[server] Prevent screen standby while clients are connected

5 files changed, 138 insertions, 17 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index af61455..adcaa9f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -30,6 +30,13 @@ INCLUDE_DIRECTORIES(
 #	${X11_Xinput_INCLUDE_PATH}
 )
 
+IF(X11_Xscreensaver_FOUND)
+    ADD_DEFINITIONS(-DX11_Xscreensaver_FOUND)
+ENDIF()
+IF(X11_dpms_FOUND)
+    ADD_DEFINITIONS(-DX11_dpms_FOUND)
+ENDIF()
+
 #IF(NOT X11_XTest_FOUND)
 #    MESSAGE(FATAL_ERROR "Could not find X11 extension XTest or its developer files.")
 #ENDIF()
@@ -48,6 +55,7 @@ SET(SYSDEP_SUFFIX _X11)
 FILE(GLOB PVSMGR_SRCS
 	src/server/*.cpp
 	src/server/*/*.cpp
+	src/server/util/platform/*${SYSDEP_SUFFIX}.cpp
 	src/shared/*.cpp
 )
 
@@ -163,7 +171,8 @@ ADD_EXECUTABLE(pvsclient
 TARGET_LINK_LIBRARIES(pvsmgr
     ${QT_LIBRARIES}
 #    ${VNC_LIBRARIES}
-#    ${X11_LIBRARIES}
+    ${X11_LIBRARIES}
+    ${X11_Xscreensaver_LIB}
 )
 
 TARGET_LINK_LIBRARIES(pvsclient
diff --git a/src/server/mainwindow/mainwindow.cpp b/src/server/mainwindow/mainwindow.cpp
index 0a77240..a984173 100644
--- a/src/server/mainwindow/mainwindow.cpp
+++ b/src/server/mainwindow/mainwindow.cpp
@@ -35,6 +35,7 @@
 #include "../net/filedownloader.h"
 // Others
 #include "../../shared/settings.h"
+#include "../util/platform/screensaver.h"
 // Auto-generated ui class
 #include "ui_mainwindow.h"
 #include "ui_reloadroom.h"
@@ -62,7 +63,8 @@ using std::endl;
  * @param parent
  */
 MainWindow::MainWindow(QWidget* parent) :
-	QMainWindow(parent), ui(new Ui::MainWindow), _tbIconSize(24), _tbArea(Qt::LeftToolBarArea)
+	QMainWindow(parent), ui(new Ui::MainWindow), _tbIconSize(24), _tbArea(Qt::LeftToolBarArea),
+	_lastClientCount(0)
 {
 	qDebug() << "MainWindow(parent)";
 	_mode = Mode::Multicast;
@@ -108,7 +110,7 @@ MainWindow::MainWindow(QWidget* parent) :
 	ui->toolBar->insertWidget(ui->action_TutorToStudent, _examModeLabel);
 
 	serverApp->setExam(false);
-	updateExamMode();
+	clientCountChanged();
 
 	// Close button in tool bar
 	connect(ui->action_Exit, SIGNAL(triggered()), this, SLOT(onButtonExit()));
@@ -181,22 +183,22 @@ MainWindow::MainWindow(QWidget* parent) :
 /** this function determines if the number of clients in exam mode comprise
 * more than 50%. In that case the whole manager switches to exam mode,
 * disabling many features in the toolbar **/
-void MainWindow::updateExamMode()
+void MainWindow::clientCountChanged()
 {
-	int numerator = 0;
-	int denominator = 0;
+	int examClientCount = 0;
+	int clientCount = 0;
 
 
 	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
 		Client* c = (*it)->client();
 		if (c != NULL) {
 			bool b = c->isExamMode();
-			numerator += b ? 1 : 0;
-			denominator++;
+			examClientCount += b ? 1 : 0;
+			clientCount++;
 		}
 	}
 
-	serverApp->setExam(numerator * 2 >= denominator && denominator > 0);
+	serverApp->setExam(examClientCount * 2 >= clientCount && clientCount > 0);
 	bool e = serverApp->isExam();
 	qDebug() << "isExam is " << e;
 	ui->action_TutorToAll->setVisible(!e);
@@ -207,8 +209,15 @@ void MainWindow::updateExamMode()
 	_examModeLabel->setVisible(e);
 	_examModeLabel->setFixedHeight(e ? 400 : 0);
 
-
-
+	if (_lastClientCount != clientCount) {
+		if (clientCount == 0) {
+			ScreenSaver::allowSaverAndStandby(true);
+		} else {
+			ScreenSaver::forceUnlockAndScreenOn();
+			ScreenSaver::allowSaverAndStandby(false);
+		}
+		_lastClientCount = clientCount;
+	}
 }
 
 MainWindow::~MainWindow()
@@ -1149,7 +1158,7 @@ void MainWindow::onClientAuthenticated(Client* client)
 		// qDebug() << "Should go into this if clause.";
 		existing->assignClient(client);
 		tellClientCurrentSituation(client);
-		updateExamMode();
+		clientCountChanged();
 		return;
 	}
 
@@ -1160,7 +1169,7 @@ void MainWindow::onClientAuthenticated(Client* client)
 
 	//resizeEvent(NULL); // This is where all the positioning should be
 	tellClientCurrentSituation(client);
-	updateExamMode();
+	clientCountChanged();
 
 }
 
@@ -1294,7 +1303,7 @@ void MainWindow::onDeleteClient()
 			frame->deleteLater();
 			_clientFrames.removeOne(frame);
 			lockContextButtons();
-			updateExamMode();
+			clientCountChanged();
 			return;
 		}
 	}
diff --git a/src/server/mainwindow/mainwindow.h b/src/server/mainwindow/mainwindow.h
index 988ac50..27bf264 100644
--- a/src/server/mainwindow/mainwindow.h
+++ b/src/server/mainwindow/mainwindow.h
@@ -76,6 +76,8 @@ private:
 	ListenServer            *_listenServer;
 	DiscoveryListener       *_discoveryListener;
 
+	int _lastClientCount;
+
 	QPoint closestFreeSlot(QPoint preferredPixels, ConnectionFrame* toIgnore);
 	void placeFrameInFreeSlot(ConnectionFrame* frame, QPoint preferred = QPoint(-1, -1));
 	ConnectionFrame* createFrame();
@@ -101,6 +103,10 @@ private:
 
 	void reloadCurrentRoom();
 
+	void DisableButtons();
+	void EnableButtons();
+	void clientCountChanged();
+
 protected slots:
 	void onSessionNameClick();
 	void onSessionNameUpdate();
@@ -121,8 +127,6 @@ protected slots:
 
 	void onButtonExit();
 	void onButtonHelp();
-	void DisableButtons();
-	void EnableButtons();
 	// connection frame
 	void onPlaceFrame(ConnectionFrame* frame);
 	void onFrameClicked(ConnectionFrame* frame);
@@ -133,6 +137,5 @@ protected slots:
 	void onVncServerStateChange(Client* client);
 	void onVncClientStateChange(Client* client);
 
-	void updateExamMode();
 };
 #endif
diff --git a/src/server/util/platform/screensaver.h b/src/server/util/platform/screensaver.h
new file mode 100644
index 0000000..d62f9e1
--- /dev/null
+++ b/src/server/util/platform/screensaver.h
@@ -0,0 +1,26 @@
+#ifndef SCREENSAVER_H_
+#define SCREENSAVER_H_
+
+namespace ScreenSaver {
+
+	/**
+	 * Whether we want to allow the screen saver
+	 * to activate or the screen to enter standby.
+	 * Note: If the screen is already in standby,
+	 * this will not power it on again, or disable
+	 * the screen saver, so to be safe, you might
+	 * want to call forceOn() too.
+	 * @param allow true to allow ss/standby
+	 */
+	void allowSaverAndStandby(bool allow);
+
+	/**
+	 * Disable the screen saver (only if password
+	 * locking is disabled!), power screen on if
+	 * it's in standby.
+	 */
+	void forceUnlockAndScreenOn();
+
+}
+
+#endif /* SCREENSAVER_H_ */
diff --git a/src/server/util/platform/screensaver_X11.cpp b/src/server/util/platform/screensaver_X11.cpp
new file mode 100644
index 0000000..efffba9
--- /dev/null
+++ b/src/server/util/platform/screensaver_X11.cpp
@@ -0,0 +1,74 @@
+#include "screensaver.h"
+
+#include <QX11Info>
+#include <QStringList>
+#include <QProcess>
+#include <X11/Xlib.h>
+
+#ifdef X11_Xscreensaver_FOUND
+#	include <X11/extensions/scrnsaver.h>
+#endif
+#ifdef X11_dpms_FOUND
+#include <X11/extensions/dpms.h>
+#endif
+
+namespace {
+
+	Display *display = NULL;
+	bool extensionSupported = false;
+	bool dpmsSupported = false;
+
+	bool init()
+	{
+		if (display != NULL) {
+			return true;
+		}
+		display = QX11Info::display();
+		if (display == NULL) {
+			return false;
+		}
+#ifdef X11_Xscreensaver_FOUND
+		int dummy;
+		extensionSupported = (XScreenSaverQueryExtension(display, &dummy, &dummy) == True);
+#endif
+#ifdef X11_dpms_FOUND
+		dpmsSupported = (DPMSCapable(display) == True);
+#endif
+		return true;
+	}
+
+}
+
+namespace ScreenSaver {
+
+	void allowSaverAndStandby(bool allow)
+	{
+		if (!init())
+			return;
+#ifdef X11_Xscreensaver_FOUND
+		if (extensionSupported) {
+			XScreenSaverSuspend(display, allow ? False : True);
+			return;
+		}
+#endif
+		// TODO: Maybe try some fallback, call xset, or trigger some event periodically
+	}
+
+	void forceUnlockAndScreenOn()
+	{
+		if (!init())
+			return;
+		QProcess process;
+		process.start("xscreensaver-command", QStringList() << "-deactivate");
+		process.waitForFinished(100);
+#ifdef X11_dpms_FOUND
+		CARD16 power_level;
+		BOOL state;
+		if (DPMSInfo(display, &power_level, &state) && state) {
+			DPMSForceLevel(display, DPMSModeOn);
+			return;
+		}
+#endif
+	}
+
+}