Silently prevent window opening on sleeping, invalid, and disconnected players

Author: NichtStudioCode

invui/src/main/java/xyz/xenondevs/invui/window/AbstractWindow.java

@@ -530,10 +530,8 @@ private boolean fireBukkitDragEvent(PlayerUpdateReason.Drag reason) {
     @Override
     public void open() {
         Player viewer = getViewer();
-        if (isOpen)
+        if (isOpen || viewer.isSleeping() || !viewer.isValid() || !viewer.isConnected())
             return;
-        if (!viewer.isValid())
-            throw new IllegalStateException("Viewer is not valid");
         if (isInOpeningContext.get())
             throw new IllegalStateException("Opening a window is not allowed to trigger opening another window.");
         if (isInCloseHandlerContext.get() > 0)

invui/src/main/java/xyz/xenondevs/invui/window/Window.java

@@ -78,7 +78,12 @@ static Builder.Normal.Merged mergedBuilder() {
 
     /**
      * Shows the window to the viewer.
-     * Does nothing if the window is already open.
+     * Does nothing if the window is already open or if the window cannot be opened because
+     * the viewer is {@link Player#isValid() invalid}, {@link Player#isConnected() disconnected},
+     * {@link Player#isSleeping() sleeping}, or similar.
+     * 
+     * @throws IllegalStateException If this function was called while opening another window
+     * @throws IllegalStateException If this function was called while closing another window
      */
     void open();