Add a BlogActivity that shows a list of blog posts

This commit lays the groundwork for #415

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

@@ -0,0 +1,174 @@
+package org.briarproject.android.blogs;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.support.design.widget.Snackbar;
+import android.support.v7.widget.LinearLayoutManager;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+
+import org.briarproject.R;
+import org.briarproject.android.ActivityComponent;
+import org.briarproject.android.BriarActivity;
+import org.briarproject.android.util.BriarRecyclerView;
+import org.briarproject.api.blogs.BlogManager;
+import org.briarproject.api.blogs.BlogPostHeader;
+import org.briarproject.api.db.DbException;
+import org.briarproject.api.db.NoSuchGroupException;
+import org.briarproject.api.sync.GroupId;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import static android.support.design.widget.Snackbar.LENGTH_LONG;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+
+public class BlogActivity extends BriarActivity {
+
+	static final String BLOG_NAME = "briar.BLOG_NAME";
+	static final String IS_MY_BLOG = "briar.IS_MY_BLOG";
+	static final String IS_NEW_BLOG = "briar.IS_NEW_BLOG";
+	private static final int WRITE_POST = 1;
+
+	private static final Logger LOG =
+			Logger.getLogger(BlogActivity.class.getName());
+
+	private BlogPostAdapter adapter;
+	private BriarRecyclerView list;
+	private String blogName;
+	private boolean myBlog;
+
+	// Fields that are accessed from background threads must be volatile
+	private volatile GroupId groupId = null;
+	private volatile boolean scrollToTop = false;
+	@Inject
+	volatile BlogManager blogManager;
+
+	@Override
+	public void onCreate(Bundle state) {
+		super.onCreate(state);
+
+		setContentView(R.layout.activity_blog);
+
+		Intent i = getIntent();
+		byte[] b = i.getByteArrayExtra(GROUP_ID);
+		if (b == null) throw new IllegalStateException("No Group in intent.");
+		groupId = new GroupId(b);
+		blogName = i.getStringExtra(BLOG_NAME);
+		if (blogName != null) setTitle(blogName);
+		myBlog = i.getBooleanExtra(IS_MY_BLOG, false);
+
+		adapter = new BlogPostAdapter(this, blogName);
+		list = (BriarRecyclerView) this.findViewById(R.id.postList);
+		list.setLayoutManager(new LinearLayoutManager(this));
+		list.setAdapter(adapter);
+		if (myBlog) {
+			list.setEmptyText(
+					getString(R.string.blogs_my_blogs_blog_empty_state));
+		} else {
+			list.setEmptyText(getString(R.string.blogs_other_blog_empty_state));
+		}
+
+		// show snackbar if this blog was just created
+		boolean isNew = i.getBooleanExtra(IS_NEW_BLOG, false);
+		if (isNew) {
+			Snackbar s = Snackbar.make(list, R.string.blogs_my_blogs_created,
+					LENGTH_LONG);
+			s.getView().setBackgroundResource(R.color.briar_primary);
+			s.show();
+		}
+	}
+
+	@Override
+	public void onResume() {
+		super.onResume();
+		loadBlogPosts();
+	}
+
+	@Override
+	public boolean onCreateOptionsMenu(Menu menu) {
+		if (myBlog) {
+			MenuInflater inflater = getMenuInflater();
+			inflater.inflate(R.menu.blogs_my_blog_actions, menu);
+		}
+		return super.onCreateOptionsMenu(menu);
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(final MenuItem item) {
+		switch (item.getItemId()) {
+			case R.id.action_write_blog_post:
+/*				Intent i = new Intent(this, WriteBlogPostActivity.class);
+				i.putExtra(GROUP_ID, groupId.getBytes());
+				i.putExtra(BLOG_NAME, blogName);
+				startActivityForResult(i, WRITE_POST);
+*/				return true;
+			default:
+				return super.onOptionsItemSelected(item);
+		}
+	}
+
+	@Override
+	public void onActivityResult(int requestCode, int resultCode, Intent data) {
+		if (requestCode == WRITE_POST && resultCode == RESULT_OK) {
+			scrollToTop = true;
+		}
+	}
+
+	@Override
+	public void injectActivity(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	private void loadBlogPosts() {
+		runOnDbThread(new Runnable() {
+			@Override
+			public void run() {
+				try {
+					// load blog posts
+					long now = System.currentTimeMillis();
+					Collection<BlogPostItem> posts = new ArrayList<>();
+					try {
+						Collection<BlogPostHeader> header =
+								blogManager.getPostHeaders(groupId);
+						for (BlogPostHeader h : header) {
+							posts.add(new BlogPostItem(h));
+						}
+					} catch (NoSuchGroupException e) {
+						// Continue
+					}
+					displayBlogPosts(posts);
+					long duration = System.currentTimeMillis() - now;
+					if (LOG.isLoggable(INFO))
+						LOG.info("Post header load took " + duration + " ms");
+				} catch (DbException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+				}
+			}
+		});
+	}
+
+	private void displayBlogPosts(final Collection<BlogPostItem> items) {
+		runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				if (items.size() == 0) {
+					list.showData();
+				} else {
+					adapter.addAll(items);
+					if (scrollToTop) list.scrollToPosition(0);
+				}
+				scrollToTop = false;
+			}
+		});
+	}
+
+	// TODO listen to events and add new blog posts as they come in
+
+}