Compass View : View « UI « Android

1. Android
2. UI
3. View

Compass View

    
//package apps.compass;

import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class CompassView extends View {

  private float mGraduationRotateAngle = 0;
  private float mPointerRotateAngle = 0;
    
    private Drawable mGraduationDrawable = null;
    private Drawable mPointerDrawable = null;
    
    private float mGraduationDrawableRadius = 0;
    private float mPointerDrawableRadius = 0;

    private float mCanvasCenterX = 0;
    private float mCanvasCenterY =0;
    
    private float mPreTouchX = 0;
    private float mPreTouchY = 0;

  public CompassView(Context context) {
    super(context);
  
    Resources res = context.getResources();
//    mGraduationDrawable = res.getDrawable();
    mGraduationDrawable.setBounds(0, 0, 300, 300);
  //  mPointerDrawable = res.getDrawable();
    mPointerDrawable.setBounds(0, 0, 250, 250);
    
    mGraduationDrawableRadius = 300 / 2;
    mPointerDrawableRadius = 250 / 2;
  }

  public void setPointerRotateAngle(float angle) {
    if (angle - mPointerRotateAngle > 2 ) {
      while (angle - mPointerRotateAngle > 0.2) {
        mPointerRotateAngle += 0.2;
        this.invalidate();
      }
    }
    else if (angle - mPointerRotateAngle < -2) {
      while (mPointerRotateAngle - angle > 0.2) {
        mPointerRotateAngle -= 0.2;
        this.invalidate();
      }  
    }
  }
  
  public void setGraduationRotateAngle(float angle) {
    mGraduationRotateAngle = angle;
  }
  
  public boolean onTouchEvent(MotionEvent event) {

    boolean hasRotation = false;
    boolean isClockwise = true;
    float dx = event.getX() - mPreTouchX;
    float dy = event.getY() - mPreTouchY;
    
    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
      break;
    case MotionEvent.ACTION_MOVE:
      if (mPreTouchX > mCanvasCenterX && mPreTouchX < mCanvasCenterX + mGraduationDrawableRadius) {
        if (mPreTouchY > mCanvasCenterY && mPreTouchY < mCanvasCenterY + mGraduationDrawableRadius) {
          if (dx > 0 && dy < 0) {isClockwise = true; hasRotation = true;}
          else if (dx < 0 && dy > 0) {isClockwise = false; hasRotation = true;}
          else {hasRotation = false;}
        }
        else if (mPreTouchY > mCanvasCenterY - mGraduationDrawableRadius && mPreTouchY < mCanvasCenterY){
          if (dx > 0 && dy > 0) {isClockwise = false; hasRotation = true;}
          else if (dx < 0 && dy < 0) {isClockwise = true; hasRotation = true;}
          else {hasRotation = false;}
        }
      }
      else if (mPreTouchX > mCanvasCenterX - mGraduationDrawableRadius && mPreTouchX < mCanvasCenterX){
        if (mPreTouchY > mCanvasCenterY && mPreTouchY < mCanvasCenterY + mGraduationDrawableRadius) {
          if (dx > 0 && dy > 0) {isClockwise = true; hasRotation = true;}
          else if (dx < 0 && dy < 0) {isClockwise = false; hasRotation = true;}
          else {hasRotation = false;}
        }
        else if (mPreTouchY > mCanvasCenterY - mGraduationDrawableRadius && mPreTouchY < mCanvasCenterY) {
          if (dx > 0 && dy < 0) {isClockwise = false; hasRotation = true;}
          else if (dx < 0 && dy > 0) {isClockwise = true; hasRotation = true;}
          else {hasRotation = false;}
        }
      }
      break;
    }
    
    if (hasRotation) {
      float touchXToCenterX = mPreTouchX - mCanvasCenterX;
      float touchYToCenterY = mPreTouchY - mCanvasCenterY;
      float touchRadius = (float)Math.sqrt(touchXToCenterX * touchXToCenterX + touchYToCenterY * touchYToCenterY);
      float touchPathLen = (float) Math.sqrt(dx * dx + dy * dy);
      float rotateDegree = (float) Math.toDegrees(touchPathLen / touchRadius);
      Log.d("On Touch", "angle: "+rotateDegree);
      if (isClockwise)
        this.setGraduationRotateAngle(mGraduationRotateAngle + rotateDegree);
      else
        this.setGraduationRotateAngle(mGraduationRotateAngle - rotateDegree);
      this.invalidate();      
    }
    mPreTouchX = event.getX();
    mPreTouchY = event.getY();
    return true;
  }

  protected void onDraw(Canvas canvas) {
    
      int w = canvas.getWidth();
    int h = canvas.getHeight();
    mCanvasCenterX = w / 2;
    mCanvasCenterY = h / 2;
   
    canvas.save();
    canvas.translate(mCanvasCenterX, mCanvasCenterY);
    canvas.rotate(-mGraduationRotateAngle);
    canvas.translate(-mGraduationDrawableRadius, -mGraduationDrawableRadius);
    mGraduationDrawable.draw(canvas);
    canvas.restore();
    
    canvas.translate(mCanvasCenterX, mCanvasCenterY);
    canvas.rotate(-mPointerRotateAngle);
    canvas.translate(-mPointerDrawableRadius, -mPointerDrawableRadius);
    mPointerDrawable.draw(canvas);
  }
}
 class Compass extends Activity {
  private SensorManager mSensorManager = null;
  private CompassView mView = null;

  private final SensorEventListener mSensorEventListener = new SensorEventListener() {
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
    }

    public void onSensorChanged(SensorEvent event) {
      if (mView != null) {
        mView.setPointerRotateAngle(event.values[0]);
      }
    }
  };

  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
     mView = new CompassView(this);
     setContentView(mView);
  }

  public void onResume() {
    super.onResume();
    List<Sensor> sensorList = mSensorManager
        .getSensorList(Sensor.TYPE_ORIENTATION);
    if (!sensorList.isEmpty()) {
      Sensor sensor = (Sensor) sensorList.get(0);
      if (sensor != null)
        mSensorManager.registerListener(mSensorEventListener, sensor,
            SensorManager.SENSOR_DELAY_GAME);
    }
  }

  public void onStop() {
    mSensorManager.unregisterListener(mSensorEventListener);
    super.onStop();
  }
}

   
    
    
    
  

Related examples in the same category