- Add support for loading configuration via a file rather than the command line

- Added "-c" command line option to look for config file "slide.options.json" in. Otherwise looks in ~/.config/slide/slide.options.json or /etc/slide/slide.options.json
- Added code to reload config options at runtime (when the image is scheduled to update)

src/imageswitcher.h

@@ -5,6 +5,7 @@
 #include <QTimer>
 #include <iostream>
 #include <memory>
+#include <functional>
 
 class MainWindow;
 class ImageSelector;
@@ -12,19 +13,22 @@ class ImageSwitcher : public QObject
 {
     Q_OBJECT
 public:
-    ImageSwitcher(MainWindow& w, unsigned int timeout, std::unique_ptr<ImageSelector>& selector);
+    ImageSwitcher(MainWindow& w, unsigned int timeoutMsec, std::shared_ptr<ImageSelector>& selector);
     void start();
     void scheduleImageUpdate();
+    void setConfigFileReloader(std::function<void()> reloadConfigIfNeededIn);
+    void setRotationTime(unsigned int timeoutMsec);
 
 public slots:
     void updateImage();
 private:
     MainWindow& window;
     unsigned int timeout;
-    std::unique_ptr<ImageSelector>& selector;
+    std::shared_ptr<ImageSelector>& selector;
     QTimer timer;
     const unsigned int timeoutNoContent = 5 * 1000; // 5 sec
     QTimer timerNoContent;
+    std::function<void()> reloadConfigIfNeeded;
 };
 
 #endif // IMAGESWITCHER_H