Text invokes this list, passing a pointer to an XmTextVerifyCallbackStruct as the widget data, before moving the insertion cursor. The application can prevent the action by setting the doit member of the callback struct to False.

Text invokes this list, passing a pointer to an XmTextVerifyCallbackStruct structure or an XmTextVerifyCallbackStructWcs structure as the widget data, before deleting or inserting any text. The application can prevent the action by setting the doit member of the callback struct to False.

Text invokes this list, passing a pointer to an XmAnyCallbackStruct as the widget data, after text is inserted or deleted.

Text invokes this list, passing a pointer to an XmAnyCallbackStruct as the widget data, when the widget gains input focus.

Text invokes this list, passing a pointer to an XmTextVerifyCallbackStruct as the widget data, before the widget loses input focus. The application can prevent the action by setting the doit member of the callback struct to False.

Text invokes this list, passing a pointer to an XmAnyCallbackStruct as the widget data, when the widget gains ownership of the primary selection.

Text invokes this list, passing a pointer to an XmAnyCallbackStruct as the widget data, when the widget loses ownership of the primary selection.

Text invokes this list, passing a pointer to an XmAnyCallbackStruct as the widget data, when the activate() action is invoked. By default no translations are bound to this action, but in a single-line Text widget or a TextField widget, pressing osfActivate invokes theXmNactivateCallback callbacks.

These callbacks provide a great deal of flexibility for an application to alter the behavior of the Text widget. For example, an application can prevent text from being inserted, as when the user types a password, by using the XmNmodifyVerifyCallback or XmNmodifyVerifyCallbackWcs callbacks. The application can prevent any text from appearing by setting the doit member of the XmTextVerifyCallbackStruct (or XmTextVerifyCallbackStructWcs) to False. The application can also alter the text that will appear by creating a new text string and setting the ptr member of the XmTextBlockRec structure (or the wcsptr member of the XmTextBlockRecWcs structure) to the new string.

Following is an example of an XmNmodifyVerifyCallback that substitutes a string of characters for any text a user enters. Because the XmNmodifyVerifyCallback procedures are most commonly invoked after the user enters a character, this routine usually substitutes the replacement string for each character the user types. This example could be used with a single-line Text widget as part of a simple password-entry program. In this case, the XmNmodifyVerifyCallback procedure would need additional code to save the characters the user types, and the program would need an XmNactivateCallback procedure to check whether the saved characters match the password.

/* XmNmodifyVerifyCallback procedure that replaces text the user enters
 * with a replacement string passed in as application data. */
void ModifyVerifyCB(Widget w, XtPointer app_data,
                    XtPointer widget_data)
{
  char *replace_string = (char *) app_data;
  XmTextVerifyCallbackStruct *widget_info =
    (XmTextVerifyCallbackStruct *) widget_data;
  if (widget_info->text->length > 0) {
    widget_info->text->length = strlen(replace_string);
    widget_info->text->ptr = replace_string;
/* The widget will automatically free this ptr.  Therefore,
 * your app should make a copy of it with strcpy. */
  }
}

Text and TextField differ from most other Motif widgets in that calling some convenience routines and setting some resources causes the widget to invoke callback procedures. In general