Added button support.

common/gui/button.h

@@ -0,0 +1,35 @@
+
+typedef void (*BUTTON_CALLBACK)(void *button);	//!< Function pointer used...
+typedef struct {
+	TOUCH_AREA_STRUCT base; 
+	uint16_t bgcolor;
+	BUTTON_CALLBACK callback; //Callback
+	uint16_t txtcolor;
+	uint8_t font;
+	const char *text;
+	
+} BUTTON_STRUCT;
+/*
+typedef struct {
+	TOUCH_AREA_STRUCT base;
+	unsigned int bgcolor;
+	BUTTON_CALLBACK callback; //Callback
+	unsigned char imgwidth;
+	unsigned char imgheight;
+	char* filename;
+} BITMAPBUTTON_STRUCT;
+*/
+//Notice that the first 3 Members are Equal, so it's possible to cast it to a BUTTON_STRUCT even if it's a BITMAPBUTTON_STRUCT (when changeing only the first 3 Members).
+
+#define AUTO 0
+
+bool gui_button_add(BUTTON_STRUCT* button);
+void gui_button_remove(BUTTON_STRUCT* button);
+void gui_button_redraw(BUTTON_STRUCT* button);
+
+/*
+bool guiAddBitmapButton(BITMAPBUTTON_STRUCT* button);
+void guiRemoveBitmapButton(BITMAPBUTTON_STRUCT* button);
+void guiRedrawBitmapButton(BITMAPBUTTON_STRUCT* button);
+
+*/