refactor

packages/share/android/src/main/java/dev/flutter/plugins/share/SharePlugin.java

@@ -5,7 +5,8 @@
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
 import io.flutter.plugin.common.MethodChannel;
-import io.flutter.plugins.share.MethodChannelHandler;
+import io.flutter.plugins.share.MethodCallHandler;
+import io.flutter.plugins.share.Share;
 
 /**
  * Plugin implementation that uses the new {@code io.flutter.embedding} package.
@@ -15,14 +16,16 @@
 public class SharePlugin implements FlutterPlugin, ActivityAware {
 
   private static final String CHANNEL = "plugins.flutter.io/share";
-  MethodChannelHandler handler;
-  Activity activity;
+  private MethodCallHandler handler;
+  private Activity activity;
+  private Share share;
 
   @Override
   public void onAttachedToEngine(FlutterPluginBinding binding) {
     final MethodChannel methodChannel =
         new MethodChannel(binding.getFlutterEngine().getDartExecutor(), CHANNEL);
-    handler = new MethodChannelHandler(activity);
+    share = new Share(activity);
+    handler = new MethodCallHandler(share);
     methodChannel.setMethodCallHandler(handler);
   }
 
@@ -32,13 +35,13 @@ public void onDetachedFromEngine(FlutterPluginBinding binding) {}
   @Override
   public void onAttachedToActivity(ActivityPluginBinding binding) {
     activity = binding.getActivity();
-    handler.setActivity(activity);
+    share.setActivity(activity);
   }
 
   @Override
   public void onDetachedFromActivity() {
     activity = null;
-    handler.setActivity(null);
+    share.setActivity(null);
   }
 
   @Override

packages/share/android/src/main/java/io/flutter/plugins/share/MethodCallHandler.java

@@ -0,0 +1,36 @@
+// Copyright 2019 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.plugins.share;
+
+
+import androidx.annotation.NonNull;
+import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.MethodChannel;
+import java.util.Map;
+
+/** Handles the method channel for the plugin. */
+public class MethodCallHandler implements MethodChannel.MethodCallHandler {
+
+  private Share share;
+
+  /** Constructs the MethodChannelHandler */
+  public MethodCallHandler(@NonNull Share share) {
+    this.share = share;
+  }
+
+  @Override
+  public void onMethodCall(MethodCall call, MethodChannel.Result result) {
+    if (call.method.equals("share")) {
+      if (!(call.arguments instanceof Map)) {
+        throw new IllegalArgumentException("Map argument expected");
+      }
+      // Android does not support showing the share sheet at a particular point on screen.
+      share.share((String) call.argument("text"), (String) call.argument("subject"));
+      result.success(null);
+    } else {
+      result.notImplemented();
+    }
+  }
+}

packages/share/android/src/main/java/io/flutter/plugins/share/Share.java

@@ -0,0 +1,49 @@
+package io.flutter.plugins.share;
+
+import android.app.Activity;
+import android.content.Intent;
+import androidx.annotation.Nullable;
+
+/** Handles share intent. */
+public class Share {
+
+  private Activity activity;
+
+  /**
+   * Constructs a Share object.
+   *
+   * @param activity the activity used to fire share intent.
+   */
+  public Share(@Nullable Activity activity) {
+    this.activity = activity;
+  }
+
+  /**
+   * Sets the activity.
+   *
+   * @param activity if the activity becomes unavailable, call this with a null parameter to set it
+   *     to null.
+   */
+  public void setActivity(@Nullable Activity activity) {
+    this.activity = activity;
+  }
+
+  void share(String text, String subject) {
+    if (text == null || text.isEmpty()) {
+      throw new IllegalArgumentException("Non-empty text expected");
+    }
+
+    Intent shareIntent = new Intent();
+    shareIntent.setAction(Intent.ACTION_SEND);
+    shareIntent.putExtra(Intent.EXTRA_TEXT, text);
+    shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
+    shareIntent.setType("text/plain");
+    Intent chooserIntent = Intent.createChooser(shareIntent, null /* dialog title optional */);
+    if (activity != null) {
+      activity.startActivity(chooserIntent);
+    } else {
+      chooserIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+      activity.startActivity(chooserIntent);
+    }
+  }
+}

packages/share/android/src/main/java/io/flutter/plugins/share/SharePlugin.java

@@ -14,8 +14,8 @@ public class SharePlugin {
 
   public static void registerWith(Registrar registrar) {
     MethodChannel channel = new MethodChannel(registrar.messenger(), CHANNEL);
-
-    MethodChannelHandler handler = new MethodChannelHandler(registrar.activity());
+    Share share = new Share(registrar.activity());
+    MethodCallHandler handler = new MethodCallHandler(share);
     channel.setMethodCallHandler(handler);
   }
 }