import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
  private Button buttonLocal, buttonCamera;
  private ImageView imageView;
  //相機拍攝的頭像文件(本次演示存放在SD卡根目錄下)
  private static final File USER_ICON = new File(Environment.getExternalStorageDirectory(), "user_icon.jpg");
  //請求識別碼(分別為本地相冊、相機、圖片裁剪)
  private static final int CODE_PHOTO_REQUEST = 1;
  private static final int CODE_CAMERA_REQUEST = 2;
  private static final int CODE_PHOTO_CLIP = 3;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    buttonLocal = (Button) findViewById(R.id.buttonLocal);
    buttonCamera = (Button) findViewById(R.id.buttonCamera);
    imageView = (ImageView) findViewById(R.id.imageView);
    buttonLocal.setOnClickListener(this);
    buttonCamera.setOnClickListener(this);
  }
  //設置點擊事件
  @Override
  public void onClick(View view) {
    switch (view.getId()) {
      case R.id.buttonLocal:
        //調用獲取本地圖片的方法
        getPicFromLocal();
        break;
      case R.id.buttonCamera:
        //調用相機拍照的方法
        getPicFromCamera();
        break;
      default:
        break;
    }
  }
  /**
   * 從本機相冊獲取圖片
   */
  private void getPicFromLocal() {
    Intent intent = new Intent();
    // 獲取本地相冊方法一
    intent.setAction(Intent.ACTION_GET_CONTENT);
    intent.setType("image/*");
    //獲取本地相冊方法二
//    intent.setAction(Intent.ACTION_PICK);
//    intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
//        "image/*");
    startActivityForResult(intent, CODE_PHOTO_REQUEST);
  }
  /**
   * 通過相機拍攝獲取圖片，
   * 并存入設置的路徑中
   */
  private void getPicFromCamera() {
    Intent intent = new Intent();
    intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
    // 下面這句指定調用相機拍照后的照片存儲的路徑
    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(USER_ICON));
    startActivityForResult(intent, CODE_CAMERA_REQUEST);
  }
  /**
   * 圖片裁剪
   *
   * @param uri
   */
  private void photoClip(Uri uri) {
    // 調用系統(tǒng)中自帶的圖片剪裁
    Intent intent = new Intent();
    intent.setAction("com.android.camera.action.CROP");
    intent.setDataAndType(uri, "image/*");
    // 下面這個crop=true是設置在開啟的Intent中設置顯示的VIEW可裁剪
    intent.putExtra("crop", "true");
    // aspectX aspectY 是寬高的比例
    intent.putExtra("aspectX", 1);
    intent.putExtra("aspectY", 1);
    /*outputX outputY 是裁剪圖片寬高
     *這里僅僅是頭像展示，不建議將值設置過高
     * 否則超過binder機制的緩存大小的1M限制
     * 報TransactionTooLargeException
     */
    intent.putExtra("outputX", 150);
    intent.putExtra("outputY", 150);
    intent.putExtra("return-data", true);
    startActivityForResult(intent, CODE_PHOTO_CLIP);
  }
  /**
   * 提取保存裁剪之后的圖片數(shù)據(jù)，并設置頭像部分的View
   */
  private void setImageToHeadView(Intent intent) {
    Bundle extras = intent.getExtras();
    if (extras != null) {
      Bitmap photo = extras.getParcelable("data");
      imageView.setImageBitmap(photo);
    }
  }
  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // 用戶沒有進行有效的設置操作，返回
    if (resultCode == RESULT_CANCELED) {
      Toast.makeText(MainActivity.this, "取消", Toast.LENGTH_LONG).show();
      return;
    }
    switch (requestCode) {
      case CODE_CAMERA_REQUEST:
        if (USER_ICON.exists()) {
          photoClip(Uri.fromFile(USER_ICON));
        }
        break;
      case CODE_PHOTO_REQUEST:
        if (data != null) {
          photoClip(data.getData());
        }
        break;
      case CODE_PHOTO_CLIP:
        if (data != null) {
          setImageToHeadView(data);
        }
        break;
    }
    super.onActivityResult(requestCode, resultCode, data);
  }
}