Android Open Source - android-rss Post View

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License

The source code is released under:
GNU General Public License
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Java Source Code

/*
 * $Id: PostView.java 112 2008-02-14 00:34:50Z jasta00 $
 *//from   w  w w.j a va2  s.c  om
 * Copyright (C) 2007 Josh Guilfoyle <jasta@devtcg.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

package org.devtcg.rssreader.activity;

import org.devtcg.rssreader.R;
import org.devtcg.rssreader.provider.RSSReader;
import org.devtcg.rssreader.util.KeyUtils;
import org.devtcg.rssreader.view.ChannelHead;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.webkit.WebView;
import android.widget.TextView;

public class PostView extends Activity
{
  private static final String TAG = "PostView";
  
  private final static int NEXT_POST_ID = Menu.FIRST;
  private final static int PREV_POST_ID = Menu.FIRST + 1;
  
  private static final String[] PROJECTION = new String[] {
    RSSReader.Posts._ID, RSSReader.Posts.CHANNEL_ID,
    RSSReader.Posts.TITLE, RSSReader.Posts.BODY, RSSReader.Posts.READ,
    RSSReader.Posts.URL };
  
  private long mChannelID = -1;
  private long mPostID = -1;
  
  private Cursor mCursor;
  
  private long mPrevPostID = -1;
  private long mNextPostID = -1;
  
  @Override
  protected void onCreate(Bundle icicle)
  {
    super.onCreate(icicle);    
    setContentView(R.layout.post_view);

//    RSSChannelHead head = (RSSChannelHead)findViewById(R.id.postViewHead);
//    PostScrollView scroll = (PostScrollView)findViewById(R.id.postViewScroll);
//    scroll.setChannelHead(head);
    
    Uri uri = getIntent().getData();

    mCursor = managedQuery(uri, PROJECTION, null, null, null);

    if (mCursor == null || mCursor.first() == false)
      finish();

    mChannelID = mCursor.getLong(mCursor.getColumnIndex(RSSReader.Posts.CHANNEL_ID));
    mPostID = Long.parseLong(uri.getPathSegments().get(1));

    /* TODO: Should this be in onStart() or onResume() or something?  */
    initWithData();
  }

  @Override
  protected void onStart()
  {
    super.onStart();

    if (mCursor == null || mCursor.first() == false)
      return;

    /* Set the post to read. */
    mCursor.updateInt(mCursor.getColumnIndex(RSSReader.Posts.READ), 1);
    mCursor.commitUpdates();
  }

  private void initWithData()
  {  
    ContentResolver cr = getContentResolver();

    Cursor cChannel = cr.query(ContentUris.withAppendedId(RSSReader.Channels.CONTENT_URI, mChannelID),
      new String[] { RSSReader.Channels.ICON, RSSReader.Channels.LOGO, RSSReader.Channels.TITLE }, null, null, null);

    assert(cChannel.count() == 1);
    cChannel.first();

    /* Make the view useful. */
    ChannelHead head = (ChannelHead)findViewById(R.id.postViewHead);
    head.setLogo(cChannel);
//    head.setPost(mCursor);

    cChannel.close();

    TextView postTitle = (TextView)findViewById(R.id.postTitle);
    postTitle.setText(mCursor, mCursor.getColumnIndex(RSSReader.Posts.TITLE));

    WebView postText = (WebView)findViewById(R.id.postText);

    /* TODO: I want the background transparent, but that doesn't seem 
     * possible.  Black will do for now. */
    String html =
      "<html><head><style type=\"text/css\">body { background-color: #201c19; color: white; } a { color: #ddf; }</style></head><body>" +
      getBody() +
      "</body></html>";

    postText.loadData(html, "text/html", "utf-8");
  }
  
  /* Apply some simple heuristics to the post text to determine what special
   * features we want to show. */
  private String getBody()
  {
    String body =
      mCursor.getString(mCursor.getColumnIndex(RSSReader.Posts.BODY));
    
    String url =
      mCursor.getString(mCursor.getColumnIndex(RSSReader.Posts.URL));
  
    if (hasMoreLink(body, url) == false)
      body += "<p><a href=\"" + url + "\">Read more...</a></p>";
    
    /* TODO: We should add a check for "posted by", "written by",
     * "posted on", etc, and optionally add our own tagline if
     * the information is in the feed. */
    return body;
  }
  
  private boolean hasMoreLink(String body, String url)
  {
    int urlpos;

    /* Check if the body contains an anchor reference with the
     * destination of the read more URL we got from the feed. */
    if ((urlpos = body.indexOf(url)) <= 0)
      return false;
    
    try
    {
      /* TODO: Improve this check with a full look-behind parse. */
      if (body.charAt(urlpos - 1) != '>')
        return false;

      if (body.charAt(urlpos + url.length() + 1) != '<')
        return false;
    }
    catch (IndexOutOfBoundsException e)
    {
      return false;
    }
      
    return true;
  }
  
  private void getSiblings()
  {
    if (mNextPostID < 0 || mPrevPostID < 0)
    {
        Cursor cPostList = getContentResolver().query
         (ContentUris.withAppendedId(RSSReader.Posts.CONTENT_URI_LIST, mChannelID),
          new String[] { RSSReader.Posts._ID }, null, null, null);

        /* TODO: This is super lame; we need to use SQLite queries to
         * determine posts either newer or older than the current one
         * without. */
        cPostList.first();
        
        int indexId = cPostList.getColumnIndex(RSSReader.Posts._ID);
        
        long lastId = -1;
        
        for (cPostList.first(); cPostList.isLast() == false; cPostList.next())
        {
          long thisId = cPostList.getLong(indexId);
          
          if (thisId == mPostID)
            break;
          
          lastId = thisId;
        }

        /* Remember, the order is descending by date. */
        if (mNextPostID < 0)
          mNextPostID = lastId;

        if (mPrevPostID < 0)
        {
          if (cPostList.isLast() == false)
          {
            cPostList.next();
            mPrevPostID = cPostList.getLong(indexId);
          }
        }
    }    
  }

  @Override
  public boolean onPrepareOptionsMenu(Menu menu)
  {
    menu.removeGroup(0);
    
    getSiblings();

    if (mNextPostID >= 0)
    {
      menu.add(0, NEXT_POST_ID, "Newer Post").
              setShortcut('1', '[');
    }
      
    if (mPrevPostID >= 0)
    {
      menu.add(0, PREV_POST_ID, "Older Post").
        setShortcut('3', ']');
      
      menu.setDefaultItem(PREV_POST_ID);
    }
    
    return true;
  }
  
  private void moveTo(long id)
  {
    Intent intent = new Intent(Intent.VIEW_ACTION,
      ContentUris.withAppendedId(RSSReader.Posts.CONTENT_URI, id));
    
    startActivity(intent);
    
    /* Assume that user would do not want to keep the [now read]
     * current post in the history stack. */
    finish();
  }
  
  private boolean prevPost()
  {
    if (mPrevPostID < 0)
      return false;
    
    moveTo(mPrevPostID);
    return true;
  }
  
  private boolean nextPost()
  {
    if (mNextPostID < 0)
      return false;
    
    moveTo(mNextPostID);
    return true;
  }

    @Override
    public boolean onOptionsItemSelected(Menu.Item item)
    {
      switch (item.getId())
      {
      case PREV_POST_ID:
        return prevPost();
        
      case NEXT_POST_ID:
        return nextPost();
      }
      
      return super.onOptionsItemSelected(item);
    }
    
    @Override
  public boolean onKeyUp(int keyCode, KeyEvent event)
    {
      /*
       * If the user actually presses left or right, let's pass that key
       * press on to the WebView in case scrolling is necessary.  All 
       * other direction keypresses (keypad, bracket, etc) as defined
       * by KeyUtils.interpretDirection() will still be honored.
       */
      if (keyCode != KeyEvent.KEYCODE_DPAD_LEFT &&
          keyCode != KeyEvent.KEYCODE_DPAD_RIGHT)
      {
        switch (KeyUtils.interpretDirection(keyCode))
        {
        case KeyEvent.KEYCODE_DPAD_LEFT:
          getSiblings();
          return nextPost();

        case KeyEvent.KEYCODE_DPAD_RIGHT:
          getSiblings();
          return prevPost();
        }
      }
      
      return false;
    }

//    /* 
//     * Special ScrollView class that is used to determine if the post title
//     * is currently visible.  If not, it will change it to show the
//     * RSSChannelHead to show the title with a flashy animation to show
//     * off Android goodness.
//     */
//    public static class PostScrollView extends ScrollView
//    {
//      private int mTitleTop = 0;
//      private ChannelHead mHead;
//      
//      public PostScrollView(Context context)
//      {
//        super(context);
//      }
//
//      public PostScrollView(Context context, AttributeSet attrs, Map inflateParams)
//      {
//        super(context, attrs, inflateParams);
//      }
//
//      public PostScrollView(Context context, AttributeSet attrs, Map inflateParams, int defStyle)
//      {
//        super(context, attrs, inflateParams, defStyle);
//      }
//      
//      public void setChannelHead(ChannelHead head)
//      {
//        mHead = head;
//      }
//      
//      @Override
//        /* TODO: Overriding computeScroll() does not seem to be an efficient
//         * way to tackle this problem.  Any suggestions for improvement? */ 
//      public void computeScroll()
//      {
//        super.computeScroll();
//
//        if (mTitleTop < 0)
//        {
//          TextView title = (TextView)findViewById(R.id.postTitle);
//
//          if (title != null)
//          {
//            mTitleTop = title.getLineHeight() / 2;
//            assert(mTitleTop > 0);
//          }
//        }
//        else
//        {
//          if (mScrollY > mTitleTop)
//          {
//            if (mHead.isPostTitleVisible() == false)
//              mHead.showPostTitle();
//          }
//          else
//          {
//            if (mHead.isPostTitleVisible() == true)
//              mHead.showChannelTitle();
//          }
//        }
//      }
//    }
}
Java Source Code List
