XCameraActivity.java

/*
 Copyright 2012-2013, Polyvi Inc. (http://polyvi.github.io/openxface)
 This program is distributed under the terms of the GNU General Public License.

 This file is part of xFace.

 xFace 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 3 of the License, or
 (at your option) any later version.

 xFace 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.

 You should have received a copy of the GNU General Public License
 along with xFace.  If not, see <http://www.gnu.org/licenses/>.
*/

package com.polyvi.xface.extension.zbar;

import java.io.UnsupportedEncodingException;

import net.sourceforge.zbar.Config;
import net.sourceforge.zbar.Image;
import net.sourceforge.zbar.ImageScanner;
import net.sourceforge.zbar.Symbol;
import net.sourceforge.zbar.SymbolSet;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PreviewCallback;
import android.hardware.Camera.Size;
import android.os.Bundle;
import android.os.Handler;
import android.os.Vibrator;
import android.widget.LinearLayout;

import com.polyvi.xface.util.XLog;

/*
 * 通过activity启动摄像机，返回preview 图片，scanner（so库）对preview 图片进行分析，
 * 如果发现条形码就返回分析结果，扫描结果通过intent将返回。
 */
public class XCameraActivity extends Activity {
    private static final String CLASS_NAME = XCameraActivity.class.getSimpleName();
    private static final long VIBRATE_DURATION = 200L;

    private Camera mCamera;
    private XCameraPreview mPreview;
    private Handler mAutoFocusHandler;
    private ImageScanner mScanner;
    private boolean mPreviewing = true;

    static {
        System.loadLibrary("iconv");
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        try {
            LinearLayout layout = new LinearLayout(this);
            setContentView(layout);

            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

            mCamera = getCameraInstance();
            if(null == mCamera) {
                Intent intent = new Intent();
                setResult(RESULT_CANCELED, intent);
                finish();
                return;
            }
            mAutoFocusHandler = new Handler();
            /* Instance barcode scanner */
            mScanner = new ImageScanner();
            mScanner.setConfig(0, Config.X_DENSITY, 3);
            mScanner.setConfig(0, Config.Y_DENSITY, 3);
            mPreview = new XCameraPreview(this, mCamera, previewCb, autoFocusCB);
            layout.addView(mPreview);

            mCamera.setPreviewCallback(previewCb);
            mCamera.startPreview();
            mPreviewing = true;
            mCamera.autoFocus(autoFocusCB);
        } catch (Exception e) {
            XLog.e(CLASS_NAME, "Error in onCreate:" + e.getMessage());
        }
    }

    public void onPause() {
        super.onPause();
        releaseCamera();
    }

    /** A safe way to get an instance of the Camera object. */
    private Camera getCameraInstance() {
        Camera c = null;
        //TODO:api level 9可选择摄像头，比如前置摄像头
        try {
            c = Camera.open();
        } catch (Exception e) {
            XLog.e(CLASS_NAME, "open camera fail");
        }
        return c;
    }

    private void releaseCamera() {
        if (mCamera != null) {
            mPreviewing = false;
            mCamera.setPreviewCallback(null);
            mCamera.release();
            mCamera = null;
        }
    }

    private Runnable doAutoFocus = new Runnable() {
        public void run() {
            if (mPreviewing) {
                try {
                    mCamera.autoFocus(autoFocusCB);
                } catch (Exception e) {
                   XLog.e(CLASS_NAME, "Error when running autoFocusCB"+ e.getMessage());
                }
            }
        }
    };

    private PreviewCallback previewCb = new PreviewCallback() {
        public void onPreviewFrame(byte[] data, Camera camera) {
            Camera.Parameters parameters = camera.getParameters();
            Size size = parameters.getPreviewSize();

            Image barcode = new Image(size.width, size.height, "Y800");
            barcode.setData(data);

            int result = mScanner.scanImage(barcode);

            if (result != 0) {
                mPreviewing = false;
                mCamera.setPreviewCallback(null);
                mCamera.stopPreview();

                SymbolSet syms = mScanner.getResults();

                playVibrate();// 振动代表成功获取二维码

				for (Symbol sym : syms) {
					try {
						byte[] b = sym.getDataBytes();
						if (b[0] == -24) {
							b = sym.getData().getBytes("sjis");
						}
						String str = new String(b);
						Intent intent = new Intent();
						intent.putExtra("Code", str);
						setResult(RESULT_OK, intent);
						finish();
					} catch (UnsupportedEncodingException e) {
						e.printStackTrace();
					}
				}
			}
		}
	};

    // Mimic continuous auto-focusing
    private AutoFocusCallback autoFocusCB = new AutoFocusCallback() {
        public void onAutoFocus(boolean success, Camera camera) {
            mAutoFocusHandler.postDelayed(doAutoFocus, 1000);
        }
    };

    /**
     * 震动
     */
    private void playVibrate() {
        // 打开震动
        Vibrator vibrator = (Vibrator) getSystemService(VIBRATOR_SERVICE);
        vibrator.vibrate(VIBRATE_DURATION);
    }
}