Java tutorial
/* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package edu.winlab.minijarvis.activity; import android.annotation.SuppressLint; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.Paint.Align; import android.hardware.Camera; import android.hardware.Camera.PictureCallback; import android.os.AsyncTask; import android.os.Bundle; import android.os.CountDownTimer; import android.os.Environment; import android.os.Handler; import android.os.HandlerThread; import android.util.Log; import android.view.MotionEvent; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.WindowManager; import android.widget.ImageView; import android.widget.TextView; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import org.apache.http.client.HttpClient; import org.apache.http.client.ResponseHandler; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.mime.HttpMultipartMode; import org.apache.http.entity.mime.MultipartEntity; import org.apache.http.entity.mime.content.FileBody; import org.apache.http.impl.client.BasicResponseHandler; import org.apache.http.impl.client.DefaultHttpClient; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.google.android.glass.touchpad.Gesture; import com.google.android.glass.touchpad.GestureDetector; import edu.winlab.minijarvis.R; /** * This is the main activity. It opens camera and takes images every 10 seconds. Each image is sent to server. * The server does object/face recognition and sends back annotation to glassware. If faces are recognized, the * annotation is displayed on the glass for approx 5s. * @author Saumya * */ public class CameraActivity extends Activity implements SurfaceHolder.Callback { private static final String TAG = "CameraActivity"; private SurfaceView mPreview; private Camera mCamera; private GestureDetector mGestureDetector = null; private String ip = "192.168.1.1"; // ip of my server static JSONObject jsonResponse; boolean stop = false; public final Handler handler = new Handler(); SurfaceHolder holder; private String fileName; TextView mCounter; ImageView imgView; private Paint rectPaint; private Paint textPaint; private Paint background; Bitmap bitmap; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); //to prevent screen from dimming getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN); getWindow().setFormat(PixelFormat.TRANSLUCENT); setContentView(R.layout.activity_main); mPreview = (SurfaceView) findViewById(R.id.preview); mCounter = (TextView) findViewById(R.id.counter); imgView = (ImageView) findViewById(R.id.image); holder = mPreview.getHolder(); holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); holder.addCallback(this); //Set Paint objects setRectPaint(); setTextPaint(); setBackground(); //to detect gestures mGestureDetector = createGestureDetector(this); //To safely open camera // Start the main thread. Image is captured when preview starts. Sync sync = new Sync(call, 500); } @Override protected void onPause() { super.onPause(); if (mCamera != null) { mCamera.release(); mCamera = null; } } @Override protected void onDestroy() { super.onDestroy(); if (mCamera != null) { mCamera.release(); mCamera = null; } } public class Sync { Runnable task; public Sync(Runnable task, long time) { this.task = task; for (int i = 0; i < 3; i++) { mCamera = getCameraInstance(); if (mCamera != null) break; try { Thread.sleep(500); } catch (InterruptedException e) { e.printStackTrace(); } } if (mCamera == null) { debug("Camera cannot be locked"); } handler.removeCallbacks(task); handler.postDelayed(task, time); } } /** * Thread to capture image every 10s */ final private Runnable call = new Runnable() { @Override public void run() { //stop variable is false when user requests further info. No more iages are taken. if (stop == false) { try { Thread.sleep(4000); } catch (InterruptedException e) { e.printStackTrace(); } // Timer to take images every 10s new CountDownTimer(10000, 1000) { //Countdown is displayed on the view public void onTick(long millisUntilFinished) { mCamera.startPreview(); mCounter.setVisibility(View.VISIBLE); mCounter.setText(Long.toString(millisUntilFinished / 1000)); jsonResponse = null; imgView.setVisibility(View.GONE); } //Image is captured after countdown and sent to server for recognition. The timer restarts after 8s public void onFinish() { mCounter.setVisibility(View.GONE); mCamera.takePicture(null, null, mPictureCallback); //Current timer thread is cancelled. this.cancel(); handler.postDelayed(call, 7 * 1000); } }.start(); } } }; /** * To get camera instance * @return Camera */ private static Camera getCameraInstance() { Camera camera = null; try { camera = Camera.open(); // Work around for Camera preview issues Camera.Parameters params = camera.getParameters(); params.setPreviewFpsRange(30000, 30000); camera.setParameters(params); } catch (Exception e) { System.out.println(e.toString()); e.printStackTrace(); } return camera; } /* * Sets Paint object to draw rectangles. */ public void setRectPaint() { rectPaint = new Paint(); rectPaint.setColor(Color.GREEN); rectPaint.setStyle(Paint.Style.STROKE); rectPaint.setStrokeWidth(5); } /* * Sets Paint object for annotations */ public void setTextPaint() { textPaint = new Paint(); textPaint.setColor(Color.GREEN); textPaint.setFlags(Paint.ANTI_ALIAS_FLAG); textPaint.setTextSize(60); textPaint.setTextAlign(Align.CENTER); } /* * Sets Paint object to draw rectangles for text background. */ public void setBackground() { background = new Paint(); background.setColor(Color.BLACK); background.setStyle(Paint.Style.FILL); background.setStrokeWidth(5); } /* * Callback when the picture is taken */ private final PictureCallback mPictureCallback = new PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) { Log.d(TAG, "Picture taken!"); mCounter.setVisibility(View.GONE); fileName = Environment.getExternalStorageDirectory().getPath() + "/picture.jpg"; //saved with filename picture FileOutputStream imageFileOS; try { imageFileOS = new FileOutputStream(fileName); imageFileOS.write(data); imageFileOS.flush(); imageFileOS.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } bitmap = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getPath() + "/picture.jpg") .copy(Bitmap.Config.ARGB_8888, true); //AsyncTask method to access server. new LongOperation().execute(fileName); } }; @Override public void surfaceCreated(SurfaceHolder holder) { try { mCamera.setPreviewDisplay(holder); mCamera.startPreview(); } catch (IOException e) { e.printStackTrace(); } } @Override public void surfaceDestroyed(SurfaceHolder holder) { if (mCamera != null) { mCamera.stopPreview(); mCamera.release(); mCamera = null; } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { try { if (mCamera != null) { mCamera.stopPreview(); mCamera.release(); mCamera = null; } mCamera = getCameraInstance(); mCamera.setPreviewDisplay(holder); mCamera.startPreview(); } catch (IOException e) { e.printStackTrace(); } } //To detect gestures private GestureDetector createGestureDetector(Context context) { GestureDetector gestureDetector = new GestureDetector(context); //Create a base listener for generic gestures gestureDetector.setBaseListener(new GestureDetector.BaseListener() { @Override public boolean onGesture(Gesture gesture) { if (gesture == Gesture.LONG_PRESS) { if (jsonResponse.optJSONArray("responses") != null && jsonResponse.optJSONArray("responses").length() > 0) { stop = true; mCamera.release(); mCamera = null; Intent intent = new Intent(CameraActivity.this, SearchResultsActivity.class); intent.putExtra("JSON_Object", jsonResponse.toString()); startActivity(intent); } } return false; } }); return gestureDetector; } /* * Send generic motion events to the gesture detector */ @Override public boolean onGenericMotionEvent(MotionEvent event) { if (mGestureDetector != null) { return mGestureDetector.onMotionEvent(event); } return false; } // Class for server call. Better to do server call with AsyncTask public class LongOperation extends AsyncTask<String, String, String> { public LongOperation() { } //Send image to server using http post protected String doInBackground(String... picturePath) { File file = new File(picturePath[0]); try { HttpClient httpClient = new DefaultHttpClient(); HttpPost postRequest = new HttpPost("http://" + ip + ":8080/MJFaceServer/image"); MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE); reqEntity.addPart("image", new FileBody(file)); postRequest.setEntity(reqEntity); ResponseHandler<String> handler = new BasicResponseHandler(); String content = httpClient.execute(postRequest, handler); jsonResponse = new JSONObject(content); httpClient.getConnectionManager().shutdown(); } catch (IOException e) { e.printStackTrace(); } catch (JSONException e) { e.printStackTrace(); } return picturePath[0]; } // Get results from server and display @Override protected void onPostExecute(String filePath) { imgView.setVisibility(View.VISIBLE); Canvas canvas = new Canvas(bitmap); canvas.drawBitmap(bitmap, 0, 0, null); if (jsonResponse != null) { Log.d(TAG, jsonResponse.toString()); JSONArray annotations = jsonResponse.optJSONArray("annotations"); if (annotations != null && annotations.length() > 0) { for (int i = 0; i < annotations.length(); i++) { JSONObject annotation = null; try { annotation = (JSONObject) annotations.get(i); } catch (JSONException e) { e.printStackTrace(); } int left = annotation.optInt("x"); int top = annotation.optInt("y"); int right = annotation.optInt("x") + annotation.optInt("width"); int bottom = annotation.optInt("y") + annotation.optInt("height"); canvas.drawRect(left, top, right, bottom, rectPaint); canvas.drawText(annotation.optString("text"), annotation.optInt("x") + 5, annotation.optInt("y") - 5, textPaint); } } else { String s = "No faces found or unknown faces"; canvas.drawRect(canvas.getWidth() / 2 - textPaint.measureText(s) / 2, canvas.getHeight() / 2 - textPaint.getTextSize(), canvas.getWidth() / 2 + textPaint.measureText(s) / 2, canvas.getHeight() / 2, background); canvas.drawText(s, canvas.getWidth() / 2, canvas.getHeight() / 2, textPaint); } // // if(jsonResponse.optJSONArray("responses")!=null && jsonResponse.optJSONArray("responses").length()>0){ // canvas.drawRect(0, canvas.getHeight()/2,canvas.getWidth(), canvas.getHeight()/2+70, background); // canvas.drawText("Long press for detailed information", canvas.getWidth()/2,canvas.getHeight()/2, textPaint); // } } else { String s = "Server error! try later"; canvas.drawRect(canvas.getWidth() / 2 - textPaint.measureText(s) / 2, canvas.getHeight() / 2 - textPaint.getTextSize(), canvas.getWidth() / 2 + textPaint.measureText(s) / 2, canvas.getHeight() / 2, background); canvas.drawText(s, canvas.getWidth() / 2, canvas.getHeight() / 2, textPaint); } imgView.setImageBitmap( Bitmap.createScaledBitmap(bitmap, imgView.getWidth(), imgView.getHeight(), false)); } } private void debug(String message) { Log.d(TAG, message); } }