[android] Add gap between attached image previews

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

@@ -10,12 +10,12 @@ import android.view.View;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.util.UiUtils;
 
 import static org.briarproject.briar.android.conversation.ImageAdapter.isBottomRow;
 import static org.briarproject.briar.android.conversation.ImageAdapter.isLeft;
 import static org.briarproject.briar.android.conversation.ImageAdapter.isTopRow;
 import static org.briarproject.briar.android.conversation.ImageAdapter.singleInRow;
+import static org.briarproject.briar.android.util.UiUtils.isRtl;
 
 @NotNullByDefault
 class ImageItemDecoration extends ItemDecoration {
@@ -35,7 +35,7 @@ class ImageItemDecoration extends ItemDecoration {
 		border = realBorderSize / 2;
 
 		// find out if we are showing a RTL language
-		isRtl = UiUtils.isRtl(ctx);
+		isRtl = isRtl(ctx);
 	}
 
 	@Override

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

@@ -48,6 +48,7 @@ public class ImagePreview extends ConstraintLayout {
 
 		// find list
 		imageList = findViewById(R.id.imageList);
+		imageList.addItemDecoration(new ImagePreviewDecoration(context));
 
 		// set cancel listener
 		findViewById(R.id.imageCancelButton).setOnClickListener(view -> {

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

+package org.briarproject.briar.android.view;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Rect;
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.RecyclerView.ItemDecoration;
+import android.support.v7.widget.RecyclerView.State;
+import android.view.View;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.R;
+
+@NotNullByDefault
+class ImagePreviewDecoration extends ItemDecoration {
+
+	private final int border;
+
+	ImagePreviewDecoration(Context ctx) {
+		Resources res = ctx.getResources();
+		border = res.getDimensionPixelSize(R.dimen.message_bubble_border);
+	}
+
+	@Override
+	public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
+			State state) {
+		if (state.getItemCount() == parent.getChildAdapterPosition(view) + 1) {
+			// no decoration for last item in the list
+			return;
+		}
+		outRect.right = border;
+	}
+
+}