Implement (beta) export to excel file support

Author: neziw

README.md

@@ -22,11 +22,34 @@
 - [Requirements](#-requirements)
 - [Quick Start](#-quick-start)
 - [Usage](#-usage)
-- [Building](#-building)
 - [License](#-license)
 
 ---
 
+<div align="center">
+
+## 🎉 What's New
+
+### 📊 Excel Export Support
+
+Export your data and regression analysis directly to **Excel (.xlsx)** files! 
+
+### ✨ **Features:**
+
+📈 **Visual Charts** - Automatically generated scatter plots with regression lines
+
+📋 **Data Sheets** - Complete data tables with all your X and Y values
+
+📊 **Regression Parameters** - Detailed regression statistics (intercept, slope, R²)
+
+🎨 **Professional Formatting** - Ready-to-present Excel files with styled charts
+
+`The exported Excel files include both raw data and beautiful visualizations, making it perfect for reports and presentations!`
+
+</div>
+
+---
+
 ## ✨ Features
 
 - 📈 **Dynamic Chart** - Real-time linear regression visualization
@@ -38,6 +61,7 @@
 - 📊 **Auto Calculation** - Automatic regression line calculation (minimum 2 points)
 - 🟢 **Colors Selection** - Customizable colors for data points and regression line
 - 💫 **Symbol Selection** - Choose your favourite symbol for data points
+- 📐 **Excel Export** - Export data and charts to Excel (.xlsx) files
 
 ---
 
@@ -90,8 +114,9 @@
 
 - **Delete Values**: Select cells and press `Delete` or `Backspace`
 - **Move Values**: Select cells, drag to another location, and drop
-- **Save Data**: Click "Zapisz do pliku" to save data as JSON
+- **Save Data**: Click "Zapisz do pliku" to save data as JSON (includes chart settings)
 - **Load Data**: Click "Załaduj z pliku" to load data from JSON file
+- **Export to Excel**: Click "Eksportuj do Excela" to export data and charts to Excel (.xlsx)
 
 ### Chart Features
 
@@ -112,6 +137,7 @@ This project is licensed under the MIT License - see the [LICENSE](LICENSE) file
 - Built with [JFreeChart](https://www.jfree.org/jfreechart/) for chart visualization
 - GUI powered by [FlatLaf](https://www.formdev.com/flatlaf/)
 - JSON handling with [Gson](https://github.com/google/gson)
+- Excel export powered by [Apache POI](https://poi.apache.org/)
 
 ---
 

assets/screen.png

@@ -20,7 +20,11 @@ tasks.withType<ShadowJar> {
         "org/intellij/lang/annotations/**",
         "org/jetbrains/annotations/**",
         "org/checkerframework/**",
-        "META-INF/**",
+        "META-INF/DEPENDENCIES",
+        "META-INF/LICENSE",
+        "META-INF/LICENSE.txt",
+        "META-INF/NOTICE",
+        "META-INF/NOTICE.txt",
         "javax/**"
     )
     manifest {
@@ -49,6 +53,8 @@ dependencies {
     implementation("org.jfree:jfreechart:1.5.6")
     implementation("com.formdev:flatlaf:3.6.2")
     implementation("com.google.code.gson:gson:2.13.2")
+    implementation("org.apache.poi:poi:5.4.0")
+    implementation("org.apache.poi:poi-ooxml:5.4.0")
 }
 
 tasks.build {

build.gradle.kts

@@ -61,6 +61,14 @@ public RegressionResult(final double slope, final double intercept) {
             this.intercept = intercept;
         }
 
+        public double getSlope() {
+            return this.slope;
+        }
+
+        public double getIntercept() {
+            return this.intercept;
+        }
+
         public double predict(final double x) {
             return this.slope * x + this.intercept;
         }

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

@@ -90,11 +90,11 @@ private void updateRendererSettings() {
         this.renderer.setSeriesLinesVisible(1, true);
         this.renderer.setSeriesShapesVisible(1, false);
         this.renderer.setSeriesPaint(1, this.settings.getRegressionLineColor());
-        
+
         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);
+            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);
         }

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

@@ -41,6 +41,7 @@
 import ovh.neziw.visualizer.gui.FileDialogManager;
 import ovh.neziw.visualizer.gui.TableConfiguration;
 import ovh.neziw.visualizer.gui.UIManagerConfigurator;
+import ovh.neziw.visualizer.io.ExcelExportManager;
 import ovh.neziw.visualizer.io.TableFileManager;
 
 public class RegressionVisualizer extends JFrame {
@@ -50,6 +51,7 @@ public class RegressionVisualizer extends JFrame {
     private final RegressionChart chart;
     private final ChartUpdater chartUpdater;
     private final TableFileManager fileManager;
+    private final ExcelExportManager excelExportManager;
     private final ChartSettings chartSettings;
     private final ChartSettingsPanel settingsPanel;
 
@@ -62,7 +64,9 @@ public RegressionVisualizer() {
         this.chartUpdater = new ChartUpdater(this.tableModel, this.chart);
         this.setupTableListeners();
         this.settingsPanel = this.createSettingsPanel();
-        this.fileManager = this.createFileManager();
+        final FileDialogManager dialogManager = new FileDialogManager(this);
+        this.fileManager = this.createFileManager(dialogManager);
+        this.excelExportManager = this.createExcelExportManager(dialogManager);
         this.setupUI();
     }
 
@@ -89,11 +93,14 @@ private JTable createTable() {
         return table;
     }
 
-    private TableFileManager createFileManager() {
-        final FileDialogManager dialogManager = new FileDialogManager(this);
+    private TableFileManager createFileManager(final FileDialogManager dialogManager) {
         return new TableFileManager(this.tableModel, dialogManager, this::onDataLoaded, this.chartSettings);
     }
 
+    private ExcelExportManager createExcelExportManager(final FileDialogManager dialogManager) {
+        return new ExcelExportManager(this.tableModel, dialogManager);
+    }
+
     private void onDataLoaded() {
         if (this.settingsPanel != null) {
             this.settingsPanel.refreshUI();
@@ -154,7 +161,8 @@ private JSplitPane createSplitPane(final JScrollPane tableScrollPane) {
     private ButtonPanel createButtonPanel() {
         return new ButtonPanel(
             () -> this.fileManager.saveToFile(this),
-            () -> this.fileManager.loadFromFile(this)
+            () -> this.fileManager.loadFromFile(this),
+            () -> this.excelExportManager.exportToExcel(this)
         );
     }
 

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

@@ -24,18 +24,37 @@
 package ovh.neziw.visualizer.gui;
 
 import java.awt.FlowLayout;
+import javax.swing.ImageIcon;
 import javax.swing.JButton;
 import javax.swing.JPanel;
 
 public class ButtonPanel extends JPanel {
 
-    public ButtonPanel(final Runnable onSave, final Runnable onLoad) {
+    public ButtonPanel(final Runnable onSave, final Runnable onLoad, final Runnable onExport) {
         this.setLayout(new FlowLayout(FlowLayout.LEFT));
         final JButton saveButton = new JButton("Zapisz do pliku");
         saveButton.addActionListener(e -> onSave.run());
         final JButton loadButton = new JButton("Załaduj z pliku");
         loadButton.addActionListener(e -> onLoad.run());
+        final JButton exportButton = new JButton("Eksportuj do Excela");
+        final ImageIcon excelIcon = this.loadExcelIcon();
+        if (excelIcon != null) {
+            exportButton.setIcon(excelIcon);
+        }
+        exportButton.addActionListener(e -> onExport.run());
         this.add(saveButton);
         this.add(loadButton);
+        this.add(exportButton);
+    }
+
+    private ImageIcon loadExcelIcon() {
+        try {
+            final java.net.URL iconUrl = ButtonPanel.class.getResource("/excel.png");
+            if (iconUrl != null) {
+                return new ImageIcon(iconUrl);
+            }
+        } catch (final Exception exception) {
+        }
+        return null;
     }
 }

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

@@ -122,7 +122,7 @@ private void setupPanel() {
         final JButton shapeButton = this.createShapeButton();
         this.add(shapeButton);
 
-        this.dashedLineCheckBox = new JCheckBox("Linia przerywana", 
+        this.dashedLineCheckBox = new JCheckBox("Linia przerywana",
             this.settings.isDashedLine());
         this.dashedLineCheckBox.addActionListener(e -> {
             this.settings.setDashedLine(this.dashedLineCheckBox.isSelected());

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

@@ -33,6 +33,9 @@ public class FileDialogManager {
     private static final String JSON_EXTENSION = "json";
     private static final String JSON_DESCRIPTION = "Pliki JSON (*.json)";
     private static final String DEFAULT_FILENAME = "dane.json";
+    private static final String EXCEL_EXTENSION = "xlsx";
+    private static final String EXCEL_DESCRIPTION = "Pliki Excel (*.xlsx)";
+    private static final String DEFAULT_EXCEL_FILENAME = "dane.xlsx";
 
     private final JFrame parentFrame;
 
@@ -68,10 +71,30 @@ private JFileChooser createFileChooser() {
         return fileChooser;
     }
 
+    public File showExcelSaveDialog() {
+        final JFileChooser fileChooser = new JFileChooser();
+        fileChooser.setFileFilter(new FileNameExtensionFilter(EXCEL_DESCRIPTION, EXCEL_EXTENSION));
+        fileChooser.setDialogTitle("Eksportuj do Excela");
+        fileChooser.setSelectedFile(new File(DEFAULT_EXCEL_FILENAME));
+        final int result = fileChooser.showSaveDialog(this.parentFrame);
+        if (result == JFileChooser.APPROVE_OPTION) {
+            final File file = fileChooser.getSelectedFile();
+            return this.ensureExcelExtension(file);
+        }
+        return null;
+    }
+
     private File ensureJsonExtension(final File file) {
         if (!file.getName().toLowerCase().endsWith("." + JSON_EXTENSION)) {
             return new File(file.getParent(), file.getName() + "." + JSON_EXTENSION);
         }
         return file;
     }
+
+    private File ensureExcelExtension(final File file) {
+        if (!file.getName().toLowerCase().endsWith("." + EXCEL_EXTENSION)) {
+            return new File(file.getParent(), file.getName() + "." + EXCEL_EXTENSION);
+        }
+        return file;
+    }
 }

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

@@ -0,0 +1,72 @@
+/*
+ * This file is part of "linear-regression-visualizer", licensed under MIT License.
+ *
+ *  Copyright (c) 2025 neziw
+ *
+ *  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 ovh.neziw.visualizer.io;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.List;
+import javax.swing.JFrame;
+import javax.swing.JOptionPane;
+import ovh.neziw.visualizer.DataTableModel;
+import ovh.neziw.visualizer.gui.FileDialogManager;
+
+public class ExcelExportManager {
+
+    private final DataTableModel tableModel;
+    private final ExcelExporter exporter;
+    private final FileDialogManager dialogManager;
+
+    public ExcelExportManager(final DataTableModel tableModel, final FileDialogManager dialogManager) {
+        this.tableModel = tableModel;
+        this.exporter = new ExcelExporter();
+        this.dialogManager = dialogManager;
+    }
+
+    public void exportToExcel(final JFrame parentFrame) {
+        final File file = this.dialogManager.showExcelSaveDialog();
+        if (file == null) {
+            return;
+        }
+        try (final FileOutputStream outputStream = new FileOutputStream(file)) {
+            final List<DataTableModel.DataPoint> dataPoints = this.tableModel.getAllDataPoints();
+            this.exporter.exportToExcel(outputStream, dataPoints);
+            this.showSuccessMessage(parentFrame,
+                "Dane zostały wyeksportowane do pliku: " + file.getName());
+        } catch (final IOException exception) {
+            this.showErrorMessage(parentFrame,
+                "Błąd podczas eksportowania do pliku Excel:\n" + exception.getMessage());
+        }
+    }
+
+    private void showSuccessMessage(final JFrame parentFrame, final String message) {
+        JOptionPane.showMessageDialog(parentFrame, message, "Sukces",
+            JOptionPane.INFORMATION_MESSAGE);
+    }
+
+    private void showErrorMessage(final JFrame parentFrame, final String message) {
+        JOptionPane.showMessageDialog(parentFrame, message, "Błąd",
+            JOptionPane.ERROR_MESSAGE);
+    }
+}