From 61ffc55ec3927c2543d431819dc92a9e6dbaef03 Mon Sep 17 00:00:00 2001
From: Marshall Greenblatt <magreenblatt@gmail.com>
Date: Thu, 11 Sep 2014 18:23:10 +0000
Subject: [PATCH] Linux: Reduce resource usage when the window is minimized
 (issue #1369).

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1832 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
---
 libcef/browser/window_x11.cc      | 39 ++++++++++++++++++-
 tests/cefclient/cefclient_gtk.cpp | 65 +++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/libcef/browser/window_x11.cc b/libcef/browser/window_x11.cc
index ef62f7878..13fd01444 100644
--- a/libcef/browser/window_x11.cc
+++ b/libcef/browser/window_x11.cc
@@ -17,17 +17,21 @@
 
 namespace {
 
+const char kAtom[] = "ATOM";
 const char kWMDeleteWindow[] = "WM_DELETE_WINDOW";
 const char kWMProtocols[] = "WM_PROTOCOLS";
-const char kNetWMPing[] = "_NET_WM_PING";
 const char kNetWMPid[] = "_NET_WM_PID";
+const char kNetWMPing[] = "_NET_WM_PING";
+const char kNetWMState[] = "_NET_WM_STATE";
 const char kXdndProxy[] = "XdndProxy";
 
 const char* kAtomsToCache[] = {
+  kAtom,
   kWMDeleteWindow,
   kWMProtocols,
-  kNetWMPing,
   kNetWMPid,
+  kNetWMPing,
+  kNetWMState,
   kXdndProxy,
   NULL
 };
@@ -360,6 +364,37 @@ uint32_t CefWindowX11::DispatchEvent(const ui::PlatformEvent& event) {
       if (focus_pending_)
         focus_pending_ = false;
       break;
+    case PropertyNotify: {
+      ::Atom changed_atom = xev->xproperty.atom;
+      if (changed_atom == atom_cache_.GetAtom(kNetWMState)) {
+        // State change event like minimize/maximize.
+        if (browser_) {
+          ::Window child = FindChild(xdisplay_, xwindow_);
+          if (child) {
+            // Forward the state change to the child DesktopWindowTreeHostX11
+            // window so that resource usage will be reduced while the window is
+            // minimized.
+            std::vector< ::Atom> atom_list;
+            if (ui::GetAtomArrayProperty(xwindow_, kNetWMState, &atom_list) &&
+                !atom_list.empty()) {
+              ui::SetAtomArrayProperty(child, kNetWMState, "ATOM", atom_list);
+            } else {
+              // Set an empty list of property values to pass the check in
+              // DesktopWindowTreeHostX11::OnWMStateUpdated().
+              XChangeProperty(xdisplay_,
+                              child,
+                              atom_cache_.GetAtom(kNetWMState),  // name
+                              atom_cache_.GetAtom(kAtom),  // type
+                              32,  // size in bits of items in 'value'
+                              PropModeReplace,
+                              NULL,
+                              0);  // num items
+            }
+          }
+        }
+      }
+      break;
+    }
   }
 
   return ui::POST_DISPATCH_STOP_PROPAGATION;
diff --git a/tests/cefclient/cefclient_gtk.cpp b/tests/cefclient/cefclient_gtk.cpp
index 8aef60129..1b4bf347f 100644
--- a/tests/cefclient/cefclient_gtk.cpp
+++ b/tests/cefclient/cefclient_gtk.cpp
@@ -16,6 +16,7 @@
 #include <string>
 
 #include "cefclient/cefclient.h"
+#include "include/base/cef_scoped_ptr.h"
 #include "include/cef_app.h"
 #include "include/cef_browser.h"
 #include "include/cef_frame.h"
@@ -115,6 +116,68 @@ gboolean WindowFocusIn(GtkWidget* widget,
   return FALSE;
 }
 
+gboolean WindowState(GtkWidget* widget,
+                     GdkEventWindowState* event,
+                     gpointer user_data) {
+  if (!(event->changed_mask & GDK_WINDOW_STATE_ICONIFIED))
+    return TRUE;
+
+  if (!g_handler)
+    return TRUE;
+  CefRefPtr<CefBrowser> browser = g_handler->GetBrowser();
+  if (!browser)
+    return TRUE;
+
+  const bool iconified = (event->new_window_state & GDK_WINDOW_STATE_ICONIFIED);
+  if (browser->GetHost()->IsWindowRenderingDisabled()) {
+    // Notify the off-screen browser that it was shown or hidden.
+    browser->GetHost()->WasHidden(iconified);
+  } else {
+    // Forward the state change event to the browser window.
+    ::Display* xdisplay = cef_get_xdisplay();
+    ::Window xwindow = browser->GetHost()->GetWindowHandle();
+
+    // Retrieve the atoms required by the below XChangeProperty call.
+    const char* kAtoms[] = {
+      "_NET_WM_STATE",
+      "ATOM",
+      "_NET_WM_STATE_HIDDEN"
+    };
+    Atom atoms[3];
+    int result = XInternAtoms(xdisplay, const_cast<char**>(kAtoms), 3, false,
+                              atoms);
+    if (!result)
+      NOTREACHED();
+
+    if (iconified) {
+      // Set the hidden property state value.
+      scoped_ptr<Atom[]> data(new Atom[1]);
+      data[0] = atoms[2];
+
+      XChangeProperty(xdisplay,
+                      xwindow,
+                      atoms[0],  // name
+                      atoms[1],  // type
+                      32,  // size in bits of items in 'value'
+                      PropModeReplace,
+                      reinterpret_cast<const unsigned char*>(data.get()),
+                      1);  // num items
+    } else {
+      // Set an empty array of property state values.
+      XChangeProperty(xdisplay,
+                      xwindow,
+                      atoms[0],  // name
+                      atoms[1],  // type
+                      32,  // size in bits of items in 'value'
+                      PropModeReplace,
+                      NULL,
+                      0);  // num items
+    }
+  }
+
+  return TRUE;
+}
+
 // Callback for Tests > Get Source... menu item.
 gboolean GetSourceActivated(GtkWidget* widget) {
   if (g_handler.get() && g_handler->GetBrowserId())
@@ -357,6 +420,8 @@ int main(int argc, char* argv[]) {
   gtk_window_set_default_size(GTK_WINDOW(window), 800, 600);
   g_signal_connect(window, "focus-in-event",
                    G_CALLBACK(WindowFocusIn), NULL);
+  g_signal_connect(window, "window-state-event", 
+                   G_CALLBACK(WindowState), NULL);
 
   GtkWidget* vbox = gtk_vbox_new(FALSE, 0);
   g_signal_connect(vbox, "size-allocate",