PE_SETTARGETS
Sent to an application
window so that it can set its own targeting structure. Submessage of
WM_PENEVENT.
Parameters
wParam
PE_SETTARGETS.
lParam
Address of a
far pointer to a TARGINFO
structure. (Note that lParam is a pointer to a pointer.)
Return Value
The application
should return LRET_DONE to indicate that it has set up the targeting
information for the child windows. A return of 0 indicates that the application
is the only target. The application can also return LRET_ABORT to abort the
targeting process altogether.
Comments
The DefWindowProc function enumerates all
the descendants of the window specified in its first parameter and sends each
one a PE_GETPCMINFO message. For every descendant that returns 1 to this
message, the PCM_RECTBOUND and PCM_RECTEXCLUDE flags of the PCMINFO structure are examined. If
the PCM_RECTBOUND flag is set, the descendant is included in the list of
potential targets and the rectBound member in PCMINFO is copied
to the rectBound member of the TARGET1AOCY_ structure. If the PCM_RECTEXCLUDE flag is
set, the rectExclude member of PCMINFO is added to an exclusion
region that is passed (as the hrgnExclude member of the PCMINFO
structure) to the StartInput call. If there are no descendants, or if
the window procedure of hwnd returns 0, a TARGINFO structure is
constructed with hwnd as the single target.
For default
processing behavior, the application should allow PE_SETTARGETS to fall through
to DefWindowProc.
A PE_GETPCMINFO message will follow to establish targets or termination
conditions (buttons, for example).
For further
information about PE_SETTARGETS, see Chapter 2, Starting Out with System Defaults.
An
application can replace the default targeting with a set of targets it defines
itself. In this case, the application allocates enough memory for the TARGINFO structure plus all the TARGET structures.
Example
The following
example illustrates how to handle PW_SETTARGETS for n targets, where
each target is in the array rgHwnd. Notice the code increases the
allocation by n-1 TARGET
structures, since TARGINFO already contains one TARGET structure.
DWORD cbAlloc
= sizeof(TARGINFO) + (n-1) * sizeof(TARGET);
HGLOBAL hTargets
= GlobalAlloc( GHND, cbAlloc );
LPTARGINFO lptarginfo = GlobalLock( hTargets );
lptarginfo->cbSize = sizeof(TARGINFO);
lptarginfo->cTargets = n; // Number of targets
lptarginfo->htrgOwner = HtrgFromHwnd(hwnd); // Macro in penwin.h
lptarginfo->dwFlags = TPT_TEXTUAL; // For text
for (i = 0; i < n; i++)
{
HWND hwnd
= (HTRG)rgHwnd[i]; // Window
of this target
lptarginfo->rgTarget[i].dwFlags = 0; //
Reserved
lptarginfo->rgTarget[i].idTarget = i;
lptarginfo->rgTarget[i].htrgTarget
= HtrgFromHwnd(hwnd);
lptarginfo->rgTarget[i].dwData
= 0;
// Use
screen coords of each window:
{
// Note: rectBound is a RECTL. In 16-bit code, one
has to assign each
// field separately. In 32-bit code, you can use the
rectBound directly.
RECT rect;
GetClientRect(
hwnd, &rect);
ClientToScreen(
hwnd, (LPPOINT)&rectBound.left);
ClientToScreen(
hwnd, (LPPOINT)&rectBound.right);
lptarginfo->rgTarget[i].rectBound.left = rect.left;
lptarginfo->rgTarget[i].rectBound.top = rect.top;
lptarginfo->rgTarget[i].rectBound.right = rect.right;
lptarginfo->rgTarget[i].rectBound.bottom = rect.bottom;
}
}
// Return our structures:
*(LPTARGINFO FAR *)lParam = lptarginfo;
See Also