Fix for issue #111 - Wrong bars placement when category count over 12

xchart-demo/src/main/java/com/xeiam/xchart/standalone/TestForIssue111.java

+/**
+ * Copyright 2013 Xeiam LLC.
+ *
+ * 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 com.xeiam.xchart.standalone;
+
+import com.xeiam.xchart.Chart;
+import com.xeiam.xchart.ChartBuilder;
+import com.xeiam.xchart.StyleManager.ChartType;
+import com.xeiam.xchart.SwingWrapper;
+
+/**
+ * @author timmolter
+ */
+public class TestForIssue111 {
+
+  public static void main(String[] args) {
+
+    int[] x = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 };
+    int[] y = new int[] { 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1 };
+    // int[] x = new int[] { 0, 1, 2, 3, 4, 5, 6, 7 };
+    // int[] y = new int[] { 1, 0, 1, 0, 1, 0, 0, 0 };
+
+    Chart chart = new ChartBuilder().chartType(ChartType.Bar).width(640).height(480).build();
+    chart.addSeries("test", x, y);
+    chart.getStyleManager().setLegendVisible(false);
+    new SwingWrapper(chart).displayChart();
+  }
+
+}

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

@@ -54,7 +54,7 @@ public class AxisTickBarChartCalculator extends AxisTickCalculator {
     int tickSpace = (int) (styleManager.getAxisTickSpacePercentage() * workingSpace); // in plot space
 
     // where the tick should begin in the working space in pixels
-    double margin = Utils.getTickStartOffset(workingSpace, tickSpace); // in plot space double gridStep = getGridStepForDecimal(tickSpace);
+    double margin = Utils.getTickStartOffset(workingSpace, tickSpace);
 
     // get all categories
     List<Object> categories = new ArrayList<Object>();
@@ -100,55 +100,34 @@ public class AxisTickBarChartCalculator extends AxisTickCalculator {
         tickLocations.add(tickLabelPosition);
       }
     }
-    else if (categories.size() < 13) { // Number or Date and 12 or less categories. give each category a tick label
 
-      double gridStep = (tickSpace / (double) categories.size());
-      double firstPosition = gridStep / 2.0;
+    double gridStep = (tickSpace / (double) categories.size());
+    double firstPosition = gridStep / 2.0;
 
-      // generate all tickLabels and tickLocations from the first to last position
-      NumberFormatter numberFormatter = null;
-      DateFormatter dateFormatter = null;
+    // generate all tickLabels and tickLocations from the first to last position
+    NumberFormatter numberFormatter = null;
+    DateFormatter dateFormatter = null;
 
-      if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Number) {
-        numberFormatter = new NumberFormatter(styleManager);
-      }
-      else if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Date) {
-        dateFormatter = new DateFormatter(chartPainter.getStyleManager());
-      }
-      int counter = 0;
-
-      for (Object category : categories) {
-        if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Number) {
-          tickLabels.add(numberFormatter.formatNumber(new BigDecimal(category.toString()), minValue, maxValue, axisDirection));
-        }
-        else if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Date) {
-          long span = (long) Math.abs(maxValue - minValue); // in data space
-          long gridStepHint = (long) (span / (double) tickSpace * styleManager.getXAxisTickMarkSpacingHint());
-          long timeUnit = dateFormatter.getTimeUnit(gridStepHint);
-          tickLabels.add(dateFormatter.formatDate(((Number) category).doubleValue(), timeUnit));
-        }
-        double tickLabelPosition = (int) (margin + firstPosition + gridStep * counter++);
-        tickLocations.add(tickLabelPosition);
-      }
+    if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Number) {
+      numberFormatter = new NumberFormatter(styleManager);
     }
-    else { // Number or Date and more than 12 categories. divide up the axis tick space according to normal date oor number axis layout
-
-      // generate all tickLabels and tickLocations from the first to last position
+    else if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Date) {
+      dateFormatter = new DateFormatter(chartPainter.getStyleManager());
+    }
+    int counter = 0;
 
+    for (Object category : categories) {
       if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Number) {
-
-        AxisTickNumericalCalculator axisTickNumericalCalculator = new AxisTickNumericalCalculator(axisDirection, workingSpace, minValue, maxValue, styleManager);
-        tickLabels = axisTickNumericalCalculator.getTickLabels();
-        tickLocations = axisTickNumericalCalculator.getTickLocations();
-
+        tickLabels.add(numberFormatter.formatNumber(new BigDecimal(category.toString()), minValue, maxValue, axisDirection));
       }
       else if (chartPainter.getAxisPair().getXAxis().getAxisType() == AxisType.Date) {
-
-        AxisTickDateCalculator axisTickDateCalculator = new AxisTickDateCalculator(axisDirection, workingSpace, minValue, maxValue, styleManager);
-        tickLabels = axisTickDateCalculator.getTickLabels();
-        tickLocations = axisTickDateCalculator.getTickLocations();
+        long span = (long) Math.abs(maxValue - minValue); // in data space
+        long gridStepHint = (long) (span / (double) tickSpace * styleManager.getXAxisTickMarkSpacingHint());
+        long timeUnit = dateFormatter.getTimeUnit(gridStepHint);
+        tickLabels.add(dateFormatter.formatDate(((Number) category).doubleValue(), timeUnit));
       }
-
+      double tickLabelPosition = (int) (margin + firstPosition + gridStep * counter++);
+      tickLocations.add(tickLabelPosition);
     }
 
   }