Merge lp:~3v1n0/unity/lockscreen-shield-ensure-grab into lp:unity

[Marco Trevisan (Treviño)]

LockScreenShield: Add GrabScreen function and retry to make sure we really get grab

It might happen that the grab is not possible because the PluginAdapter::IsScreenGrabbed
request has still not being fully processed, and thus nux is not able to grab the
pointer/keyboard. By doing this we instead try to grab the screen, and if this is
not happening, we wait a little until we don't get the ungrab event.

In this way, if we eventually get the grab, all will work as expected.
Otherwise, we cancel the lock request (very unlikely to happen).

[Brandon Schaefer (brandontschaefer)]

LGTM

review: Approve

[Andrea Azzarone (azzar1)]

LGTM.

review: Approve

=== modified file 'lockscreen/LockScreenController.cpp'
--- lockscreen/LockScreenController.cpp	2014-06-19 18:41:29 +0000
+++ lockscreen/LockScreenController.cpp	2014-07-30 23:50:31 +0000
@@ -45,9 +45,9 @@
   bool AcceptKeyNavFocus() override { return true; }
   bool InspectKeyEvent(unsigned int, unsigned int, const char*) override { return true; };
 };
-}
 
 DECLARE_LOGGER(logger, "unity.lockscreen");
+}
 
 Controller::Controller(DBusManager::Ptr const& dbus_manager,
                        session::Manager::Ptr const& session_manager,

=== modified file 'lockscreen/LockScreenShield.cpp'
--- lockscreen/LockScreenShield.cpp	2014-06-05 19:48:27 +0000
+++ lockscreen/LockScreenShield.cpp	2014-07-30 23:50:31 +0000
@@ -19,6 +19,7 @@
 
 #include "LockScreenShield.h"
 
+#include <NuxCore/Logger.h>
 #include <Nux/VLayout.h>
 #include <Nux/HLayout.h>
 #include <Nux/PaintLayer.h>
@@ -35,6 +36,11 @@
 {
 namespace lockscreen
 {
+namespace
+{
+DECLARE_LOGGER(logger, "unity.lockscreen.shield");
+const unsigned MAX_GRAB_WAIT = 50;
+}
 
 Shield::Shield(session::Manager::Ptr const& session_manager, indicator::Indicators::Ptr const& indicators, Accelerators::Ptr const& accelerators, int monitor_num, bool is_primary)
   : AbstractShield(session_manager, indicators, accelerators, monitor_num, is_primary)
@@ -56,12 +62,7 @@
   });
 
   primary.changed.connect([this] (bool is_primary) {
-    if (!is_primary)
-    {
-      UnGrabPointer();
-      UnGrabKeyboard();
-    }
-
+    regrab_conn_->disconnect();
     is_primary ? ShowPrimaryView() : ShowSecondaryView();
     if (panel_view_) panel_view_->SetInputEventSensitivity(is_primary);
     QueueRelayout();
@@ -86,17 +87,41 @@
   }
 }
 
+void Shield::GrabScreen(bool cancel_on_failure)
+{
+  auto& wc = nux::GetWindowCompositor();
+
+  if (wc.GrabPointerAdd(this) && wc.GrabKeyboardAdd(this))
+  {
+    regrab_conn_->disconnect();
+    regrab_timeout_.reset();
+  }
+  else
+  {
+    auto const& retry_cb = sigc::bind(sigc::mem_fun(this, &Shield::GrabScreen), false);
+    regrab_conn_ = WindowManager::Default().screen_ungrabbed.connect(retry_cb);
+
+    if (cancel_on_failure)
+    {
+      regrab_timeout_.reset(new glib::Timeout(MAX_GRAB_WAIT, [this] {
+        LOG_ERROR(logger) << "Impossible to get the grab to lock the screen";
+        session_manager_->unlock_requested.emit();
+        return false;
+      }));
+    }
+  }
+}
+
 void Shield::ShowPrimaryView()
 {
-  GrabPointer();
-  GrabKeyboard();
-
   if (primary_layout_)
   {
+    GrabScreen(false);
     SetLayout(primary_layout_.GetPointer());
     return;
   }
 
+  GrabScreen(true);
   nux::Layout* main_layout = new nux::VLayout();
   primary_layout_ = main_layout;
   SetLayout(primary_layout_.GetPointer());
@@ -149,19 +174,7 @@
       }
       else
       {
-        auto& wc = nux::GetWindowCompositor();
-
-        if (!wc.GrabPointerAdd(this) || !wc.GrabKeyboardAdd(this))
-        {
-          regrab_conn_ = WindowManager::Default().screen_ungrabbed.connect([this] {
-            if (primary())
-            {
-              GrabPointer();
-              GrabKeyboard();
-            }
-            regrab_conn_->disconnect();
-          });
-        }
+        GrabScreen(false);
       }
     }
   });

=== modified file 'lockscreen/LockScreenShield.h'
--- lockscreen/LockScreenShield.h	2014-06-05 19:48:27 +0000
+++ lockscreen/LockScreenShield.h	2014-07-30 23:50:31 +0000
@@ -21,6 +21,7 @@
 #define UNITY_LOCKSCREEN_SHIELD_H
 
 #include <UnityCore/ConnectionManager.h>
+#include <UnityCore/GLibSource.h>
 #include "LockScreenAbstractShield.h"
 
 namespace unity
@@ -48,6 +49,7 @@
 
 private:
   void UpdateBackgroundTexture();
+  void GrabScreen(bool cancel_on_failure);
   void ShowPrimaryView();
   void ShowSecondaryView();
   Panel* CreatePanel();
@@ -59,6 +61,7 @@
   nux::ObjectPtr<nux::Layout> cof_layout_;
   connection::Wrapper panel_active_conn_;
   connection::Wrapper regrab_conn_;
+  glib::Source::UniquePtr regrab_timeout_;
   UserPromptView* prompt_view_;
   Panel* panel_view_;
 };

=== modified file 'unity-shared/PluginAdapter.cpp'
--- unity-shared/PluginAdapter.cpp	2014-06-19 18:40:55 +0000
+++ unity-shared/PluginAdapter.cpp	2014-07-30 23:50:31 +0000
@@ -1254,6 +1254,7 @@
   if (ret == GrabSuccess)
   {
     XUngrabKeyboard(dpy, CurrentTime);
+    XFlush(dpy);
 
     if (CompWindow* w = m_Screen->findWindow(m_Screen->activeWindow()))
       w->moveInputFocusTo();