[share] Add sharing file support (android & ios)

packages/share/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.6.5
+
+* Added support for sharing files
+
 ## 0.6.4+5
 
 * Update package:e2e -> package:integration_test

packages/share/README.md

@@ -39,3 +39,9 @@ sharing to email.
 ``` dart
 Share.share('check out my website https://example.com', subject: 'Look what I made!');
 ```
+
+To share one or multiple files invoke the static `shareFiles` method anywhere in your Dart code. Optionally you can also pass in `text` and `subject`.
+``` dart
+Share.shareFiles(['${directory.path}/image.jpg'], text: 'Great picture');
+Share.shareFiles(['${directory.path}/image1.jpg', '${directory.path}/image2.jpg']);
+```

packages/share/android/build.gradle

@@ -31,4 +31,9 @@ android {
     lintOptions {
         disable 'InvalidPackage'
     }
+
+    dependencies {
+        implementation 'androidx.core:core:1.3.1'
+        implementation 'androidx.annotation:annotation:1.1.0'
+    }
 }

packages/share/android/src/main/AndroidManifest.xml

@@ -1,3 +1,14 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="io.flutter.plugins.share">
+    <application>
+      <provider
+        android:name="io.flutter.plugins.share.ShareFileProvider"
+        android:authorities="${applicationId}.flutter.share_provider"
+        android:exported="false"
+        android:grantUriPermissions="true">
+        <meta-data
+          android:name="android.support.FILE_PROVIDER_PATHS"
+          android:resource="@xml/flutter_share_file_paths"/>
+      </provider>
+    </application>
 </manifest>

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

@@ -6,6 +6,8 @@
 
 import io.flutter.plugin.common.MethodCall;
 import io.flutter.plugin.common.MethodChannel;
+import java.io.*;
+import java.util.List;
 import java.util.Map;
 
 /** Handles the method calls for the plugin. */
@@ -19,15 +21,37 @@ class MethodCallHandler implements MethodChannel.MethodCallHandler {
 
   @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();
+    switch (call.method) {
+      case "share":
+        expectMapArguments(call);
+        // 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);
+        break;
+      case "shareFiles":
+        expectMapArguments(call);
+
+        // Android does not support showing the share sheet at a particular point on screen.
+        try {
+          share.shareFiles(
+              (List<String>) call.argument("paths"),
+              (List<String>) call.argument("mimeTypes"),
+              (String) call.argument("text"),
+              (String) call.argument("subject"));
+          result.success(null);
+        } catch (IOException e) {
+          result.error(e.getMessage(), null, null);
+        }
+        break;
+      default:
+        result.notImplemented();
+        break;
+    }
+  }
+
+  private void expectMapArguments(MethodCall call) throws IllegalArgumentException {
+    if (!(call.arguments instanceof Map)) {
+      throw new IllegalArgumentException("Map argument expected");
     }
   }
 }

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

@@ -5,19 +5,36 @@
 package io.flutter.plugins.share;
 
 import android.app.Activity;
+import android.content.Context;
 import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.content.pm.ResolveInfo;
+import android.net.Uri;
+import android.os.Environment;
+import androidx.annotation.NonNull;
+import androidx.core.content.FileProvider;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.List;
 
 /** Handles share intent. */
 class Share {
 
+  private Context context;
   private Activity activity;
 
   /**
-   * Constructs a Share object. The {@code activity} is used to start the share intent. It might be
-   * null when constructing the {@link Share} object and set to non-null when an activity is
-   * available using {@link #setActivity(Activity)}.
+   * Constructs a Share object. The {@code context} and {@code activity} are used to start the share
+   * intent. The {@code activity} might be null when constructing the {@link Share} object and set
+   * to non-null when an activity is available using {@link #setActivity(Activity)}.
    */
-  Share(Activity activity) {
+  Share(Context context, Activity activity) {
+    this.context = context;
     this.activity = activity;
   }
 
@@ -40,11 +57,177 @@ void share(String text, String subject) {
     shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
     shareIntent.setType("text/plain");
     Intent chooserIntent = Intent.createChooser(shareIntent, null /* dialog title optional */);
+    startActivity(chooserIntent);
+  }
+
+  void shareFiles(List<String> paths, List<String> mimeTypes, String text, String subject)
+      throws IOException {
+    if (paths == null || paths.isEmpty()) {
+      throw new IllegalArgumentException("Non-empty path expected");
+    }
+
+    clearExternalShareFolder();
+    ArrayList<Uri> fileUris = getUrisForPaths(paths);
+
+    Intent shareIntent = new Intent();
+    if (fileUris.isEmpty()) {
+      share(text, subject);
+      return;
+    } else if (fileUris.size() == 1) {
+      shareIntent.setAction(Intent.ACTION_SEND);
+      shareIntent.putExtra(Intent.EXTRA_STREAM, fileUris.get(0));
+      shareIntent.setType(
+          !mimeTypes.isEmpty() && mimeTypes.get(0) != null ? mimeTypes.get(0) : "*/*");
+    } else {
+      shareIntent.setAction(Intent.ACTION_SEND_MULTIPLE);
+      shareIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, fileUris);
+      shareIntent.setType(reduceMimeTypes(mimeTypes));
+    }
+    if (text != null) shareIntent.putExtra(Intent.EXTRA_TEXT, text);
+    if (subject != null) shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
+    shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+    Intent chooserIntent = Intent.createChooser(shareIntent, null /* dialog title optional */);
+
+    List<ResolveInfo> resInfoList =
+        getContext()
+            .getPackageManager()
+            .queryIntentActivities(chooserIntent, PackageManager.MATCH_DEFAULT_ONLY);
+    for (ResolveInfo resolveInfo : resInfoList) {
+      String packageName = resolveInfo.activityInfo.packageName;
+      for (Uri fileUri : fileUris) {
+        getContext()
+            .grantUriPermission(
+                packageName,
+                fileUri,
+                Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
+      }
+    }
+
+    startActivity(chooserIntent);
+  }
+
+  private void startActivity(Intent intent) {
     if (activity != null) {
-      activity.startActivity(chooserIntent);
+      activity.startActivity(intent);
+    } else if (context != null) {
+      intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+      context.startActivity(intent);
+    } else {
+      throw new IllegalStateException("Both context and activity are null");
+    }
+  }
+
+  private ArrayList<Uri> getUrisForPaths(List<String> paths) throws IOException {
+    ArrayList<Uri> uris = new ArrayList<>(paths.size());
+    for (String path : paths) {
+      File file = new File(path);
+      if (!fileIsOnExternal(file)) {
+        file = copyToExternalShareFolder(file);
+      }
+
+      uris.add(
+          FileProvider.getUriForFile(
+              getContext(), getContext().getPackageName() + ".flutter.share_provider", file));
+    }
+    return uris;
+  }
+
+  private String reduceMimeTypes(List<String> mimeTypes) {
+    if (mimeTypes.size() > 1) {
+      String reducedMimeType = mimeTypes.get(0);
+      for (int i = 1; i < mimeTypes.size(); i++) {
+        String mimeType = mimeTypes.get(i);
+        if (!reducedMimeType.equals(mimeType)) {
+          if (getMimeTypeBase(mimeType).equals(getMimeTypeBase(reducedMimeType))) {
+            reducedMimeType = getMimeTypeBase(mimeType) + "/*";
+          } else {
+            reducedMimeType = "*/*";
+            break;
+          }
+        }
+      }
+      return reducedMimeType;
+    } else if (mimeTypes.size() == 1) {
+      return mimeTypes.get(0);
     } else {
-      chooserIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-      activity.startActivity(chooserIntent);
+      return "*/*";
+    }
+  }
+
+  @NonNull
+  private String getMimeTypeBase(String mimeType) {
+    if (mimeType == null || !mimeType.contains("/")) {
+      return "*";
+    }
+
+    return mimeType.substring(0, mimeType.indexOf("/"));
+  }
+
+  private boolean fileIsOnExternal(File file) {
+    try {
+      String filePath = file.getCanonicalPath();
+      File externalDir = Environment.getExternalStorageDirectory();
+      return externalDir != null && filePath.startsWith(externalDir.getCanonicalPath());
+    } catch (IOException e) {
+      return false;
+    }
+  }
+
+  @SuppressWarnings("ResultOfMethodCallIgnored")
+  private void clearExternalShareFolder() {
+    File folder = getExternalShareFolder();
+    if (folder.exists()) {
+      for (File file : folder.listFiles()) {
+        file.delete();
+      }
+      folder.delete();
+    }
+  }
+
+  @SuppressWarnings("ResultOfMethodCallIgnored")
+  private File copyToExternalShareFolder(File file) throws IOException {
+    File folder = getExternalShareFolder();
+    if (!folder.exists()) {
+      folder.mkdirs();
+    }
+
+    File newFile = new File(folder, file.getName());
+    copy(file, newFile);
+    return newFile;
+  }
+
+  @NonNull
+  private File getExternalShareFolder() {
+    return new File(getContext().getExternalCacheDir(), "share");
+  }
+
+  private Context getContext() {
+    if (activity != null) {
+      return activity;
+    }
+    if (context != null) {
+      return context;
+    }
+
+    throw new IllegalStateException("Both context and activity are null");
+  }
+
+  private static void copy(File src, File dst) throws IOException {
+    InputStream in = new FileInputStream(src);
+    try {
+      OutputStream out = new FileOutputStream(dst);
+      try {
+        // Transfer bytes from in to out
+        byte[] buf = new byte[1024];
+        int len;
+        while ((len = in.read(buf)) > 0) {
+          out.write(buf, 0, len);
+        }
+      } finally {
+        out.close();
+      }
+    } finally {
+      in.close();
     }
   }
 }

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

@@ -0,0 +1,14 @@
+// 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.core.content.FileProvider;
+
+/**
+ * Providing a custom {@code FileProvider} prevents manifest {@code <provider>} name collisions.
+ *
+ * <p>See https://developer.android.com/guide/topics/manifest/provider-element.html for details.
+ */
+public class ShareFileProvider extends FileProvider {}

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

@@ -5,6 +5,7 @@
 package io.flutter.plugins.share;
 
 import android.app.Activity;
+import android.content.Context;
 import io.flutter.embedding.engine.plugins.FlutterPlugin;
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
@@ -22,12 +23,12 @@ public class SharePlugin implements FlutterPlugin, ActivityAware {
 
   public static void registerWith(Registrar registrar) {
     SharePlugin plugin = new SharePlugin();
-    plugin.setUpChannel(registrar.activity(), registrar.messenger());
+    plugin.setUpChannel(registrar.context(), registrar.activity(), registrar.messenger());
   }
 
   @Override
   public void onAttachedToEngine(FlutterPluginBinding binding) {
-    setUpChannel(null, binding.getBinaryMessenger());
+    setUpChannel(binding.getApplicationContext(), null, binding.getBinaryMessenger());
   }
 
   @Override
@@ -57,9 +58,9 @@ public void onDetachedFromActivityForConfigChanges() {
     onDetachedFromActivity();
   }
 
-  private void setUpChannel(Activity activity, BinaryMessenger messenger) {
+  private void setUpChannel(Context context, Activity activity, BinaryMessenger messenger) {
     methodChannel = new MethodChannel(messenger, CHANNEL);
-    share = new Share(activity);
+    share = new Share(context, activity);
     handler = new MethodCallHandler(share);
     methodChannel.setMethodCallHandler(handler);
   }

packages/share/android/src/main/res/xml/flutter_share_file_paths.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <external-path name="external" path="."/>
+    <external-files-path name="external_files" path="."/>
+    <external-cache-path name="external_cache" path="."/>
+</paths>

packages/share/example/ios/Runner/Info.plist

@@ -45,5 +45,11 @@
 	</array>
 	<key>UIViewControllerBasedStatusBarAppearance</key>
 	<false/>
+	<key>NSPhotoLibraryUsageDescription</key>
+	<string>This app requires access to the photo library for sharing images.</string>
+	<key>NSMicrophoneUsageDescription</key>
+	<string>This app does not require access to the microphone for sharing images.</string>
+	<key>NSCameraUsageDescription</key>
+	<string>This app requires access to the camera for sharing images.</string>
 </dict>
 </plist>