[idd] project: organize driver sources by responsibility

Group the IDD sources and Visual Studio filters by subsystem.

Split the device and swap-chain implementations into focused units,
rename the context classes, and reduce header coupling.

idd/LGIdd/display/CMonitorManager.h

@@ -0,0 +1,89 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#pragma once
+
+#include <Windows.h>
+#include <wdf.h>
+#include <IddCx.h>
+#include <atomic>
+#include <vector>
+
+#include "config/CSettings.h"
+
+class CDeviceContext;
+
+class CMonitorManager
+{
+public:
+  enum class ReplugAction
+  {
+    NONE,
+    CREATE,
+  };
+
+  enum class DeferredAction
+  {
+    NONE,
+    CREATE,
+    REPLUG,
+  };
+
+  struct ReadyAction
+  {
+    CSettings::DisplayMode mode    = {};
+    bool                   setMode = false;
+    bool                   replug  = false;
+  };
+
+private:
+  IDDCX_MONITOR m_monitor = nullptr;
+
+  // Guards the monitor/replug/swap-chain state. These values are touched by
+  // IddCx callback threads, the swap-chain thread, and the LGMP timer.
+  SRWLOCK m_lock = SRWLOCK_INIT;
+
+  bool m_replugMonitor           = false;
+  bool m_replugPending           = false;
+  bool m_monitorDeparted         = false;
+  bool m_swapChainAssigned       = false;
+  bool m_swapChainReady          = false;
+  bool m_waitForSwapChainRelease = false;
+
+  CSettings::DisplayMode m_setMode  = {};
+  bool                   m_doSetMode = false;
+
+  std::atomic<LONG> m_createQueued = 0;
+  std::atomic<LONG> m_replugQueued = 0;
+
+public:
+  void Create(UINT connectorIndex, IDDCX_ADAPTER adapter,
+    std::vector<BYTE> edid, CDeviceContext * owner);
+  ReplugAction Replug();
+  void RequestMode(const CSettings::DisplayMode& mode);
+
+  void OnDestroyed(IDDCX_MONITOR monitor);
+  void OnSwapChainAssigned();
+  void OnSwapChainReleased();
+  ReadyAction OnSwapChainReady();
+  void QueueReplug();
+
+  DeferredAction TakeDeferredAction();
+};