[idd] helper: use CWindow helper to avoid global state

idd/LGIddHelper/CWindow.cpp

@@ -0,0 +1,60 @@
+#include "CWindow.h"
+#include <strsafe.h>
+#include <CDebug.h>
+
+ATOM CWindow::s_atom = 0;
+static HINSTANCE hInstance = (HINSTANCE)GetModuleHandle(NULL);
+
+bool CWindow::registerClass()
+{
+  WNDCLASSEX wx = {};
+  wx.cbSize = sizeof(WNDCLASSEX);
+  wx.lpfnWndProc = wndProc;
+  wx.hInstance = hInstance;
+  wx.lpszClassName = L"LookingGlassIddHelper";
+  wx.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+  wx.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+  wx.hCursor = LoadCursor(NULL, IDC_ARROW);
+  wx.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
+
+  s_atom = RegisterClassEx(&wx);
+  return s_atom;
+}
+
+CWindow::CWindow()
+{
+  CreateWindowEx(0, MAKEINTATOM(s_atom), NULL,
+    0, 0, 0, 0, 0, NULL, NULL, hInstance, this);
+}
+
+LRESULT CWindow::wndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+  CWindow *self;
+  if (uMsg == WM_NCCREATE)
+  {
+    LPCREATESTRUCT lpcs = (LPCREATESTRUCT)lParam;
+    self = (CWindow*)lpcs->lpCreateParams;
+    self->m_hwnd = hwnd;
+    SetWindowLongPtr(hwnd, GWLP_USERDATA, (LPARAM) self);
+  }
+  else
+  {
+    self = (CWindow*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
+  }
+
+  if (self)
+    return self->handleMessage(uMsg, wParam, lParam);
+  else
+    return DefWindowProc(hwnd, uMsg, wParam, lParam);
+}
+
+LRESULT CWindow::handleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+  return DefWindowProc(m_hwnd, uMsg, wParam, lParam);  
+}
+
+CWindow::~CWindow()
+{
+  if (m_hwnd)
+    DestroyWindow(m_hwnd);
+}

idd/LGIddHelper/CWindow.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <shellapi.h>
+
+#define WM_NOTIFY_ICON (WM_USER)
+
+class CWindow {
+  static ATOM s_atom;
+  static LRESULT CALLBACK wndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
+
+  HWND m_hwnd = NULL;
+  LRESULT handleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam);
+
+public:
+  static bool registerClass();
+  CWindow();
+  ~CWindow();
+};

idd/LGIddHelper/LGIddHelper.vcxproj

@@ -178,11 +178,13 @@ copy /Y "$(ProjectDir)VERSION" "$(SolutionDir)$(Platform)\$(Configuration)\LGIdd
   <ItemGroup>
     <ClCompile Include="$(SolutionDir)LGCommon\*.cpp" />
     <ClCompile Include="CPipeClient.cpp" />
+    <ClCompile Include="CWindow.cpp" />
     <ClCompile Include="main.cpp" />
   </ItemGroup>
   <ItemGroup>
     <CLInclude Include="$(SolutionDir)LGCommon\*.h" />
     <ClInclude Include="CPipeClient.h" />
+    <ClInclude Include="CWindow.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />

idd/LGIddHelper/main.cpp

@@ -1,4 +1,4 @@
-#include <Windows.h>
+#include <Windows.h>
 #include <wrl.h>
 #include <UserEnv.h>
 
@@ -11,6 +11,7 @@ using namespace Microsoft::WRL::Wrappers::HandleTraits;
 #include "CDebug.h"
 #include "VersionInfo.h"
 #include "CPipeClient.h"
+#include "CWindow.h"
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof*(x))
 #define SVCNAME L"Looking Glass (IDD Helper)"
@@ -31,11 +32,6 @@ static std::wstring              l_exitEventName;
 
 static void Launch();
 
-LRESULT CALLBACK DummyWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
-{
-  return DefWindowProc(hwnd, msg, wParam, lParam);
-}
-
 int WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR lpCmdLine, _In_ int nShowCmd)
 {
   g_debug.Init("looking-glass-iddhelper");
@@ -80,24 +76,13 @@ int WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
     return EXIT_FAILURE;
   }
 
-  WNDCLASSEX wx = {};
+  if (!CWindow::registerClass())
-  wx.cbSize        = sizeof(WNDCLASSEX);
-  wx.lpfnWndProc   = DummyWndProc;
-  wx.hInstance     = hInstance;
-  wx.lpszClassName = L"DUMMY_CLASS";
-  wx.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
-  wx.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);
-  wx.hCursor       = LoadCursor(NULL, IDC_ARROW);
-  wx.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
-  ATOM aclass;
-  if (!(aclass = RegisterClassEx(&wx)))
   {
     DEBUG_ERROR("Failed to register message window class");
     return EXIT_FAILURE;
   }
 
-  HWND msgWnd = CreateWindowEx(0, MAKEINTATOM(aclass), NULL,
+  CWindow window;
-    0, 0, 0, 0, 0, NULL, NULL, hInstance, NULL);
 
   bool running = g_pipe.Init();
   while (running)
@@ -128,7 +113,6 @@ int WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
   }
   g_pipe.DeInit();
 
-  DestroyWindow(msgWnd);
   return EXIT_SUCCESS;
 }