Extend BlogActivity to also show individual posts

This allows for swiping left/right to read other posts by using
a ViewPager.

This hasn't been done as a separate activity, but with
fragments, so both can share the `BlogPersistentData` without
needing to reload it.

Closes #428

briar-android/src/org/briarproject/android/blogs/BlogPostFragment.java

@@ -0,0 +1,157 @@
+package org.briarproject.android.blogs;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.text.format.DateUtils;
+import android.view.LayoutInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import org.briarproject.R;
+import org.briarproject.android.ActivityComponent;
+import org.briarproject.android.controller.handler.UiResultHandler;
+import org.briarproject.android.fragment.BaseFragment;
+import org.briarproject.android.util.TrustIndicatorView;
+import org.briarproject.api.identity.Author;
+import org.briarproject.api.sync.GroupId;
+import org.briarproject.api.sync.MessageId;
+import org.briarproject.util.StringUtils;
+
+import javax.inject.Inject;
+
+import im.delight.android.identicons.IdenticonDrawable;
+
+import static android.view.View.GONE;
+import static android.widget.Toast.LENGTH_SHORT;
+import static org.briarproject.android.BriarActivity.GROUP_ID;
+
+public class BlogPostFragment extends BaseFragment {
+
+	public final static String TAG = BlogPostFragment.class.getName();
+
+	private final static String BLOG_POST_ID = "briar.BLOG_NAME";
+
+	private GroupId groupId;
+	private MessageId postId;
+	private BlogPostViewHolder ui;
+
+	@Inject
+	BlogController blogController;
+
+	static BlogPostFragment newInstance(GroupId groupId, MessageId postId) {
+		BlogPostFragment f = new BlogPostFragment();
+
+		Bundle bundle = new Bundle();
+		bundle.putByteArray(GROUP_ID, groupId.getBytes());
+		bundle.putByteArray(BLOG_POST_ID, postId.getBytes());
+
+		f.setArguments(bundle);
+		return f;
+	}
+
+	@Nullable
+	@Override
+	public View onCreateView(LayoutInflater inflater, ViewGroup container,
+			Bundle savedInstanceState) {
+
+		setHasOptionsMenu(true);
+
+		byte[] b = getArguments().getByteArray(GROUP_ID);
+		if (b == null) throw new IllegalStateException("No Group found.");
+		groupId = new GroupId(b);
+		byte[] p = getArguments().getByteArray(BLOG_POST_ID);
+		if (p == null) throw new IllegalStateException("No MessageId found.");
+		postId = new MessageId(p);
+
+		View v = inflater.inflate(R.layout.fragment_blog_post, container,
+				false);
+		ui = new BlogPostViewHolder(v);
+		return v;
+	}
+
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	@Override
+	public void onStart() {
+		super.onStart();
+		blogController.loadBlog(groupId, false,
+				new UiResultHandler<Boolean>((Activity) listener) {
+					@Override
+					public void onResultUi(Boolean result) {
+						listener.hideLoadingScreen();
+						if (result) {
+							BlogPostItem post =
+									blogController.getBlogPost(postId);
+							if (post != null) {
+								bind(post);
+							}
+						} else {
+							Toast.makeText(getActivity(),
+									R.string.blogs_blog_post_failed_to_load,
+									LENGTH_SHORT).show();
+						}
+					}
+				});
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(final MenuItem item) {
+		switch (item.getItemId()) {
+			case android.R.id.home:
+				getActivity().onBackPressed();
+				return true;
+			default:
+				return super.onOptionsItemSelected(item);
+		}
+	}
+
+	@Override
+	public String getUniqueTag() {
+		return TAG;
+	}
+
+	private void bind(BlogPostItem post) {
+		Author author = post.getAuthor();
+		IdenticonDrawable d = new IdenticonDrawable(author.getId().getBytes());
+		ui.avatar.setImageDrawable(d);
+		ui.authorName.setText(author.getName());
+		ui.trust.setTrustLevel(post.getAuthorStatus());
+		ui.date.setText(
+				DateUtils.getRelativeTimeSpanString(post.getTimestamp()));
+
+		if (post.getTitle() != null) {
+			ui.title.setText(post.getTitle());
+		} else {
+			ui.title.setVisibility(GONE);
+		}
+
+		ui.body.setText(StringUtils.fromUtf8(post.getBody()));
+	}
+
+	private static class BlogPostViewHolder {
+		private ImageView avatar;
+		private TextView authorName;
+		private TrustIndicatorView trust;
+		private TextView date;
+		private TextView title;
+		private TextView body;
+
+		BlogPostViewHolder(View v) {
+			avatar = (ImageView) v.findViewById(R.id.avatar);
+			authorName = (TextView) v.findViewById(R.id.authorName);
+			trust = (TrustIndicatorView) v.findViewById(R.id.trustIndicator);
+			date = (TextView) v.findViewById(R.id.date);
+			title = (TextView) v.findViewById(R.id.title);
+			body = (TextView) v.findViewById(R.id.body);
+		}
+	}
+
+}