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7.6 Property Editor Widgets

Files: gui/properties.h, gui/properties.c, gui/units.c

In many VRR windows, a property value needs to be displayed, edited, and updated in reaction to kernel property hooks. To do this, the windows use the property editor widgets. All property editor widgets are generated using the same code, which assures that all editor widgets for the same property type and subtype look the same and behave in the same way.

There is a data structure containing everything needed for a property editor widget:

     struct prop_item
         struct o * o;
         string key;
         uns type, subtype;
         GtkWidget * value_edit;
         GtkWidget * unit_edit;
         uns flags;
         struct window * pw;

The o pointer represents the object to which the property belongs. key is the property unique identifier, type and subtype store the current property type and subtype (which might change). The two GtkWidget objects, value_edit and unit_edit, are the editor widgets of the property value and of the property unit. The unit editor does not have to be present; in that case the pointer is NULL. The flags bitmask is used only in the Property Window for property selection. pw points to a parent window, which is either NULL or the parent Property Window.

To create a property editor widget, you need to allocate a prop_item structure, fill it with the o, key, type and subtype values and call these functions:

     void prop_value_edit_create( struct prop_item * pi );
     void prop_unit_edit_create( struct prop_item * pi );
     void prop_sync( struct prop_item * pi );

(where prop_sync updates the editor value with the current property value. This function should be called after each change of the property value announced by kernel hooks).

Or do it all in a more convenient way using

     void prop_item_init( struct prop_item * pi, struct o * o, string key );

Then the created widgets can be packed into the window where needed.