Merge pull request #824 from jmpalomar/allow-stacked-and-overlapped

Allow having stacked and overlapped category series

xchart-demo/src/main/java/org/knowm/xchart/demo/charts/bar/BarChart12.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2024 Energía Plus. All rights reserved.
+ */
+
+package org.knowm.xchart.demo.charts.bar;
+
+import org.knowm.xchart.CategoryChart;
+import org.knowm.xchart.CategoryChartBuilder;
+import org.knowm.xchart.CategorySeries;
+import org.knowm.xchart.SwingWrapper;
+import org.knowm.xchart.demo.charts.ExampleChart;
+
+import java.awt.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+
+/**
+ * Stacked Bars with Overlapped Line Chart
+ *
+ * <p>Demonstrates the following:
+ *
+ * <ul>
+ *   <li>bar series are stacked
+ *   <li>line series is overlapped
+ */
+public class BarChart12 implements ExampleChart<CategoryChart> {
+
+  public static void main(String[] args) {
+
+    ExampleChart<CategoryChart> exampleChart = new BarChart12();
+    CategoryChart chart = exampleChart.getChart();
+    new SwingWrapper<>(chart).displayChart();
+  }
+
+  private static List<String> getMonths() {
+    return Arrays.asList(
+        "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
+  }
+
+  private static List<Double> getRandomValues(int count) {
+
+    List<Double> values = new ArrayList<>(count);
+    Random rand = new Random();
+    for (int i = 0; i < count; i++) {
+      values.add(rand.nextDouble() * 1000);
+    }
+    return values;
+  }
+
+  @Override
+  public CategoryChart getChart() {
+
+    // Create Chart
+    CategoryChart chart =
+        new CategoryChartBuilder()
+            .width(800)
+            .height(600)
+            .title(getClass().getSimpleName())
+            .xAxisTitle("Month")
+            .yAxisTitle("Consumption")
+            .build();
+
+    // Customize Chart
+    chart.getStyler().setPlotGridVerticalLinesVisible(false);
+    chart.getStyler().setLegendVisible(true);
+    chart.getStyler().setStacked(true);
+    chart
+        .getStyler()
+        .setSeriesColors(
+            new Color[] {
+              Color.decode("#2133D0"),
+              Color.decode("#FF3B47"),
+              Color.decode("#FFBD00"),
+              Color.DARK_GRAY
+            });
+
+    List<String> months = getMonths();
+    List<Double> period1Values = getRandomValues(12);
+    List<Double> period2Values = getRandomValues(12);
+    List<Double> period3Values = getRandomValues(12);
+    List<Double> averageValues = new ArrayList<>();
+    for (int i = 0; i < 12; i++) {
+      averageValues.add((period1Values.get(i) + period2Values.get(i) + period3Values.get(i)) / 3);
+    }
+
+    // Series
+    CategorySeries staked1 = chart.addSeries("Period 1", months, period1Values);
+    CategorySeries staked2 = chart.addSeries("Period 2", months, period2Values);
+    CategorySeries staked3 = chart.addSeries("Period 3", months, period3Values);
+    CategorySeries overlappedLine = chart.addSeries("Average", months, averageValues);
+    overlappedLine.setOverlapped(true);
+    overlappedLine.setChartCategorySeriesRenderStyle(CategorySeries.CategorySeriesRenderStyle.Line);
+
+    return chart;
+  }
+
+  @Override
+  public String getExampleChartName() {
+
+    return getClass().getSimpleName() + " - Stacked Bars with Overlapped Line Chart";
+  }
+}

xchart/src/main/java/org/knowm/xchart/CategorySeries.java

@@ -9,6 +9,8 @@
 /** A Series containing category data to be plotted on a Chart */
 public class CategorySeries extends AxesChartSeriesCategory {
 
+  private boolean isOverlapped = false;
+
   private CategorySeriesRenderStyle chartCategorySeriesRenderStyle = null;
 
   /**
@@ -42,6 +44,15 @@ public CategorySeries setChartCategorySeriesRenderStyle(
     return this;
   }
 
+  public boolean isOverlapped() {
+    return isOverlapped;
+  }
+
+  public CategorySeries setOverlapped(boolean overlapped) {
+    isOverlapped = overlapped;
+    return this;
+  }
+
   @Override
   public LegendRenderType getLegendRenderType() {
 

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

@@ -174,7 +174,7 @@ public void doPaint(Graphics2D g) {
               } else {
                 yBottom = y;
               }
-              if (stylerCategory.isStacked()) {
+              if (stylerCategory.isStacked() && !series.isOverlapped()) {
                 yTop += accumulatedStackOffsetPos[categoryCounter];
                 yBottom += accumulatedStackOffsetPos[categoryCounter];
                 accumulatedStackOffsetPos[categoryCounter] += (yTop - yBottom);
@@ -190,7 +190,7 @@ public void doPaint(Graphics2D g) {
                 // yBottom.
               }
               yBottom = y;
-              if (stylerCategory.isStacked()) {
+              if (stylerCategory.isStacked() && !series.isOverlapped()) {
                 yTop -= accumulatedStackOffsetNeg[categoryCounter];
                 yBottom -= accumulatedStackOffsetNeg[categoryCounter];
                 accumulatedStackOffsetNeg[categoryCounter] += (yTop - yBottom);