+typedef enum {
+ VIK_LAYER_WIDGET_CHECKBUTTON=0,
+ VIK_LAYER_WIDGET_RADIOGROUP,
+ VIK_LAYER_WIDGET_RADIOGROUP_STATIC,
+ VIK_LAYER_WIDGET_SPINBUTTON,
+ VIK_LAYER_WIDGET_ENTRY,
+ VIK_LAYER_WIDGET_PASSWORD,
+ VIK_LAYER_WIDGET_FILEENTRY,
+ VIK_LAYER_WIDGET_FOLDERENTRY,
+ VIK_LAYER_WIDGET_HSCALE,
+ VIK_LAYER_WIDGET_COLOR,
+ VIK_LAYER_WIDGET_COMBOBOX,
+ VIK_LAYER_WIDGET_FILELIST,
+} VikLayerWidgetType;
+
+/* id is index */
+typedef enum {
+VIK_LAYER_PARAM_DOUBLE=1,
+VIK_LAYER_PARAM_UINT,
+VIK_LAYER_PARAM_INT,
+
+/* in my_layer_set_param, if you want to use the string, you should dup it
+ * in my_layer_get_param, the string returned will NOT be free'd, you are responsible for managing it (I think) */
+VIK_LAYER_PARAM_STRING,
+VIK_LAYER_PARAM_BOOLEAN,
+VIK_LAYER_PARAM_COLOR,
+
+/* NOTE: string list works uniquely: data.sl should NOT be free'd when
+ * the internals call get_param -- i.e. it should be managed w/in the layer.
+ * The value passed by the internals into set_param should also be managed
+ * by the layer -- i.e. free'd by the layer.
+ */
+
+VIK_LAYER_PARAM_STRING_LIST,
+} VikLayerParamType;
+
+typedef enum {
+ VIK_LAYER_AGGREGATE = 0,
+ VIK_LAYER_TRW,
+ VIK_LAYER_COORD,
+ VIK_LAYER_GEOREF,
+ VIK_LAYER_GPS,
+ VIK_LAYER_MAPS,
+ VIK_LAYER_DEM,
+ VIK_LAYER_NUM_TYPES // Also use this value to indicate no layer association
+} VikLayerTypeEnum;
+
+// Default value has to be returned via a function
+// because certain types value are can not be statically allocated
+// (i.e. a string value that is dependent on other functions)
+// Also easier for colours to be set via a function call rather than a static assignment
+typedef VikLayerParamData (*VikLayerDefaultFunc) ( void );
+
+// Convert between the value held internally and the value used for display
+// e.g. keep the internal value in seconds yet use days in the display
+typedef VikLayerParamData (*VikLayerConvertFunc) ( VikLayerParamData );
+