The bug is "screen.width/availWidth returns different value with FireFox in Linux dual monitor environment", FireFox uses Xinerama to get screen width/height information. If we cannot use Xinerama, return the same width/height info as before.

BUG=28560
TEST=1, Prepare dual monitor Linux system which can use Xinerama. 2, Launch browser and run javascript "document.write("screen.witdh = " + screen.width + "<br>");". 3, Make sure the width is in single monitor width size.

Patch by Takano.Naoki@gmail.com.
Original Review: http://codereview.chromium.org/6714036/
Review URL: http://codereview.chromium.org/6725024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79226 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 89 insertions, 26 deletions

diff --git a/content/browser/renderer_host/render_message_filter_gtk.cc b/content/browser/renderer_host/render_message_filter_gtk.cc
index 8d91b57..163285a 100644
--- a/content/browser/renderer_host/render_message_filter_gtk.cc
+++ b/content/browser/renderer_host/render_message_filter_gtk.cc
@@ -2,35 +2,45 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <dlfcn.h>
+
 #include "content/browser/renderer_host/render_message_filter.h"
 
 #include "chrome/common/render_messages.h"
 #include "content/browser/browser_thread.h"
 #include "content/common/view_messages.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebRect.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScreenInfo.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/x11/WebScreenInfoFactory.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/gfx/gtk_native_view_id_manager.h"
 
+// We want to obey the alphabetical order for including header files, but
+// #define macros in X11 header files affect chrome header files
+// (e.g. Success), so include Xinerama.h here.
+#include <X11/extensions/Xinerama.h>
+
 using WebKit::WebScreenInfo;
 using WebKit::WebScreenInfoFactory;
 
-// We get null window_ids passed into the two functions below; please see
-// http://crbug.com/9060 for more details.
+namespace {
 
-void RenderMessageFilter::DoOnGetScreenInfo(gfx::NativeViewId view,
-                                            IPC::Message* reply_msg) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::BACKGROUND_X11));
-  Display* display = ui::GetSecondaryDisplay();
-  int screen = ui::GetDefaultScreen(display);
-  WebScreenInfo results = WebScreenInfoFactory::screenInfo(display, screen);
-  ViewHostMsg_GetScreenInfo::WriteReplyParams(reply_msg, results);
-  Send(reply_msg);
+// Return the top-level parent of the given window. Called on the
+// BACKGROUND_X11 thread.
+XID GetTopLevelWindow(XID window) {
+  bool parent_is_root;
+  XID parent_window;
+
+  if (!ui::GetWindowParent(&parent_window, &parent_is_root, window))
+    return 0;
+  if (parent_is_root)
+    return window;
+
+  return GetTopLevelWindow(parent_window);
 }
 
-void RenderMessageFilter::DoOnGetWindowRect(gfx::NativeViewId view,
-                                            IPC::Message* reply_msg) {
+gfx::Rect GetWindowRectFromView(gfx::NativeViewId view) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::BACKGROUND_X11));
   // This is called to get the x, y offset (in screen coordinates) of the given
   // view and its width and height.
@@ -46,23 +56,77 @@ void RenderMessageFilter::DoOnGetWindowRect(gfx::NativeViewId view,
         rect = gfx::Rect(x, y, width, height);
     }
   }
-
-  ViewHostMsg_GetWindowRect::WriteReplyParams(reply_msg, rect);
-  Send(reply_msg);
+  return rect;
 }
 
-// Return the top-level parent of the given window. Called on the
-// BACKGROUND_X11 thread.
-static XID GetTopLevelWindow(XID window) {
-  bool parent_is_root;
-  XID parent_window;
+}  // namespace
 
-  if (!ui::GetWindowParent(&parent_window, &parent_is_root, window))
-    return 0;
-  if (parent_is_root)
-    return window;
+// We get null window_ids passed into the two functions below; please see
+// http://crbug.com/9060 for more details.
 
-  return GetTopLevelWindow(parent_window);
+void RenderMessageFilter::DoOnGetScreenInfo(gfx::NativeViewId view,
+                                            IPC::Message* reply_msg) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::BACKGROUND_X11));
+  Display* display = ui::GetSecondaryDisplay();
+
+  WebScreenInfo results = WebScreenInfoFactory::screenInfo(display,
+      ui::GetDefaultScreen(display));
+
+  // First check if we can use Xinerama.
+  XineramaScreenInfo* screen_info = NULL;
+  int screen_num = 0;
+  void* xinerama_lib = dlopen("libXinerama.so.1", RTLD_LAZY);
+  if (xinerama_lib) {
+    // Prototypes for Xinerama functions.
+    typedef Bool (*XineramaIsActiveFunction)(Display* display);
+    typedef XineramaScreenInfo*
+        (*XineramaQueryScreensFunction)(Display* display, int* num);
+
+    XineramaIsActiveFunction is_active = (XineramaIsActiveFunction)
+        dlsym(xinerama_lib, "XineramaIsActive");
+
+    XineramaQueryScreensFunction query_screens = (XineramaQueryScreensFunction)
+        dlsym(xinerama_lib, "XineramaQueryScreens");
+
+    // Get the number of screens via Xinerama
+    if (is_active && query_screens && is_active(display))
+      screen_info = query_screens(display, &screen_num);
+
+    if (screen_info) {
+      // We can use Xinerama information. Calculate the intersect rect size
+      // between window rect and screen rect, and choose the biggest size.
+      gfx::Rect rect = GetWindowRectFromView(view);
+      int max_intersect_index = 0;
+      for (int i = 0, max_intersect_size = 0; i < screen_num; ++i) {
+        gfx::Rect screen_rect(screen_info[i].x_org, screen_info[i].y_org,
+                              screen_info[i].width, screen_info[i].height);
+        gfx::Rect intersect_rect = screen_rect.Intersect(rect);
+        int intersect_size = intersect_rect.width() * intersect_rect.height();
+        if (intersect_size > max_intersect_size) {
+          max_intersect_size = intersect_size;
+          max_intersect_index = i;
+        }
+      }
+      XineramaScreenInfo& target_screen = screen_info[max_intersect_index];
+      results.rect = WebKit::WebRect(target_screen.x_org,
+                                     target_screen.y_org,
+                                     target_screen.width,
+                                     target_screen.height);
+      results.availableRect = results.rect;
+
+      XFree(screen_info);
+    }
+  }
+
+  ViewHostMsg_GetScreenInfo::WriteReplyParams(reply_msg, results);
+  Send(reply_msg);
+}
+
+void RenderMessageFilter::DoOnGetWindowRect(gfx::NativeViewId view,
+                                            IPC::Message* reply_msg) {
+  ViewHostMsg_GetWindowRect::WriteReplyParams(reply_msg,
+                                              GetWindowRectFromView(view));
+  Send(reply_msg);
 }
 
 void RenderMessageFilter::DoOnGetRootWindowRect(gfx::NativeViewId view,
@@ -116,4 +180,3 @@ void RenderMessageFilter::OnGetRootWindowRect(gfx::NativeViewId view,
       NewRunnableMethod(
           this, &RenderMessageFilter::DoOnGetRootWindowRect, view, reply_msg));
 }
-