Add null checks and improve dialog window handling

Flow.Launcher.Infrastructure/DialogJump/DialogJump.cs

@@ -9,7 +9,7 @@
 using Flow.Launcher.Infrastructure.DialogJump.Models;
 using Flow.Launcher.Infrastructure.UserSettings;
 using Flow.Launcher.Plugin;
 using NHotkey;
 using Windows.Win32;
 using Windows.Win32.Foundation;
 using Windows.Win32.UI.Accessibility;
@@ -106,7 +106,7 @@
         {
             if (_initialized) return;
 
             // Initialize preinstalled Dialog Jump explorers & dialogs
             _dialogJumpExplorers.TryAdd(WindowsDialogJumpExplorer, null);
             _dialogJumpDialogs.TryAdd(WindowsDialogJumpDialog, null);
 
@@ -168,27 +168,27 @@
                 // Unhook events
                 if (!_foregroundChangeHook.IsNull)
                 {
                     PInvoke.UnhookWinEvent(_foregroundChangeHook);
                     _foregroundChangeHook = HWINEVENTHOOK.Null;
                 }
                 if (!_locationChangeHook.IsNull)
                 {
                     PInvoke.UnhookWinEvent(_locationChangeHook);
                     _locationChangeHook = HWINEVENTHOOK.Null;
                 }
                 if (!_destroyChangeHook.IsNull)
                 {
                     PInvoke.UnhookWinEvent(_destroyChangeHook);
                     _destroyChangeHook = HWINEVENTHOOK.Null;
                 }
                 if (!_hideChangeHook.IsNull)
                 {
                     PInvoke.UnhookWinEvent(_hideChangeHook);
                     _hideChangeHook = HWINEVENTHOOK.Null;
                 }
                 if (!_dialogEndChangeHook.IsNull)
                 {
                     PInvoke.UnhookWinEvent(_dialogEndChangeHook);
                     _dialogEndChangeHook = HWINEVENTHOOK.Null;
                 }
 
@@ -329,7 +329,7 @@
                         if (PublicApi.Instance.PluginModified(explorer.Metadata.ID) || // Plugin is modified
                             explorer.Metadata.Disabled) continue; // Plugin is disabled
 
                         var explorerWindow = explorer.Plugin.CheckExplorerWindow(hWnd);
                         if (explorerWindow != null)
                         {
                             _dialogJumpExplorers[explorer] = explorerWindow;
@@ -496,6 +496,8 @@
             uint dwmsEventTime
         )
         {
+            if (hwnd.IsNull) return;
+
             await _foregroundChangeLock.WaitAsync();
             try
             {
@@ -647,6 +649,8 @@
             uint dwmsEventTime
         )
         {
+            if (hwnd.IsNull) return;
+
             // If the dialog window is moved, update the Dialog Jump window position
             var dialogWindowExist = false;
             lock (_dialogWindowLock)
@@ -672,6 +676,8 @@
             uint dwmsEventTime
         )
         {
+            if (hwnd.IsNull) return;
+
             // If the dialog window is moved or resized, update the Dialog Jump window position
             if (_dragMoveTimer != null)
             {
@@ -697,6 +703,8 @@
             uint dwmsEventTime
         )
         {
+            if (hwnd.IsNull) return;
+
             // If the dialog window is destroyed, set _dialogWindowHandle to null
             var dialogWindowExist = false;
             lock (_dialogWindowLock)
@@ -728,6 +736,8 @@
             uint dwmsEventTime
         )
         {
+            if (hwnd.IsNull) return;
+
             // If the dialog window is hidden, set _dialogWindowHandle to null
             var dialogWindowExist = false;
             lock (_dialogWindowLock)
@@ -759,6 +769,8 @@
             uint dwmsEventTime
         )
         {
+            if (hwnd.IsNull) return;
+
             // If the dialog window is ended, set _dialogWindowHandle to null
             var dialogWindowExist = false;
             lock (_dialogWindowLock)