linux aura: Fix window activation in some X11 window managers.

ui/views/widget/desktop_aura/x11_desktop_handler.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 "ui/views/widget/desktop_aura/x11_desktop_handler.h"
 
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+
 #include "base/message_loop/message_loop.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/x/x11_util.h"
 
 #if !defined(OS_CHROMEOS)
 #include "ui/views/ime/input_method.h"
 #include "ui/views/widget/desktop_aura/desktop_root_window_host_x11.h"
 #endif
 
 namespace {
 
 const char* kAtomsToCache[] = {
   "_NET_ACTIVE_WINDOW",
+  "_NET_SUPPORTED",
   NULL
 };
 
 // Our global instance. Deleted when our Env() is deleted.
 views::X11DesktopHandler* g_handler = NULL;
 
 }  // namespace
 
 namespace views {
 
 // static
 X11DesktopHandler* X11DesktopHandler::get() {
   if (!g_handler)
     g_handler = new X11DesktopHandler;
 
   return g_handler;
 }
 
 X11DesktopHandler::X11DesktopHandler()
     : xdisplay_(gfx::GetXDisplay()),
       x_root_window_(DefaultRootWindow(xdisplay_)),
       current_window_(None),
-      atom_cache_(xdisplay_, kAtomsToCache) {
+      atom_cache_(xdisplay_, kAtomsToCache),
+      wm_supports_active_window_(false) {
   base::MessagePumpX11::Current()->AddDispatcherForRootWindow(this);
   aura::Env::GetInstance()->AddObserver(this);
 
   XWindowAttributes attr;
   XGetWindowAttributes(xdisplay_, x_root_window_, &attr);
   XSelectInput(xdisplay_, x_root_window_,
                attr.your_event_mask | PropertyChangeMask |
                StructureNotifyMask | SubstructureNotifyMask);
+
+  const int kMaxWMAtoms = 64;
+  size_t atoms_count = 0;
+  Atom* atoms = NULL;
+  Atom type;
+  int format;
+  size_t bytes;
+  XGetWindowProperty(xdisplay_, x_root_window_,
+                     atom_cache_.GetAtom("_NET_SUPPORTED"),
+                     0, kMaxWMAtoms,
+                     False, XA_ATOM,
+                     &type, &format, &atoms_count, &bytes,
+                     reinterpret_cast<unsigned char**>(&atoms));

[Elliot Glaysher, 2013/11/14 18:37:38]

ui::GetAtomArrayProperty()?

[sadrul, 2013/11/14 19:06:41]

Done.

+  if (type == XA_ATOM) {
+    Atom active_window = atom_cache_.GetAtom("_NET_ACTIVE_WINDOW");
+    for (size_t i = 0; i < atoms_count; ++i) {
+      if (atoms[i] == active_window) {
+        wm_supports_active_window_ = true;
+        break;
+      }
+    }
+  }
 }
 
 X11DesktopHandler::~X11DesktopHandler() {
   aura::Env::GetInstance()->RemoveObserver(this);
   base::MessagePumpX11::Current()->RemoveDispatcherForRootWindow(this);
 }
 
 void X11DesktopHandler::ActivateWindow(::Window window) {
-  DCHECK_EQ(gfx::GetXDisplay(), xdisplay_);
+  if (wm_supports_active_window_) {
+    DCHECK_EQ(gfx::GetXDisplay(), xdisplay_);
 
-  XEvent xclient;
-  memset(&xclient, 0, sizeof(xclient));
-  xclient.type = ClientMessage;
-  xclient.xclient.window = window;
-  xclient.xclient.message_type = atom_cache_.GetAtom("_NET_ACTIVE_WINDOW");
-  xclient.xclient.format = 32;
-  xclient.xclient.data.l[0] = 1;  // Specified we are an app.
-  xclient.xclient.data.l[1] = CurrentTime;
-  xclient.xclient.data.l[2] = None;
-  xclient.xclient.data.l[3] = 0;
-  xclient.xclient.data.l[4] = 0;
+    XClientMessageEvent xclient;

[Elliot Glaysher, 2013/11/14 18:37:38]

piman would disprove. He's told me several times to specify the toplevel type.

[sadrul, 2013/11/14 19:06:41]

Reverted (I hadn't meant to include this in the CL)

+    memset(&xclient, 0, sizeof(xclient));
+    xclient.type = ClientMessage;
+    xclient.window = window;
+    xclient.message_type = atom_cache_.GetAtom("_NET_ACTIVE_WINDOW");
+    xclient.format = 32;
+    xclient.data.l[0] = 1;  // Specified we are an app.
+    xclient.data.l[1] = CurrentTime;
+    xclient.data.l[2] = None;
+    xclient.data.l[3] = 0;
+    xclient.data.l[4] = 0;
 
-  XSendEvent(xdisplay_, x_root_window_, False,
-             SubstructureRedirectMask | SubstructureNotifyMask,
-             &xclient);
+    XSendEvent(xdisplay_, x_root_window_, False,
+               SubstructureRedirectMask | SubstructureNotifyMask,
+               (XEvent*)&xclient);
+  } else {
+    XRaiseWindow(xdisplay_, window);
+    OnActiveWindowChanged(window);
+  }
 }
 
 bool X11DesktopHandler::IsActiveWindow(::Window window) const {
   return window == current_window_;
 }
 
 bool X11DesktopHandler::Dispatch(const base::NativeEvent& event) {
   // Check for a change to the active window.
   switch (event->type) {
     case PropertyNotify: {
@@ skipping 30 matching lines @@
 
   DesktopRootWindowHostX11* new_host =
       views::DesktopRootWindowHostX11::GetHostForXID(xid);
   if (new_host)
     new_host->HandleNativeWidgetActivationChanged(true);
 
   current_window_ = xid;
 }
 
 }  // namespace views