//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
// The loop the thread uses to wait for queue items to process
private void WaitForWork()
{
SafeWaitHandle handle = _ev.SafeWaitHandle;
UnsafeNativeMethods.MSG msg = new UnsafeNativeMethods.MSG();
while (!_quitting)
{
// pump any messages
while (UnsafeNativeMethods.PeekMessage(ref msg, NativeMethods.HWND.NULL, 0, 0, UnsafeNativeMethods.PM_REMOVE))
{
if (msg.message == UnsafeNativeMethods.WM_QUIT)
{
break;
}
// From the Windows SDK documentation:
// The return value specifies the value returned by the window procedure.
// Although its meaning depends on the message being dispatched, the return
// value generally is ignored.
#pragma warning suppress 6031, 6523
UnsafeNativeMethods.DispatchMessage(ref msg);
}
// do any work items in the queue
DrainQueue();
int lastWin32Error = 0;
int result = Misc.TryMsgWaitForMultipleObjects(handle, false, UnsafeNativeMethods.INFINITE, UnsafeNativeMethods.QS_ALLINPUT, ref lastWin32Error);
if (result == UnsafeNativeMethods.WAIT_FAILED || result == UnsafeNativeMethods.WAIT_TIMEOUT)
{
DrainQueue();
Debug.Assert(_quitting, "MsgWaitForMultipleObjects failed while WaitForWork");
break;
}
}
DrainQueue();
}
// Set focus to specified HWND
private static bool SetFocus( NativeMethods.HWND hwnd )
{
// If already focused, leave as-is. Calling SetForegroundWindow
// on an already focused HWND will remove focus!
if( GetFocusedWindow() == hwnd )
{
return true;
}
// If this is an MDI Child window, send WM_MDIACTIVATE message
int exStyle = GetWindowExStyle(hwnd);
if (IsBitSet(exStyle, SafeNativeMethods.WS_EX_MDICHILD))
{
NativeMethods.HWND parent = SafeNativeMethods.GetAncestor(hwnd, SafeNativeMethods.GA_PARENT);
if (parent == IntPtr.Zero)
{
return false;
}
IntPtr lresult = Misc.SendMessageTimeout(parent, UnsafeNativeMethods.WM_MDIACTIVATE, (IntPtr)hwnd, IntPtr.Zero);
return lresult == IntPtr.Zero;
}
// Use the hotkey technique:
// Register a hotkey and send it to ourselves - this gives us the
// input, and allows us to call SetForegroundWindow.
short atom = Misc.GlobalAddAtom("FocusHotKey");
if (atom == 0)
{
return false;
}
byte vk = 0xB9;
bool gotHotkey = false;
for( int tries = 0 ; tries < 10 ; tries++ )
{
if( Misc.RegisterHotKey( NativeMethods.HWND.NULL, atom, 0, vk ) )
{
gotHotkey = true;
break;
}
vk++; // try another key
}
if( gotHotkey )
{
// Get state of modifiers - and temporarilly release them...
bool fShiftDown = ( UnsafeNativeMethods.GetAsyncKeyState( UnsafeNativeMethods.VK_SHIFT ) & unchecked((int)0x80000000) ) != 0;
bool fAltDown = ( UnsafeNativeMethods.GetAsyncKeyState( UnsafeNativeMethods.VK_MENU ) & unchecked((int)0x80000000) ) != 0;
bool fCtrlDown = ( UnsafeNativeMethods.GetAsyncKeyState( UnsafeNativeMethods.VK_CONTROL ) & unchecked((int)0x80000000) ) != 0;
if( fShiftDown )
Input.SendKeyboardInputVK( UnsafeNativeMethods.VK_SHIFT, false );
if( fAltDown )
Input.SendKeyboardInputVK( UnsafeNativeMethods.VK_MENU, false );
if( fCtrlDown )
Input.SendKeyboardInputVK( UnsafeNativeMethods.VK_CONTROL, false );
Input.SendKeyboardInputVK( vk, true );
Input.SendKeyboardInputVK( vk, false );
// Restore release modifier keys...
if( fShiftDown )
Input.SendKeyboardInputVK( UnsafeNativeMethods.VK_SHIFT, true );
if( fAltDown )
Input.SendKeyboardInputVK( UnsafeNativeMethods.VK_MENU, true );
if( fCtrlDown )
Input.SendKeyboardInputVK( UnsafeNativeMethods.VK_CONTROL, true );
// Spin in this message loop until we get the hot key
while (true)
{
// If the hotkey input gets lost (eg due to desktop switch), GetMessage may not return -
// so use MsgWait first so we can timeout if there's no message present instead of blocking.
int result = Misc.MsgWaitForMultipleObjects(null, false, 2000, UnsafeNativeMethods.QS_ALLINPUT);
if (result == UnsafeNativeMethods.WAIT_FAILED || result == UnsafeNativeMethods.WAIT_TIMEOUT)
break;
UnsafeNativeMethods.MSG msg = new UnsafeNativeMethods.MSG();
if (Misc.GetMessage(ref msg, NativeMethods.HWND.NULL, 0, 0) == 0)
break;
// TranslateMessage() will not set an error to be retrieved with GetLastError,
// so set the pragma to ignore the PERSHARP warning.
#pragma warning suppress 6031, 6523
UnsafeNativeMethods.TranslateMessage(ref msg);
// From the Windows SDK documentation:
// The return value specifies the value returned by the window procedure.
// Although its meaning depends on the message being dispatched, the return
// value generally is ignored.
#pragma warning suppress 6031, 6523
UnsafeNativeMethods.DispatchMessage(ref msg);
if (msg.message == UnsafeNativeMethods.WM_HOTKEY
&& msg.wParam == (IntPtr) atom)
{
break;
}
}
Misc.UnregisterHotKey(NativeMethods.HWND.NULL, atom);
}
Misc.GlobalDeleteAtom(atom);
// Using this method uses the actual codepath the Alt+Tab uses
UnsafeNativeMethods.SwitchToThisWindow(hwnd, true);
return true;
}
