1 files changed, 106 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSessionHandler.java b/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSessionHandler.java
new file mode 100644
index 0000000000..629211a4a6
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSessionHandler.java
@@ -0,0 +1,106 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * vim: ts=4 sw=4 expandtab:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.geckoview;
+
+import android.util.Log;
+import androidx.annotation.UiThread;
+import org.mozilla.gecko.util.BundleEventListener;
+import org.mozilla.gecko.util.EventCallback;
+import org.mozilla.gecko.util.GeckoBundle;
+
+/* package */ abstract class GeckoSessionHandler<Delegate> implements BundleEventListener {
+
+  private static final String LOGTAG = "GeckoSessionHandler";
+  private static final boolean DEBUG = false;
+
+  private final String mModuleName;
+  private final String[] mEvents;
+  private Delegate mDelegate;
+  private boolean mRegisteredListeners;
+
+  /* package */ GeckoSessionHandler(
+      final String module, final GeckoSession session, final String[] events) {
+    this(module, session, events, new String[] {});
+  }
+
+  /* package */ GeckoSessionHandler(
+      final String module,
+      final GeckoSession session,
+      final String[] events,
+      final String[] defaultEvents) {
+    session.handlersCount++;
+
+    mModuleName = module;
+    mEvents = events;
+
+    // Default events are always active
+    session.getEventDispatcher().registerUiThreadListener(this, defaultEvents);
+  }
+
+  public Delegate getDelegate() {
+    return mDelegate;
+  }
+
+  public void setDelegate(final Delegate delegate, final GeckoSession session) {
+    if (mDelegate == delegate) {
+      return;
+    }
+
+    mDelegate = delegate;
+
+    if (!mRegisteredListeners && delegate != null) {
+      session.getEventDispatcher().registerUiThreadListener(this, mEvents);
+      mRegisteredListeners = true;
+    }
+
+    // If session is not open, we will update module state during session opening.
+    if (!session.isOpen()) {
+      return;
+    }
+
+    final GeckoBundle msg = new GeckoBundle(2);
+    msg.putString("module", mModuleName);
+    msg.putBoolean("enabled", isEnabled());
+    session.getEventDispatcher().dispatch("GeckoView:UpdateModuleState", msg);
+  }
+
+  public String getName() {
+    return mModuleName;
+  }
+
+  public boolean isEnabled() {
+    return mDelegate != null;
+  }
+
+  @Override
+  @UiThread
+  public void handleMessage(
+      final String event, final GeckoBundle message, final EventCallback callback) {
+    if (DEBUG) {
+      Log.d(LOGTAG, mModuleName + " handleMessage: event = " + event);
+    }
+
+    if (mDelegate != null) {
+      handleMessage(mDelegate, event, message, callback);
+    } else {
+      handleDefaultMessage(event, message, callback);
+    }
+  }
+
+  protected abstract void handleMessage(
+      final Delegate delegate,
+      final String event,
+      final GeckoBundle message,
+      final EventCallback callback);
+
+  protected void handleDefaultMessage(
+      final String event, final GeckoBundle message, final EventCallback callback) {
+    if (callback != null) {
+      callback.sendError("No delegate registered");
+    }
+  }
+}