Whenever a Replay File is being written or modified and the user is not in-game, a GuiReplaySaving is opened and asks him to wait

src/main/java/eu/crushedpixel/replaymod/registry/ReplayFileAppender.java

@@ -1,10 +1,14 @@
 package eu.crushedpixel.replaymod.registry;
 
+import eu.crushedpixel.replaymod.gui.GuiReplaySaving;
 import eu.crushedpixel.replaymod.utils.ReplayFileIO;
+import net.minecraft.client.Minecraft;
+import net.minecraftforge.fml.client.FMLClientHandler;
 import org.apache.commons.lang3.tuple.Pair;
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Queue;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
@@ -12,6 +16,31 @@ public class ReplayFileAppender extends Thread {
 
     private Queue<Pair<Pair<File, String>, File>> filesToMove = new ConcurrentLinkedQueue<Pair<Pair<File, String>, File>>();
     private boolean shutdown = false;
+    private List<GuiReplaySaving> listeners = new ArrayList<GuiReplaySaving>();
+
+    //this is true if the DataListener is currently busy saving a newly recorded Replay File
+    private boolean newReplayFileWriting = false;
+
+    public void startNewReplayFileWriting() {
+        newReplayFileWriting = true;
+
+        if(!FMLClientHandler.instance().isGUIOpen(GuiReplaySaving.class)) {
+            Minecraft.getMinecraft().addScheduledTask(new Runnable() {
+                @Override
+                public void run() {
+                    final GuiReplaySaving savingScreen = new GuiReplaySaving(null);
+                    addFinishListener(savingScreen);
+
+                    Minecraft.getMinecraft().displayGuiScreen(savingScreen);
+                }
+            });
+        }
+    }
+
+    public void replayFileWritingFinished() {
+        newReplayFileWriting = false;
+        callListeners();
+    }
 
     public ReplayFileAppender() {
         Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
@@ -36,6 +65,14 @@ public class ReplayFileAppender extends Thread {
         shutdown = true;
     }
 
+    public boolean isBusy() {
+        return !filesToMove.isEmpty() && !newReplayFileWriting;
+    }
+
+    public void addFinishListener(GuiReplaySaving gui) {
+        listeners.add(gui);
+    }
+
     @Override
     public void run() {
         while(!shutdown || !filesToMove.isEmpty()) {
@@ -47,6 +84,8 @@ public class ReplayFileAppender extends Thread {
                     } catch(Exception e) {
                         e.printStackTrace();
                         filesToMove.add(mv);
+                    } finally {
+                        callListeners();
                     }
                 } else {
                     filesToMove.add(mv);
@@ -58,4 +97,19 @@ public class ReplayFileAppender extends Thread {
         }
     }
 
+    private void callListeners() {
+        if(filesToMove.isEmpty() && !newReplayFileWriting) {
+            for(final GuiReplaySaving gui : listeners) {
+                Minecraft.getMinecraft().addScheduledTask(new Runnable() {
+                    @Override
+                    public void run() {
+                        gui.dispatch();
+                    }
+                });
+            }
+
+            listeners = new ArrayList<GuiReplaySaving>();
+        }
+    }
+
 }