unit tests, pulled out grid step calculations, working towards bar charts and logarithmic axes

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/area/AreaChart01.java

@@ -17,9 +17,9 @@ package com.xeiam.xchart.demo.charts.area;
 
 import com.xeiam.xchart.Chart;
 import com.xeiam.xchart.ChartBuilder;
-import com.xeiam.xchart.ChartBuilder.ChartType;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.demo.charts.line.ExampleChart;
+import com.xeiam.xchart.style.StyleManager.ChartType;
 import com.xeiam.xchart.style.StyleManager.LegendPosition;
 
 /**
@@ -40,7 +40,7 @@ public class AreaChart01 implements ExampleChart {
   public Chart getChart() {
 
     // Create Chart
-    Chart chart = new ChartBuilder().chartType(ChartType.Area).width(800).height(600).title("LineChart11").xAxisTitle("X").yAxisTitle("Y").build();
+    Chart chart = new ChartBuilder().chartType(ChartType.Area).width(800).height(600).title("AreaChart01").xAxisTitle("X").yAxisTitle("Y").build();
     chart.addSeries("a", new double[] { 0, 3, 5, 7, 9 }, new double[] { -3, 5, 9, 6, 5 });
     chart.addSeries("b", new double[] { 0, 2, 4, 6, 9 }, new double[] { -1, 6, 4, 0, 4 });
     chart.addSeries("c", new double[] { 0, 1, 3, 8, 9 }, new double[] { -2, -1, 1, 0, 1 });

xchart/src/main/java/com/xeiam/xchart/LineChart.java → xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/bar/BarChart01.java

@@ -19,34 +19,38 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package com.xeiam.xchart;
+package com.xeiam.xchart.demo.charts.bar;
+
+import com.xeiam.xchart.Chart;
+import com.xeiam.xchart.ChartBuilder;
+import com.xeiam.xchart.SwingWrapper;
+import com.xeiam.xchart.demo.charts.line.ExampleChart;
+import com.xeiam.xchart.style.StyleManager.ChartType;
+import com.xeiam.xchart.style.StyleManager.LegendPosition;
 
 /**
- * A Scatter Chart is a contains series with no lines drawn between the points
- * 
  * @author timmolter
  */
-public class LineChart extends Chart {
-
-  /**
-   * Constructor
-   * 
-   * @param width
-   * @param height
-   */
-  public LineChart(int width, int height) {
+public class BarChart01 implements ExampleChart {
 
-    super(width, height);
+  public static void main(String[] args) {
 
+    ExampleChart exampleChart = new BarChart01();
+    Chart chart = exampleChart.getChart();
+    new SwingWrapper(chart).displayChart();
   }
 
-  /**
-   * Constructor
-   * 
-   * @param chartBuilder
-   */
-  public LineChart(ChartBuilder chartBuilder) {
+  @Override
+  public Chart getChart() {
+
+    // Create Chart
+    Chart chart = new ChartBuilder().chartType(ChartType.Bar).width(800).height(600).title("BarChart01").xAxisTitle("X").yAxisTitle("Y").build();
+    chart.addSeries("a", new double[] { 0, 1, 2, 3, 4 }, new double[] { -3, 5, 9, 6, 5 });
+
+    // Customize Chart
+    chart.getStyleManager().setChartTitleVisible(false);
+    chart.getStyleManager().setLegendPosition(LegendPosition.InsideNW);
 
-    super(chartBuilder);
+    return chart;
   }
 }

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart01.java

@@ -19,7 +19,6 @@ import java.util.Arrays;
 import java.util.Collection;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.style.Series;
 import com.xeiam.xchart.style.SeriesMarker;
@@ -79,7 +78,7 @@ public class LineChart01 implements ExampleChart {
     Collection<Number> yData = Arrays.asList(yDataArray);
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // Customize Chart
     chart.setChartTitle("LineChart01");

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart02.java

@@ -19,7 +19,6 @@ import java.util.ArrayList;
 import java.util.List;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.style.Series;
 import com.xeiam.xchart.style.SeriesColor;
@@ -57,7 +56,7 @@ public class LineChart02 implements ExampleChart {
     }
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // Customize Chart
     chart.getStyleManager().setChartTitleVisible(false);

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart03.java

@@ -19,7 +19,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 
 /**
@@ -38,7 +37,7 @@ public class LineChart03 implements ExampleChart {
   public Chart getChart() {
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     for (int i = 1; i <= 14; i++) {
 

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart04.java

@@ -24,7 +24,6 @@ import java.util.Date;
 import java.util.TimeZone;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.style.Series;
 import com.xeiam.xchart.style.StyleManager.LegendPosition;
@@ -50,7 +49,7 @@ public class LineChart04 implements ExampleChart {
   public Chart getChart() {
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // generates linear data
     Collection<Date> xData = new ArrayList<Date>();

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart06.java

@@ -16,7 +16,6 @@
 package com.xeiam.xchart.demo.charts.line;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 
 /**
@@ -35,7 +34,7 @@ public class LineChart06 implements ExampleChart {
   public Chart getChart() {
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // Customize Chart
     chart.setChartTitle("LineChart06");

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart07.java

@@ -19,7 +19,6 @@ import java.util.Arrays;
 import java.util.Collection;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 
 /**
@@ -41,7 +40,7 @@ public class LineChart07 implements ExampleChart {
     Collection<Number> yData = Arrays.asList(new Number[] { 0.0, 1.0, 2.0, 0.0, 1.0, 2.0, 0.0, 1.0, 2.0, 0.0 });
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
     chart.setChartTitle("LineChart07");
     chart.setXAxisTitle("X");
     chart.setYAxisTitle("Y");

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart08.java

@@ -19,7 +19,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.style.Series;
 import com.xeiam.xchart.style.SeriesColor;
@@ -53,7 +52,7 @@ public class LineChart08 implements ExampleChart {
     }
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // Customize Chart
     chart.getStyleManager().setChartTitleVisible(false);

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart09.java

@@ -26,7 +26,6 @@ import java.util.Date;
 import java.util.Locale;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.style.ChartColor;
 import com.xeiam.xchart.style.Series;
@@ -50,7 +49,7 @@ public class LineChart09 implements ExampleChart {
   public Chart getChart() {
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // generates linear data
     Collection<Date> xData = new ArrayList<Date>();

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/line/LineChart10.java

@@ -16,7 +16,6 @@
 package com.xeiam.xchart.demo.charts.line;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.LineChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.style.Series;
 import com.xeiam.xchart.style.SeriesColor;
@@ -39,7 +38,7 @@ public class LineChart10 implements ExampleChart {
   public Chart getChart() {
 
     // Create Chart
-    Chart chart = new LineChart(800, 600);
+    Chart chart = new Chart(800, 600);
 
     // Customize Chart
     chart.setChartTitle("LineChart10");

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/scatter/ScatterChart01.java

@@ -20,9 +20,9 @@ import java.util.List;
 import java.util.Random;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.ScatterChart;
 import com.xeiam.xchart.SwingWrapper;
 import com.xeiam.xchart.demo.charts.line.ExampleChart;
+import com.xeiam.xchart.style.StyleManager.ChartType;
 
 /**
  * Gaussian Blob
@@ -51,7 +51,8 @@ public class ScatterChart01 implements ExampleChart {
     }
 
     // Create Chart
-    Chart chart = new ScatterChart(800, 600);
+    Chart chart = new Chart(800, 600);
+    chart.getStyleManager().setChartType(ChartType.Scatter);
 
     // Customize Chart
     chart.getStyleManager().setChartTitleVisible(false);

xchart/src/main/java/com/xeiam/xchart/Chart.java

@@ -35,7 +35,7 @@ import com.xeiam.xchart.style.theme.Theme;
  * 
  * @author timmolter
  */
-public abstract class Chart {
+public class Chart {
 
   private int width;
   private int height;
@@ -74,6 +74,7 @@ public abstract class Chart {
     setXAxisTitle(chartBuilder.xAxisTitle);
     setYAxisTitle(chartBuilder.yAxisTitle);
     setTheme(chartBuilder.theme);
+    getStyleManager().setChartType(chartBuilder.chartType);
   }
 
   /**

xchart/src/main/java/com/xeiam/xchart/ChartBuilder.java

@@ -21,6 +21,7 @@
  */
 package com.xeiam.xchart;
 
+import com.xeiam.xchart.style.StyleManager.ChartType;
 import com.xeiam.xchart.style.theme.Theme;
 import com.xeiam.xchart.style.theme.XChartTheme;
 
@@ -29,11 +30,6 @@ import com.xeiam.xchart.style.theme.XChartTheme;
  */
 public class ChartBuilder {
 
-  public enum ChartType {
-
-    Line, Scatter, Area
-  }
-
   protected ChartType chartType = ChartType.Line;
   protected int width = 800;
   protected int height = 600;
@@ -91,16 +87,7 @@ public class ChartBuilder {
    */
   public Chart build() {
 
-    switch (chartType) {
-    case Line:
-      return new LineChart(this);
-    case Scatter:
-      return new ScatterChart(this);
-    case Area:
-      return new AreaChart(this);
-    default:
-      return new LineChart(this);
-    }
+    return new Chart(this);
 
   }
 

xchart/src/main/java/com/xeiam/xchart/QuickChart.java

@@ -72,7 +72,7 @@ public final class QuickChart {
   public static Chart getChart(String chartTitle, String xTitle, String yTitle, String[] seriesNames, double[] xData, double[][] yData) {
 
     // Create Chart
-    Chart chart = new LineChart(WIDTH, HEIGHT);
+    Chart chart = new Chart(WIDTH, HEIGHT);
 
     // Customize Chart
     chart.setChartTitle(chartTitle);
@@ -108,7 +108,7 @@ public final class QuickChart {
   public static Chart getChart(String chartTitle, String xTitle, String yTitle, String seriesName, Collection<Number> xData, Collection<Number> yData) {
 
     // Create Chart
-    Chart chart = new LineChart(WIDTH, HEIGHT);
+    Chart chart = new Chart(WIDTH, HEIGHT);
 
     // Customize Chart
     chart.setChartTitle(chartTitle);

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/Axis.java

@@ -33,7 +33,7 @@ public class Axis implements ChartPart {
 
   public enum AxisType {
 
-    NUMBER, DATE;
+    Number, Date, Logarithmic;
   }
 
   /** parent */
@@ -66,7 +66,7 @@ public class Axis implements ChartPart {
   private Rectangle paintZone;
 
   /** An axis direction */
-  protected enum Direction {
+  public enum Direction {
 
     /** the constant to represent X axis */
     X,

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisPair.java

@@ -87,19 +87,19 @@ public class AxisPair implements ChartPart {
       Iterator<?> itr = xData.iterator();
       Object dataPoint = itr.next();
       if (dataPoint instanceof Number) {
-        xAxis.setAxisType(AxisType.NUMBER);
+        xAxis.setAxisType(AxisType.Number);
       } else if (dataPoint instanceof Date) {
-        xAxis.setAxisType(AxisType.DATE);
+        xAxis.setAxisType(AxisType.Date);
       }
-      yAxis.setAxisType(AxisType.NUMBER);
+      yAxis.setAxisType(AxisType.Number);
       series = new Series(seriesName, xData, xAxis.getAxisType(), yData, yAxis.getAxisType(), errorBars, seriesColorMarkerLineStyleCycler.getNextSeriesColorMarkerLineStyle());
     } else { // generate xData
       Collection<Number> generatedXData = new ArrayList<Number>();
       for (int i = 1; i < yData.size() + 1; i++) {
         generatedXData.add(i);
       }
-      xAxis.setAxisType(AxisType.NUMBER);
-      yAxis.setAxisType(AxisType.NUMBER);
+      xAxis.setAxisType(AxisType.Number);
+      yAxis.setAxisType(AxisType.Number);
       series = new Series(seriesName, generatedXData, xAxis.getAxisType(), yData, yAxis.getAxisType(), errorBars, seriesColorMarkerLineStyleCycler.getNextSeriesColorMarkerLineStyle());
     }
 

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTick.java

@@ -17,25 +17,15 @@ package com.xeiam.xchart.internal.chartpart;
 
 import java.awt.Graphics2D;
 import java.awt.Rectangle;
-import java.math.BigDecimal;
-import java.util.LinkedList;
 import java.util.List;
 
 import com.xeiam.xchart.Chart;
-import com.xeiam.xchart.internal.chartpart.Axis.AxisType;
-import com.xeiam.xchart.internal.chartpart.Axis.Direction;
 
 /**
  * An axis tick
  */
 public class AxisTick implements ChartPart {
 
-  /** the default tick mark step hint for x axis */
-  private static final int DEFAULT_TICK_MARK_STEP_HINT_X = 74;
-
-  /** the default tick mark step hint for y axis */
-  private static final int DEFAULT_TICK_MARK_STEP_HINT_Y = 44;
-
   /** parent */
   private Axis axis;
 
@@ -45,20 +35,14 @@ public class AxisTick implements ChartPart {
   /** the axistickmarks */
   private AxisTickMarks axisTickMarks;
 
-  /** the List of tick label position in pixels */
-  private List<Integer> tickLocations;
-
-  /** the List of tick label values */
-  private List<String> tickLabels;
-
-  private int workingSpace;
-
   /** the bounds */
   private Rectangle bounds;
 
   /** the visibility state of axistick */
   private boolean isVisible = true; // default to true
 
+  AxisTickComputer axisTickComputer;
+
   /**
    * Constructor
    * 
@@ -84,6 +68,7 @@ public class AxisTick implements ChartPart {
 
     bounds = new Rectangle();
 
+    int workingSpace = 0;
     if (axis.getDirection() == Axis.Direction.Y) {
       workingSpace = (int) axis.getPaintZone().getHeight(); // number of pixels the axis has to work with for drawing AxisTicks
       // System.out.println("workingspace= " + workingSpace);
@@ -92,16 +77,10 @@ public class AxisTick implements ChartPart {
       // System.out.println("workingspace= " + workingSpace);
     }
 
-    determineAxisTick();
-
-    // for (Integer position : tickLocations) {
-    // System.out.println(position);
-    // }
-    // for (String label : tickLabels) {
-    // System.out.println(label);
-    // }
+    axisTickComputer = new AxisTickComputer(axis.getDirection(), workingSpace, axis.getMin(), axis.getMax(), getChart().getValueFormatter(), axis.getAxisType());
 
     if (isVisible) {
+
       axisTickLabels.paint(g);
       axisTickMarks.paint(g);
 
@@ -121,136 +100,6 @@ public class AxisTick implements ChartPart {
 
   }
 
-  /**
-   * 
-   */
-  private void determineAxisTick() {
-
-    tickLocations = new LinkedList<Integer>();
-    tickLabels = new LinkedList<String>();
-
-    // System.out.println("workingSpace= " + workingSpace);
-
-    int tickSpace = AxisPair.getTickSpace(workingSpace);
-    // System.out.println("tickSpace= " + tickSpace);
-
-    int margin = AxisPair.getTickStartOffset(workingSpace, tickSpace);
-
-    // a check if all axis data are the exact same values
-    if (axis.getMax() == axis.getMin()) {
-      tickLabels.add(format(axis.getMax()));
-      tickLocations.add((int) (margin + tickSpace / 2.0));
-    } else {
-
-      final BigDecimal min = new BigDecimal(axis.getMin().doubleValue());
-      BigDecimal firstPosition;
-      BigDecimal gridStep = getGridStep(tickSpace);
-
-      double xyz = min.remainder(gridStep).doubleValue();
-      if (xyz <= 0.0) {
-        firstPosition = min.subtract(min.remainder(gridStep));
-      } else {
-        firstPosition = min.subtract(min.remainder(gridStep)).add(gridStep);
-      }
-
-      for (BigDecimal b = firstPosition; b.compareTo(axis.getMax()) <= 0; b = b.add(gridStep)) {
-
-        // System.out.println("b= " + b);
-        tickLabels.add(format(b));
-        int tickLabelPosition = (int) (margin + ((b.subtract(axis.getMin())).doubleValue() / (axis.getMax().subtract(axis.getMin())).doubleValue() * tickSpace));
-        // System.out.println("tickLabelPosition= " + tickLabelPosition);
-
-        tickLocations.add(tickLabelPosition);
-      }
-    }
-  }
-
-  private BigDecimal getGridStep(int tickSpace) {
-
-    double length = Math.abs(axis.getMax().subtract(axis.getMin()).doubleValue());
-    // System.out.println(axis.getMax());
-    // System.out.println(axis.min);
-    // System.out.println(length);
-    int tickMarkSpaceHint = (axis.getDirection() == Direction.X ? DEFAULT_TICK_MARK_STEP_HINT_X : DEFAULT_TICK_MARK_STEP_HINT_Y);
-    // for very short plots, squeeze some more ticks in than normal
-    if (axis.getDirection() == Direction.Y && tickSpace < 160) {
-      tickMarkSpaceHint = 25;
-    }
-    double gridStepHint = length / tickSpace * tickMarkSpaceHint;
-
-    // gridStepHint --> mantissa * 10 ** exponent
-    // e.g. 724.1 --> 7.241 * 10 ** 2
-    double mantissa = gridStepHint;
-    int exponent = 0;
-    if (mantissa == 0) {
-      exponent = 1;
-    } else if (mantissa < 1) {
-      while (mantissa < 1) {
-        mantissa *= 10.0;
-        exponent--;
-      }
-    } else {
-      while (mantissa >= 10) {
-        mantissa /= 10.0;
-        exponent++;
-      }
-    }
-
-    // calculate the grid step with hint.
-    BigDecimal gridStep;
-    if (mantissa > 7.5) {
-      // gridStep = 10.0 * 10 ** exponent
-      gridStep = BigDecimal.TEN.multiply(pow(10, exponent));
-    } else if (mantissa > 3.5) {
-      // gridStep = 5.0 * 10 ** exponent
-      gridStep = new BigDecimal(new Double(5).toString()).multiply(pow(10, exponent));
-    } else if (mantissa > 1.5) {
-      // gridStep = 2.0 * 10 ** exponent
-      gridStep = new BigDecimal(new Double(2).toString()).multiply(pow(10, exponent));
-    } else {
-      // gridStep = 1.0 * 10 ** exponent
-      gridStep = pow(10, exponent);
-    }
-    return gridStep;
-  }
-
-  /**
-   * Calculates the value of the first argument raised to the power of the second argument.
-   * 
-   * @param base the base
-   * @param exponent the exponent
-   * @return the value <tt>a<sup>b</sup></tt> in <tt>BigDecimal</tt>
-   */
-  private BigDecimal pow(double base, int exponent) {
-
-    BigDecimal value;
-    if (exponent > 0) {
-      value = new BigDecimal(new Double(base).toString()).pow(exponent);
-    } else {
-      value = BigDecimal.ONE.divide(new BigDecimal(new Double(base).toString()).pow(-exponent));
-    }
-    return value;
-  }
-
-  /**
-   * Format the number
-   * 
-   * @param value The number to be formatted
-   * @return The formatted number in String form
-   */
-  private String format(BigDecimal value) {
-
-    if (axis.getAxisType() == AxisType.NUMBER) {
-
-      return getChart().getValueFormatter().formatNumber(value);
-
-    } else {
-
-      return getChart().getValueFormatter().formatDateValue(value, axis.getMin(), axis.getMax());
-    }
-
-  }
-
   @Override
   public Chart getChart() {
 
@@ -259,23 +108,23 @@ public class AxisTick implements ChartPart {
 
   // Getters /////////////////////////////////////////////////
 
-  public List<Integer> getTickLocations() {
+  public Axis getAxis() {
 
-    return tickLocations;
+    return axis;
   }
 
-  public List<String> getTickLabels() {
+  public AxisTickLabels getAxisTickLabels() {
 
-    return tickLabels;
+    return axisTickLabels;
   }
 
-  public Axis getAxis() {
+  public List<Integer> getTickLocations() {
 
-    return axis;
+    return axisTickComputer.getTickLocations();
   }
 
-  public AxisTickLabels getAxisTickLabels() {
+  public List<String> getTickLabels() {
 
-    return axisTickLabels;
+    return axisTickComputer.getTickLabels();
   }
 }

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickComputer.java

+/**
+ * Copyright (C) 2013 Xeiam LLC http://xeiam.com
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.xeiam.xchart.internal.chartpart;
+
+import java.math.BigDecimal;
+import java.util.LinkedList;
+import java.util.List;
+
+import com.xeiam.xchart.internal.chartpart.Axis.AxisType;
+import com.xeiam.xchart.internal.chartpart.Axis.Direction;
+import com.xeiam.xchart.internal.chartpart.gridstep.DecimalGridStep;
+import com.xeiam.xchart.style.ValueFormatter;
+
+/**
+ * This class encapsulates the logic to generate the axis tick mark and axis tick label data for rendering the axis ticks
+ * 
+ * @author timmolter
+ */
+public class AxisTickComputer {
+
+  /** the List of tick label position in pixels */
+  private List<Integer> tickLocations = new LinkedList<Integer>();;
+
+  /** the List of tick label values */
+  private List<String> tickLabels = new LinkedList<String>();
+
+  private final Direction axisDirection;
+
+  private final int workingSpace;
+
+  private final BigDecimal minValue;
+
+  private final BigDecimal maxValue;
+
+  private final ValueFormatter valueFormatter;
+
+  private final AxisType axisType;
+
+  /**
+   * Constructor
+   * 
+   * @param axisDirection
+   * @param workingSpace
+   * @param minValue
+   * @param maxValue
+   * @param valueFormatter
+   * @param axisType
+   */
+  public AxisTickComputer(Direction axisDirection, int workingSpace, BigDecimal minValue, BigDecimal maxValue, ValueFormatter valueFormatter, AxisType axisType) {
+
+    this.axisDirection = axisDirection;
+    this.workingSpace = workingSpace;
+    this.minValue = minValue;
+    this.maxValue = maxValue;
+    this.valueFormatter = valueFormatter;
+    this.axisType = axisType;
+
+    computeAxisTick();
+  }
+
+  private void computeAxisTick() {
+
+    System.out.println("workingSpace= " + workingSpace);
+
+    // a check if all axis data are the exact same values
+    if (maxValue == minValue) {
+      tickLabels.add(format(maxValue));
+      tickLocations.add((int) (workingSpace / 2.0));
+      return;
+    }
+
+    // tick space - a percentage of the working space available for ticks, i.e. 95%
+    int tickSpace = AxisPair.getTickSpace(workingSpace); // in plot space
+    System.out.println("tickSpace= " + tickSpace);
+
+    // where the tick should begin in the working space in pixels
+    int margin = AxisPair.getTickStartOffset(workingSpace, tickSpace); // in plot space
+
+    // the span of the data
+    double span = Math.abs(maxValue.subtract(minValue).doubleValue()); // in data space
+
+    BigDecimal gridStep = null;
+    BigDecimal firstPosition = null;
+    if (axisType == AxisType.Number) {
+
+      DecimalGridStep decimalGridStepHelper = new DecimalGridStep();
+      gridStep = decimalGridStepHelper.getGridStepForDecimal(axisDirection, span, tickSpace);
+      firstPosition = decimalGridStepHelper.getFirstPosition(minValue, gridStep);
+
+    } else if (axisType == AxisType.Date) {
+
+    } else if (axisType == AxisType.Logarithmic) {
+
+    }
+
+    // generate all tickLabels and tickLocations from the first to last position
+    for (BigDecimal tickPosition = firstPosition; tickPosition.compareTo(maxValue) <= 0; tickPosition = tickPosition.add(gridStep)) {
+
+      tickLabels.add(format(tickPosition));
+      // here we convert tickPosition finally to plot space, i.e. pixels
+      int tickLabelPosition = (int) (margin + ((tickPosition.subtract(minValue)).doubleValue() / (maxValue.subtract(minValue)).doubleValue() * tickSpace));
+      tickLocations.add(tickLabelPosition);
+    }
+
+  }
+
+  /**
+   * Format the number
+   * 
+   * @param value The number to be formatted
+   * @return The formatted number in String form
+   */
+  private String format(BigDecimal value) {
+
+    if (axisType == AxisType.Number) {
+
+      return valueFormatter.formatNumber(value);
+    } else {
+
+      return valueFormatter.formatDateValue(value, minValue, maxValue);
+    }
+  }
+
+  public List<Integer> getTickLocations() {
+
+    return tickLocations;
+  }
+
+  public List<String> getTickLabels() {
+
+    return tickLabels;
+  }
+
+}

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/AxisTickMarks.java

@@ -87,6 +87,7 @@ public class AxisTickMarks implements ChartPart {
     } else { // X-Axis
 
       int xOffset = (int) (axisTick.getAxis().getPaintZone().getX());
+      // int yOffset = (int) (axisTick.getAxisTickLabels().getBounds().getY() - getChart().getStyleManager().getAxisTickPadding());
       int yOffset = (int) (axisTick.getAxisTickLabels().getBounds().getY() - getChart().getStyleManager().getAxisTickPadding());
 
       // tick marks