BOOL IMsoComponentManager.FOnComponentExitState(
UIntPtr dwComponentID,
msocstate uStateID,
msoccontext uContext,
uint cpicmExclude,
void **rgpicmExclude)
{
_currentState = 0;
Debug.WriteLineIf(
CompModSwitches.MSOComponentManager.TraceInfo,
$"ComponentManager: Component exit state. ID: {dwComponentID} state: {uStateID}");
if (uContext == msoccontext.All || uContext == msoccontext.Mine)
{
Debug.Indent();
// We should notify all components we contain that the state has changed.
foreach (ComponentHashtableEntry entry in OleComponents.Values)
{
Debug.WriteLineIf(CompModSwitches.MSOComponentManager.TraceInfo, $"Notifying {entry.component}");
entry.component.OnEnterState(uStateID, BOOL.FALSE);
}
Debug.Unindent();
}
return(BOOL.FALSE);
}
BOOL IMsoComponentManager.FPushMessageLoop(
UIntPtr dwComponentID,
msoloop uReason,
void *pvLoopData)
{
// Hold onto old state to allow restore before we exit...
msocstate currentLoopState = _currentState;
BOOL continueLoop = BOOL.TRUE;
if (!OleComponents.TryGetValue(dwComponentID, out ComponentHashtableEntry entry))
{
return(BOOL.FALSE);
}
IMsoComponent prevActive = _activeComponent;
try
{
User32.MSG msg = new User32.MSG();
IMsoComponent requestingComponent = entry.component;
_activeComponent = requestingComponent;
Debug.WriteLineIf(
CompModSwitches.MSOComponentManager.TraceInfo,
$"ComponentManager : Pushing message loop {uReason}");
Debug.Indent();
while (continueLoop.IsTrue())
{
// Determine the component to route the message to
IMsoComponent component = _trackingComponent ?? _activeComponent ?? requestingComponent;
bool useAnsi = false;
BOOL peeked = User32.PeekMessageW(ref msg);
if (peeked.IsTrue())
{
useAnsi = msg.hwnd != IntPtr.Zero && User32.IsWindowUnicode(msg.hwnd).IsFalse();
if (useAnsi)
{
peeked = User32.PeekMessageA(ref msg);
}
}
if (peeked.IsTrue())
{
continueLoop = component.FContinueMessageLoop(uReason, pvLoopData, &msg);
// If the component wants us to process the message, do it.
if (continueLoop.IsTrue())
{
if (useAnsi)
{
User32.GetMessageA(ref msg);
Debug.Assert(User32.IsWindowUnicode(msg.hwnd).IsFalse());
}
else
{
User32.GetMessageW(ref msg);
Debug.Assert(msg.hwnd == IntPtr.Zero || User32.IsWindowUnicode(msg.hwnd).IsTrue());
}
if (msg.message == User32.WM.QUIT)
{
Debug.WriteLineIf(
CompModSwitches.MSOComponentManager.TraceInfo,
"ComponentManager : Normal message loop termination");
ThreadContext.FromCurrent().DisposeThreadWindows();
if (uReason != msoloop.Main)
{
User32.PostQuitMessage((int)msg.wParam);
}
continueLoop = BOOL.FALSE;
break;
}
// Now translate and dispatch the message.
//
// Reading through the rather sparse documentation,
// it seems we should only call FPreTranslateMessage
// on the active component.
if (component.FPreTranslateMessage(&msg).IsFalse())
{
User32.TranslateMessage(ref msg);
if (useAnsi)
{
User32.DispatchMessageA(ref msg);
}
else
{
User32.DispatchMessageW(ref msg);
}
}
}
}
else
{
// If this is a DoEvents loop, then get out. There's nothing left for us to do.
if (uReason == msoloop.DoEvents || uReason == msoloop.DoEventsModal)
{
break;
}
// Nothing is on the message queue. Perform idle processing and then do a WaitMessage.
bool continueIdle = false;
if (OleComponents != null)
{
IEnumerator enumerator = OleComponents.Values.GetEnumerator();
while (enumerator.MoveNext())
{
ComponentHashtableEntry idleEntry = (ComponentHashtableEntry)enumerator.Current;
continueIdle |= idleEntry.component.FDoIdle(msoidlef.All).IsTrue();
}
}
// Give the component one more chance to terminate the message loop.
continueLoop = component.FContinueMessageLoop(uReason, pvLoopData, null);
if (continueLoop.IsTrue())
{
if (continueIdle)
{
// If someone has asked for idle time, give it to them. However,
// don't cycle immediately; wait up to 100ms. Why? Because we don't
// want someone to attach to idle, forget to detach, and then cause
// CPU to end up in race condition. For Windows Forms this generally isn't an issue because
// our component always returns false from its idle request
User32.MsgWaitForMultipleObjectsEx(0, IntPtr.Zero, 100, User32.QS.ALLINPUT, User32.MWMO.INPUTAVAILABLE);
}
else
{
// We should call GetMessage here, but we cannot because
// the component manager requires that we notify the
// active component before we pull the message off the
// queue. This is a bit of a problem, because WaitMessage
// waits for a NEW message to appear on the queue. If a
// message appeared between processing and now WaitMessage
// would wait for the next message. We minimize this here
// by calling PeekMessage.
if (User32.PeekMessageW(ref msg, IntPtr.Zero, 0, 0, User32.PM.NOREMOVE).IsFalse())
{
User32.WaitMessage();
}
}
}
}
}
Debug.Unindent();
Debug.WriteLineIf(CompModSwitches.MSOComponentManager.TraceInfo, $"ComponentManager : message loop {uReason} complete.");
}
finally
{
_currentState = currentLoopState;
_activeComponent = prevActive;
}
return(continueLoop.IsFalse() ? BOOL.TRUE : BOOL.FALSE);
}
BOOL IMsoComponentManager.FInState(msocstate uStateID, void *pvoid) => _currentState == uStateID ? BOOL.TRUE : BOOL.FALSE;