ApCreateWidget()

Create a widget by copying it from a PhAB widget database

Synopsis:

#include <Ap.h>

PtWidget_t *ApCreateWidget( ApDBase_t const *db,
                            char const *wgt_name,
                            int x,
                            int y,
                            int nargs,
                            PtArg_t const *args );

Arguments:

db
A pointer to a widget database that you opened with either ApOpenDBase() or ApOpenDBaseFile().
wgt_name
The instance name of one of the widgets inside the database.
x and y
Convenience arguments for specifying the position of the widget when it's created.
Note: If y is -1, the widget's original position is used.
nargs and args
The standard resource argument counter and argument list (of type PtArg_t) used by PtCreateWidget().

Library:

Ap

Description:

This function is used to create widgets by copying a widget from a PhAB widget database. This is very useful when you need to create many instances of the same widget. For example, a file manager may want to draw a file folder for each directory it displays.

You can use ApCreateDBWidget() instead of this function. ApCreateDBWidget() lets you specify the position without having to worry about the case when y happens to be -1.

The widget is created as a child of the default parent, which is usually the most recently created container. To change the default parent, call PtSetParentWidget().

Note: Before loading widgets from an external database, you should call ApAddClass() for each widget class that you'll likely encounter in it. This will add the widget classes to the internal widget class table.

ApCreateWidget() creates only the widget named by wgt_name regardless of its class. ApCreateWidgetFamily() creates the named widget and, for container class widgets, any children of the widget.

Note: If the widget returned by this function contains images, the images reference data in the widget database. Therefore, don't close the widget database while you're using the widget. If you need to close the database, you must remove all references to image data. You can do this by destroying the widgets, unsetting images in the widgets, or changing them into images that don't reference the database by using PiDuplicateImage() to copy the images from the database.

Returns:

A pointer to the widget created for wgt_name, or NULL on failure.

Examples:

ApDBase_t         *mydbase;
PtArg_t           args[2];
PtWidget_t        *my_label;

mydbase = ApOpenDBase( ABM_mypicture );

PtSetArg( &args[0], Pt_ARG_TEXT_STRING,
          "This Widget", 0 );
ApCreateWidget( mydbase, "my_label_widget", 10, 10, 1,
                args );

PtSetArg( &args[0], Pt_ARG_TEXT_STRING,
          "That Widget", 0 );
PtSetArg( &args[1], Pt_ARG_FILL_COLOR, Pg_WHITE, 0 );
my_label = ApCreateWidget( mydbase, "my_label_widget",
                           10, 30, 2, args );
if (my_label != NULL)
{
  PtRealizeWidget( my_label );
}

ApCloseDBase( mydbase );

Classification:

Photon

Safety:
Interrupt handler No
Signal handler No
Thread No

See also:

ApCloseDBase(), ApCreateDBWidget(), ApCreateDBWidgetFamily(), ApCreateWidgetFamily(), ApGetDBWidgetInfo(), ApOpenDBase(), ApOpenDBaseFile(), ApSaveDBaseFile(), PtArg_t, PtCreateWidget(), PtSetParentWidget()

Accessing PhAB Modules from Code chapter of the Photon Programmer's Guide