Add ofxPiMapper::togglePauseForSurface and getNumSurfaces methods

For toggling video play/pause from code... close #76

src/ofxPiMapper.cpp

@@ -40,6 +40,14 @@ void ofxPiMapper::eraseActivePreset(){
 	_application.getSurfaceManager()->eraseActivePreset();
 }
 
+void ofxPiMapper::togglePauseForSurface(unsigned int i){
+	ofx::piMapper::BaseSource * s =
+		_application.getSurfaceManager()->getActivePreset()->getSurfaces().at(i)->getSource();
+	if(s->getType() == ofx::piMapper::SourceType::SOURCE_TYPE_VIDEO){
+		s->togglePause();
+	}
+}
+
 bool ofxPiMapper::loadXmlSettings(string fileName){
 	return _application.loadXmlSettings(fileName);
 }
@@ -52,6 +60,10 @@ unsigned int ofxPiMapper::getActivePresetIndex(){
 	return _application.getSurfaceManager()->getActivePresetIndex();
 }
 
+unsigned int ofxPiMapper::getNumSurfaces(){
+	return _application.getSurfaceManager()->getActivePreset()->getSurfaces().size();
+}
+
 void ofxPiMapper::setMode(ofxPiMapper::Mode m){
 	if(m == PRESENTATION_MODE){
 		_application.setPresentationMode();

src/ofxPiMapper.h

@@ -15,6 +15,9 @@
 #include "ProjectionMappingMode.h"
 #include "SourceSelectionMode.h"
 
+#include "BaseSource.h"
+#include "SourceType.h"
+
 namespace ofx {
 namespace piMapper {
 	class Application;
@@ -48,11 +51,17 @@ class ofxPiMapper {
 		void setNextPreset();
 		void cloneActivePreset();
 		void eraseActivePreset();
+	
+		// Toggle play/pause for a surface in the active preset.
+		void togglePauseForSurface(unsigned int i);
 
 		bool loadXmlSettings(string fileName);
 	
 		unsigned int getNumPresets();
 		unsigned int getActivePresetIndex();
+	
+		// Get number of surfaces in the active preset.
+		unsigned int getNumSurfaces();
 
 	private:
 		ofx::piMapper::Application _application;