Member variable XbpQuickBrowse():drawMode Foundation

The :drawMode instance variable specifies the mode used to display the XbpQuick Browse on the screen. In the default draw mode (XBP_DRAW_NORMAL), the operating system takes full control over the drawing process. In this mode, a browser object is displayed using default imagery and the object's appearance cannot be controlled by the application. However, this default behaviour can be overriden. If the value XBP_DRAW_OWNER or XBP_DRAW_OWNERADVANCED is assigned to the :drawMode instance variable, no drawing is performed by the operating system. Instead, the Xbase++ runtime system uses xbeP_CustomDrawCell()events to notify the application whenever cells of the XbpQuickBrowse need to be redrawn. The application is responsible for processing this event, and for creating the on-screen visualization. For this, the Graphics Engine commands can be used.

This protocol is called owner-drawing because it is the responsibility of the browser's owner to display the browse. Using owner-drawing, an application can customize the visualization and the behaviour of an XbpQuickBrowse object.

The drawing mode must be assigned to :drawMode before the method :create() is executed.

Changing the drawing mode of an XbpQuickBrowse object also affects the way the various browser areas are being drawn. Enabling owner-drawing for a XbpQuickBrowse object also enables owner-drawning for its heading and data areas. This causes all requests for drawing cells in a browser area to be forwarded to the XbpQuickBrowse object. See method :create() as well as XbpMultiCellGroup:customDrawCell for further information.