add sample bar chart 10, fix broken y aix tick calculator for bar charts

xchart-demo/src/main/java/org/knowm/xchart/demo/charts/bar/BarChart09.java

@@ -142,7 +142,7 @@ public class BarChart09 implements ExampleChart {
                          
     // Add data series to chart
     for (int i = 0; i < seriesNames.length; i++) {
-      Series series = chart.addSeries(seriesNames[i], xAxisKeys, Arrays.asList(dataPerSeries[i]));
+      Series series = chart.addCategorySeries(seriesNames[i], xAxisKeys, Arrays.asList(dataPerSeries[i]));
       series.setMarker(SeriesMarker.NONE);
       series.setSeriesType(SeriesType.Line);
     }

xchart-demo/src/main/java/org/knowm/xchart/demo/charts/bar/BarChart10.java

+/**
+ * Copyright 2015 Knowm Inc. (http://knowm.org) and contributors.
+ * Copyright 2011-2015 Xeiam LLC (http://xeiam.com) and contributors.
+ *
+ * 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.knowm.xchart.demo.charts.bar;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import org.knowm.xchart.Chart;
+import org.knowm.xchart.ChartBuilder;
+import org.knowm.xchart.Series;
+import org.knowm.xchart.Series.SeriesType;
+import org.knowm.xchart.StyleManager.ChartTheme;
+import org.knowm.xchart.StyleManager.ChartType;
+import org.knowm.xchart.StyleManager.LegendPosition;
+import org.knowm.xchart.SwingWrapper;
+import org.knowm.xchart.demo.charts.ExampleChart;
+
+/**
+ * Category chart with Bar and Line Series
+ * <p>
+ * Demonstrates the following:
+ * <ul>
+ * <li>Mixed series types - Bar and Line
+ * <li>Bar Chart styles - overlapped, bar width
+ */
+public class BarChart10 implements ExampleChart {
+
+  public static void main(String[] args) {
+
+    ExampleChart exampleChart = new BarChart10();
+    Chart chart = exampleChart.getChart();
+    new SwingWrapper(chart).displayChart();
+  }
+
+  @Override
+  public Chart getChart() {
+
+    // Create Chart
+    Chart chart = new ChartBuilder().chartType(ChartType.Bar).width(800).height(600).title("Value vs. Letter").xAxisTitle("Letter").yAxisTitle("Value").theme(ChartTheme.GGPlot2).build();
+    chart.addCategorySeries("China", new ArrayList<String>(Arrays.asList(new String[] { "A", "B", "C", "D", "E" })), new ArrayList<Number>(Arrays.asList(new Number[] { 11, 23, 20, 36, 5 })));
+    Series series2 = chart.addCategorySeries("World Ave.", new ArrayList<String>(Arrays.asList(new String[] { "A", "B", "C", "D", "E" })), new ArrayList<Number>(Arrays.asList(new Number[] { 13, 25,
+        22, 38, 7 })));
+    series2.setSeriesType(SeriesType.Line);
+
+    // Customize Chart
+    chart.getStyleManager().setLegendPosition(LegendPosition.InsideNW);
+    chart.getStyleManager().setBarWidthPercentage(.7);
+    chart.getStyleManager().setBarsOverlapped(true);
+
+    return chart;
+  }
+
+}

xchart/src/main/java/org/knowm/xchart/internal/chartpart/AxisTickCalculator.java

@@ -25,6 +25,8 @@ import java.util.LinkedList;
 import java.util.List;
 
 import org.knowm.xchart.StyleManager;
+import org.knowm.xchart.StyleManager.ChartType;
+import org.knowm.xchart.internal.Utils;
 import org.knowm.xchart.internal.chartpart.Axis.Direction;
 
 /**
@@ -59,16 +61,31 @@ public abstract class AxisTickCalculator {
    */
   public AxisTickCalculator(Direction axisDirection, double workingSpace, double minValue, double maxValue, StyleManager styleManager) {
 
-    // override min and maxValue if specified
+    // override min/max value for bar charts' Y-Axis
     double overrideMinValue = minValue;
     double overrideMaxValue = maxValue;
-    if (axisDirection == Direction.X && styleManager.getXAxisMin() != null) {
+    if (styleManager.getChartType() == ChartType.Bar && axisDirection == Direction.Y) { // this is the Y-Axis for a bar chart
+      if (minValue > 0.0 && maxValue > 0.0) {
+        overrideMinValue = 0.0;
+      }
+      if (minValue < 0.0 && maxValue < 0.0) {
+        overrideMaxValue = 0.0;
+      }
+    }
+
+    if (styleManager.getChartType() == ChartType.Bar && styleManager.isYAxisLogarithmic()) {
+      int logMin = (int) Math.floor(Math.log10(minValue));
+      overrideMinValue = Utils.pow(10, logMin);
+    }
+
+    // override min and maxValue if specified
+    if (axisDirection == Direction.X && styleManager.getXAxisMin() != null && styleManager.getChartType() != ChartType.Bar) { // bar chart cannot have a max or min
       overrideMinValue = styleManager.getXAxisMin();
     }
     if (axisDirection == Direction.Y && styleManager.getYAxisMin() != null) {
       overrideMinValue = styleManager.getYAxisMin();
     }
-    if (axisDirection == Direction.X && styleManager.getXAxisMax() != null) {
+    if (axisDirection == Direction.X && styleManager.getXAxisMax() != null && styleManager.getChartType() != ChartType.Bar) { // bar chart cannot have a max or min
       overrideMaxValue = styleManager.getXAxisMax();
     }
     if (axisDirection == Direction.Y && styleManager.getYAxisMax() != null) {

xchart/src/main/java/org/knowm/xchart/internal/chartpart/AxisTickCategoryChartCalculator.java

@@ -46,26 +46,6 @@ public class AxisTickCategoryChartCalculator extends AxisTickCalculator {
 
     super(axisDirection, workingSpace, minValue, maxValue, chart.getStyleManager());
 
-    // override min/max value for bar charts' Y-Axis
-    double overrideMinValue = minValue;
-    double overrideMaxValue = maxValue;
-    if (axisDirection == Direction.Y) { // this is the Y-Axis for a bar chart
-      if (minValue > 0.0 && maxValue > 0.0) {
-        overrideMinValue = 0.0;
-      }
-      if (minValue < 0.0 && maxValue < 0.0) {
-        overrideMaxValue = 0.0;
-      }
-    }
-
-    if (styleManager.isYAxisLogarithmic()) {
-      int logMin = (int) Math.floor(Math.log10(minValue));
-      overrideMinValue = Utils.pow(10, logMin);
-    }
-
-    this.minValue = overrideMinValue;
-    this.maxValue = overrideMaxValue;
-
     calculate(chart);
   }
 

xchart/src/main/java/org/knowm/xchart/internal/chartpart/ChartInternal.java

@@ -105,7 +105,7 @@ public class ChartInternal {
       // inspect the series to see what kind of data it contains (Number, Date)
       AxisType axisType = setXAxisType(xData);
       if (!(axisType == AxisType.Number || axisType == AxisType.Date)) {
-        throw new IllegalArgumentException("X-Axis data must be of type Number or Date!!!");
+        throw new IllegalArgumentException("X-Axis data must be of type Number or Date for X-Y chart types!!!");
       }
 
       axisPair.getYAxis().setAxisType(AxisType.Number);

xchart/src/main/java/org/knowm/xchart/internal/chartpart/PlotContentCategoricalChart.java

@@ -85,6 +85,7 @@ public class PlotContentCategoricalChart extends PlotContent {
       double yMin = getChartInternal().getAxisPair().getYAxis().getMin();
       double yMax = getChartInternal().getAxisPair().getYAxis().getMax();
 
+      // if (styleManager.getChartType() == ChartType.Bar) {
       // if min and max positive, set min to zero
       if (yMin > 0.0 && yMax > 0.0) {
         yMin = 0.0;
@@ -93,6 +94,7 @@ public class PlotContentCategoricalChart extends PlotContent {
       if (yMin < 0.0 && yMax < 0.0) {
         yMax = 0.0;
       }
+      // }
 
       // override min and maxValue if specified
       if (getChartInternal().getStyleManager().getYAxisMin() != null) {
@@ -111,6 +113,7 @@ public class PlotContentCategoricalChart extends PlotContent {
       else if (getChartInternal().getStyleManager().isYAxisLogarithmic()) {
         yMax = Math.log10(yMax);
       }
+
       // figure out the general form of the chart
       int chartForm = 1; // 1=positive, -1=negative, 0=span
       if (yMin > 0.0 && yMax > 0.0) {