Add export current theme JabRef#5790

* Add method for saving theme to file

* Add modal for selection witch theme to export as CSS

src/main/java/org/jabref/gui/preferences/ExportThemeDialog.fxml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+
+<?import javafx.geometry.Insets?>
+<DialogPane xmlns="http://javafx.com/javafx"
+            xmlns:fx="http://javafx.com/fxml"
+            fx:controller="org.jabref.gui.preferences.ExportThemeDialog"
+            prefHeight="300.0" prefWidth="500.0">
+
+    <content>
+        <BorderPane>
+            <center>
+                <TableView fx:id="table">
+                    <columns>
+                        <TableColumn fx:id="columnName" text="%Theme name"/>
+                        <TableColumn fx:id="columnPath" text="%Path to theme"/>
+                    </columns>
+                    <padding>
+                        <Insets bottom="30.0"/>
+                    </padding>
+                </TableView>
+            </center>
+        </BorderPane>
+    </content>
+    <ButtonType fx:constant="CLOSE"/>
+</DialogPane>

src/main/java/org/jabref/gui/preferences/ExportThemeDialog.java

@@ -0,0 +1,121 @@
+package org.jabref.gui.preferences;
+
+import com.airhacks.afterburner.views.ViewLoader;
+import javafx.beans.property.SimpleStringProperty;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.fxml.FXML;
+import javafx.scene.control.TableColumn;
+import javafx.scene.control.TablePosition;
+import javafx.scene.control.TableRow;
+import javafx.scene.control.TableView;
+import javafx.scene.control.cell.PropertyValueFactory;
+import javafx.scene.input.KeyCode;
+import org.jabref.JabRefException;
+import org.jabref.gui.DialogService;
+import org.jabref.gui.util.BaseDialog;
+import org.jabref.gui.util.FileDialogConfiguration;
+import org.jabref.gui.util.ThemeLoader;
+import org.jabref.logic.l10n.Localization;
+import org.jabref.logic.util.StandardFileType;
+import org.jabref.preferences.JabRefPreferences;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ExportThemeDialog extends BaseDialog<Void> {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(ExportThemeDialog.class);
+
+    @FXML private TableView<Theme> table;
+    @FXML private TableColumn<Theme, String> columnName;
+    @FXML private TableColumn<Theme, String> columnPath;
+
+    private JabRefPreferences preferences;
+    private DialogService dialogService;
+
+    public ExportThemeDialog(DialogService dialogService, JabRefPreferences preferences) {
+        this.dialogService = dialogService;
+        this.preferences = preferences;
+
+        ViewLoader
+                .view(this)
+                .load()
+                .setAsDialogPane(this);
+
+        this.setTitle(Localization.lang("Export Theme"));
+    }
+
+    @FXML
+    private void initialize() {
+        columnName.setCellValueFactory(new PropertyValueFactory<>("name"));
+        columnPath.setCellValueFactory(new PropertyValueFactory<>("path"));
+
+        ObservableList<Theme> data =
+                FXCollections.observableArrayList(new Theme("Light theme", ThemeLoader.MAIN_CSS), new Theme("Dark theme", ThemeLoader.DARK_CSS));
+
+        if (!(ThemeLoader.CUSTOM_CSS.isBlank() || ThemeLoader.CUSTOM_CSS.isEmpty())) {
+            data.add(new Theme("Custom theme", ThemeLoader.CUSTOM_CSS));
+        }
+
+        table.setItems(data);
+
+        table.setOnKeyPressed(event -> {
+            TablePosition tablePosition;
+            if (event.getCode().equals(KeyCode.ENTER)) {
+                tablePosition = table.getFocusModel().getFocusedCell();
+                final int row = tablePosition.getRow();
+                ObservableList<Theme> list = table.getItems();
+                Theme theme = list.get(row);
+                exportCSSFile(theme.getPath());
+            }
+        });
+
+        table.setRowFactory(tv -> {
+            TableRow<Theme> row = new TableRow<>();
+            row.setOnMouseClicked(event -> handleSelectedRowEvent(row));
+            return row;
+        });
+    }
+
+    private void handleSelectedRowEvent(TableRow<Theme> row) {
+        if (!row.isEmpty()) {
+            exportCSSFile(row.getItem().getPath());
+        }
+    }
+
+    private void exportCSSFile(String theme) {
+        FileDialogConfiguration fileDialogConfiguration = new FileDialogConfiguration.Builder()
+                .addExtensionFilter(StandardFileType.CSS)
+                .withDefaultExtension(StandardFileType.CSS)
+                .withInitialDirectory(preferences.setLastPreferencesExportPath())
+                .build();
+
+        dialogService.showFileSaveDialog(fileDialogConfiguration)
+                     .ifPresent(exportFile -> {
+                         try {
+                             preferences.exportTheme(exportFile.getFileName(), theme);
+                         } catch (JabRefException ex) {
+                             LOGGER.warn(ex.getMessage(), ex);
+                             dialogService.showErrorDialogAndWait(Localization.lang("Export theme"), ex);
+                         }
+                     });
+    }
+
+    public static class Theme {
+        private SimpleStringProperty name;
+        private SimpleStringProperty path;
+
+        public Theme(String name, String path) {
+            this.name = new SimpleStringProperty(name);
+            this.path = new SimpleStringProperty(path);
+        }
+
+        public String getName() {
+            return name.get();
+        }
+
+        public String getPath() {
+            return path.get();
+        }
+    }
+}

src/main/java/org/jabref/gui/preferences/PreferencesDialog.fxml

@@ -39,11 +39,16 @@
                     </Button>
                     <Button maxWidth="Infinity" onAction="#showAllPreferences" text="%Show preferences"/>
                     <Button maxWidth="Infinity" onAction="#resetPreferences" text="%Reset preferences"/>
-                    <Button maxWidth="Infinity" onAction="#importStyle" text="%Import CSS file">
+                    <Button maxWidth="Infinity" onAction="#importTheme" text="%Import theme">
                         <tooltip>
                             <Tooltip text="%Import custom CSS file" />
                         </tooltip>
                     </Button>
+                    <Button maxWidth="Infinity" onAction="#exportTheme" text="%Export theme">
+                    <tooltip>
+                        <Tooltip text="%Export theme as CSS" />
+                    </tooltip>
+                    </Button>
                 </VBox>
             </VBox>
             <ScrollPane fx:id="preferencesContainer" maxHeight="Infinity" maxWidth="Infinity"/>

src/main/java/org/jabref/gui/preferences/PreferencesDialogView.java

@@ -116,5 +116,8 @@ private void savePreferencesAndCloseDialog() {
     void resetPreferences() { viewModel.resetPreferences(); }
 
     @FXML
-    void importStyle() {viewModel.importCSSFile();}
+    void importTheme() {viewModel.importCSSFile();}
+
+    @FXML
+    void exportTheme() {viewModel.openExportThemeDialog();}
 }

src/main/java/org/jabref/gui/preferences/PreferencesDialogViewModel.java

@@ -210,4 +210,8 @@ public void importCSSFile() {
                     Localization.lang("You must restart JabRef for this to come into effect."));
         });
     }
+
+    public void openExportThemeDialog() {
+        new ExportThemeDialog(dialogService, preferences).showAndWait();
+    }
 }

src/main/java/org/jabref/preferences/JabRefPreferences.java

@@ -7,6 +7,7 @@
 import java.io.Reader;
 import java.io.StringReader;
 import java.net.InetAddress;
+import java.net.URISyntaxException;
 import java.net.UnknownHostException;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
@@ -37,6 +38,7 @@
 import org.jabref.Globals;
 import org.jabref.JabRefException;
 import org.jabref.JabRefMain;
+import org.jabref.gui.JabRefFrame;
 import org.jabref.gui.SidePaneType;
 import org.jabref.gui.autocompleter.AutoCompleteFirstNameMode;
 import org.jabref.gui.autocompleter.AutoCompletePreferences;
@@ -69,6 +71,7 @@
 import org.jabref.logic.exporter.TemplateExporter;
 import org.jabref.logic.importer.ImportFormatPreferences;
 import org.jabref.logic.importer.fetcher.DoiFetcher;
+import org.jabref.logic.importer.fileformat.endnote.Url;
 import org.jabref.logic.journals.JournalAbbreviationLoader;
 import org.jabref.logic.journals.JournalAbbreviationPreferences;
 import org.jabref.logic.l10n.Language;
@@ -1391,6 +1394,25 @@ public void importPreferences(Path file) throws JabRefException {
         }
     }
 
+    public void exportTheme(Path targetFile, String theme) throws JabRefException {
+        try (OutputStream os = Files.newOutputStream(targetFile)) {
+            if (theme.equals(ThemeLoader.MAIN_CSS) || theme.equals(ThemeLoader.DARK_CSS)) {
+                Path path = new File(JabRefFrame.class.getResource(theme).toURI()).toPath();
+                writeThemeToFile(path, os);
+            } else {
+                Path path = new File(theme).toPath();
+                writeThemeToFile(path, os);
+            }
+        } catch (IOException | URISyntaxException ex) {
+            throw new JabRefException("Could not export theme", Localization.lang("Could not export theme"),
+                    ex);
+        }
+    }
+
+    private void writeThemeToFile(Path path, OutputStream os) throws IOException {
+        Files.copy(path, os);
+    }
+
     /**
      * ONLY FOR TESTING!
      *