Pigeon + method invocation example (#1180)

Adds the infrastructure for Android code mirroring

permission_handler_android/android/src/main/java/com/baseflow/permissionhandler/ActivityCompatHostApiImpl.java

@@ -0,0 +1,56 @@
+package com.baseflow.permissionhandler;
+
+import android.app.Activity;
+import android.content.ActivityNotFoundException;
+
+import androidx.annotation.NonNull;
+import androidx.core.app.ActivityCompat;
+
+import com.baseflow.instancemanager.InstanceManager;
+import com.baseflow.permissionhandler.PermissionHandlerPigeon.*;
+
+import java.util.UUID;
+
+import io.flutter.plugin.common.BinaryMessenger;
+
+/**
+ * Host API implementation for `ActivityCompat`.
+ *
+ * <p>This class may handle instantiating and adding native object instances that are attached to a
+ * Dart instance or handle method calls on the associated native class or an instance of the class.
+ */
+public class ActivityCompatHostApiImpl implements ActivityCompatHostApi {
+    // To ease adding additional methods, this value is added prematurely.
+    @SuppressWarnings({"unused", "FieldCanBeLocal"})
+    private final BinaryMessenger binaryMessenger;
+
+    private final InstanceManager instanceManager;
+
+    /**
+     * Constructs an {@link ActivityCompatHostApiImpl}.
+     *
+     * @param binaryMessenger used to communicate with Dart over asynchronous messages
+     * @param instanceManager maintains instances stored to communicate with attached Dart objects
+     */
+    public ActivityCompatHostApiImpl(
+        @NonNull BinaryMessenger binaryMessenger,
+        @NonNull InstanceManager instanceManager
+    ) {
+        this.binaryMessenger = binaryMessenger;
+        this.instanceManager = instanceManager;
+    }
+
+    @NonNull
+    @Override
+    public Boolean shouldShowRequestPermissionRationale(
+        @NonNull String activityInstanceId,
+        @NonNull String permission
+    ) {
+        final UUID activityInstanceUuid = UUID.fromString(activityInstanceId);
+        final Activity activity = instanceManager.getInstance(activityInstanceUuid);
+        if (activity == null) {
+            throw new ActivityNotFoundException();
+        }
+        return ActivityCompat.shouldShowRequestPermissionRationale(activity, permission);
+    }
+}

permission_handler_android/android/src/main/java/com/baseflow/permissionhandler/ActivityFlutterApiImpl.java

@@ -0,0 +1,64 @@
+package com.baseflow.permissionhandler;
+
+import android.app.Activity;
+
+import androidx.annotation.NonNull;
+
+import com.baseflow.instancemanager.InstanceManager;
+import com.baseflow.permissionhandler.PermissionHandlerPigeon.ActivityFlutterApi;
+
+import io.flutter.plugin.common.BinaryMessenger;
+
+import java.util.UUID;
+
+/**
+ * Flutter API implementation for `Activity`.
+ *
+ * <p>This class may handle adding native instances that are attached to a Dart instance or passing
+ * arguments of callbacks methods to a Dart instance.
+ */
+public class ActivityFlutterApiImpl {
+    // To ease adding additional methods, this value is added prematurely.
+    @SuppressWarnings({"unused", "FieldCanBeLocal"})
+    private final BinaryMessenger binaryMessenger;
+
+    private final InstanceManager instanceManager;
+
+    private final ActivityFlutterApi api;
+
+    /**
+     * Constructs a {@link ActivityFlutterApiImpl}.
+     *
+     * @param binaryMessenger used to communicate with Dart over asynchronous messages
+     * @param instanceManager maintains instances stored to communicate with attached Dart objects
+     */
+    public ActivityFlutterApiImpl(
+        @NonNull BinaryMessenger binaryMessenger, @NonNull InstanceManager instanceManager) {
+        this.binaryMessenger = binaryMessenger;
+        this.instanceManager = instanceManager;
+        api = new ActivityFlutterApi(binaryMessenger);
+    }
+
+    /**
+     * Stores the `Activity` instance and notifies Dart to create and store a new `Activity`
+     * instance that is attached to this one. If `instance` has already been added, this method does
+     * nothing.
+     */
+    public void create(@NonNull Activity instance) {
+        if (!instanceManager.containsInstance(instance)) {
+            final UUID activityInstanceUuid = instanceManager.addHostCreatedInstance(instance);
+            api.create(activityInstanceUuid.toString(), reply -> {});
+        }
+    }
+
+    /**
+     * Disposes of the `Activity` instance in the instance manager and notifies Dart to do the same.
+     * If `instance` was already disposed, this method does nothing.
+     */
+    public void dispose(Activity instance) {
+        final UUID activityInstanceUuid = instanceManager.getIdentifierForStrongReference(instance);
+        if (activityInstanceUuid != null) {
+            api.dispose(activityInstanceUuid.toString(), reply -> {});
+        }
+    }
+}

permission_handler_android/android/src/main/java/com/baseflow/permissionhandler/PermissionHandlerPigeon.java

@@ -0,0 +1,154 @@
+// Autogenerated from Pigeon (v11.0.1), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+
+package com.baseflow.permissionhandler;
+
+import android.util.Log;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import io.flutter.plugin.common.BasicMessageChannel;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugin.common.MessageCodec;
+import io.flutter.plugin.common.StandardMessageCodec;
+import java.io.ByteArrayOutputStream;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/** Generated class from Pigeon. */
+@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression", "serial"})
+public class PermissionHandlerPigeon {
+
+  /** Error class for passing custom error details to Flutter via a thrown PlatformException. */
+  public static class FlutterError extends RuntimeException {
+
+    /** The error code. */
+    public final String code;
+
+    /** The error details. Must be a datatype supported by the api codec. */
+    public final Object details;
+
+    public FlutterError(@NonNull String code, @Nullable String message, @Nullable Object details) 
+    {
+      super(message);
+      this.code = code;
+      this.details = details;
+    }
+  }
+
+  @NonNull
+  protected static ArrayList<Object> wrapError(@NonNull Throwable exception) {
+    ArrayList<Object> errorList = new ArrayList<Object>(3);
+    if (exception instanceof FlutterError) {
+      FlutterError error = (FlutterError) exception;
+      errorList.add(error.code);
+      errorList.add(error.getMessage());
+      errorList.add(error.details);
+    } else {
+      errorList.add(exception.toString());
+      errorList.add(exception.getClass().getSimpleName());
+      errorList.add(
+        "Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));
+    }
+    return errorList;
+  }
+  /**
+   * Host API for `ActivityCompat`.
+   *
+   * This class may handle instantiating and adding native object instances that
+   * are attached to a Dart instance or handle method calls on the associated
+   * native class or an instance of the class.
+   *
+   * See https://developer.android.com/reference/androidx/core/app/ActivityCompat.
+   *
+   * Generated interface from Pigeon that represents a handler of messages from Flutter.
+   */
+  public interface ActivityCompatHostApi {
+    /** Gets whether you should show UI with rationale before requesting a permission. */
+    @NonNull 
+    Boolean shouldShowRequestPermissionRationale(@NonNull String activityInstanceId, @NonNull String permission);
+
+    /** The codec used by ActivityCompatHostApi. */
+    static @NonNull MessageCodec<Object> getCodec() {
+      return new StandardMessageCodec();
+    }
+    /**Sets up an instance of `ActivityCompatHostApi` to handle messages through the `binaryMessenger`. */
+    static void setup(@NonNull BinaryMessenger binaryMessenger, @Nullable ActivityCompatHostApi api) {
+      {
+        BasicMessageChannel<Object> channel =
+            new BasicMessageChannel<>(
+                binaryMessenger, "dev.flutter.pigeon.permission_handler_android.ActivityCompatHostApi.shouldShowRequestPermissionRationale", getCodec());
+        if (api != null) {
+          channel.setMessageHandler(
+              (message, reply) -> {
+                ArrayList<Object> wrapped = new ArrayList<Object>();
+                ArrayList<Object> args = (ArrayList<Object>) message;
+                String activityInstanceIdArg = (String) args.get(0);
+                String permissionArg = (String) args.get(1);
+                try {
+                  Boolean output = api.shouldShowRequestPermissionRationale(activityInstanceIdArg, permissionArg);
+                  wrapped.add(0, output);
+                }
+ catch (Throwable exception) {
+                  ArrayList<Object> wrappedError = wrapError(exception);
+                  wrapped = wrappedError;
+                }
+                reply.reply(wrapped);
+              });
+        } else {
+          channel.setMessageHandler(null);
+        }
+      }
+    }
+  }
+  /**
+   * Flutter API for `Activity`.
+   *
+   * This class may handle instantiating and adding Dart instances that are
+   * attached to a native instance or receiving callback methods from an
+   * overridden native class.
+   *
+   * See https://developer.android.com/reference/android/app/Activity.
+   *
+   * Generated class from Pigeon that represents Flutter messages that can be called from Java.
+   */
+  public static class ActivityFlutterApi {
+    private final @NonNull BinaryMessenger binaryMessenger;
+
+    public ActivityFlutterApi(@NonNull BinaryMessenger argBinaryMessenger) {
+      this.binaryMessenger = argBinaryMessenger;
+    }
+
+    /** Public interface for sending reply. */ 
+    @SuppressWarnings("UnknownNullness")
+    public interface Reply<T> {
+      void reply(T reply);
+    }
+    /** The codec used by ActivityFlutterApi. */
+    static @NonNull MessageCodec<Object> getCodec() {
+      return new StandardMessageCodec();
+    }
+    /** Create a new Dart instance and add it to the `InstanceManager`. */
+    public void create(@NonNull String instanceIdArg, @NonNull Reply<Void> callback) {
+      BasicMessageChannel<Object> channel =
+          new BasicMessageChannel<>(
+              binaryMessenger, "dev.flutter.pigeon.permission_handler_android.ActivityFlutterApi.create", getCodec());
+      channel.send(
+          new ArrayList<Object>(Collections.singletonList(instanceIdArg)),
+          channelReply -> callback.reply(null));
+    }
+    /** Dispose of the Dart instance and remove it from the `InstanceManager`. */
+    public void dispose(@NonNull String instanceIdArg, @NonNull Reply<Void> callback) {
+      BasicMessageChannel<Object> channel =
+          new BasicMessageChannel<>(
+              binaryMessenger, "dev.flutter.pigeon.permission_handler_android.ActivityFlutterApi.dispose", getCodec());
+      channel.send(
+          new ArrayList<Object>(Collections.singletonList(instanceIdArg)),
+          channelReply -> callback.reply(null));
+    }
+  }
+}