[android] Use a nested RecyclerView with a single items to show image attachments

This is preparation for showing multiple image attachments in one
message bubble.

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

@@ -3,6 +3,7 @@ package org.briarproject.briar.android.conversation;
 import android.content.Context;
 import android.support.annotation.LayoutRes;
 import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView.RecycledViewPool;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -21,11 +22,14 @@ class ConversationAdapter
 		extends BriarAdapter<ConversationItem, ConversationItemViewHolder> {
 
 	private ConversationListener listener;
+	private final RecycledViewPool imageViewPool;
 
 	ConversationAdapter(Context ctx,
 			ConversationListener conversationListener) {
 		super(ctx, ConversationItem.class);
 		listener = conversationListener;
+		// This shares the same pool for view recycling between all image lists
+		imageViewPool = new RecycledViewPool();
 	}
 
 	@LayoutRes
@@ -42,15 +46,17 @@ class ConversationAdapter
 				type, viewGroup, false);
 		switch (type) {
 			case R.layout.list_item_conversation_msg_in:
-				return new ConversationMessageViewHolder(v, true);
+				return new ConversationMessageViewHolder(v, listener, true,
+						imageViewPool);
 			case R.layout.list_item_conversation_msg_out:
-				return new ConversationMessageViewHolder(v, false);
+				return new ConversationMessageViewHolder(v, listener, false,
+						imageViewPool);
 			case R.layout.list_item_conversation_notice_in:
-				return new ConversationNoticeViewHolder(v, true);
+				return new ConversationNoticeViewHolder(v, listener, true);
 			case R.layout.list_item_conversation_notice_out:
-				return new ConversationNoticeViewHolder(v, false);
+				return new ConversationNoticeViewHolder(v, listener, false);
 			case R.layout.list_item_conversation_request:
-				return new ConversationRequestViewHolder(v, true);
+				return new ConversationRequestViewHolder(v, listener, true);
 			default:
 				throw new IllegalArgumentException("Unknown ConversationItem");
 		}
@@ -59,7 +65,7 @@ class ConversationAdapter
 	@Override
 	public void onBindViewHolder(ConversationItemViewHolder ui, int position) {
 		ConversationItem item = items.get(position);
-		ui.bind(item, listener);
+		ui.bind(item);
 		listener.onItemVisible(item);
 	}
 

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

@@ -18,14 +18,17 @@ import static org.briarproject.briar.android.util.UiUtils.formatDate;
 @NotNullByDefault
 abstract class ConversationItemViewHolder extends ViewHolder {
 
+	protected final ConversationListener listener;
 	protected final ConstraintLayout layout;
 	@Nullable
 	private final OutItemViewHolder outViewHolder;
 	private final TextView text;
 	protected final TextView time;
 
-	ConversationItemViewHolder(View v, boolean isIncoming) {
+	ConversationItemViewHolder(View v, ConversationListener listener,
+			boolean isIncoming) {
 		super(v);
+		this.listener = listener;
 		this.outViewHolder = isIncoming ? null : new OutItemViewHolder(v);
 		layout = v.findViewById(R.id.layout);
 		text = v.findViewById(R.id.text);
@@ -33,7 +36,7 @@ abstract class ConversationItemViewHolder extends ViewHolder {
 	}
 
 	@CallSuper
-	void bind(ConversationItem item, ConversationListener listener) {
+	void bind(ConversationItem item) {
 		if (item.getText() != null) {
 			text.setText(trim(item.getText()));
 		}

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

@@ -1,64 +1,47 @@
 package org.briarproject.briar.android.conversation;
 
-import android.content.res.Configuration;
-import android.graphics.Bitmap;
-import android.support.annotation.DrawableRes;
 import android.support.annotation.UiThread;
 import android.support.constraint.ConstraintSet;
 import android.support.v4.content.ContextCompat;
+import android.support.v7.widget.GridLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.RecyclerView.RecycledViewPool;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.ImageView;
-
-import com.bumptech.glide.load.Transformation;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.conversation.glide.BriarImageTransformation;
-import org.briarproject.briar.android.conversation.glide.GlideApp;
 
-import static android.os.Build.VERSION.SDK_INT;
+import static android.support.constraint.ConstraintSet.WRAP_CONTENT;
-import static android.support.v4.view.ViewCompat.LAYOUT_DIRECTION_RTL;
-import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
-import static com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions.withCrossFade;
 
 @UiThread
 @NotNullByDefault
 class ConversationMessageViewHolder extends ConversationItemViewHolder {
 
-	@DrawableRes
+	private final ImageAdapter adapter;
-	private static final int ERROR_RES = R.drawable.ic_image_broken;
-
-	private final ImageView imageView;
 	private final ViewGroup statusLayout;
 	private final int timeColor, timeColorBubble;
-	private final int radiusBig, radiusSmall;
-	private final boolean isRtl;
 	private final ConstraintSet textConstraints = new ConstraintSet();
 	private final ConstraintSet imageConstraints = new ConstraintSet();
 	private final ConstraintSet imageTextConstraints = new ConstraintSet();
 
-	ConversationMessageViewHolder(View v, boolean isIncoming) {
+	ConversationMessageViewHolder(View v, ConversationListener listener,
-		super(v, isIncoming);
+			boolean isIncoming, RecycledViewPool imageViewPool) {
-		imageView = v.findViewById(R.id.imageView);
+		super(v, listener, isIncoming);
 		statusLayout = v.findViewById(R.id.statusLayout);
-		radiusBig = v.getContext().getResources()
+
-				.getDimensionPixelSize(R.dimen.message_bubble_radius_big);
+		// image list
-		radiusSmall = v.getContext().getResources()
+		RecyclerView list = v.findViewById(R.id.imageView);
-				.getDimensionPixelSize(R.dimen.message_bubble_radius_small);
+		list.setRecycledViewPool(imageViewPool);
+		list.setLayoutManager(new GridLayoutManager(v.getContext(), 2));
+		adapter = new ImageAdapter(listener);
+		list.setAdapter(adapter);
 
 		// remember original status text color
 		timeColor = time.getCurrentTextColor();
 		timeColorBubble =
 				ContextCompat.getColor(v.getContext(), R.color.briar_white);
 
-		// find out if we are showing a RTL language, Use the configuration,
-		// because getting the layout direction of views is not reliable
-		Configuration config =
-				imageView.getContext().getResources().getConfiguration();
-		isRtl = SDK_INT >= 17 &&
-				config.getLayoutDirection() == LAYOUT_DIRECTION_RTL;
-
 		// clone constraint sets from layout files
 		textConstraints
 				.clone(v.getContext(), R.layout.list_item_conversation_msg_in);
@@ -77,32 +60,24 @@ class ConversationMessageViewHolder extends ConversationItemViewHolder {
 	}
 
 	@Override
-	void bind(ConversationItem conversationItem,
+	void bind(ConversationItem conversationItem) {
-			ConversationListener listener) {
+		super.bind(conversationItem);
-		super.bind(conversationItem, listener);
 		ConversationMessageItem item =
 				(ConversationMessageItem) conversationItem;
 		if (item.getAttachments().isEmpty()) {
 			bindTextItem();
 		} else {
-			bindImageItem(item, listener);
+			bindImageItem(item);
 		}
 	}
 
 	private void bindTextItem() {
-		clearImage();
+		resetStatusLayoutForText();
-		statusLayout.setBackgroundResource(0);
-		// also reset padding (the background drawable defines some)
-		statusLayout.setPadding(0, 0, 0, 0);
-		time.setTextColor(timeColor);
 		textConstraints.applyTo(layout);
+		adapter.clear();
 	}
 
-	private void bindImageItem(ConversationMessageItem item,
+	private void bindImageItem(ConversationMessageItem item) {
-			ConversationListener listener) {
-		// TODO show more than just the first image
-		AttachmentItem attachment = item.getAttachments().get(0);
-
 		ConstraintSet constraintSet;
 		if (item.getText() == null) {
 			statusLayout
@@ -110,52 +85,30 @@ class ConversationMessageViewHolder extends ConversationItemViewHolder {
 			time.setTextColor(timeColorBubble);
 			constraintSet = imageConstraints;
 		} else {
-			statusLayout.setBackgroundResource(0);
+			resetStatusLayoutForText();
-			// also reset padding (the background drawable defines some)
-			statusLayout.setPadding(0, 0, 0, 0);
-			time.setTextColor(timeColor);
 			constraintSet = imageTextConstraints;
 		}
 
-		// apply image size constraints, so glides picks them up for scaling
+		if (item.getAttachments().size() == 1) {
-		int width = attachment.getThumbnailWidth();
+			// apply image size constraints for a single image
-		int height = attachment.getThumbnailHeight();
+			AttachmentItem attachment = item.getAttachments().get(0);
-		constraintSet.constrainWidth(R.id.imageView, width);
+			int width = attachment.getThumbnailWidth();
-		constraintSet.constrainHeight(R.id.imageView, height);
+			int height = attachment.getThumbnailHeight();
-		constraintSet.applyTo(layout);
+			constraintSet.constrainWidth(R.id.imageView, width);
-
+			constraintSet.constrainHeight(R.id.imageView, height);
-		if (attachment.hasError()) {
-			clearImage();
-			imageView.setImageResource(ERROR_RES);
 		} else {
-			loadImage(item, attachment, listener);
+			constraintSet.constrainWidth(R.id.imageView, WRAP_CONTENT);
+			constraintSet.constrainHeight(R.id.imageView, WRAP_CONTENT);
 		}
+		constraintSet.applyTo(layout);
+		adapter.setConversationItem(item);
 	}
 
-	private void clearImage() {
+	private void resetStatusLayoutForText() {
-		GlideApp.with(imageView)
+		statusLayout.setBackgroundResource(0);
-				.clear(imageView);
+		// also reset padding (the background drawable defines some)
-		imageView.setOnClickListener(null);
+		statusLayout.setPadding(0, 0, 0, 0);
-	}
+		time.setTextColor(timeColor);
-
-	private void loadImage(ConversationMessageItem item,
-			AttachmentItem attachment, ConversationListener listener) {
-		boolean leftCornerSmall =
-				(isIncoming() && !isRtl) || (!isIncoming() && isRtl);
-		boolean bottomRound = item.getText() == null;
-		Transformation<Bitmap> transformation = new BriarImageTransformation(
-				radiusSmall, radiusBig, leftCornerSmall, bottomRound);
-
-		GlideApp.with(imageView)
-				.load(attachment)
-				.diskCacheStrategy(NONE)
-				.error(ERROR_RES)
-				.transform(transformation)
-				.transition(withCrossFade())
-				.into(imageView)
-				.waitForLayout();
-		imageView.setOnClickListener(
-				view -> listener.onAttachmentClicked(view, item, attachment));
 	}
 
 }

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

@@ -19,16 +19,17 @@ class ConversationNoticeViewHolder extends ConversationItemViewHolder {
 
 	private final TextView msgText;
 
-	ConversationNoticeViewHolder(View v, boolean isIncoming) {
+	ConversationNoticeViewHolder(View v, ConversationListener listener,
-		super(v, isIncoming);
+			boolean isIncoming) {
+		super(v, listener, isIncoming);
 		msgText = v.findViewById(R.id.msgText);
 	}
 
 	@Override
 	@CallSuper
-	void bind(ConversationItem item, ConversationListener listener) {
+	void bind(ConversationItem item) {
 		ConversationNoticeItem notice = (ConversationNoticeItem) item;
-		super.bind(notice, listener);
+		super.bind(notice);
 
 		String text = notice.getMsgText();
 		if (isNullOrEmpty(text)) {

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

@@ -17,16 +17,17 @@ class ConversationRequestViewHolder extends ConversationNoticeViewHolder {
 	private final Button acceptButton;
 	private final Button declineButton;
 
-	ConversationRequestViewHolder(View v, boolean isIncoming) {
+	ConversationRequestViewHolder(View v, ConversationListener listener,
-		super(v, isIncoming);
+			boolean isIncoming) {
+		super(v, listener, isIncoming);
 		acceptButton = v.findViewById(R.id.acceptButton);
 		declineButton = v.findViewById(R.id.declineButton);
 	}
 
 	@Override
-	void bind(ConversationItem item, ConversationListener listener) {
+	void bind(ConversationItem item) {
 		ConversationRequestItem request = (ConversationRequestItem) item;
-		super.bind(request, listener);
+		super.bind(request);
 
 		if (request.wasAnswered() && request.canBeOpened()) {
 			acceptButton.setVisibility(VISIBLE);

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

@@ -0,0 +1,81 @@
+package org.briarproject.briar.android.conversation;
+
+import android.support.annotation.Nullable;
+import android.support.v7.widget.RecyclerView.Adapter;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static java.util.Objects.requireNonNull;
+
+@NotNullByDefault
+class ImageAdapter extends Adapter<ImageViewHolder> {
+
+	private final static int TYPE_SINGLE = 0;
+	private final static int TYPE_MULTIPLE = 1;
+
+	private final List<AttachmentItem> items = new ArrayList<>();
+	private final ConversationListener listener;
+	@Nullable
+	private ConversationMessageItem conversationItem;
+
+	public ImageAdapter(ConversationListener listener) {
+		super();
+		this.listener = listener;
+	}
+
+	@Override
+	public int getItemViewType(int position) {
+		return items.size() == 1 ? TYPE_SINGLE : TYPE_MULTIPLE;
+	}
+
+	@Override
+	public ImageViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
+		View v = LayoutInflater.from(viewGroup.getContext()).inflate(
+				R.layout.list_item_image, viewGroup, false);
+		return type == TYPE_SINGLE ? new SingleImageViewHolder(v) :
+				new ImageViewHolder(v);
+	}
+
+	@Override
+	public void onBindViewHolder(ImageViewHolder imageViewHolder,
+			int position) {
+		requireNonNull(conversationItem);
+		AttachmentItem item = items.get(position);
+		imageViewHolder.itemView.setOnClickListener(v ->
+				listener.onAttachmentClicked(v, conversationItem, item)
+		);
+		if (imageViewHolder instanceof SingleImageViewHolder) {
+			boolean isIncoming = conversationItem.isIncoming();
+			boolean hasText = conversationItem.getText() != null;
+			((SingleImageViewHolder) imageViewHolder)
+					.bind(item, isIncoming, hasText);
+		} else {
+			imageViewHolder.bind(item);
+		}
+	}
+
+	@Override
+	public int getItemCount() {
+		return items.size();
+	}
+
+	void setConversationItem(ConversationMessageItem item) {
+		this.conversationItem = item;
+		this.items.clear();
+		this.items.addAll(item.getAttachments());
+		notifyDataSetChanged();
+	}
+
+	void clear() {
+		items.clear();
+		notifyDataSetChanged();
+	}
+
+}

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

@@ -0,0 +1,54 @@
+package org.briarproject.briar.android.conversation;
+
+import android.graphics.Bitmap;
+import android.support.annotation.DrawableRes;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.view.View;
+import android.widget.ImageView;
+
+import com.bumptech.glide.load.Transformation;
+import com.bumptech.glide.load.resource.bitmap.CenterCrop;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.conversation.glide.GlideApp;
+
+import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
+import static com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions.withCrossFade;
+
+@NotNullByDefault
+class ImageViewHolder extends ViewHolder {
+
+	@DrawableRes
+	private static final int ERROR_RES = R.drawable.ic_image_broken;
+
+	protected final ImageView imageView;
+	protected Transformation<Bitmap> transformation = new CenterCrop();
+
+	public ImageViewHolder(View v) {
+		super(v);
+		imageView = v.findViewById(R.id.imageView);
+	}
+
+	void bind(AttachmentItem attachment) {
+		if (attachment.hasError()) {
+			GlideApp.with(imageView)
+					.clear(imageView);
+			imageView.setImageResource(ERROR_RES);
+		} else {
+			loadImage(attachment);
+		}
+	}
+
+	private void loadImage(AttachmentItem a) {
+		GlideApp.with(imageView)
+				.load(a)
+				.diskCacheStrategy(NONE)
+				.error(ERROR_RES)
+				.transform(transformation)
+				.transition(withCrossFade())
+				.into(imageView)
+				.waitForLayout();
+	}
+
+}

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

@@ -0,0 +1,53 @@
+package org.briarproject.briar.android.conversation;
+
+import android.content.res.Configuration;
+import android.view.View;
+import android.view.ViewGroup.LayoutParams;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.conversation.glide.BriarImageTransformation;
+
+import static android.os.Build.VERSION.SDK_INT;
+import static android.support.v4.view.ViewCompat.LAYOUT_DIRECTION_RTL;
+
+@NotNullByDefault
+class SingleImageViewHolder extends ImageViewHolder {
+
+	private final int radiusBig, radiusSmall;
+	private final boolean isRtl;
+
+	public SingleImageViewHolder(View v) {
+		super(v);
+		radiusBig = v.getContext().getResources()
+				.getDimensionPixelSize(R.dimen.message_bubble_radius_big);
+		radiusSmall = v.getContext().getResources()
+				.getDimensionPixelSize(R.dimen.message_bubble_radius_small);
+
+		// find out if we are showing a RTL language, Use the configuration,
+		// because getting the layout direction of views is not reliable
+		Configuration config = v.getContext().getResources().getConfiguration();
+		isRtl = SDK_INT >= 17 &&
+				config.getLayoutDirection() == LAYOUT_DIRECTION_RTL;
+	}
+
+	void bind(AttachmentItem a, boolean isIncoming, boolean hasText) {
+		if (!a.hasError()) beforeLoadingImage(a, isIncoming, hasText);
+		super.bind(a);
+	}
+
+	private void beforeLoadingImage(AttachmentItem a, boolean isIncoming,
+			boolean hasText) {
+		// apply image size constraints, so glides picks them up for scaling
+		LayoutParams layoutParams =
+				new LayoutParams(a.getThumbnailWidth(), a.getThumbnailHeight());
+		imageView.setLayoutParams(layoutParams);
+
+		boolean leftCornerSmall =
+				(isIncoming && !isRtl) || (!isIncoming && isRtl);
+		boolean bottomRound = !hasText;
+		transformation = new BriarImageTransformation(radiusSmall, radiusBig,
+				leftCornerSmall, bottomRound);
+	}
+
+}

briar-android/src/main/res/layout/list_item_conversation_msg_image.xml

@@ -15,7 +15,7 @@
 	android:background="@drawable/msg_in"
 	android:elevation="@dimen/message_bubble_elevation">
 
-	<ImageView
+	<android.support.v7.widget.RecyclerView
 		android:id="@+id/imageView"
 		android:layout_width="@dimen/message_bubble_image_default"
 		android:layout_height="@dimen/message_bubble_image_default"
@@ -23,6 +23,7 @@
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
 		tools:ignore="ContentDescription"
+		tools:listitem="@layout/list_item_image"
 		tools:src="@drawable/alerts_and_states_error"/>
 
 	<com.vanniktech.emoji.EmojiTextView

briar-android/src/main/res/layout/list_item_conversation_msg_image_text.xml

@@ -15,7 +15,7 @@
 	android:background="@drawable/msg_in"
 	android:elevation="@dimen/message_bubble_elevation">
 
-	<ImageView
+	<android.support.v7.widget.RecyclerView
 		android:id="@+id/imageView"
 		android:layout_width="@dimen/message_bubble_image_default"
 		android:layout_height="@dimen/message_bubble_image_default"
@@ -23,6 +23,7 @@
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
 		tools:ignore="ContentDescription"
+		tools:listitem="@layout/list_item_image"
 		tools:src="@drawable/alerts_and_states_error"/>
 
 	<com.vanniktech.emoji.EmojiTextView

briar-android/src/main/res/layout/list_item_conversation_msg_in.xml

@@ -15,7 +15,7 @@
 	android:background="@drawable/msg_in"
 	android:elevation="@dimen/message_bubble_elevation">
 
-	<ImageView
+	<android.support.v7.widget.RecyclerView
 		android:id="@+id/imageView"
 		android:layout_width="@dimen/message_bubble_image_default"
 		android:layout_height="@dimen/message_bubble_image_default"
@@ -23,7 +23,8 @@
 		app:layout_constraintBottom_toTopOf="@+id/text"
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
-		tools:ignore="ContentDescription"/>
+		tools:ignore="ContentDescription"
+		tools:listitem="@layout/list_item_image"/>
 
 	<com.vanniktech.emoji.EmojiTextView
 		android:id="@+id/text"

briar-android/src/main/res/layout/list_item_conversation_msg_out.xml

@@ -21,7 +21,7 @@
 		android:background="@drawable/msg_out"
 		android:elevation="@dimen/message_bubble_elevation">
 
-		<ImageView
+		<android.support.v7.widget.RecyclerView
 			android:id="@+id/imageView"
 			android:layout_width="@dimen/message_bubble_image_default"
 			android:layout_height="@dimen/message_bubble_image_default"

briar-android/src/main/res/layout/list_item_image.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ImageView
+	android:id="@+id/imageView"
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:tools="http://schemas.android.com/tools"
+	android:layout_width="@dimen/message_bubble_image_default"
+	android:layout_height="@dimen/message_bubble_image_default"
+	tools:ignore="ContentDescription"
+	tools:src="@drawable/alerts_and_states_error"/>