Android Open Source - n4lwp N4 Wallpaper Service






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License

The source code is released under:

Copyright (c) 2012, Patrick O'Leary All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:...

If you think the Android project n4lwp listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.

Java Source Code

/*
Copyright (c) 2012, Patrick O'Leary/*from   www.j  av  a  2 s.  com*/
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met: 

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer. 
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.greentaperacing.olearyp.n4lwp;

import java.util.Random;

import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.opengl.Matrix;
import android.preference.PreferenceManager;
import android.service.wallpaper.WallpaperService;
import android.util.FloatMath;
import android.view.SurfaceHolder;

public class N4WallpaperService extends WallpaperService {

  @Override
  public Engine onCreateEngine() {
    return new N4WallpaperEngine();
  }

  private class N4WallpaperEngine extends Engine implements SensorEventListener {

    private final SensorManager mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
    private final Sensor mRotation = mSensorManager.getDefaultSensor(Sensor.TYPE_ROTATION_VECTOR);
    private final Sensor mLight = mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
    private final float illumMax = 700f;
    private float[] rotation = {0.0f, 0.0f, 0.0f};
    private float illum = illumMax;

    private final float[] dotAngles = new float[20];
    private final Bitmap[] dots = new Bitmap[dotAngles.length];

    private SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(N4WallpaperService.this);

    @Override
    public void onCreate(SurfaceHolder surfaceHolder) {
      super.onCreate(surfaceHolder);
      for(int ii = 0; ii < dotAngles.length; ii++) {
        dotAngles[ii] = (float) (ii * Math.PI / dotAngles.length);
      }
      prefs.registerOnSharedPreferenceChangeListener(prefListener);
    }


    private SharedPreferences.OnSharedPreferenceChangeListener prefListener = new SharedPreferences.OnSharedPreferenceChangeListener() {

      @Override
      public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
          String key) {
        generateDots();

      }
    };

    private int surfWidth = 0;
    private int surfHeight = 0;
    private int gridSize = 0;
    private int[][] orientations = {{0}};

    @Override
    public void onVisibilityChanged(boolean visible) {
      if (visible) {
        mSensorManager.registerListener(this, mRotation, SensorManager.SENSOR_DELAY_NORMAL);
        if(mLight != null) {
          mSensorManager.registerListener(this, mLight, SensorManager.SENSOR_DELAY_NORMAL);
        }
      } else {
        mSensorManager.unregisterListener(this);
      }
    }

    @Override
    public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
      surfWidth = width;
      surfHeight = height;
      generateDots();
    }

    @Override
    public void onSurfaceDestroyed(SurfaceHolder holder) {
      super.onSurfaceDestroyed(holder);
    }

    @Override
    public void onDestroy() {
      super.onDestroy();
      mSensorManager.unregisterListener(this);
    }

    private void draw() {
      SurfaceHolder holder = getSurfaceHolder();
      Canvas c = null;

      try {
        c = holder.lockCanvas();
        if (c != null) {
          float[] R_wd = new float[16];
          float[] R_dw = new float[16];
          SensorManager.getRotationMatrixFromVector(R_wd, rotation);
          Matrix.transposeM(R_dw, 0, R_wd, 0);

          // Compute vector normal to screen in world coordinates
          final float[] n_d = {0.0f, 0.0f, 1.0f, 1.0f};
          float[] n_w = new float[4];
          Matrix.multiplyMV(n_w, 0, R_dw, 0, n_d, 0);

          // cos(theta) = n_w[2]
          double theta = Math.acos(n_w[2]);

          // Compute screen up vector in world coordinates
          final float[] u_d = {0.0f, 1.0f, 0.0f, 1.0f};
          float[] u_w = new float[4];
          Matrix.multiplyMV(u_w, 0, R_dw, 0, u_d, 0);

          // Compute projection of world up vector onto screen, expressed in world
          float[] proj_wu_d_w = {-n_w[2]*n_w[0], -n_w[2]*n_w[1], 1.0f-n_w[2]*n_w[2], 1.0f};

          // cos(psi) = dot(u_w, proj_wu_w)/norm(proj_wu_w)
          double psi = Math.acos((u_w[0]*proj_wu_d_w[0] + u_w[1]*proj_wu_d_w[1] + u_w[2]*proj_wu_d_w[2])/norm(proj_wu_d_w));

          // We need to give psi a sign, which we can do by checking the projection in display coordinates
          float[] proj_wu_d_d = new float[4];
          Matrix.multiplyMV(proj_wu_d_d, 0, R_wd, 0, proj_wu_d_w, 0);
          if(proj_wu_d_d[0] < 0) {
            psi = -psi;
          }

          float illum_adj = 1.0f;
          if(prefs.getBoolean("luminance_enabled", true) && illum < illumMax) {
            illum_adj = (illum + 100)/(illumMax + 100);
          }

          Paint p = new Paint();
          p.setColor(prefs.getInt("color_fg", 0xFFFFFF));
          Bitmap[] preComposedDots = new Bitmap[dotAngles.length];
          Canvas cmpCanvas = new Canvas();
          for(int ii = 0; ii < dotAngles.length; ii++) {
            p.setAlpha((int) Math.round(250*Math.abs(Math.sin(theta*2.0) * Math.sin(psi - dotAngles[ii])) * illum_adj + 5));
            
            preComposedDots[ii] = Bitmap.createBitmap(gridSize, gridSize, Bitmap.Config.ARGB_8888);
            cmpCanvas.setBitmap(preComposedDots[ii]);
            cmpCanvas.drawColor(prefs.getInt("color_bg", Color.BLACK));
            cmpCanvas.drawBitmap(dots[ii], 0, 0, p);
          }

          p = new Paint();
          for(int ii = 0; ii*gridSize < surfWidth; ii++) {
            for(int jj = 0; jj*gridSize < surfHeight; jj++) {
              int dot = orientations[ii][jj];
              c.drawBitmap(preComposedDots[dot], ii*gridSize, jj*gridSize, p);
            }
          }
        }
      } finally {
        // If we get IllegalArgumentException, the Surface was destroyed and there's nothing to unlock
        try {
          if (c != null)
            holder.unlockCanvasAndPost(c);
        } catch(IllegalArgumentException e) {}
      }
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
      // pass
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
      if(event.sensor.getType() == Sensor.TYPE_ROTATION_VECTOR) {
        rotation  = event.values;
        if(surfWidth > 0) {
          draw();
        }
      } else if (event.sensor.getType() == Sensor.TYPE_LIGHT) {
        illum = event.values[0];
      }
    }

    private float norm(float[] vector) {
      return FloatMath.sqrt(vector[0] * vector[0] + vector[1] * vector[1]
          + vector[2] * vector[2]);
    }

    private void generateDots() {
      final int minScreenDim = Math.min(surfWidth, surfHeight);
      gridSize  = minScreenDim/Integer.valueOf(prefs.getString("dot_num_across", "40"));

      for(int ii = 0; ii < dotAngles.length; ii++) {
        dots[ii] = makeDot(dotAngles[ii]);
      }

      final Random rng = new Random(0);
      orientations = new int[(int) Math.ceil((double) surfWidth/gridSize)][(int) Math.ceil((double) surfHeight/gridSize)];
      for(int ii = 0; ii*gridSize < surfWidth; ii++) {
        for(int jj = 0; jj*gridSize < surfHeight; jj++) {
          orientations[ii][jj] = rng.nextInt(dots.length);
        }
      }
    }

    private Bitmap makeDot(float angle) {

      final float dotSize = ((float) gridSize)*(Float.valueOf(prefs.getString("dot_fill_pct", "80")))/100.0f;

      Bitmap b = Bitmap.createBitmap(gridSize, gridSize, Bitmap.Config.ALPHA_8);
      Canvas c = new Canvas(b);
      Paint p = new Paint();
      p.setAntiAlias(true);

      c.drawCircle(gridSize/2.0f, gridSize/2.0f, dotSize/2.0f, p);

      if(prefs.getBoolean("dot_draw_lines", true)) {
        p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
        p.setStrokeWidth(dotSize/8);

        android.graphics.Matrix R_if = new android.graphics.Matrix();
        R_if.setRotate(angle*180f/(float) Math.PI, gridSize/2.0f, gridSize/2.0f);
        float[] lineEnds = {
            gridSize/2.0f, 0,
            gridSize/2.0f, gridSize,
            gridSize/2.0f-dotSize/4.0f, 0,
            gridSize/2.0f-dotSize/4.0f, gridSize,
            gridSize/2.0f+dotSize/4.0f, 0,
            gridSize/2.0f+dotSize/4.0f, gridSize,
        };
        R_if.mapPoints(lineEnds);
        c.drawLines(lineEnds, p);
      }
      return b;
    }
  }

}




Java Source Code List

com.greentaperacing.olearyp.n4lwp.N4WallpaperService.java
com.greentaperacing.olearyp.n4lwp.N4WallpaperSettings.java