[android] allow to attach multiple images

briar-android/src/main/java/org/briarproject/briar/android/view/ImagePreview.java

 package org.briarproject.briar.android.view;
 
 import android.content.Context;
-import android.graphics.Bitmap;
 import android.net.Uri;
 import android.support.annotation.Nullable;
 import android.support.constraint.ConstraintLayout;
-import android.support.v7.graphics.Palette;
+import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
-import android.widget.ImageView;
-import android.widget.Toast;
-
-import com.bumptech.glide.load.DataSource;
-import com.bumptech.glide.load.engine.GlideException;
-import com.bumptech.glide.request.RequestListener;
-import com.bumptech.glide.request.target.Target;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.conversation.glide.GlideApp;
 
 import java.util.List;
 
 import static android.content.Context.LAYOUT_INFLATER_SERVICE;
-import static android.graphics.Color.BLACK;
-import static android.graphics.Color.WHITE;
-import static android.support.v7.app.AppCompatDelegate.MODE_NIGHT_YES;
-import static android.support.v7.app.AppCompatDelegate.getDefaultNightMode;
-import static android.widget.Toast.LENGTH_LONG;
-import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
-import static com.bumptech.glide.load.resource.bitmap.DownsampleStrategy.FIT_CENTER;
+import static android.support.v4.content.ContextCompat.getColor;
+import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 import static java.util.Objects.requireNonNull;
 
 @NotNullByDefault
 public class ImagePreview extends ConstraintLayout {
 
-	private final ImageView imageView;
-	private final int backgroundColor =
-			getDefaultNightMode() == MODE_NIGHT_YES ? BLACK : WHITE;
+	private final RecyclerView imageList;
 
 	@Nullable
 	private ImagePreviewListener listener;
@@ -59,9 +43,11 @@ public class ImagePreview extends ConstraintLayout {
 				context.getSystemService(LAYOUT_INFLATER_SERVICE));
 		inflater.inflate(R.layout.image_preview, this, true);
 
-		// find image view and set background color
-		imageView = findViewById(R.id.imageView);
-		imageView.setBackgroundColor(backgroundColor);
+		// set background color
+		setBackgroundColor(getColor(context, R.color.card_background));
+
+		// find list
+		imageList = findViewById(R.id.imageList);
 
 		// set cancel listener
 		findViewById(R.id.imageCancelButton).setOnClickListener(view -> {
@@ -74,42 +60,14 @@ public class ImagePreview extends ConstraintLayout {
 	}
 
 	void showPreview(List<Uri> imageUris) {
+		if (listener == null) throw new IllegalStateException();
+		if (imageUris.size() == 1) {
+			LayoutParams params = (LayoutParams) imageList.getLayoutParams();
+			params.width = MATCH_PARENT;
+			imageList.setLayoutParams(params);
+		}
 		setVisibility(VISIBLE);
-		GlideApp.with(imageView)
-				.asBitmap()
-				.load(imageUris.get(0))  // TODO show more than the first
-				.diskCacheStrategy(NONE)
-				.downsample(FIT_CENTER)
-				.addListener(new RequestListener<Bitmap>() {
-					@Override
-					public boolean onLoadFailed(@Nullable GlideException e,
-							Object model, Target<Bitmap> target,
-							boolean isFirstResource) {
-						if (listener != null) listener.onCancel();
-						Toast.makeText(imageView.getContext(),
-								R.string.image_attach_error, LENGTH_LONG)
-								.show();
-						return false;
-					}
-
-					@Override
-					public boolean onResourceReady(Bitmap resource,
-							Object model, Target<Bitmap> target,
-							DataSource dataSource, boolean isFirstResource) {
-						Palette.from(resource).generate(
-								ImagePreview.this::onPaletteGenerated);
-						return false;
-					}
-				})
-				.into(imageView);
-	}
-
-	void onPaletteGenerated(@Nullable Palette palette) {
-		if (palette == null) return;
-		int color = getDefaultNightMode() == MODE_NIGHT_YES ?
-				palette.getDarkMutedColor(backgroundColor) :
-				palette.getLightMutedColor(backgroundColor);
-		imageView.setBackgroundColor(color);
+		imageList.setAdapter(new ImagePreviewAdapter(imageUris, listener));
 	}
 
 	interface ImagePreviewListener {

briar-android/src/main/java/org/briarproject/briar/android/view/ImagePreviewAdapter.java

+package org.briarproject.briar.android.view;
+
+import android.net.Uri;
+import android.support.annotation.LayoutRes;
+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 org.briarproject.briar.android.view.ImagePreview.ImagePreviewListener;
+
+import java.util.List;
+
+import static java.util.Objects.requireNonNull;
+
+@NotNullByDefault
+class ImagePreviewAdapter extends Adapter<ImagePreviewViewHolder> {
+
+	private final List<Uri> items;
+	private final ImagePreviewListener listener;
+	@LayoutRes
+	private final int layout;
+
+	public ImagePreviewAdapter(List<Uri> items, ImagePreviewListener listener) {
+		this.items = items;
+		this.listener = listener;
+		this.layout = items.size() == 1 ?
+				R.layout.list_item_image_preview_single :
+				R.layout.list_item_image_preview;
+	}
+
+	@Override
+	public ImagePreviewViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
+		View v = LayoutInflater.from(viewGroup.getContext())
+				.inflate(layout, viewGroup, false);
+		return new ImagePreviewViewHolder(v, items.size() == 1,
+				requireNonNull(listener));
+	}
+
+	@Override
+	public void onBindViewHolder(ImagePreviewViewHolder viewHolder, int position) {
+		viewHolder.bind(items.get(position));
+	}
+
+	@Override
+	public int getItemCount() {
+		return items.size();
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/view/ImagePreviewViewHolder.java

+package org.briarproject.briar.android.view;
+
+import android.graphics.drawable.Drawable;
+import android.net.Uri;
+import android.support.annotation.DrawableRes;
+import android.support.annotation.Nullable;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.view.View;
+import android.widget.ImageView;
+import android.widget.ProgressBar;
+import android.widget.Toast;
+
+import com.bumptech.glide.load.DataSource;
+import com.bumptech.glide.load.engine.GlideException;
+import com.bumptech.glide.request.RequestListener;
+import com.bumptech.glide.request.target.Target;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.conversation.glide.GlideApp;
+import org.briarproject.briar.android.view.ImagePreview.ImagePreviewListener;
+
+import static android.view.View.INVISIBLE;
+import static android.widget.Toast.LENGTH_LONG;
+import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
+import static com.bumptech.glide.load.resource.bitmap.DownsampleStrategy.FIT_CENTER;
+import static com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions.withCrossFade;
+
+@NotNullByDefault
+class ImagePreviewViewHolder extends ViewHolder {
+
+	@DrawableRes
+	private static final int ERROR_RES = R.drawable.ic_image_broken;
+
+	private final boolean single;
+	private final ImagePreviewListener listener;
+
+	private final ImageView imageView;
+	private final ProgressBar progressBar;
+
+	ImagePreviewViewHolder(View v, boolean single,
+			ImagePreviewListener listener) {
+		super(v);
+		this.single = single;
+		this.listener = listener;
+		this.imageView = v.findViewById(R.id.imageView);
+		this.progressBar = v.findViewById(R.id.progressBar);
+	}
+
+	void bind(Uri uri) {
+		GlideApp.with(imageView)
+				.load(uri)
+				.diskCacheStrategy(NONE)
+				.error(ERROR_RES)
+				.downsample(FIT_CENTER)
+				.transition(withCrossFade())
+				.addListener(new RequestListener<Drawable>() {
+					@Override
+					public boolean onLoadFailed(@Nullable GlideException e,
+							Object model, Target<Drawable> target,
+							boolean isFirstResource) {
+						if (single) listener.onCancel();
+						progressBar.setVisibility(INVISIBLE);
+						Toast.makeText(imageView.getContext(),
+								R.string.image_attach_error, LENGTH_LONG)
+								.show();
+						return false;
+					}
+
+					@Override
+					public boolean onResourceReady(Drawable resource,
+							Object model, Target<Drawable> target,
+							DataSource dataSource, boolean isFirstResource) {
+						progressBar.setVisibility(INVISIBLE);
+						return false;
+					}
+				})
+				.into(imageView);
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/view/TextAttachmentController.java

@@ -81,8 +81,7 @@ public class TextAttachmentController extends TextSendController
 				ACTION_OPEN_DOCUMENT : ACTION_GET_CONTENT);
 		intent.addCategory(CATEGORY_OPENABLE);
 		intent.setType("image/*");
-		if (SDK_INT >= 18)  // TODO set true to allow attaching multiple images
-			intent.putExtra(EXTRA_ALLOW_MULTIPLE, false);
+		if (SDK_INT >= 18) intent.putExtra(EXTRA_ALLOW_MULTIPLE, true);
 		requireNonNull(imageListener).onAttachImage(intent);
 	}
 

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

@@ -13,21 +13,23 @@
 		android:id="@+id/divider"
 		style="@style/Divider.Horizontal"
 		android:layout_alignParentTop="true"
-		app:layout_constraintBottom_toTopOf="@+id/imageView"
+		app:layout_constraintBottom_toTopOf="@+id/imageList"
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toTopOf="parent"/>
 
-	<ImageView
-		android:id="@+id/imageView"
-		android:layout_width="match_parent"
+	<android.support.v7.widget.RecyclerView
+		android:id="@+id/imageList"
+		android:layout_width="wrap_content"
 		android:layout_height="match_parent"
+		android:orientation="horizontal"
+		app:layoutManager="android.support.v7.widget.LinearLayoutManager"
 		app:layout_constraintBottom_toBottomOf="parent"
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintStart_toStartOf="parent"
 		app:layout_constraintTop_toBottomOf="@+id/divider"
 		tools:ignore="ContentDescription"
-		tools:srcCompat="@tools:sample/avatars"/>
+		tools:listitem="@layout/list_item_image"/>
 
 	<android.support.design.widget.FloatingActionButton
 		android:id="@+id/imageCancelButton"

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

+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto"
+	xmlns:tools="http://schemas.android.com/tools"
+	android:layout_width="wrap_content"
+	android:layout_height="match_parent"
+	tools:layout_height="200dp">
+
+	<ProgressBar
+		android:id="@+id/progressBar"
+		style="?android:attr/progressBarStyleLarge"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_margin="16dp"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent"/>
+
+	<ImageView
+		android:id="@+id/imageView"
+		android:layout_width="0dp"
+		android:layout_height="match_parent"
+		android:scaleType="centerCrop"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintDimensionRatio="1:1"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent"
+		tools:ignore="ContentDescription"
+		tools:srcCompat="@tools:sample/avatars"
+		tools:visibility="visible"/>
+
+</android.support.constraint.ConstraintLayout>

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

+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto"
+	xmlns:tools="http://schemas.android.com/tools"
+	android:layout_width="match_parent"
+	android:layout_height="match_parent"
+	tools:layout_height="200dp">
+
+	<ProgressBar
+		android:id="@+id/progressBar"
+		style="?android:attr/progressBarStyleLarge"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_margin="16dp"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent"/>
+
+	<ImageView
+		android:id="@+id/imageView"
+		android:layout_width="0dp"
+		android:layout_height="0dp"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent"
+		tools:ignore="ContentDescription"
+		tools:srcCompat="@tools:sample/backgrounds/scenic"
+		tools:visibility="visible"/>
+
+</android.support.constraint.ConstraintLayout>