[android] Allow the user to save image attachment outside of Briar

briar-android/src/main/java/org/briarproject/briar/android/activity/RequestCodes.java

@@ -15,5 +15,6 @@ public interface RequestCodes {
 	int REQUEST_UNLOCK = 11;
 	int REQUEST_KEYGUARD_UNLOCK = 12;
 	int REQUEST_ATTACH_IMAGE = 13;
+	int REQUEST_SAVE_ATTACHMENT = 14;
 
 }

briar-android/src/main/java/org/briarproject/briar/android/conversation/AttachmentController.java

@@ -127,12 +127,14 @@ class AttachmentController {
 		}
 
 		// calculate thumbnail size
-		Size thumbnailSize = new Size(defaultSize, defaultSize);
+		Size thumbnailSize = new Size(defaultSize, defaultSize, size.mimeType);
 		if (!size.error) {
-			thumbnailSize = getThumbnailSize(size.width, size.height);
+			thumbnailSize =
+					getThumbnailSize(size.width, size.height, size.mimeType);
 		}
 		return new AttachmentItem(messageId, size.width, size.height,
-				thumbnailSize.width, thumbnailSize.height, size.error);
+				size.mimeType, thumbnailSize.width, thumbnailSize.height,
+				size.error);
 	}
 
 	/**
@@ -151,9 +153,9 @@ class AttachmentController {
 				orientation == ORIENTATION_TRANSVERSE ||
 				orientation == ORIENTATION_TRANSPOSE) {
 			//noinspection SuspiciousNameCombination
-			return new Size(height, width);
+			return new Size(height, width, "image/jpeg");
 		}
-		return new Size(width, height);
+		return new Size(width, height, "image/jpeg");
 	}
 
 	/**
@@ -165,10 +167,11 @@ class AttachmentController {
 		BitmapFactory.decodeStream(is, null, options);
 		if (options.outWidth < 1 || options.outHeight < 1)
 			return new Size();
-		return new Size(options.outWidth, options.outHeight);
+		return new Size(options.outWidth, options.outHeight,
+				options.outMimeType);
 	}
 
-	private Size getThumbnailSize(int width, int height) {
+	private Size getThumbnailSize(int width, int height, String mimeType) {
 		float widthPercentage = maxWidth / (float) width;
 		float heightPercentage = maxHeight / (float) height;
 		float scaleFactor = Math.min(widthPercentage, heightPercentage);
@@ -184,24 +187,27 @@ class AttachmentController {
 			if (thumbnailWidth > maxWidth) thumbnailWidth = maxWidth;
 			if (thumbnailHeight > maxHeight) thumbnailHeight = maxHeight;
 		}
-		return new Size(thumbnailWidth, thumbnailHeight);
+		return new Size(thumbnailWidth, thumbnailHeight, mimeType);
 	}
 
 	private static class Size {
 
 		private final int width;
 		private final int height;
+		private final String mimeType;
 		private final boolean error;
 
-		private Size(int width, int height) {
+		private Size(int width, int height, String mimeType) {
 			this.width = width;
 			this.height = height;
+			this.mimeType = mimeType;
 			this.error = false;
 		}
 
 		private Size() {
 			this.width = 0;
 			this.height = 0;
+			this.mimeType = "";
 			this.error = true;
 		}
 	}

briar-android/src/main/java/org/briarproject/briar/android/conversation/AttachmentItem.java

@@ -14,6 +14,7 @@ public class AttachmentItem implements Parcelable {
 
 	private final MessageId messageId;
 	private final int width, height;
+	private final String mimeType;
 	private final int thumbnailWidth, thumbnailHeight;
 	private final boolean hasError;
 
@@ -30,11 +31,12 @@ public class AttachmentItem implements Parcelable {
 				}
 			};
 
-	AttachmentItem(MessageId messageId, int width, int height,
+	AttachmentItem(MessageId messageId, int width, int height, String mimeType,
 			int thumbnailWidth, int thumbnailHeight, boolean hasError) {
 		this.messageId = messageId;
 		this.width = width;
 		this.height = height;
+		this.mimeType = mimeType;
 		this.thumbnailWidth = thumbnailWidth;
 		this.thumbnailHeight = thumbnailHeight;
 		this.hasError = hasError;
@@ -46,6 +48,7 @@ public class AttachmentItem implements Parcelable {
 		messageId = new MessageId(messageIdByte);
 		width = in.readInt();
 		height = in.readInt();
+		mimeType = in.readString();
 		thumbnailWidth = in.readInt();
 		thumbnailHeight = in.readInt();
 		hasError = in.readByte() != 0;
@@ -63,6 +66,10 @@ public class AttachmentItem implements Parcelable {
 		return height;
 	}
 
+	String getMimeType() {
+		return mimeType;
+	}
+
 	int getThumbnailWidth() {
 		return thumbnailWidth;
 	}
@@ -90,6 +97,7 @@ public class AttachmentItem implements Parcelable {
 		dest.writeByteArray(messageId.getBytes());
 		dest.writeInt(width);
 		dest.writeInt(height);
+		dest.writeString(mimeType);
 		dest.writeInt(thumbnailWidth);
 		dest.writeInt(thumbnailHeight);
 		dest.writeByte((byte) (hasError ? 1 : 0));

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageActivity.java

@@ -1,14 +1,20 @@
 package org.briarproject.briar.android.conversation;
 
+import android.content.DialogInterface.OnClickListener;
+import android.content.Intent;
 import android.graphics.drawable.Animatable;
 import android.graphics.drawable.Drawable;
+import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.annotation.RequiresApi;
 import android.support.design.widget.AppBarLayout;
+import android.support.design.widget.Snackbar;
+import android.support.v7.app.AlertDialog.Builder;
 import android.support.v7.widget.Toolbar;
 import android.transition.Fade;
 import android.transition.Transition;
+import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.Window;
@@ -20,14 +26,34 @@ import com.bumptech.glide.request.RequestListener;
 import com.bumptech.glide.request.target.Target;
 import com.github.chrisbanes.photoview.PhotoView;
 
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.conversation.glide.GlideApp;
 import org.briarproject.briar.android.view.PullDownLayout;
+import org.briarproject.briar.api.messaging.Attachment;
+import org.briarproject.briar.api.messaging.MessagingManager;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import static android.content.Intent.ACTION_CREATE_DOCUMENT;
+import static android.content.Intent.CATEGORY_OPENABLE;
+import static android.content.Intent.EXTRA_TITLE;
 import static android.graphics.Color.TRANSPARENT;
 import static android.os.Build.VERSION.SDK_INT;
+import static android.support.design.widget.Snackbar.LENGTH_LONG;
 import static android.view.View.GONE;
 import static android.view.View.SYSTEM_UI_FLAG_FULLSCREEN;
 import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
@@ -37,18 +63,32 @@ import static android.view.WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
 import static android.widget.ImageView.ScaleType.FIT_START;
 import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
 import static java.util.Objects.requireNonNull;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.IoUtils.copyAndClose;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SAVE_ATTACHMENT;
 import static org.briarproject.briar.android.util.UiUtils.formatDateAbsolute;
 
 public class ImageActivity extends BriarActivity
 		implements PullDownLayout.Callback {
 
+	private final static Logger LOG = getLogger(ImageActivity.class.getName());
+
 	final static String ATTACHMENT = "attachment";
 	final static String NAME = "name";
 	final static String DATE = "date";
 
+	@Inject
+	MessagingManager messagingManager;
+	@Inject
+	@IoExecutor
+	Executor ioExecutor;
+
 	private PullDownLayout layout;
 	private AppBarLayout appBarLayout;
 	private PhotoView photoView;
+	private AttachmentItem attachment;
 
 	@Override
 	public void injectActivity(ActivityComponent component) {
@@ -88,7 +128,7 @@ public class ImageActivity extends BriarActivity
 		TextView dateView = toolbar.findViewById(R.id.dateView);
 
 		// Intent Extras
-		AttachmentItem attachment = getIntent().getParcelableExtra(ATTACHMENT);
+		attachment = getIntent().getParcelableExtra(ATTACHMENT);
 		String name = getIntent().getStringExtra(NAME);
 		long time = getIntent().getLongExtra(DATE, 0);
 		String date = formatDateAbsolute(this, time);
@@ -143,17 +183,37 @@ public class ImageActivity extends BriarActivity
 				.into(photoView);
 	}
 
+	@Override
+	public boolean onCreateOptionsMenu(Menu menu) {
+		getMenuInflater().inflate(R.menu.image_actions, menu);
+		if (SDK_INT >= 19) {
+			menu.findItem(R.id.action_save_image).setVisible(true);
+		}
+		return super.onCreateOptionsMenu(menu);
+	}
+
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		switch (item.getItemId()) {
 			case android.R.id.home:
 				onBackPressed();
 				return true;
+			case R.id.action_save_image:
+				if (SDK_INT >= 19) startSaveImage();
+				return true;
 			default:
 				return super.onOptionsItemSelected(item);
 		}
 	}
 
+	@Override
+	protected void onActivityResult(int request, int result, Intent data) {
+		super.onActivityResult(request, result, data);
+		if (request == REQUEST_SAVE_ATTACHMENT && result == RESULT_OK) {
+			saveImage(data.getData());
+		}
+	}
+
 	@Override
 	public void onPullStart() {
 		appBarLayout.animate()
@@ -230,4 +290,66 @@ public class ImageActivity extends BriarActivity
 				drawableTop != appBarLayout.getTop();
 	}
 
+	@RequiresApi(api = 19)
+	private void startSaveImage() {
+		OnClickListener okListener = (dialog, which) -> {
+			Intent intent = getCreationIntent();
+			startActivityForResult(intent, REQUEST_SAVE_ATTACHMENT);
+		};
+		Builder builder = new Builder(this, R.style.BriarDialogTheme);
+		builder.setTitle(getString(R.string.dialog_title_save_image));
+		builder.setMessage(getString(R.string.dialog_message_save_image));
+		builder.setIcon(R.drawable.emoji_google_1f6af);
+		builder.setPositiveButton(R.string.save_image, okListener);
+		builder.setNegativeButton(R.string.cancel, null);
+		builder.show();
+	}
+
+	@RequiresApi(api = 19)
+	private Intent getCreationIntent() {
+		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss",
+				Locale.getDefault());
+		String fileName = sdf.format(new Date());
+		Intent intent = new Intent(ACTION_CREATE_DOCUMENT);
+		intent.addCategory(CATEGORY_OPENABLE);
+		intent.setType(attachment.getMimeType());
+		intent.putExtra(EXTRA_TITLE, fileName);
+		return intent;
+	}
+
+	private void saveImage(@Nullable Uri uri) {
+		if (uri == null) return;
+		MessageId messageId = attachment.getMessageId();
+		runOnDbThread(() -> {
+			try {
+				Attachment a = messagingManager.getAttachment(messageId);
+				copyImageFromDb(a, uri);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onImageSaveError();
+			}
+		});
+	}
+
+	private void copyImageFromDb(Attachment a, Uri uri) {
+		ioExecutor.execute(() -> {
+			try {
+				InputStream is = a.getStream();
+				OutputStream os = getContentResolver().openOutputStream(uri);
+				if (os == null) throw new IOException();
+				copyAndClose(is, os);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onImageSaveError();
+			}
+		});
+	}
+
+	private void onImageSaveError() {
+		Snackbar s =
+				Snackbar.make(layout, R.string.save_image_error, LENGTH_LONG);
+		s.getView().setBackgroundResource(R.color.briar_red);
+		s.show();
+	}
+
 }

briar-android/src/main/res/menu/image_actions.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto">
+
+	<item
+		android:id="@+id/action_save_image"
+		android:title="@string/save_image"
+		android:visible="false"
+		app:showAsAction="never"/>
+</menu>

briar-android/src/main/res/values/strings.xml

@@ -139,6 +139,10 @@
 	<string name="contact_deleted_toast">Contact deleted</string>
 	<!-- This is shown in the action bar when opening an image in fullscreen that the user sent -->
 	<string name="you">You</string>
+	<string name="save_image">Save image</string>
+	<string name="dialog_title_save_image">Save Image?</string>
+	<string name="dialog_message_save_image">Saving this image will allow other apps to access it.\n\nAre you sure you want to save?</string>
+	<string name="save_image_error">Could not save image</string>
 
 	<!-- Adding Contacts -->
 	<string name="add_contact_title">Add a Contact</string>