ApGetWidgetPtr()

Get the instance pointer for a widget in a given module

Synopsis:

#include <Ap.h>

PtWidget_t *ApGetWidgetPtr( PtWidget_t *link_instance,
                            int wgt_name );

Arguments:

link_instance

The link instance of the module that you want to search for the widget.

wgt_name

The ABN_ name of the widget that you want to find. PhAB automatically generates these name values for you when you generate your code.

Library:

Ap

Description:

ApGetWidgetPtr() is used to obtain the widget's instance pointer within the specified link_instance. For most modules, PhAB generates manifests that let you access the widgets within the module directly, provided only one instance of the module exists at a time.

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You can also use AbGetABW() to get the widget instance pointer more efficiently, though AbGetABW() does not work when there are multiple instances of the widget's window module.

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Because window modules allow you to have multiple instances you can't always use the direct access manifests; the manifest will only be valid for the last instance of the window. For windows, you may need either to save the link_instance pointer when creating the window, or to use this function to find the correct link_instance for the callback.

Once you determine the module link instance, you'll need to extract the widget pointer from it.

Returns:

A pointer to the widget within the module link_instance, or NULL if it wasn't found.

Examples:

PtArg_t        args[1];

mywindow_callback( PtWidget_t *widget, ... )
{
    PtWidget_t   *window;

    /* from which window did this come? */
    if ( window = ApGetInstance( widget ) ) {
        /* set the widget selected to red */
        PtSetArg( &args[0], Pt_ARG_FILL_COLOR,
                  Pg_RED, 0 );
        PtSetResources(
            ApGetWidgetPtr( window, ABN_mywidget ),
            1, args );
    }

    return( Pt_CONTINUE );
}

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If you compare this example with the one for ApGetInstance(), you'll notice a subtle difference. This example modifies a specific widget identified by ABN_mywidget, while the other example modifies any widget affected by the callback.

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Classification:

Photon

See also:

AbGetABW(), ApGetInstance()

"Handling multiple instances of a window" in the Working with Code chapter of the Photon Programmer's Guide