MatrixEvaluator.java

package uk.co.cogitolearning.propertyanimations_example;

import android.animation.TypeEvaluator;
import android.graphics.Color;
import android.graphics.Matrix;

public class MatrixEvaluator implements TypeEvaluator<Matrix>
{
  
  @Override
  public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue)
  {
    float[] startEntries = new float[9];
    float[] endEntries = new float[9];
    float[] currentEntries = new float[9];

    startValue.getValues(startEntries);
    endValue.getValues(endEntries);
    
    for (int i=0; i<9; i++)
      currentEntries[i] = (1-fraction)*startEntries[i] + fraction*endEntries[i];

    Matrix matrix = new Matrix();
    matrix.setValues(currentEntries);
    
    return matrix;
  }
}