Add dashed line support

Author: neziw

src/main/java/ovh/neziw/visualizer/RegressionChart.java

@@ -90,7 +90,15 @@ private void updateRendererSettings() {
         this.renderer.setSeriesLinesVisible(1, true);
         this.renderer.setSeriesShapesVisible(1, false);
         this.renderer.setSeriesPaint(1, this.settings.getRegressionLineColor());
-        this.renderer.setSeriesStroke(1, new BasicStroke(2.0f));
+        
+        final BasicStroke stroke;
+        if (this.settings.isDashedLine()) {
+            stroke = new BasicStroke(2.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER, 
+                10.0f, new float[]{5.0f, 5.0f}, 0.0f);
+        } else {
+            stroke = new BasicStroke(2.0f);
+        }
+        this.renderer.setSeriesStroke(1, stroke);
     }
 
     public void applySettings() {

src/main/java/ovh/neziw/visualizer/gui/ChartSettings.java

@@ -32,6 +32,7 @@ public class ChartSettings {
     private Color dataPointColor = Color.BLUE;
     private Color regressionLineColor = Color.RED;
     private Shape dataPointShape = new java.awt.geom.Ellipse2D.Double(-3, -3, 6, 6);
+    private boolean dashedLine = false;
 
     public double getPaddingPercent() {
         return this.paddingPercent;
@@ -64,5 +65,13 @@ public Shape getDataPointShape() {
     public void setDataPointShape(final Shape dataPointShape) {
         this.dataPointShape = dataPointShape;
     }
+
+    public boolean isDashedLine() {
+        return this.dashedLine;
+    }
+
+    public void setDashedLine(final boolean dashedLine) {
+        this.dashedLine = dashedLine;
+    }
 }
 

src/main/java/ovh/neziw/visualizer/gui/ChartSettingsPanel.java

@@ -26,6 +26,7 @@
 import java.awt.Color;
 import java.awt.Shape;
 import javax.swing.JButton;
+import javax.swing.JCheckBox;
 import javax.swing.JColorChooser;
 import javax.swing.JLabel;
 import javax.swing.JOptionPane;
@@ -119,6 +120,14 @@ private void setupPanel() {
 
         final JButton shapeButton = this.createShapeButton();
         this.add(shapeButton);
+
+        final JCheckBox dashedLineCheckBox = new JCheckBox("Linia przerywana", 
+            this.settings.isDashedLine());
+        dashedLineCheckBox.addActionListener(e -> {
+            this.settings.setDashedLine(dashedLineCheckBox.isSelected());
+            this.onSettingsChanged.run();
+        });
+        this.add(dashedLineCheckBox);
     }
 
     private JButton createColorButton(final String text,