[Offline Page] Offline page sharing implementation

chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
index 9f0590a64eaaa24ec6345cea8b28e4da7fa34e56..e1bdefa49b6d7a5ead1c9233d1f9db2156913c21 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
@@ -24,6 +24,8 @@ import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
+import android.os.Environment;
+import android.support.v4.content.FileProvider;
 import android.support.v7.app.AlertDialog;
 import android.util.Pair;
 import android.view.MenuItem;
@@ -44,8 +46,10 @@ import org.chromium.components.dom_distiller.core.DomDistillerUrlUtils;
 import org.chromium.ui.UiUtils;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.nio.channels.FileChannel;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
@@ -190,6 +194,89 @@ public class ShareHelper {
         }
     }
 
+    /*
+     * This is a tryout function that only called when user shares offline pages
+     * */
+    public static void shareOfflinePage(final boolean shareDirectly, final Activity activity,

[dewittj, 2016/06/23 01:26:49]

There seems to be a lot of code here that is very similar to the bitmap sharing
code.  Possibly it would be best to encapsulate the Bitmap -> File process and
the offlineUrl -> File process.  Then you'd have a common thing that you could
pass to ShareHelper#Share, which does the appropriate file copy etc at the right
time.

+            final String title, final String offlineUrl, final Context context) {
+        // try copy file to external directory
+        new AsyncTask<Void, Void, File>() {
+            @Override
+            protected File doInBackground(Void... params) {
+                File offlinePageInternal = new File(offlineUrl);
+                File externalDataDir =
+                        Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);
+                File externalOfflinePageDir =
+                        new File(externalDataDir.getAbsolutePath() + "/OfflinePages");
+
+                boolean success = true;
+                if (!externalOfflinePageDir.exists()) {
+                    success = externalOfflinePageDir.mkdir();
+                }
+                if (success) {
+                    File offlinePageExternal = new File(externalOfflinePageDir.getAbsolutePath()
+                            + File.separator + offlinePageInternal.getName());
+
+                    if (!offlinePageExternal.exists()) {
+                        try {
+                            copyToExternal(offlinePageInternal, offlinePageExternal);

[dewittj, 2016/06/23 01:26:49]

I would prefer if we copied to internal if possible.  Based on other code in
ShareHelper, it seems that after a certain version of Android we are able to
share internal files.  Let's try to emulate that and see if there's any common
code.

+                        } catch (IOException e) {
+                            Log.e(TAG, "failed to copy the file: " + offlinePageInternal.getName());
+                        }
+                    }
+                    return offlinePageExternal;
+
+                } else {
+                    Log.e(TAG, "Unable to create subdirectory in external storage");
+                }
+                return null;
+            }
+
+            @Override
+            protected void onPostExecute(File offlinePageExternal) {
+                if (offlinePageExternal == null) return;
+                // sharing from external file
+                try {
+                    Uri offlinePageUri = FileProvider.getUriForFile(
+                            context, "org.chromium.chrome.FileProvider", offlinePageExternal);
+                    Intent chooserIntent =
+                            Intent.createChooser(getShareOfflinePageIntent(offlinePageUri),
+                                    activity.getString(R.string.share_link_chooser_title));
+                    activity.startActivity(chooserIntent);
+                } catch (IllegalArgumentException e) {
+                    Log.e(TAG,
+                            "The selected file can't be shared: " + offlinePageExternal.getName());
+                }
+            }
+        }.execute();
+
+        return;
+    }
+
+    private static Intent getShareOfflinePageIntent(Uri offlinePageUri) {
+        Intent intent = new Intent(Intent.ACTION_SEND);
+        intent.addFlags(ApiCompatibilityUtils.getActivityNewDocumentFlag());
+        intent.setType("multipart/related");
+        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+        intent.putExtra(Intent.EXTRA_STREAM, offlinePageUri);
+        return intent;
+    }
+
+    /*
+     * This is a helper function that copies an offline page file from internal storage to external
+     * */
+    public static void copyToExternal(File src, File dst) throws IOException {

[dewittj, 2016/06/23 01:26:48]

I'm surprised that this is the first time in Chromium that this has been done;
is there a helper function somewhere that you could use?

+        FileChannel inChannel = new FileInputStream(src).getChannel();
+        FileChannel outChannel = new FileOutputStream(dst).getChannel();
+        try {
+            inChannel.transferTo(0, inChannel.size(), outChannel);
+        } finally {
+            if (inChannel != null) inChannel.close();
+            if (outChannel != null) outChannel.close();
+        }
+        return;
+    }
+
     /**
      * Trigger the share action for the given image data.
      * @param activity The activity used to trigger the share action.