Example code for FileProvider.

Shows simple usage of FileProvider to share a private thumbnail
across process boundaries.  Also serves as sample code for javadoc
on FileProvider.

Bug: 7005318
Change-Id: I0ca12977a3832c7c2ac1c254d411a547ffee0a51
diff --git a/samples/Support4Demos/AndroidManifest.xml b/samples/Support4Demos/AndroidManifest.xml
index b747876..0cb5442 100644
--- a/samples/Support4Demos/AndroidManifest.xml
+++ b/samples/Support4Demos/AndroidManifest.xml
@@ -279,5 +279,27 @@
         <provider android:authorities="com.example.supportv4.content.sharingsupportprovider"
                   android:name=".content.SharingSupportProvider" />
 
+        <!-- FileProvider Example -->
+
+        <activity android:name=".content.FileProviderExample"
+                android:label="@string/file_provider_example">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="com.example.android.supportv4.SUPPORT4_SAMPLE_CODE" />
+            </intent-filter>
+        </activity>
+
+<!-- BEGIN_INCLUDE(file_provider_declaration) -->
+        <provider
+            android:name="android.support.v4.content.FileProvider"
+            android:authorities="com.example.android.supportv4.my_files"
+            android:grantUriPermissions="true"
+            android:exported="false">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/my_paths" />
+        </provider>
+<!-- END_INCLUDE(file_provider_declaration) -->
+
     </application>
 </manifest>
diff --git a/samples/Support4Demos/res/layout/file_provider_example.xml b/samples/Support4Demos/res/layout/file_provider_example.xml
new file mode 100644
index 0000000..2e53c3b
--- /dev/null
+++ b/samples/Support4Demos/res/layout/file_provider_example.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 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.
+-->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:padding="16dp"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <Button
+        android:text="@string/share_file"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:onClick="onShareFileClick" />
+
+</LinearLayout>
diff --git a/samples/Support4Demos/res/values/strings.xml b/samples/Support4Demos/res/values/strings.xml
index 35cbb75..1ac30aa 100644
--- a/samples/Support4Demos/res/values/strings.xml
+++ b/samples/Support4Demos/res/values/strings.xml
@@ -134,4 +134,6 @@
     <string name="sharing_support_title">ShareCompat Demo</string>
     <string name="sharing_receiver_title">ShareCompat Receiver</string>
 
+    <string name="file_provider_example">FileProvider example</string>
+
 </resources>
diff --git a/samples/Support4Demos/res/xml/my_paths.xml b/samples/Support4Demos/res/xml/my_paths.xml
new file mode 100644
index 0000000..f7223d3
--- /dev/null
+++ b/samples/Support4Demos/res/xml/my_paths.xml
@@ -0,0 +1,14 @@
+<!-- BEGIN_INCLUDE(file_provider_paths_declaration) -->
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Offer access to files under Context.getFilesDir() + "thumbs/"
+         through alias "my_thumbs" -->
+    <files-path name="my_thumbs" path="thumbs/" />
+
+    <!-- Offer access to files under Environment.getExternalStorageDirectory()
+         through alias "my_external" -->
+    <external-path name="my_external" />
+
+    <!-- Offer access to files under "/proc" through alias "my_proc" -->
+    <root-path name="my_proc" path="proc/" />
+</paths>
+<!-- END_INCLUDE(file_provider_paths_declaration) -->
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/content/FileProviderExample.java b/samples/Support4Demos/src/com/example/android/supportv4/content/FileProviderExample.java
new file mode 100644
index 0000000..926c632
--- /dev/null
+++ b/samples/Support4Demos/src/com/example/android/supportv4/content/FileProviderExample.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2011 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.supportv4.content;
+import android.app.Activity;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.net.Uri;
+import android.os.Bundle;
+import android.support.v4.content.FileProvider;
+import android.view.View;
+
+import com.example.android.supportv4.R;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Sample that shows how private files can be easily shared.
+ */
+public class FileProviderExample extends Activity {
+    private static final String AUTHORITY = "com.example.android.supportv4.my_files";
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.file_provider_example);
+    }
+
+    public void onShareFileClick(View view) {
+        // Save a thumbnail to file
+        final File thumbsDir = new File(getFilesDir(), "thumbs");
+        thumbsDir.mkdirs();
+        final File file = new File(thumbsDir, "private.png");
+        saveThumbnail(view, file);
+
+        // Now share that private file using FileProvider
+        final Uri uri = FileProvider.getUriForFile(this, AUTHORITY, file);
+        final Intent intent = new Intent(Intent.ACTION_SEND);
+        intent.setType("image/png");
+        intent.putExtra(Intent.EXTRA_STREAM, uri);
+        startActivity(intent);
+    }
+
+    /**
+     * Save thumbnail of given {@link View} to {@link File}.
+     */
+    private void saveThumbnail(View view, File file) {
+        final Bitmap bitmap = Bitmap.createBitmap(
+                view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
+        final Canvas canvas = new Canvas(bitmap);
+        view.draw(canvas);
+
+        try {
+            final OutputStream os = new FileOutputStream(file);
+            try {
+                bitmap.compress(Bitmap.CompressFormat.PNG, 100, os);
+            } finally {
+                os.close();
+            }
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}