wpQueryContent
This instance method is called to allow the folder to specify its contents.
Syntax
_wpQueryContent(somSelf, Object, ulOption)
Parameters
- somSelf (WPFolder *) - input
- Pointer to the object on which the method is being invoked.
- Points to an object of class WPFolder.
- Object (WPObject *) - input
- Pointer to a workplace object. This field is ignored unless QC_NEXT is specified in ulOption.
- ulOption (ULONG) - input
- Flag indicating the object to query (QC_FIRST, QC_NEXT,QC_LAST).
Returns
- item (WPObject *) - returns
- Pointer to the correct item in the folder's content list.
Remarks
This method allows the user to query the folder's content in various ways using the ulOption flag. QC_FIRST returns the first item in the content list, QC_LAST returns the last item, and QC_NEXT returns the next item after 'Object' in the list.
Usage
This method is generally called to look for a specific object or to query the contents in a specific folder.
How to Override
This method is generally not overridden.
Example Code
SOM_Scope HWND SOMLINK myfold_wpOpen(MYFOLDER *somSelf,
HWND hwndCnr,
ULONG ulView,
ULONG param)
{
HWND hwndFromParentOpen = NULLHANDLE;
MYFOLDERData *somThis = MYFOLDERGetData(somSelf);
MYFOLDERMethodDebug("MYFOLDER","myfold_wpOpen");
if (_queryFirstViewHandle(somSelf) == NULLHANDLE)
{
/* ONLY do this on FIRST open of the folder. */
if (_wpPopulate(somSelf, NULLHANDLE, NULL, FALSE))
{
WPObject *Obj;
WPObject *LastFoundObj = NULL;
/* Check contents of folder and see which are instances of
* WPFolder, we'll delete any WPFolders as a cleanup step */
for ( Obj = _wpQueryContent(somSelf,NULL,(ULONG)QC_First);
Obj;
Obj = _wpQueryContent(somSelf, Obj, (ULONG) QC_Next ))
{
/* delete the last object found on the previous iteration
* of the loop (we couldn't delete it then, because we
* needed it at the top of the loop for this iteration)
*/
if (LastFoundObj) {
_wpDelete(LastFoundObj,0);
LastFoundObj = NULL;
} /* endif */
/* we want to make sure that all previously
* existing folders are deleted */
if (_somIsA(Obj, _WPFolder)) {
LastFoundObj = Obj;
} /* endif */
} /* endfor */
/* if there is still one object left to delete, do it now */
if (LastFoundObj) {
_wpDelete(LastFoundObj,0);
LastFoundObj = NULL;
} /* endif */
} /* end if populate */
} /* end if first open */
/* Show the opened folder */
hwndFromParentOpen = parent_wpOpen(somSelf, hwndCnr, ulView, param);
/* If this is the first open, set our global flag */
if (_queryFirstViewHandle(somSelf) == NULLHANDLE) {
_setFirstViewHandle(somSelf, hwndFromParentOpen);
} /* endif */
return( hwndFromParentOpen );
}
This example code shows how to call wpQueryContent.
cbIconSize = _wpQueryIconData(Object,NULL);
pIconSize = (PICONINFO)_wpAllocMem(Object,cbIconSize,NULL);
if (pIconInfo != NULL)
{
_wpQueryIconData(Object,pIconInfo);
}