Properties

The Properties cluster contains all the common properties available for EiffelVision 2 widgets and items. Every EiffelVision 2 widget has the same set of properties inherited from EV_WIDGET, but many widgets also inherit additional properties, further refining the behavior of the widget.

EV_WIDGET inherits the following properties:

• EV_PICK_AND_DROPABLE
  • For an overview of the Pick and Drop mechanism, click here .

• EV_SENSITIVE
  • If an EiffelVision 2 component inherits from EV_SENSITIVE, it can be made to ignore events.
    

Use disable_sensitive to disable event handling, and enable_sensitive to restore event handling.

• EV_COLORIZABLE
  • If a EiffelVision 2 component inherits from EV_COLORIZABLE, it has facilities for modifying its foreground and background colors.
    

Use set_foreground_color to set foreground_color and set_background_color to set background_color.
Use set_default_colors to restore the colors to their defaults.

• EV_HELP_CONTEXTABLE
  • If a EiffelVision 2 component inherits from EV_HELP_CONTEXTABLE, facilities are provided for associating help to the component when F1 or Shift F1 is pressed.

• EV_POSITIONED
  • If a EiffelVision 2 component inherits from EV_POSITIONED, it is possible to query its current position, size and minimum size.
    

Use x_position and y_position to find its position relative to its parent.
Use width and height to find its size.
Use minimum_width and minimum_height to find its minimum size.

• EV_CONTAINABLE
  • If a EiffelVision 2 component inherits from EV_CONTAINABLE, it is able make calls on its parent. Use parent to make calls on the current parent.

Note: EV_CONTAINABLE has no features for setting the parent. In EiffelVision 2, a child has no features for setting its parent, while a parent such a descendant of EV_CONTAINER contains routines for adding children (one example is extend).

The following are several more properties used within EiffelVision 2:

• EV_DESELECTABLE
• EV_DRAWABLE
• EV_FONTABLE
• EV_PIXMAPABLE
• EV_POSITIONABLE
• EV_SELECTABLE
• EV_TEXTABLE
• EV_TOOLTIPABLE

For a full list of properties available, see the "interface/properties" sub-cluster of the EiffelVision 2 library.