Fixed issues identified by VS code analysis

Mamesaver/BlankScreen.cs

@@ -10,7 +10,7 @@
 
 namespace Mamesaver
 {
-    internal class BlankScreen
+    internal class BlankScreen : IDisposable
     {
         private readonly PowerManager _powerManager;
         public BackgroundForm BackgroundForm { get; }
@@ -96,5 +96,21 @@ private void ReleaseDeviceContext()
                 Log.Error(ex, "Error releasing device context for {screen}", Screen.DeviceName);
             }
         }
+
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+       }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!disposing) return;
+
+            _powerManager?.Dispose();
+            BackgroundForm?.Dispose();
+        }
+
+        ~BlankScreen() => Dispose(false);
     }
 }

Mamesaver/CaptureScreen.cs

@@ -33,7 +33,7 @@ public void Dispose()
             GC.SuppressFinalize(this);
         }
 
-        public virtual void Dispose(bool disposing) => ReleaseUnmanagedResources();
+        protected virtual void Dispose(bool disposing) => ReleaseUnmanagedResources();
         ~CaptureScreen() => Dispose(false);
 
         private void ReleaseUnmanagedResources()

Mamesaver/GamePlayManager.cs

@@ -26,9 +26,9 @@ internal class GamePlayManager : IDisposable
         private readonly PowerManager _powerManager;
         private readonly MameInvoker _invoker;
 
-        public delegate void PlayGameEventHandler(object sender, EventArgs args);
-        public delegate void StartGameEventHandler(object sender, EventArgs args);
-        public delegate void GameStartedEventHandler(object sender, EventArgs args);
+        public delegate void PlayGameEventHandler(object sender, EventArgs e);
+        public delegate void StartGameEventHandler(object sender, EventArgs e);
+        public delegate void GameStartedEventHandler(object sender, EventArgs e);
 
         /// <summary>
         ///     Game has been started by MAME.

Mamesaver/MameScreen.cs

@@ -12,7 +12,7 @@ namespace Mamesaver
     ///     A screen that will launch MAME with a random game from the list. If configured, this screen also handles hotkey events which
     ///     affect the MAME process.
     /// </summary>
-    internal class MameScreen : BlankScreen, IDisposable
+    internal class MameScreen : BlankScreen
     {
         private readonly Settings _settings;
         private readonly GamePlayManager _gamePlayManager;
@@ -163,8 +163,10 @@ private void GameTimerTick(object sender, EventArgs e)
         ///     Stop the timer, set cancelled flag, close any current process and close the background form.
         ///     Once this has all been done, the application should end.
         /// </summary>
-        public virtual void Dispose(bool disposing)
+        protected override void Dispose(bool disposing)
         {
+            base.Dispose(disposing);
+
             if (!disposing || !_initialised) return;
 
             Log.Information("Closing primary MAME screen {screen}", Screen.DeviceName);
@@ -187,12 +189,6 @@ private void DisposeTimers()
             _gameTimer = _splashTimer = null;
         }
 
-        public void Dispose()
-        {
-            Dispose(true);
-            GC.SuppressFinalize(this);
-        }
-
         ~MameScreen() => Dispose(false);
     }
 }

Mamesaver/Power/PowerEventWatcher.cs

@@ -8,7 +8,7 @@ namespace Mamesaver.Power
     ///     Listens for power source change events, firing a <see cref="PowerStateChanged"/> event
     ///     if received.
     /// </summary>
-    public class PowerEventWatcher
+    public class PowerEventWatcher : IDisposable
     {
         /// <summary>
         ///     Value of event corresponding to a power state change.
@@ -21,7 +21,7 @@ public class PowerEventWatcher
         private ManagementEventWatcher _managementEventWatcher;
         public event PowerEventHandler PowerStateChanged;
 
-        public delegate void PowerEventHandler(object sender, EventArgs args);
+        public delegate void PowerEventHandler(object sender, EventArgs e);
 
         /// <summary>
         ///     Initialises the power event watcher to fire <see cref="PowerStateChanged"/>
@@ -51,7 +51,7 @@ private void PowerEventArrived(object sender, EventArrivedEventArgs args)
             }
         }
 
-        public virtual void Dispose(bool disposing)
+        protected virtual void Dispose(bool disposing)
         {
             if (!disposing) return;
 

Mamesaver/Power/PowerManager.cs

@@ -21,7 +21,7 @@ public class PowerManager : IDisposable
         private readonly PowerEventWatcher _eventWatcher;
         private Timer _sleepTimer;
 
-        public delegate void SleepTriggerManager(object sender, EventArgs args);
+        public delegate void SleepTriggerManager(object sender, EventArgs e);
 
         /// <summary>
         ///     Fired when the screensaver should turn the display to sleep.
@@ -165,7 +165,7 @@ public void Dispose()
             GC.SuppressFinalize(this);
         }
 
-        public virtual void Dispose(bool disposing)
+        protected virtual void Dispose(bool disposing)
         {
             if (!disposing) return;
             _sleepTimer?.Dispose();

Mamesaver/Windows/PlatformInvokeGDI32.cs

@@ -4,38 +4,38 @@
 
 namespace Mamesaver.Windows
 {
-    public class PlatformInvokeGdi32
+    internal class PlatformInvokeGdi32
     {
-        public const int SRCOPY = 13369376;
+        internal const int SRCOPY = 13369376;
 
         [DllImport("gdi32.dll", EntryPoint = "DeleteDC")]
-        public static extern IntPtr DeleteDC(IntPtr hDc);
+        internal static extern IntPtr DeleteDC(IntPtr hDc);
 
         [DllImport("gdi32.dll", EntryPoint = "DeleteObject")]
-        public static extern IntPtr DeleteObject(IntPtr hDc);
+        internal static extern IntPtr DeleteObject(IntPtr hDc);
 
         [DllImport("gdi32.dll", EntryPoint = "BitBlt")]
-        public static extern bool BitBlt(IntPtr hdcDest, int xDest, int yDest, int wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, int rasterOp);
+        internal static extern bool BitBlt(IntPtr hdcDest, int xDest, int yDest, int wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, int rasterOp);
 
         [DllImport("gdi32.dll", EntryPoint = "StretchBlt")]
-        public static extern bool StretchBlt(IntPtr hdcDest, int xDest, int yDest, int wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, int wSrc, int hSrc, int RasterOp);
+        internal static extern bool StretchBlt(IntPtr hdcDest, int xDest, int yDest, int wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, int wSrc, int hSrc, int RasterOp);
 
         [DllImport("gdi32.dll")]
-        public static extern IntPtr CreateCompatibleDC(IntPtr hdc);
+        internal static extern IntPtr CreateCompatibleDC(IntPtr hdc);
 
         [DllImport("gdi32.dll")]
-        public static extern IntPtr CreateCompatibleBitmap(IntPtr hdc, int nWidth, int nHeight);
+        internal static extern IntPtr CreateCompatibleBitmap(IntPtr hdc, int nWidth, int nHeight);
 
         [DllImport("gdi32.dll", EntryPoint = "SelectObject")]
-        public static extern IntPtr SelectObject(IntPtr hdc, IntPtr bmp);
+        internal static extern IntPtr SelectObject(IntPtr hdc, IntPtr bmp);
 
         [DllImport("gdi32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
-        public static extern int GetDeviceCaps(IntPtr hDC, int nIndex);
+        internal static extern int GetDeviceCaps(IntPtr hDC, int nIndex);
 
         /// <summary>
         /// DeviceCap - Device capabilities
         /// </summary>
-        public enum DeviceCap
+        internal enum DeviceCap
         {
             /// <summary>
             /// Logical pixels inch in X

Mamesaver/Windows/PlatformInvokeUSER32.cs

@@ -4,51 +4,51 @@
 
 namespace Mamesaver.Windows
 {
-    public class PlatformInvokeUser32
+    internal class PlatformInvokeUser32
     {
-        public const int SM_CXSCREEN = 0;
-        public const int SM_CYSCREEN = 1;
-        public const int SW_MINIMIZE = 6;
+        internal const int SM_CXSCREEN = 0;
+        internal const int SM_CYSCREEN = 1;
+        internal const int SW_MINIMIZE = 6;
 
         [DllImport("user32.dll", CharSet = CharSet.Auto)]
-        public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, IntPtr lParam);
+        internal static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, IntPtr lParam);
 
         [DllImport("user32.dll")]
-        public static extern void SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter, int x, int y, int width, int height, uint flags);
+        internal static extern void SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter, int x, int y, int width, int height, uint flags);
 
         [DllImport("user32.dll", EntryPoint = "GetDesktopWindow")]
-        public static extern IntPtr GetDesktopWindow();
+        internal static extern IntPtr GetDesktopWindow();
 
         [DllImport("user32.dll", EntryPoint = "GetDC")]
-        public static extern IntPtr GetDC(IntPtr ptr);
+        internal static extern IntPtr GetDC(IntPtr ptr);
 
         [DllImport("user32.dll", EntryPoint = "GetSystemMetrics")]
-        public static extern int GetSystemMetrics(int abc);
+        internal static extern int GetSystemMetrics(int abc);
 
         [DllImport("user32.dll", EntryPoint = "GetWindowDC")]
-        public static extern IntPtr GetWindowDC(Int32 ptr);
+        internal static extern IntPtr GetWindowDC(Int32 ptr);
 
         [DllImport("user32.dll", EntryPoint = "ReleaseDC")]
-        public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
+        internal static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
 
         [DllImport("user32.dll")]
         [return: MarshalAs(UnmanagedType.Bool)]
-        public static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);
+        internal static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);
 
         [DllImport("user32.dll")]
         [return: MarshalAs(UnmanagedType.Bool)]
-        public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
+        internal static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
 
         [StructLayout(LayoutKind.Sequential)]
-        public struct RECT
+        internal struct RECT
         {
-            public int Left;        // x position of upper-left corner
-            public int Top;         // y position of upper-left corner
-            public int Right;       // x position of lower-right corner
-            public int Bottom;      // y position of lower-right corner
+            internal int Left;        // x position of upper-left corner
+            internal int Top;         // y position of upper-left corner
+            internal int Right;       // x position of lower-right corner
+            internal int Bottom;      // y position of lower-right corner
         }
 
         [DllImport("user32.dll")]
-        public static extern bool SetProcessDPIAware();
+        internal static extern bool SetProcessDPIAware();
     }
 }

Mamesaver/Windows/UserActivityHook.cs

@@ -480,18 +480,21 @@ public UserActivityHook(bool InstallMouseHook, bool InstallKeyboardHook)
         }
 
         public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        protected virtual void Dispose(bool disposing)
         {
             //uninstall hooks and do not throw exceptions
-            Stop(true, true, false); 
+            Stop(true, true, false);
         }
 
         /// <summary>
         /// Destruction.
         /// </summary>
-        ~UserActivityHook()
-        {
-            Dispose();
-        }
+        ~UserActivityHook() => Dispose(false);
 
         /// <summary>
         /// Occurs when the user moves the mouse, presses any mouse button or scrolls the wheel