andlabs-ui/redo/uitask_windows.c

120 lines
3.4 KiB
C

// 17 july 2014
#include "winapi_windows.h"
#include "_cgo_export.h"
// note that this includes the terminating '\0'
// this also assumes WC_TABCONTROL is longer than areaWindowClass
#define NCLASSNAME (sizeof WC_TABCONTROL / sizeof WC_TABCONTROL[0])
void uimsgloop(void)
{
MSG msg;
int res;
HWND active, focus;
WCHAR classchk[NCLASSNAME];
BOOL dodlgmessage;
BOOL istab;
BOOL idm;
for (;;) {
SetLastError(0);
res = GetMessageW(&msg, NULL, 0, 0);
if (res < 0)
xpanic("error calling GetMessage()", GetLastError());
if (res == 0) // WM_QUIT
break;
active = GetActiveWindow();
if (active != NULL) {
// bit of logic involved here:
// we don't want dialog messages passed into Areas, so we don't call IsDialogMessageW() there
// as for Tabs, we can't have both WS_TABSTOP and WS_EX_CONTROLPARENT set at the same time, so we hotswap the two styles to get the behavior we want
// theoretically we could use the class atom to avoid a wcscmp()
// however, raymond chen advises against this - http://blogs.msdn.com/b/oldnewthing/archive/2004/10/11/240744.aspx (and we're not in control of the Tab class, before you say anything)
// we could also theoretically just send msgAreaDefocuses directly, but what DefWindowProc() does to a WM_APP message is undocumented
dodlgmessage = TRUE;
istab = FALSE;
focus = GetFocus();
if (focus != NULL) {
if (GetClassNameW(focus, classchk, NCLASSNAME) == 0)
xpanic("error getting name of focused window class for Area check", GetLastError());
if (wcscmp(classchk, areaWindowClass) == 0)
dodlgmessage = FALSE;
else if (wcscmp(classchk, WC_TABCONTROL) == 0)
// THIS BIT IS IMPORTANT
// if the current tab has no children, then there will be no children left in the dialog to tab to, and IsDialogMessageW() will loop forever
istab = (BOOL) SendMessageW(focus, msgTabCurrentTabHasChildren, 0, 0);
}
if (dodlgmessage) {
if (istab)
tabEnterChildren(focus);
idm = IsDialogMessageW(active, &msg);
if (istab)
tabLeaveChildren(focus);
if (idm != 0)
continue;
}
}
TranslateMessage(&msg);
DispatchMessageW(&msg);
}
}
void issue(void *request)
{
SetLastError(0);
if (PostMessageW(msgwin, msgRequest, 0, (LPARAM) request) == 0)
xpanic("error issuing request", GetLastError());
}
HWND msgwin;
#define msgwinclass L"gouimsgwin"
static LRESULT CALLBACK msgwinproc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
LRESULT shared;
if (sharedWndProc(hwnd, uMsg, wParam, lParam, &shared))
return shared;
switch (uMsg) {
case msgRequest:
doissue((void *) lParam);
return 0;
default:
return DefWindowProcW(hwnd, uMsg, wParam, lParam);
}
xmissedmsg("message-only", "msgwinproc()", uMsg);
return 0; // unreachable
}
DWORD makemsgwin(char **errmsg)
{
WNDCLASSW wc;
HWND hwnd;
ZeroMemory(&wc, sizeof (WNDCLASSW));
wc.lpfnWndProc = msgwinproc;
wc.hInstance = hInstance;
wc.hIcon = hDefaultIcon;
wc.hCursor = hArrowCursor;
wc.hbrBackground = (HBRUSH) (COLOR_BTNFACE + 1);
wc.lpszClassName = msgwinclass;
if (RegisterClassW(&wc) == 0) {
*errmsg = "error registering message-only window classs";
return GetLastError();
}
msgwin = CreateWindowExW(
0,
msgwinclass, L"package ui message-only window",
0,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
HWND_MESSAGE, NULL, hInstance, NULL);
if (msgwin == NULL) {
*errmsg = "error creating message-only window";
return GetLastError();
}
return 0;
}