X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=gtk2_ardour%2Fcairo_widget.h;h=8665f66198981e03ed39a2fd932ede6025979beb;hb=9c4f5ac000ad91b55e4cf91317b7a89f6239870e;hp=ee0bed114b2b657ee47d2b0acc2813f40a95c27f;hpb=3cdc0d104a407ad29de68bbed624fdd80bb1b1f1;p=ardour.git

diff --git a/gtk2_ardour/cairo_widget.h b/gtk2_ardour/cairo_widget.h
index ee0bed114b..8665f66198 100644
--- a/gtk2_ardour/cairo_widget.h
+++ b/gtk2_ardour/cairo_widget.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2009 Paul Davis 
+    Copyright (C) 2009 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -22,6 +22,11 @@
 
 #include <gtkmm/eventbox.h>
 
+/** A parent class for widgets that are made up of a pixmap rendered using Cairo.
+ *  The pixmap is painted to screen on GTK expose events, but the rendering
+ *  is only done after set_dirty() has been called.
+ */
+
 class CairoWidget : public Gtk::EventBox
 {
 public:
@@ -31,16 +36,17 @@ public:
 	void set_dirty ();
 
 protected:
+	/** Render the widget to the given Cairo context */
 	virtual void render (cairo_t *) = 0;
 	virtual bool on_expose_event (GdkEventExpose *);
 	void on_size_allocate (Gtk::Allocation &);
 
 	int _width; ///< pixmap width
 	int _height; ///< pixmap height
-	
+
 private:
-	bool _dirty;
-	GdkPixmap* _pixmap;
+	bool _dirty; ///< true if the pixmap requires re-rendering
+	GdkPixmap* _pixmap; ///< our pixmap
 };
 
 #endif