(#17) Added doc comments to window_manager interface

Author: Simon Hofmann

Diff for: src/window_manager.h

@@ -6,10 +6,31 @@
 #include <string>
 #include "types.h"
 
+/**
+ * `getWindows` returns a list of 64bit window handles listing all top-level windows
+ */
 std::vector<WindowHandle> getWindows();
+/**
+ * `getActiveWindow` returns the 64bit window handle of the currently active top-level window.
+ * If no window is active, the return value is platform dependent.
+ * On Windows, if no particular window is focused, it may return either size and position of the Windows task bar (might be focues unintentionally),
+ * or size and position of the desktop window (which results in (0, 0, X_RESOLUTION, Y_RESOLUTION)).
+ * On macOS, if no window is focused the return value will be the error return of window handle -1 and (0, 0, 0, 0) for size and position.
+ * On Linux it returns the desktop window as well (which results in (0, 0, X_RESOLUTION, Y_RESOLUTION)).
+ */
 WindowHandle getActiveWindow();
 
+/**
+ * `getWindowTitle` returns an std::string holding the window title for a window adressed via its window handle.
+ * The respective window handle may be aquired via `getWindows` or `getActiveWindow`
+ */
 std::string getWindowTitle(const WindowHandle windowHandle);
+/**
+ * `getWindowRect` returns an MMRect struct representing the window's size and position.
+ * Windows are adressed via their window handle.
+ * That is, a window's top left position given as `x` and `y` coordinate, as well as it's window size given as `width` and `height`
+ * The respective window handle may be aquired via `getWindows` or `getActiveWindow`
+ */
 MMRect getWindowRect(const WindowHandle windowHandle);
 
 #endif