Add API demo for sharing.

Change-Id: I8f65979ab67297932e82f26eba8c4729725ee6d5

samples/ApiDemos/src/com/example/android/apis/content/FileProvider.java

@@ -111,14 +111,19 @@ public class FileProvider extends ContentProvider
     }
 
     @Override
-    public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException {
+    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
         // Try to open an asset with the given name.
         try {
-            InputStream is = getContext().getAssets().open(uri.getPath());
-            // Start a new thread that pipes the stream data back to the caller.
-            return new AssetFileDescriptor(
-                    openPipeHelper(uri, null, null, is, this), 0,
-                    AssetFileDescriptor.UNKNOWN_LENGTH);
+            String path = uri.getPath();
+            int off = path.indexOf('/', 1);
+            if (off < 0 || off >= (path.length()-1)) {
+                throw new FileNotFoundException("Unable to open " + uri);
+            }
+            int cookie = Integer.parseInt(path.substring(1, off));
+            String assetPath = path.substring(off+1);
+            AssetFileDescriptor asset = getContext().getAssets().openNonAssetFd(cookie, assetPath);
+            return new ParcelFileDescriptor(openPipeHelper(uri, null, null,
+                    asset.createInputStream(), this));
         } catch (IOException e) {
             FileNotFoundException fnf = new FileNotFoundException("Unable to open " + uri);
             throw fnf;

samples/ApiDemos/src/com/example/android/apis/content/ShareContent.java

@@ -0,0 +1,59 @@
+/**
+ * Copyright (c) 2015, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.apis.content;
+
+import android.app.Activity;
+import android.content.ClipData;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Bundle;
+import android.util.TypedValue;
+import android.view.View;
+import android.widget.Button;
+import com.example.android.apis.R;
+
+/**
+ * Example of sharing content from a private content provider.
+ */
+public class ShareContent extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setContentView(R.layout.share_content);
+
+        // Watch for button clicks.
+        ((Button)findViewById(R.id.share_image)).setOnClickListener(new View.OnClickListener() {
+            @Override public void onClick(View v) {
+                Intent intent = new Intent(Intent.ACTION_SEND);
+                intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+                Uri.Builder b = new Uri.Builder();
+                b.scheme("content");
+                b.authority("com.example.android.apis.content.FileProvider");
+                TypedValue tv = new TypedValue();
+                getResources().getValue(R.drawable.jellies, tv, true);
+                b.appendEncodedPath(Integer.toString(tv.assetCookie));
+                b.appendEncodedPath(tv.string.toString());
+                Uri uri = b.build();
+                intent.setType("image/jpeg");
+                intent.putExtra(Intent.EXTRA_STREAM, uri);
+                intent.setClipData(ClipData.newUri(getContentResolver(), "image", uri));
+                startActivity(Intent.createChooser(intent, "Select share target"));
+            }
+        });
+    }
+}