Android Open Source - OpenHSK Exam Result Pie Chart

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License

The source code is released under:

This work is licensed under a Creative Commons Attribution 3.0 Unported License. Original author of word lists: http://lingomi.com/ Original author of definitions: http://cc-cedict.org Original autho...

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Java Source Code

package edu.openhsk.views;
/*from   www .  j a v a2s .c  o  m*/
import java.util.ArrayList;

import edu.openhsk.R;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class ExamResultPieChart extends View {

  private static final String LOG_TAG = ExamResultPieChart.class.getName();
  private static String[] PIE_COLORS = {"#038C17", "#BF1A0B"};
  private RectF rectangle;
  private ArrayList<Float> percentages = new ArrayList<Float>();
  private Paint paintPieFill;
  private Paint paintPieBorder;

  public ExamResultPieChart(Context context, AttributeSet attrs) {
    super(context, attrs);

    // used for paint circle
    paintPieFill = new Paint(Paint.ANTI_ALIAS_FLAG);
    paintPieFill.setStyle(Paint.Style.FILL);
    
    // used for paint border
    paintPieBorder = new Paint(Paint.ANTI_ALIAS_FLAG);
    paintPieBorder.setStyle(Paint.Style.STROKE);
    paintPieBorder.setStrokeWidth(fnGetRealPxFromDp(3));
    paintPieBorder.setColor(Color.WHITE);
    Log.i(LOG_TAG, "PieChart init done");

  }

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    
    float fStartAngle = 0f;
    for (int i = 0; i < percentages.size(); i++) {

      // check whether the data size larger than color list size
      if (i >= 2) {
        paintPieFill.setColor(Color.parseColor(PIE_COLORS[i % 2]));
      } else {
        paintPieFill.setColor(Color.parseColor(PIE_COLORS[i]));
      }

      float fEndAngle = percentages.get(i);

      // convert percentage to angle
      fEndAngle = fEndAngle / 100 * 360;

      canvas.drawArc(rectangle, fStartAngle, fEndAngle, true, paintPieFill);

      fStartAngle = fStartAngle + fEndAngle;
    }

    Log.i(LOG_TAG, "onDraw done");
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    // get screen size
    int iDisplayWidth = MeasureSpec.getSize(widthMeasureSpec);
    int iDisplayHeight = MeasureSpec.getSize(heightMeasureSpec);

    if (iDisplayWidth > iDisplayHeight) {
      iDisplayWidth = iDisplayHeight;
    }

    //determine the rectangle size
    int iCenterWidth = iDisplayWidth / 2;
    int iR = iCenterWidth - (int) fnGetRealPxFromDp(40);
    if (rectangle == null) {
      rectangle = new RectF(iCenterWidth - iR, // top
          iCenterWidth - iR, // left
          iCenterWidth + iR, // rights
          iCenterWidth + iR); // bottom
    }
    setMeasuredDimension(iDisplayWidth, iDisplayWidth);
  }

  private float fnGetRealPxFromDp(float fDp) {
    float fDensity = this.getResources().getDisplayMetrics().density;
    return (fDensity != 1.0f) ? fDensity * fDp : fDp;
  }
  
  public void setAdapter(ArrayList<Float> percentages) throws DisproportionatePieChartSumException {
    this.percentages = percentages;
    float fSum = 0;
    for (int i = 0; i < percentages.size(); i++) {
      fSum += percentages.get(i);
    }
    if (fSum != 100) {
      throw new DisproportionatePieChartSumException();
    }
  }
  
  public class DisproportionatePieChartSumException extends Exception {
    private static final long serialVersionUID = 1L;

    @Override
    public String getMessage() {
      return (String) ExamResultPieChart.this.getResources().getText(R.string.piechart_error_msg);
    }
  }

}

Java Source Code List