Fixed window will never show up again if the window is closed when minimized (#977)

* `Show()` must be called before changing `WindowState`, otherwise the internal state of the window will be messed up.

If you don't do this, when the window is closed when minimized, even if you click the tray menu icon, it will never show up.

* Remember window state before minimized. If window was maximized before minimized, it should be restore to maximized when `Focus_Window` called.

Dotnet/MainForm.cs

@@ -25,11 +25,25 @@ namespace VRCX
         private int LastSizeWidth;
         private int LastSizeHeight;
 
+        private FormWindowState _LastWindowStateToRestore = FormWindowState.Normal;
+        private FormWindowState LastWindowStateToRestore
+        {
+            get => _LastWindowStateToRestore;
+            set
+            {
+                // Used to restore window state after minimized
+                if (FormWindowState.Minimized != value)
+                {
+                    _LastWindowStateToRestore = value;
+                }
+            }
+        }
+
         public MainForm()
         {
             Instance = this;
             InitializeComponent();
-            
+
             // adding a 5s delay here to avoid excessive writes to disk
             _saveTimer = new Timer();
             _saveTimer.Interval = 5000;
@@ -129,28 +143,32 @@ namespace VRCX
                 jslogger.Error(ex);
             }
 
+            LastWindowStateToRestore = WindowState;
+
             // 가끔 화면 위치가 안맞음.. 이걸로 해결 될지는 모르겠음
             Browser.Invalidate();
         }
 
         private void MainForm_Resize(object sender, System.EventArgs e)
         {
+            LastWindowStateToRestore = WindowState;
+
             if (WindowState != FormWindowState.Normal)
             {
                 return;
             }
             LastSizeWidth = Size.Width;
             LastSizeHeight = Size.Height;
-            
+
             _saveTimer?.Start();
         }
-        
+
         private void SaveTimer_Tick(object sender, EventArgs e)
         {
             SaveWindowState();
             _saveTimer?.Stop();
         }
-        
+
         private void MainForm_Move(object sender, System.EventArgs e)
         {
             if (WindowState != FormWindowState.Normal)
@@ -159,7 +177,7 @@ namespace VRCX
             }
             LastLocationX = Location.X;
             LastLocationY = Location.Y;
-            
+
             _saveTimer?.Start();
         }
 
@@ -172,7 +190,7 @@ namespace VRCX
                 Hide();
             }
         }
-        
+
         private void SaveWindowState()
         {
             VRCXStorage.Instance.Set("VRCX_LocationX", LastLocationX.ToString());
@@ -203,11 +221,11 @@ namespace VRCX
 
         public void Focus_Window()
         {
+            Show();
             if (WindowState == FormWindowState.Minimized)
             {
-                WindowState = FormWindowState.Normal;
+                WindowState = LastWindowStateToRestore;
             }
-            Show();
             // Focus();
             Activate();
         }