Added parent closed check to utility window workaround (#433)

- Added parent closed check to utility window workaround
- This is fix proposal for #429

Author: DaleStan

Yafc.UI/Core/Ui.cs

@@ -151,6 +151,7 @@ public static void ProcessEvents() {
                                 window.FocusLost();
                                 break;
                             case SDL.SDL_WindowEventID.SDL_WINDOWEVENT_FOCUS_GAINED:
+                                window.FocusGained();
                                 window.Rebuild();
                                 break;
                             case SDL.SDL_WindowEventID.SDL_WINDOWEVENT_MINIMIZED:

Yafc.UI/Core/Window.cs

@@ -40,6 +40,8 @@ public abstract class Window : IDisposable {
 
     public event OnFocusLost? onFocusLost;
 
+    public Window? ChildWindow { get; set; }
+
     internal void Create() {
         if (surface is null) {
             throw new InvalidOperationException($"surface must be set by a derived class before calling {nameof(Create)}.");
@@ -166,6 +168,7 @@ public void Repaint() {
     protected internal virtual void Close() {
         visible = false;
         closed = true;
+        ChildWindow?.Close();
         surface?.Dispose();
         SDL.SDL_DestroyWindow(window);
         Dispose();
@@ -183,6 +186,8 @@ private void Focus() {
 
     public virtual void FocusLost() => onFocusLost?.Invoke();
 
+    internal void FocusGained() => ChildWindow?.Focus();
+
     public virtual void Minimized() { }
 
     public void SetNextRepaint(long nextRepaintTime) {

Yafc.UI/Core/WindowUtility.cs

@@ -14,6 +14,9 @@ protected void Create(string? title, float width, Window? parent) {
         }
 
         this.parent = parent;
+        if (parent != null) {
+            parent.ChildWindow = this;
+        }
         contentSize.X = width;
         int display = parent == null ? 0 : SDL.SDL_GetWindowDisplayIndex(parent.window);
         pixelsPerUnit = CalculateUnitsToPixels(display);
@@ -59,18 +62,13 @@ protected override void MainRender() {
     }
 
     protected internal override void Close() {
+        if (parent != null && !parent.closed) {
+            parent.ChildWindow = null;
+        }
         base.Close();
         parent = null;
     }
 
-    // TODO this is work-around for inability to create utility or modal window in SDL2
-    // Fake utility windows are closed on focus lost
-    public override void FocusLost() {
-        if (parent != null) {
-            Close();
-        }
-        base.FocusLost();
-    }
 }
 
 internal class UtilityWindowDrawingSurface : SoftwareDrawingSurface {

changelog.txt

@@ -29,6 +29,7 @@ Date:
         - Hide fluid temperature options when not part of a recipe or not accepted by that recipe.
         - Modify text colors for highlighted rows in dark mode to improve readability.
         - Don't draw table intermediates as <1μ ingredients/products.
+        - The file-picker on the Welcome Screen no longer closes by itself right after being opened.
     Internal changes:
         - Enable mod-fixes for the data, data-updates, and data-final-fixes files.
         - Recompile the lua lib for linux (PR 515). The script now uses CFLAGS and LDFLAGS.