implement osx grabber .... not tested! need testers!

tune usage hints in external grabbers


Former-commit-id: 816821dd773e90b8076e9b50ced9eb052f43c2f4

src/hyperion-osx/OsxWrapper.h

@@ -0,0 +1,42 @@
+
+// QT includes
+#include <QTimer>
+
+// Hyperion-Dispmanx includes
+#include <grabber/OsxFrameGrabber.h>
+
+class OsxWrapper : public QObject
+{
+	Q_OBJECT
+public:
+	OsxWrapper(const unsigned display, const unsigned grabWidth, const unsigned grabHeight, const unsigned updateRate_Hz);
+
+	const Image<ColorRgb> & getScreenshot();
+
+	///
+	/// Starts the timed capturing of screenshots
+	///
+	void start();
+
+	void stop();
+
+signals:
+	void sig_screenshot(const Image<ColorRgb> & screenshot);
+
+private slots:
+	///
+	/// Performs a single screenshot capture and publishes the capture screenshot on the screenshot signal.
+	///
+	void capture();
+
+private:
+	/// The QT timer to generate capture-publish events
+	QTimer _timer;
+
+	/// The grabber for creating screenshots
+	OsxFrameGrabber   _grabber;
+
+	// image buffers
+	Image<ColorRgb>  _screenshot;
+
+};