RangeBarChart.java

/**
 * Copyright (C) 2009 - 2013 SC 4ViewSoft SRL
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.achartengine.chart;

import java.util.List;

import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.model.XYSeries;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.renderer.XYSeriesRenderer;

import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;

/**
 * The range bar chart rendering class.
 */
public class RangeBarChart extends BarChart {
  /** The chart type. */
  public static final String TYPE = "RangeBar";

  RangeBarChart() {
  }

  RangeBarChart(Type type) {
    super(type);
  }

  /**
   * Builds a new range bar chart instance.
   * 
   * @param dataset the multiple series dataset
   * @param renderer the multiple series renderer
   * @param type the range bar chart type
   */
  public RangeBarChart(XYMultipleSeriesDataset dataset, XYMultipleSeriesRenderer renderer, Type type) {
    super(dataset, renderer, type);
  }

  /**
   * The graphical representation of a series.
   * 
   * @param canvas the canvas to paint to
   * @param paint the paint to be used for drawing
   * @param points the array of points to be used for drawing the series
   * @param seriesRenderer the series renderer
   * @param yAxisValue the minimum value of the y axis
   * @param seriesIndex the index of the series currently being drawn
   * @param startIndex the start index of the rendering points
   */
  @Override
  public void drawSeries(Canvas canvas, Paint paint, List<Float> points,
      XYSeriesRenderer seriesRenderer, float yAxisValue, int seriesIndex, int startIndex) {
    int seriesNr = mDataset.getSeriesCount();
    int length = points.size();
    paint.setColor(seriesRenderer.getColor());
    paint.setStyle(Style.FILL);
    float halfDiffX = getHalfDiffX(points, length, seriesNr);
    int start = 0;
    if (startIndex > 0) {
      start = 2;
    }
    for (int i = start; i < length; i += 4) {
      if (points.size() > i + 3) {
        float xMin = points.get(i);
        float yMin = points.get(i + 1);
        // xMin = xMax
        float xMax = points.get(i + 2);
        float yMax = points.get(i + 3);
        drawBar(canvas, xMin, yMin, xMax, yMax, halfDiffX, seriesNr, seriesIndex, paint);
      }
    }
    paint.setColor(seriesRenderer.getColor());
  }

  /**
   * The graphical representation of the series values as text.
   * 
   * @param canvas the canvas to paint to
   * @param series the series to be painted
   * @param renderer the series renderer
   * @param paint the paint to be used for drawing
   * @param points the array of points to be used for drawing the series
   * @param seriesIndex the index of the series currently being drawn
   * @param startIndex the start index of the rendering points
   */
  protected void drawChartValuesText(Canvas canvas, XYSeries series, XYSeriesRenderer renderer,
      Paint paint, List<Float> points, int seriesIndex, int startIndex) {
    int seriesNr = mDataset.getSeriesCount();
    float halfDiffX = getHalfDiffX(points, points.size(), seriesNr);
    int start = 0;
    if (startIndex > 0) {
      start = 2;
    }
    for (int i = start; i < points.size(); i += 4) {
      int index = startIndex + i / 2;
      float x = points.get(i);
      if (mType == Type.DEFAULT) {
        x += seriesIndex * 2 * halfDiffX - (seriesNr - 1.5f) * halfDiffX;
      }

      if (!isNullValue(series.getY(index + 1)) && points.size() > i + 3) {
        // draw the maximum value
        drawText(canvas, getLabel(renderer.getChartValuesFormat(), series.getY(index + 1)), x,
            points.get(i + 3) - renderer.getChartValuesSpacing(), paint, 0);
      }
      if (!isNullValue(series.getY(index)) && points.size() > i + 1) {
        // draw the minimum value
        drawText(
            canvas,
            getLabel(renderer.getChartValuesFormat(), series.getY(index)),
            x,
            points.get(i + 1) + renderer.getChartValuesTextSize()
                + renderer.getChartValuesSpacing() - 3, paint, 0);
      }
    }
  }

  /**
   * Returns the value of a constant used to calculate the half-distance.
   * 
   * @return the constant value
   */
  protected float getCoeficient() {
    return 0.5f;
  }

  /**
   * Returns the chart type identifier.
   * 
   * @return the chart type
   */
  public String getChartType() {
    return TYPE;
  }

}