Fix remaining IDE warnings in xchart-demo and xchart-site

- Remove unused local variables (series1/2 in BarChart11, staked1/2/3
  in BarChart12, series in DialChart02/LineChart08, bubbleSeries in
  TestForIssue545, min/max/nbInstances in TestForIssue390)
- Parameterize XChartPanel raw types in ChartStylePanel and XChartStyleDemo
- Fix raw Chart type in TestForIssue1 (List<Chart> -> List<XYChart>)
- Remove unnecessary @SuppressWarnings("unchecked") in GenerateSite
- Remove now-unused series imports after variable removals

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: timmolter

xchart-demo/src/main/java/org/knowm/xchart/demo/ChartStylePanel.java

@@ -526,9 +526,9 @@ public TableCellEditor getCellEditor(int row, int column) {
   }
 
   private EditorTable table;
-  private XChartPanel chartPanel;
+  private XChartPanel<?> chartPanel;
 
-  public ChartStylePanel(XChartPanel chartPanel) {
+  public ChartStylePanel(XChartPanel<?> chartPanel) {
     this.chartPanel = chartPanel;
     table = new EditorTable(this, chartPanel.getChart());
     JScrollPane scrollpane = new JScrollPane(table);
@@ -538,7 +538,7 @@ public ChartStylePanel(XChartPanel chartPanel) {
     setPreferredSize(new Dimension(800, 600));
   }
 
-  public void changeChart(XChartPanel chartPanel) {
+  public void changeChart(XChartPanel<?> chartPanel) {
 
     this.chartPanel = chartPanel;
     table.changeChart(chartPanel.getChart());

xchart-demo/src/main/java/org/knowm/xchart/demo/XChartStyleDemo.java

@@ -21,7 +21,7 @@ public XChartStyleDemo() {
 
   @Override
   public void valueChanged(TreeSelectionEvent e) {
-    XChartPanel oldChartPanel = chartPanel;
+    XChartPanel<?> oldChartPanel = chartPanel;
     super.valueChanged(e);
     if (chartPanel != oldChartPanel) {
       stylePanel.changeChart(chartPanel);

xchart-demo/src/main/java/org/knowm/xchart/demo/charts/bar/BarChart11.java

@@ -5,7 +5,6 @@
 import java.util.Random;
 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;
 
@@ -72,10 +71,8 @@ public CategoryChart getChart() {
     chart.getStyler().setLabelsRotation(45);
 
     // Series
-    CategorySeries series1 =
-        chart.addSeries("series1", getLinearValues(0, 200, 6), getRandomValues(10, 50, 6));
-    CategorySeries series2 =
-        chart.addSeries("series2", getLinearValues(0, 200, 6), getRandomValues(10, 50, 6));
+    chart.addSeries("series1", getLinearValues(0, 200, 6), getRandomValues(10, 50, 6));
+    chart.addSeries("series2", getLinearValues(0, 200, 6), getRandomValues(10, 50, 6));
 
     return chart;
   }

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

@@ -85,9 +85,9 @@ public CategoryChart getChart() {
     }
 
     // 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);
+    chart.addSeries("Period 1", months, period1Values);
+    chart.addSeries("Period 2", months, period2Values);
+    chart.addSeries("Period 3", months, period3Values);
     CategorySeries overlappedLine = chart.addSeries("Average", months, averageValues);
     overlappedLine.setOverlapped(true);
     overlappedLine.setChartCategorySeriesRenderStyle(CategorySeries.CategorySeriesRenderStyle.Line);

xchart-demo/src/main/java/org/knowm/xchart/demo/charts/dial/DialChart02.java

@@ -5,7 +5,6 @@
 import java.awt.Font;
 import org.knowm.xchart.DialChart;
 import org.knowm.xchart.DialChartBuilder;
-import org.knowm.xchart.DialSeries;
 import org.knowm.xchart.SwingWrapper;
 import org.knowm.xchart.XChartPanel;
 import org.knowm.xchart.demo.charts.ExampleChart;
@@ -46,7 +45,7 @@ public DialChart getChart() {
             .build();
 
     // Series
-    DialSeries series = chart.addSeries("Rate", 0.55, "55 %");
+    chart.addSeries("Rate", 0.55, "55 %");
 
     chart.getStyler().setLegendVisible(true);
     chart.getStyler().setArcAngle(330);

xchart-demo/src/main/java/org/knowm/xchart/demo/charts/line/LineChart08.java

@@ -62,7 +62,7 @@ public XYChart getChart() {
     // chart.getStyler().setXAxisLabelRotation(0);
 
     // Series
-    XYSeries series = chart.addSeries("10^x", xData, yData);
+    chart.addSeries("10^x", xData, yData);
 
     return chart;
   }

xchart-demo/src/main/java/org/knowm/xchart/standalone/issues/TestForIssue1.java

@@ -5,16 +5,16 @@
 import org.knowm.xchart.BitmapEncoder;
 import org.knowm.xchart.BitmapEncoder.BitmapFormat;
 import org.knowm.xchart.XYChart;
-import org.knowm.xchart.internal.chartpart.Chart;
+
 
 /** Creates a list of Charts and saves it as a PNG file. */
 public class TestForIssue1 {
 
   public static void main(String[] args) throws Exception {
 
-    List<Chart> charts =
+    List<XYChart> charts =
         Arrays.asList(
-            new Chart[] {
+            new XYChart[] {
               createChart("chart1", new double[] {2.0, 1.0, 0.0}),
               createChart("chart2", new double[] {3.0, 4.0, 0.0}),
               createChart("chart3", new double[] {4.0, 1.5, 0.0}),

xchart-demo/src/main/java/org/knowm/xchart/standalone/issues/TestForIssue390.java

@@ -16,10 +16,7 @@ public static XYChart getChart() {
 
     Random rand = new Random();
 
-    double min = 0;
-    double max = 20;
     int nbServices = 20;
-    int nbInstances = 50;
 
     long s = 24;
     rand.setSeed(s);

xchart-demo/src/main/java/org/knowm/xchart/standalone/issues/TestForIssue545.java

@@ -4,7 +4,6 @@
 import java.text.ParseException;
 import org.knowm.xchart.BubbleChart;
 import org.knowm.xchart.BubbleChartBuilder;
-import org.knowm.xchart.BubbleSeries;
 import org.knowm.xchart.SwingWrapper;
 import org.knowm.xchart.style.BubbleStyler;
 import org.knowm.xchart.style.Styler;
@@ -31,9 +30,8 @@ public static BubbleChart getBubbleChart() {
             .yAxisTitle("Rate")
             .build();
     setBubbleStyler(chart);
-    BubbleSeries bubbleSeries =
-        chart.addSeries(
-            "serieName", new double[] {data[0]}, new double[] {data[1]}, new double[] {data[2]});
+    chart.addSeries(
+        "serieName", new double[] {data[0]}, new double[] {data[1]}, new double[] {data[2]});
     //    bubbleSeries.setCustomToolTips(true);
     //    String tooltip =
     //        new DecimalFormat("#%").format(data[1]) + " (" + ((int) data[2]) + "/" + ((int)

xchart-site/src/main/java/org/knowm/xchart/site/GenerateSite.java

@@ -416,7 +416,6 @@ private String buildFooter() {
 
   // ── Package scanning ─────────────────────────────────────────────────────────
 
-  @SuppressWarnings("unchecked")
   private List<Class<?>> scanPackage(String packageName) throws Exception {
     List<Class<?>> classes = new ArrayList<>();
     String packagePath = packageName.replace('.', '/');