reload instance after i18n file change

src/main/java/de/marhali/easyi18n/DataStore.java

@@ -1,6 +1,8 @@
 package de.marhali.easyi18n;
 
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.vfs.*;
 
 import de.marhali.easyi18n.io.IOStrategy;
 import de.marhali.easyi18n.io.json.JsonIOStrategy;
@@ -9,6 +11,7 @@ import de.marhali.easyi18n.io.properties.PropertiesIOStrategy;
 import de.marhali.easyi18n.io.yaml.YamlIOStrategy;
 import de.marhali.easyi18n.model.SettingsState;
 import de.marhali.easyi18n.model.TranslationData;
+import de.marhali.easyi18n.service.FileChangeListener;
 import de.marhali.easyi18n.service.SettingsService;
 
 import org.jetbrains.annotations.NotNull;
@@ -31,13 +34,18 @@ public class DataStore {
        new PropertiesIOStrategy()
     ));
 
-    private final Project project;
+    private final @NotNull Project project;
+    private final @NotNull FileChangeListener changeListener;
 
     private @NotNull TranslationData data;
 
-    protected DataStore(Project project) {
+    protected DataStore(@NotNull Project project) {
         this.project = project;
         this.data = new TranslationData(true, true); // Initialize with hard-coded configuration
+        this.changeListener = new FileChangeListener(project);
+
+        VirtualFileManager.getInstance().addAsyncFileListener(
+                this.changeListener, Disposer.newDisposable("EasyI18n"));
     }
 
     public @NotNull TranslationData getData() {
@@ -58,6 +66,8 @@ public class DataStore {
             return;
         }
 
+        this.changeListener.updateLocalesPath(localesPath);
+
         IOStrategy strategy = this.determineStrategy(state, localesPath);
 
         strategy.read(this.project, localesPath, state, (data) -> {

src/main/java/de/marhali/easyi18n/service/FileChangeListener.java

@@ -0,0 +1,66 @@
+package de.marhali.easyi18n.service;
+
+import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vfs.AsyncFileListener;
+import com.intellij.openapi.vfs.LocalFileSystem;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.openapi.vfs.newvfs.events.VFileEvent;
+
+import de.marhali.easyi18n.InstanceManager;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.File;
+import java.util.List;
+
+/**
+ * Listens for file changes inside configured @localesPath. See {@link AsyncFileListener}.
+ * Will trigger the reload function of the i18n instance if a relevant file was changed.
+ * @author marhali
+ */
+public class FileChangeListener implements AsyncFileListener {
+
+    private static final Logger logger = Logger.getInstance(FileChangeListener.class);
+
+    private final @NotNull Project project;
+    private @Nullable String localesPath;
+
+    public FileChangeListener(@NotNull Project project) {
+        this.project = project;
+        this.localesPath = null; // Wait for any update before listening to file changes
+    }
+
+    public void updateLocalesPath(@Nullable String localesPath) {
+        if(localesPath != null && !localesPath.isEmpty()) {
+            VirtualFile file = LocalFileSystem.getInstance().findFileByIoFile(new File(localesPath));
+
+            if(file != null && file.isDirectory()) {
+                this.localesPath = file.getPath();
+                return;
+            }
+        }
+
+        this.localesPath = null;
+    }
+
+    @Override
+    public ChangeApplier prepareChange(@NotNull List<? extends @NotNull VFileEvent> events) {
+        return new ChangeApplier() {
+            @Override
+            public void afterVfsChange() {
+                if(localesPath != null) {
+                    events.forEach((e) -> {
+                        if(e.getPath().contains(localesPath)) { // Perform reload
+                            logger.debug("Detected file change. Reloading instance...");
+                            InstanceManager manager = InstanceManager.get(project);
+                            manager.store().loadFromPersistenceLayer((success) -> {
+                                manager.bus().propagate().onUpdateData(manager.store().getData());
+                            });
+                        }
+                    });
+                }
+            }
+        };
+    }
+}