おちゃハウスに行ってきました。

お茶の水女子大学のおちゃハウスを使って自分のやっていることを発表する場をも設けてくれたので、未踏とは全く関係のないProcessingを布教してきました。制作展の案内をしたり、ProcessingからTwitter Streaming APIを呼ぶライブラリを作ったのでそこからsayコマンドを起動させて遊んだりしました。

未踏の話をしなかったのですが、こっちのほうが楽しいし聞いている人の役に立ちそうなのでテーマ選びは冒険をしましたがよかったです。

参考

• Language Reference (API) \ Processing 3+
• http://apiwiki.twitter.com/Streaming-API-Documentation

世界のナベアツ

void setup() {
  size(1200, 800);
  PFont f = createFont("FFScala", 200);
  textFont(f);
  print("Hello, World"); 
  frameRate(5);
}

int count = 1;

void draw() {
  background(0xFF);
  fill(0x0);
  print("drawing!");
  if (count % 3 == 0 
      || (""+count).indexOf("3") != -1) {
    fill(0xFF);
    background(0x0);
    showString("Hoge!");
  } else {
    showString("" + count);
  }
  count++;
}
void showString(String s) {
  text(s, 300, 400); 
}

TwitterSreamingTrack

今回のネタ。ProcessingからTwitter Streaming APIを利用するコード

/*
  TwitterStreamingTrackTest.pde
*/
TwitterStreamingTrack tst;

void setup() {
    size(1200, 800);
    PFont f = createFont("FFScala", 100);
    textFont(f);
    tst = new TwitterStreamingTrack(this, "#nowplaying",
                                    "account", "password");
    background(0xFF);
}

void draw() {
    Tweet t = tst.getNewTweet();
    if (t != null) {
        fill(0x0);
        String msg = t.msg;
        text(msg,250 - int(random(500)), int(random(1000)) - 100);

        String com = "say \"" + msg + "\"";
        Process pro;
        try {
            pro = Runtime.getRuntime().exec(com);
        } catch(IOException e) {
            println(e.toString());
            exit();
        }
    }
}

上のコードで使われているTwitterStreamingTrackクラスは事前に用意しておいて渡しました。
TwitterStreamingTrackでは次の二つのクラスライブラリを使います。

• http://processing.org/discourse/yabb2/YaBB.pl?num=1163101573/6
• http://www.source-code.biz/base64coder/java/Base64Coder.html

/*
  TwitterStreamingTrack.pde
*/
import org.json.*;
import biz.source_code.*;
import processing.net.*;

public class TwitterStreamingTrack {
    private PApplet parent;
    private Client client;
    private int byteBuffersNum = 10;
    private byte[][] byteBuffers = new byte[byteBuffersNum][4096];
    private byte[] currentByteBuffer;
    private int byteBuffersIndex = 0;
    private int byteBuffersStart = 0;
    private int[] byteBuffersSizes = new int[byteBuffersNum];
    private String encoding = "UTF-8";
    private final String twitterStreamingServer="stream.twitter.com";
    private final String twitterStreamingMethod="POST";
    private final int twitterStreamingPort=80;
    private final String twitterStreamingPath="/1/statuses/filter.json";
    private String twitterStreamingAuthUser;
    private String twitterStreamingAuthPass;
    private String authKey;
    private Tweet recentTweet = null;
    private Pattern HTTPResponsePattern = Pattern.compile("(HTTP/1.1 (\\d+).+)");
    private Pattern HTTPBodyPattern1 = Pattern.compile("\r\n\r\n[^{]+\r\n(.*)", Pattern.DOTALL);
    private Pattern HTTPBodyPattern2 = Pattern.compile("[0-9A-Z]\r\n(.*)", Pattern.DOTALL);


    /*
      parent: usually ``this''
      keywords: keyword list, comma separated
    */
    public TwitterStreamingTrack(PApplet parent, String keywords,
                                 String username, String password) {
        twitterStreamingAuthUser = username;
        twitterStreamingAuthPass = password;
        this.parent = parent;
        initClient();
        prepareAuthKey();

        String encoded_keywords = "logcafe";
        try {
            encoded_keywords= java.net.URLEncoder.encode(keywords, encoding);
        } catch (UnsupportedEncodingException e) {
            println(e.toString());
        }
        sendHTTPRequest(encoded_keywords);
        currentByteBuffer = byteBuffers[byteBuffersIndex];
    }

    /*
      This method should be called each frame.
    */
    public Tweet getNewTweet() {
        recentTweet = null;
        checkBytes();
        return recentTweet;
    }

    private void initClient() {
        client = new Client(parent, twitterStreamingServer,
                            twitterStreamingPort);
    }

    private void prepareAuthKey() {
        /*
          http://www.source-code.biz/base64coder/java/
        */
        authKey = Base64Coder.encodeString(twitterStreamingAuthUser + ":" +
                                           twitterStreamingAuthPass);

    }

    private void sendHTTPRequest(String keywords) {
        sendPostRequest("track="+keywords);
    }
    /*
      requestBody is assumed to be already url-encoded (?).
    */
    private void sendPostRequest(String requestBody) {
        String requestLine = twitterStreamingMethod + " "
            + twitterStreamingPath + " HTTP/1.1";
        String hostParam = "Host: " + twitterStreamingServer + ":" +
            twitterStreamingPort;
        String userAgentParam = "User-Agent: curl/7.19.4 (universal-apple-darwin10.0) libcurl/7.19.4 OpenSSL/0.9.8l zlib/1.2.3";
        String authParam = "Authorization: Basic " + authKey;
        String acceptParam = "Accept: " + "*"+ "/"+"*";
        String contentLengthParam = "Content-Length: " + requestBody.length();
        String contentTypeParam = "Content-Type: application/x-www-form-urlencoded";
        sendln(requestLine);
        sendln(authParam);
        sendln(userAgentParam);
        sendln(hostParam);
        sendln(acceptParam);
        sendln(contentLengthParam);
        sendln(contentTypeParam);
        sendln("");// empty line before request body
        sendln(requestBody);
        sendln("");
        sendln(""); // end of request, that is two new line
    }

    private void sendln(String line) {
        client.write(line + "\r\n");
    }

    private void clearByteBuffer(byte[] buf) {
        for (int i = 0; i<buf.length; ++i) {
            buf[i] = 0;
        }
    }


    private void checkBytes() {
        if (client.available() > 0) {
            int byteCount = client.readBytes(currentByteBuffer);
            if (byteCount > 0 ) {
                String response;
                byteBuffersSizes[byteBuffersIndex] = byteCount;
                //                println("received: " + byteCount + " to buffer#" + byteBuffersIndex);

                int r =  processByteBuffers();
                if (r == 0) {
                    byteBuffersStart = (byteBuffersIndex+1)%byteBuffersNum;
                }
                byteBuffersIndex = (byteBuffersIndex+1)%byteBuffersNum;
                currentByteBuffer = byteBuffers[byteBuffersIndex];
                clearByteBuffer(currentByteBuffer);
            }
        }
    }

    private int processByteBuffers() {
        int ssize = 1<<13;
        byte[] s = new byte[ssize];
        int i;
        int k = byteBuffersStart;
        String response;
        /*
          append butters to the first.
          buteBuffersStart = 7, byteBuffersIndex = 0.
          - byteBuffers[7] = {a, b, c}  (s)
          - byteBuffers[8] = {k, l}
          - byteBuffers[9] = {j}
          - byteBuffers[0] = {r, t, i}
          - byteBuffers[1] = {a, o}

          => s = {a, b, c, k, l, j, r, t, i, a, o}

        */
        for (i=0; i<ssize; ++i) {
            s[i] = 0;
        }
        for (i=0; i<byteBuffersSizes[byteBuffersStart]; ++i) {
            s[i] = byteBuffers[k][i];
        }
        k = (k+1) % byteBuffersNum;
        i = byteBuffersSizes[byteBuffersStart];
        //        println("startBuffer's size: " + i);
        if (byteBuffersIndex != byteBuffersStart) {
            while(true){
                byte[] b = byteBuffers[k];
                int bs = byteBuffersSizes[k];
                for (int j=0; j<bs; ++j) {
                    s[i] = b[j];
                    ++i;
                    if (i>=ssize) {
                        // reset the buffer, but doesn't update recentTweet
                        return 0;
                    }
                }
                //                println("appended size:" + bs);
                if (k == byteBuffersIndex) break;
                k = (k+1)%byteBuffersNum;
            }
        }
        try {
            response = new String(s, encoding);
        } catch (UnsupportedEncodingException e) {
            response = "encoding error";
        }
        return processHTTPResponse(response);
    }

    private int processHTTPResponse(String response) {
        Boolean ret;
        String responseBody;
        String statusLine, statusCode;
        Matcher matcher;
        matcher = HTTPResponsePattern.matcher(response);
        // matches the first occurance.
        if (matcher.find()) {
            statusLine = matcher.group(1);
            statusCode = matcher.group(2);
            if (!statusCode.equals("200")) {
                println("Error: status line is " + statusLine);
                return -1;
            }
        }
        matcher = HTTPBodyPattern1.matcher(response);
        if (!matcher.find()) {
            matcher = HTTPBodyPattern2.matcher(response);
            if (!matcher.find()) {
                return -1;
            }
        }
        responseBody = matcher.group(1);
        return processHTTPResponseBody(responseBody);
    }

    private int processHTTPResponseBody(String responseBody) {
        String twitScreenName, twitRealName;
        JSONObject j, user;
        String twitPostedTime;
        String twitText;

        try {
            //            println(responseBody);
            j = new JSONObject(responseBody);
            // if an exception occurs, go to checkBytes.

            twitText = j.getString("text");
            user = j.getJSONObject("user");
            twitScreenName = user.getString("screen_name");
            twitRealName = user.getString("name");
            twitPostedTime = j.getString("created_at");
            recentTweet = new Tweet(twitText, twitScreenName,
                                    twitRealName, twitPostedTime);
        } catch(JSONException e) {
            return -2;
        }
        return 0;
    }
}

/*
  Tweet.pde
*/
public class Tweet{
    public String msg;
    public String scname;
    public String username;
    public String time;

    public Tweet(){
        msg = "";
        scname = "";
        username = "";
        time = "";
    }

    public Tweet(String _msg, String _scname, String _username, String _time) {
        msg = _msg;
        scname = _scname;
        username = _username;
        time = _time;
    }
}

任意のコマンドを実行してしまう恐れのあるコードなのであくまでサンプルとして。