MM_ACM_FILTERCHOOSE
The
MM_ACM_FILTERCHOOSE message notifies an acmFilterChoose dialog box hook function
before adding an element to one of the three drop-down list boxes. This message
allows an application to further customize the selections available through the
user interface.
MM_ACM_FILTERCHOOSE
wParam = (WPARAM) wDropDown
lParam = (LONG) lCustom
Parameters
wDropDown
Drop-down
list box being initialized and a verify or add operation.
FILTERCHOOSE_CUSTOM_VERIFY
The lParam
parameter is a pointer to a WAVEFILTER structure to be added to the custom Name drop-down
list box.
FILTERCHOOSE_FILTER_ADD
The lParam
parameter is a pointer to a buffer that will accept a WAVEFILTER
structure to be added to the Filter drop-down list box. The application must
copy the filter structure to be added into this buffer.
FILTERCHOOSE_FILTER_VERIFY
The lParam
parameter is a pointer to a WAVEFILTER structure to be added to the Filter drop-down
list box.
FILTERCHOOSE_FILTERTAG_ADD
The lParam
parameter is a pointer to a DWORD that will accept a waveform-audio
filter tag to be added to the Filter Tag drop-down list box.
FILTERCHOOSE_FILTERTAG_VERIFY
The lParam
parameter is a waveform-audio filter tag to be listed in the Filter Tag
drop-down list box.
lCustom
Value defined
by the listbox specified in the wParam parameter.
Return Values
Returns TRUE
if an application handles this message or FALSE otherwise.
Remarks
If the
application processes the FILTERCHOOSE_FILTER_ADD operation, the size of the
memory buffer supplied in lParam will be determined from the acmMetrics function.
If the
application processes a verify operation, the application must precede the return
value with SetWindowLong(hwnd, DWL_MSGRESULT, (LONG) FALSE) to prevent
the dialog box from listing this selection or with SetWindowLong(hwnd,
DWL_MSGRESULT, (LONG)TRUE) to allow the dialog box to list this selection. If
processing an add operation, the application must precede the return with SetWindowLong(hwnd,
DWL_MSGRESULT, (LONG)FALSE) to indicate that no more additions are required or
with SetWindowLong(hwnd, DWL_MSGRESULT, (LONG)TRUE) if more additions
are required.
See Also