/**
* Copyright (C) 2009, 2010 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 org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.model.XYSeries;
import org.achartengine.renderer.SimpleSeriesRenderer;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.util.MathHelper;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.graphics.drawable.GradientDrawable;
import android.graphics.drawable.GradientDrawable.Orientation;
/**
* The bar chart rendering class.
*/
public class BarChart extends XYChart {
/** The constant to identify this chart type. */
public static final String TYPE = "Bar";
/** The legend shape width. */
private static final int SHAPE_WIDTH = 12;
/** The chart type. */
protected Type mType = Type.DEFAULT;
/**
* The bar chart type enum.
*/
public enum Type {
DEFAULT, STACKED;
}
BarChart() {
}
/**
* Builds a new bar chart instance.
*
* @param dataset the multiple series dataset
* @param renderer the multiple series renderer
* @param type the bar chart type
*/
public BarChart(XYMultipleSeriesDataset dataset, XYMultipleSeriesRenderer renderer, Type type) {
super(dataset, renderer);
mType = type;
}
@Override
protected RectF[] clickableAreasForPoints(float[] points, float yAxisValue, int seriesIndex) {
int seriesNr = mDataset.getSeriesCount();
int length = points.length;
RectF[] ret = new RectF[length / 2];
float halfDiffX = getHalfDiffX(points, length, seriesNr);
for (int i = 0; i < length; i += 2) {
float x = points[i];
float y = points[i + 1];
if (mType == Type.STACKED) {
ret[i / 2] = new RectF(x - halfDiffX, y, x + halfDiffX, yAxisValue);
} else {
float startX = x - seriesNr * halfDiffX + seriesIndex * 2 * halfDiffX;
ret[i / 2] = new RectF(startX, y, startX + 2 * halfDiffX, yAxisValue);
}
}
return ret;
}
/**
* 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
*/
public void drawSeries(Canvas canvas, Paint paint, float[] points,
SimpleSeriesRenderer seriesRenderer, float yAxisValue, int seriesIndex) {
int seriesNr = mDataset.getSeriesCount();
int length = points.length;
paint.setColor(seriesRenderer.getColor());
paint.setStyle(Style.FILL);
float halfDiffX = getHalfDiffX(points, length, seriesNr);
for (int i = 0; i < length; i += 2) {
float x = points[i];
float y = points[i + 1];
drawBar(canvas, x, yAxisValue, x, y, halfDiffX, seriesNr, seriesIndex, paint);
}
paint.setColor(seriesRenderer.getColor());
}
/**
* Draws a bar.
* @param canvas the canvas
* @param xMin the X axis minimum
* @param yMin the Y axis minimum
* @param xMax the X axis maximum
* @param yMax the Y axis maximum
* @param halfDiffX half the size of a bar
* @param seriesNr the total number of series
* @param seriesIndex the current series index
* @param paint the paint
*/
protected void drawBar(Canvas canvas, float xMin, float yMin, float xMax, float yMax,
float halfDiffX, int seriesNr, int seriesIndex, Paint paint) {
int scale = mDataset.getSeriesAt(seriesIndex).getScaleNumber();
if (mType == Type.STACKED) {
drawBar(canvas, xMin - halfDiffX, yMax, xMax + halfDiffX, yMin, scale, seriesIndex, paint);
} else {
float startX = xMin - seriesNr * halfDiffX + seriesIndex * 2 * halfDiffX;
drawBar(canvas, startX, yMax, startX + 2 * halfDiffX, yMin, scale, seriesIndex, paint);
}
}
private void drawBar(Canvas canvas, float xMin, float yMin, float xMax, float yMax, int scale,
int seriesIndex, Paint paint) {
SimpleSeriesRenderer renderer = mRenderer.getSeriesRendererAt(seriesIndex);
if (renderer.isGradientEnabled()) {
float minY = (float) toScreenPoint(new double[] { 0, renderer.getGradientStopValue() }, scale)[1];
float maxY = (float) toScreenPoint(new double[] { 0, renderer.getGradientStartValue() },
scale)[1];
float gradientMinY = Math.max(minY, yMin);
float gradientMaxY = Math.min(maxY, yMax);
int gradientMinColor = renderer.getGradientStopColor();
int gradientMaxColor = renderer.getGradientStartColor();
int gradientStartColor = gradientMaxColor;
int gradientStopColor = gradientMinColor;
if (yMin < minY) {
paint.setColor(gradientMinColor);
canvas.drawRect(Math.round(xMin), Math.round(yMin), Math.round(xMax),
Math.round(gradientMinY), paint);
} else {
gradientStopColor = getGradientPartialColor(gradientMinColor, gradientMaxColor,
(maxY - gradientMinY) / (maxY - minY));
}
if (yMax > maxY) {
paint.setColor(gradientMaxColor);
canvas.drawRect(Math.round(xMin), Math.round(gradientMaxY), Math.round(xMax),
Math.round(yMax), paint);
} else {
gradientStartColor = getGradientPartialColor(gradientMaxColor, gradientMinColor,
(gradientMaxY - minY) / (maxY - minY));
}
GradientDrawable gradient = new GradientDrawable(Orientation.BOTTOM_TOP, new int[] {
gradientStartColor, gradientStopColor });
gradient.setBounds(Math.round(xMin), Math.round(gradientMinY), Math.round(xMax),
Math.round(gradientMaxY));
gradient.draw(canvas);
} else {
canvas
.drawRect(Math.round(xMin), Math.round(yMin), Math.round(xMax), Math.round(yMax), paint);
}
}
private int getGradientPartialColor(int minColor, int maxColor, float fraction) {
int alpha = Math.round(fraction * Color.alpha(minColor) + (1 - fraction)
* Color.alpha(maxColor));
int r = Math.round(fraction * Color.red(minColor) + (1 - fraction) * Color.red(maxColor));
int g = Math.round(fraction * Color.green(minColor) + (1 - fraction) * Color.green(maxColor));
int b = Math.round(fraction * Color.blue(minColor) + (1 - fraction) * Color.blue((maxColor)));
return Color.argb(alpha, r, g, b);
}
/**
* 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
*/
protected void drawChartValuesText(Canvas canvas, XYSeries series, SimpleSeriesRenderer renderer,
Paint paint, float[] points, int seriesIndex) {
int seriesNr = mDataset.getSeriesCount();
float halfDiffX = getHalfDiffX(points, points.length, seriesNr);
for (int i = 0; i < points.length; i += 2) {
int index = i / 2;
if (series.getY(index) != MathHelper.NULL_VALUE) {
float x = points[i];
if (mType == Type.DEFAULT) {
x += seriesIndex * 2 * halfDiffX - (seriesNr - 1.5f) * halfDiffX;
}
drawText(canvas, getLabel(series.getY(index)), x,
points[i + 1] - renderer.getChartValuesSpacing(), paint, 0);
}
}
}
/**
* Returns the legend shape width.
*
* @param seriesIndex the series index
* @return the legend shape width
*/
public int getLegendShapeWidth(int seriesIndex) {
return SHAPE_WIDTH;
}
/**
* The graphical representation of the legend shape.
*
* @param canvas the canvas to paint to
* @param renderer the series renderer
* @param x the x value of the point the shape should be drawn at
* @param y the y value of the point the shape should be drawn at
* @param seriesIndex the series index
* @param paint the paint to be used for drawing
*/
public void drawLegendShape(Canvas canvas, SimpleSeriesRenderer renderer, float x, float y,
int seriesIndex, Paint paint) {
float halfShapeWidth = SHAPE_WIDTH / 2;
canvas.drawRect(x, y - halfShapeWidth, x + SHAPE_WIDTH, y + halfShapeWidth, paint);
}
/**
* Calculates and returns the half-distance in the graphical representation of
* 2 consecutive points.
*
* @param points the points
* @param length the points length
* @param seriesNr the series number
* @return the calculated half-distance value
*/
protected float getHalfDiffX(float[] points, int length, int seriesNr) {
int div = length;
if (length > 2) {
div = length - 2;
}
float halfDiffX = (points[length - 2] - points[0]) / div;
if (halfDiffX == 0) {
halfDiffX = 10;
}
if (mType != Type.STACKED) {
halfDiffX /= seriesNr;
}
return (float) (halfDiffX / (getCoeficient() * (1 + mRenderer.getBarSpacing())));
}
/**
* Returns the value of a constant used to calculate the half-distance.
*
* @return the constant value
*/
protected float getCoeficient() {
return 1f;
}
/**
* Returns if the chart should display the null values.
*
* @return if null values should be rendered
*/
protected boolean isRenderNullValues() {
return true;
}
/**
* Returns the default axis minimum.
*
* @return the default axis minimum
*/
public double getDefaultMinimum() {
return 0;
}
/**
* Returns the chart type identifier.
*
* @return the chart type
*/
public String getChartType() {
return TYPE;
}
}