  virtual bool ShouldStopIterating(XID window) OVERRIDE {
-    if (BaseWindowFinder::ShouldIgnoreWindow(window))
-      return false;
-
-    if (window == target_) {
-      // Window is topmost, stop iterating.
-      is_top_most_ = true;
-      return true;
-    }
-
-    if (!ui::IsWindowVisible(window)) {
-      // The window isn't visible, keep iterating.
-      return false;
-    }
-
-    // At this point we haven't found our target window, so this window is
-    // higher in the z-order than the target window.  If this window contains
-    // the point, then we can stop the search now because this window is
-    // obscuring the target window at this point.
-    return ui::WindowContainsPoint(window, screen_loc_);
-  }
-
- private:
-  TopMostFinder(XID window,
-                const gfx::Point& screen_loc,
-                const std::set<aura::Window*>& ignore)
-    : BaseWindowFinder(ignore),
-      target_(window),
-      screen_loc_(screen_loc),
-      is_top_most_(false) {
-    ui::EnumerateTopLevelWindows(this);
-  }
-
-  // The window we're looking for.
-  XID target_;
-
-  // Location of window to find.
-  gfx::Point screen_loc_;
-
-  // Is target_ the top most window? This is initially false but set to true
-  // in ShouldStopIterating if target_ is passed in.
-  bool is_top_most_;
-
-  DISALLOW_COPY_AND_ASSIGN(TopMostFinder);
-};
-
-////////////////////////////////////////////////////////////////////////////////
-// LocalProcessWindowFinder
-//
-// Helper class to determine if a particular point of a window from our process
-// is not obscured by another window.
-class LocalProcessWindowFinder : public BaseWindowFinder {
- public:
-  // Returns the XID from our process at screen_loc that is not obscured by
-  // another window. Returns 0 otherwise.
-  static XID GetProcessWindowAtPoint(const gfx::Point& screen_loc,
-                                     const std::set<aura::Window*>& ignore) {
-    LocalProcessWindowFinder finder(screen_loc, ignore);
-    if (finder.result_ &&
-        TopMostFinder::IsTopMostWindowAtPoint(finder.result_, screen_loc,
-                                              ignore)) {
-      return finder.result_;
-    }
-    return 0;
-  }
-
- protected:
-  virtual bool ShouldStopIterating(XID window) OVERRIDE {
-    if (BaseWindowFinder::ShouldIgnoreWindow(window))
-      return false;
-
-    // Check if this window is in our process.
-    if (!aura::WindowTreeHost::GetForAcceleratedWidget(window))
-      return false;
-
-    if (!ui::IsWindowVisible(window))
-      return false;
-
-    if (ui::WindowContainsPoint(window, screen_loc_)) {
-      result_ = window;
-      return true;
-    }
-
-    return false;
-  }
-
- private:
-  LocalProcessWindowFinder(const gfx::Point& screen_loc,
-                           const std::set<aura::Window*>& ignore)
-    : BaseWindowFinder(ignore),
-      screen_loc_(screen_loc),
-      result_(0) {
-    ui::EnumerateTopLevelWindows(this);
-  }
-
-  // Position of the mouse.
-  gfx::Point screen_loc_;
-
-  // The resulting window. This is initially null but set to true in
-  // ShouldStopIterating if an appropriate window is found.
-  XID result_;
-
-  DISALLOW_COPY_AND_ASSIGN(LocalProcessWindowFinder);
-};
-
-}  // namespace
-
 aura::Window* GetLocalProcessWindowAtPoint(
     chrome::HostDesktopType host_desktop_type,
     const gfx::Point& screen_point,
     const std::set<aura::Window*>& ignore) {
 #if defined(USE_ASH)
   if (host_desktop_type == chrome::HOST_DESKTOP_TYPE_ASH)
     return GetLocalProcessWindowAtPointAsh(screen_point, ignore);
 #endif
+
   // The X11 server is the canonical state of what the window stacking order
   // is.
-  XID xid =
-      LocalProcessWindowFinder::GetProcessWindowAtPoint(screen_point, ignore);
-  return views::DesktopWindowTreeHostX11::GetContentWindowForXID(xid);
+  views::X11TopmostWindowFinder finder;
+  return finder.FindLocalProcessWindowAt(screen_point, ignore);
 }