src/main/java/com/andrewlalis/perfin/PerfinApp.java

@@ -93,6 +93,8 @@ public class PerfinApp extends Application {
             router.map("balance-record", PerfinApp.class.getResource("/balance-record-view.fxml"));
             router.map("vendors", PerfinApp.class.getResource("/vendors-view.fxml"));
             router.map("edit-vendor", PerfinApp.class.getResource("/edit-vendor.fxml"));
+            router.map("categories", PerfinApp.class.getResource("/categories-view.fxml"));
+            router.map("edit-category", PerfinApp.class.getResource("/edit-category.fxml"));
 
             // Help pages.
             helpRouter.map("home", PerfinApp.class.getResource("/help-pages/home.fxml"));

src/main/java/com/andrewlalis/perfin/control/CategoriesViewController.java

@@ -0,0 +1,33 @@
+package com.andrewlalis.perfin.control;
+
+import com.andrewlalis.javafx_scene_router.RouteSelectionListener;
+import com.andrewlalis.perfin.data.TransactionCategoryRepository;
+import com.andrewlalis.perfin.model.Profile;
+import com.andrewlalis.perfin.view.BindingUtil;
+import com.andrewlalis.perfin.view.component.CategoryTile;
+import javafx.application.Platform;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.fxml.FXML;
+import javafx.scene.layout.VBox;
+
+public class CategoriesViewController implements RouteSelectionListener {
+    @FXML public VBox categoriesVBox;
+    private final ObservableList<TransactionCategoryRepository.CategoryTreeNode> categoryTreeNodes = FXCollections.observableArrayList();
+
+    @FXML public void initialize() {
+        BindingUtil.mapContent(categoriesVBox.getChildren(), categoryTreeNodes, node -> new CategoryTile(node, this::refreshCategories));
+    }
+
+    @Override
+    public void onRouteSelected(Object context) {
+        refreshCategories();
+    }
+
+    private void refreshCategories() {
+        Profile.getCurrent().dataSource().mapRepoAsync(
+                TransactionCategoryRepository.class,
+                TransactionCategoryRepository::findTree
+        ).thenAccept(nodes -> Platform.runLater(() -> categoryTreeNodes.setAll(nodes)));
+    }
+}

src/main/java/com/andrewlalis/perfin/control/EditCategoryController.java

@@ -0,0 +1,108 @@
+package com.andrewlalis.perfin.control;
+
+import com.andrewlalis.javafx_scene_router.RouteSelectionListener;
+import com.andrewlalis.perfin.data.TransactionCategoryRepository;
+import com.andrewlalis.perfin.model.Profile;
+import com.andrewlalis.perfin.model.TransactionCategory;
+import com.andrewlalis.perfin.view.component.validation.ValidationApplier;
+import com.andrewlalis.perfin.view.component.validation.validators.PredicateValidator;
+import javafx.fxml.FXML;
+import javafx.scene.control.Button;
+import javafx.scene.control.ColorPicker;
+import javafx.scene.control.TextField;
+import javafx.scene.paint.Color;
+
+import java.util.concurrent.CompletableFuture;
+
+import static com.andrewlalis.perfin.PerfinApp.router;
+
+public class EditCategoryController implements RouteSelectionListener {
+    public record CategoryRouteContext(TransactionCategory category) implements RouteContext {}
+    public record AddSubcategoryRouteContext(TransactionCategory parent) implements RouteContext {}
+    private sealed interface RouteContext permits AddSubcategoryRouteContext, CategoryRouteContext {}
+
+    private TransactionCategory category;
+    private TransactionCategory parent;
+
+    @FXML public TextField nameField;
+    @FXML public ColorPicker colorPicker;
+
+    @FXML public Button saveButton;
+
+    @FXML public void initialize() {
+        var nameValid = new ValidationApplier<>(new PredicateValidator<String>()
+                .addTerminalPredicate(s -> s != null && !s.isBlank(), "Name is required.")
+                .addPredicate(s -> s.strip().length() <= TransactionCategory.NAME_MAX_LENGTH, "Name is too long.")
+                .addAsyncPredicate(
+                        s -> {
+                            if (Profile.getCurrent() == null) return CompletableFuture.completedFuture(false);
+                            return Profile.getCurrent().dataSource().mapRepoAsync(
+                                    TransactionCategoryRepository.class,
+                                    repo -> {
+                                        var categoryByName = repo.findByName(s).orElse(null);
+                                        if (this.category != null) {
+                                            return this.category.equals(categoryByName) || categoryByName == null;
+                                        }
+                                        return categoryByName == null;
+                                    }
+                            );
+                        },
+                        "Category with this name already exists."
+                )
+        ).validatedInitially().attachToTextField(nameField);
+
+        saveButton.disableProperty().bind(nameValid.not());
+    }
+
+    @Override
+    public void onRouteSelected(Object context) {
+        this.category = null;
+        this.parent = null;
+        if (context instanceof RouteContext ctx) {
+            switch (ctx) {
+                case CategoryRouteContext(var cat):
+                    this.category = cat;
+                    nameField.setText(cat.getName());
+                    colorPicker.setValue(cat.getColor());
+                    break;
+                case AddSubcategoryRouteContext(var par):
+                    this.parent = par;
+                    nameField.setText(null);
+                    colorPicker.setValue(parent.getColor());
+                    break;
+            }
+        } else {
+            nameField.setText(null);
+            colorPicker.setValue(Color.WHITE);
+        }
+    }
+
+    @FXML public void save() {
+        final String name = nameField.getText().strip();
+        final Color color = colorPicker.getValue();
+        if (this.category == null && this.parent == null) {
+            // New top-level category.
+            Profile.getCurrent().dataSource().useRepo(
+                    TransactionCategoryRepository.class,
+                    repo -> repo.insert(name, color)
+            );
+        } else if (this.category == null) {
+            // New subcategory.
+            Profile.getCurrent().dataSource().useRepo(
+                    TransactionCategoryRepository.class,
+                    repo -> repo.insert(parent.id, name, color)
+            );
+        } else if (this.parent == null) {
+            // Save edits to an existing category.
+            Profile.getCurrent().dataSource().useRepo(
+                    TransactionCategoryRepository.class,
+                    repo -> repo.update(category.id, name, color)
+            );
+        }
+        router.replace("categories");
+    }
+
+    @FXML public void cancel() {
+        router.navigateBackAndClear();
+    }
+}

src/main/java/com/andrewlalis/perfin/control/EditTransactionController.java

@@ -62,7 +62,9 @@ public class EditTransactionController implements RouteSelectionListener {
     @FXML public ComboBox<String> vendorComboBox;
     @FXML public Hyperlink vendorsHyperlink;
     @FXML public ComboBox<String> categoryComboBox;
+    @FXML public Hyperlink categoriesHyperlink;
     @FXML public ComboBox<String> tagsComboBox;
+    @FXML public Hyperlink tagsHyperlink;
     @FXML public Button addTagButton;
     @FXML public VBox tagsVBox;
     private final ObservableList<String> selectedTags = FXCollections.observableArrayList();
@@ -92,6 +94,8 @@ public class EditTransactionController implements RouteSelectionListener {
         initializeTagSelectionUi();
         // Setup hyperlinks.
         vendorsHyperlink.setOnAction(event -> router.navigate("vendors"));
+        categoriesHyperlink.setOnAction(event -> router.navigate("categories"));
+//        tagsHyperlink.setOnAction(event -> router.navigate("tags"));
 
         var formValid = timestampValid.and(amountValid).and(descriptionValid).and(linkedAccountsValid);
         saveButton.disableProperty().bind(formValid.not());

src/main/java/com/andrewlalis/perfin/control/VendorsViewController.java

@@ -5,15 +5,11 @@ import com.andrewlalis.perfin.data.TransactionVendorRepository;
 import com.andrewlalis.perfin.model.Profile;
 import com.andrewlalis.perfin.model.TransactionVendor;
 import com.andrewlalis.perfin.view.BindingUtil;
+import com.andrewlalis.perfin.view.component.VendorTile;
 import javafx.application.Platform;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
 import javafx.fxml.FXML;
-import javafx.geometry.Pos;
-import javafx.scene.Node;
-import javafx.scene.control.Button;
-import javafx.scene.control.Label;
-import javafx.scene.layout.BorderPane;
 import javafx.scene.layout.VBox;
 
 import java.util.List;
@@ -25,36 +21,7 @@ public class VendorsViewController implements RouteSelectionListener {
     private final ObservableList<TransactionVendor> vendors = FXCollections.observableArrayList();
 
     @FXML public void initialize() {
-        BindingUtil.mapContent(vendorsVBox.getChildren(), vendors, this::buildVendorTile);
-    }
-
-    private Node buildVendorTile(TransactionVendor transactionVendor) {
-        BorderPane pane = new BorderPane();
-        pane.getStyleClass().addAll("tile", "std-spacing");
-        pane.setOnMouseClicked(event -> router.navigate("edit-vendor", transactionVendor));
-
-        Label nameLabel = new Label(transactionVendor.getName());
-        nameLabel.getStyleClass().addAll("bold-text");
-        Label descriptionLabel = new Label(transactionVendor.getDescription());
-        descriptionLabel.setWrapText(true);
-        VBox contentVBox = new VBox(nameLabel, descriptionLabel);
-        contentVBox.getStyleClass().addAll("std-spacing");
-        pane.setCenter(contentVBox);
-        BorderPane.setAlignment(contentVBox, Pos.TOP_LEFT);
-
-        Button removeButton = new Button("Remove");
-        removeButton.setOnAction(event -> {
-            boolean confirm = Popups.confirm(removeButton, "Are you sure you want to remove this vendor? Any transactions with assigned to this vendor will have their vendor field cleared. This cannot be undone.");
-            if (confirm) {
-                Profile.getCurrent().dataSource().useRepo(TransactionVendorRepository.class, repo -> {
-                    repo.deleteById(transactionVendor.id);
-                });
-                refreshVendors();
-            }
-        });
-        pane.setRight(removeButton);
-
-        return pane;
+        BindingUtil.mapContent(vendorsVBox.getChildren(), vendors, vendor -> new VendorTile(vendor, this::refreshVendors));
     }
 
     @Override

src/main/java/com/andrewlalis/perfin/data/TransactionCategoryRepository.java

@@ -13,5 +13,9 @@ public interface TransactionCategoryRepository extends Repository, AutoCloseable
     List<TransactionCategory> findAll();
     long insert(long parentId, String name, Color color);
     long insert(String name, Color color);
+    void update(long id, String name, Color color);
     void deleteById(long id);
+
+    record CategoryTreeNode(TransactionCategory category, List<CategoryTreeNode> children){}
+    List<CategoryTreeNode> findTree();
 }

src/main/java/com/andrewlalis/perfin/data/impl/JdbcTransactionCategoryRepository.java

@@ -9,6 +9,7 @@ import javafx.scene.paint.Color;
 import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 
@@ -69,11 +70,62 @@ public record JdbcTransactionCategoryRepository(Connection conn) implements Tran
         );
     }
 
+    @Override
+    public void update(long id, String name, Color color) {
+        DbUtil.doTransaction(conn, () -> {
+            TransactionCategory category = findById(id).orElseThrow();
+            if (!category.getName().equals(name)) {
+                DbUtil.updateOne(
+                        conn,
+                        "UPDATE transaction_category SET name = ? WHERE id = ?",
+                        name,
+                        id
+                );
+            }
+            if (!category.getColor().equals(color)) {
+                DbUtil.updateOne(
+                        conn,
+                        "UPDATE transaction_category SET color = ? WHERE id = ?",
+                        ColorUtil.toHex(color),
+                        id
+                );
+            }
+        });
+    }
+
     @Override
     public void deleteById(long id) {
         DbUtil.updateOne(conn, "DELETE FROM transaction_category WHERE id = ?", id);
     }
 
+    @Override
+    public List<CategoryTreeNode> findTree() {
+        List<TransactionCategory> rootCategories = DbUtil.findAll(
+                conn,
+                "SELECT * FROM transaction_category WHERE parent_id IS NULL ORDER BY name ASC",
+                JdbcTransactionCategoryRepository::parseCategory
+        );
+        List<CategoryTreeNode> rootNodes = new ArrayList<>(rootCategories.size());
+        for (var category : rootCategories) {
+            rootNodes.add(findTreeRecursive(category));
+        }
+        return rootNodes;
+    }
+
+    private CategoryTreeNode findTreeRecursive(TransactionCategory root) {
+        CategoryTreeNode node = new CategoryTreeNode(root, new ArrayList<>());
+        List<TransactionCategory> childCategories = DbUtil.findAll(
+                conn,
+                "SELECT * FROM transaction_category WHERE parent_id = ? ORDER BY name ASC",
+                List.of(root.id),
+                JdbcTransactionCategoryRepository::parseCategory
+        );
+        for (var childCategory : childCategories) {
+            node.children().add(findTreeRecursive(childCategory));
+        }
+        return node;
+    }
+
     @Override
     public void close() throws Exception {
         conn.close();

src/main/java/com/andrewlalis/perfin/view/component/CategoryTile.java

@@ -0,0 +1,65 @@
+package com.andrewlalis.perfin.view.component;
+
+import com.andrewlalis.perfin.control.EditCategoryController;
+import com.andrewlalis.perfin.control.Popups;
+import com.andrewlalis.perfin.data.TransactionCategoryRepository;
+import com.andrewlalis.perfin.model.Profile;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.layout.BorderPane;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.VBox;
+import javafx.scene.shape.Circle;
+
+import static com.andrewlalis.perfin.PerfinApp.router;
+
+public class CategoryTile extends VBox {
+    public CategoryTile(
+            TransactionCategoryRepository.CategoryTreeNode treeNode,
+            Runnable categoriesRefresh
+    ) {
+        this.getStyleClass().addAll("tile", "hand-cursor");
+        this.setStyle("-fx-border-width: 1px; -fx-border-color: grey;");
+        this.setOnMouseClicked(event -> {
+            event.consume();
+            router.navigate(
+                    "edit-category",
+                    new EditCategoryController.CategoryRouteContext(treeNode.category())
+            );
+        });
+
+        BorderPane borderPane = new BorderPane();
+        borderPane.getStyleClass().addAll("std-padding");
+        Label nameLabel = new Label(treeNode.category().getName());
+        nameLabel.getStyleClass().addAll("bold-text");
+        Circle colorCircle = new Circle(10, treeNode.category().getColor());
+        HBox contentBox = new HBox(colorCircle, nameLabel);
+        contentBox.getStyleClass().addAll("std-spacing");
+        borderPane.setLeft(contentBox);
+
+        Button addChildButton = new Button("Add Subcategory");
+        addChildButton.setOnAction(event -> router.navigate(
+                "edit-category",
+                new EditCategoryController.AddSubcategoryRouteContext(treeNode.category())
+        ));
+        Button removeButton = new Button("Remove");
+        removeButton.setOnAction(event -> {
+            boolean confirm = Popups.confirm(removeButton, "Are you sure you want to remove this category? It will permanently remove the category from all linked transactions, and all subcategories will also be removed. This cannot be undone.");
+            if (confirm) {
+                Profile.getCurrent().dataSource().useRepo(
+                        TransactionCategoryRepository.class,
+                        repo -> repo.deleteById(treeNode.category().id)
+                );
+                categoriesRefresh.run();
+            }
+        });
+        HBox buttonsBox = new HBox(addChildButton, removeButton);
+        buttonsBox.getStyleClass().addAll("std-spacing");
+        borderPane.setRight(buttonsBox);
+
+        this.getChildren().add(borderPane);
+        for (var child : treeNode.children()) {
+            this.getChildren().add(new CategoryTile(child, categoriesRefresh));
+        }
+    }
+}

src/main/java/com/andrewlalis/perfin/view/component/VendorTile.java

@@ -0,0 +1,46 @@
+package com.andrewlalis.perfin.view.component;
+
+import com.andrewlalis.perfin.control.Popups;
+import com.andrewlalis.perfin.data.TransactionVendorRepository;
+import com.andrewlalis.perfin.model.Profile;
+import com.andrewlalis.perfin.model.TransactionVendor;
+import javafx.geometry.Pos;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.layout.BorderPane;
+import javafx.scene.layout.VBox;
+
+import static com.andrewlalis.perfin.PerfinApp.router;
+
+public class VendorTile extends BorderPane {
+    public VendorTile(TransactionVendor vendor, Runnable vendorRefresh) {
+        this.getStyleClass().addAll("tile", "std-spacing", "hand-cursor");
+        this.setOnMouseClicked(event -> router.navigate("edit-vendor", vendor));
+
+        Label nameLabel = new Label(vendor.getName());
+        nameLabel.getStyleClass().addAll("bold-text");
+        Label descriptionLabel = new Label(vendor.getDescription());
+        descriptionLabel.setWrapText(true);
+        VBox contentVBox = new VBox(nameLabel, descriptionLabel);
+        contentVBox.getStyleClass().addAll("std-spacing");
+        this.setCenter(contentVBox);
+        BorderPane.setAlignment(contentVBox, Pos.TOP_LEFT);
+
+        this.setRight(getRemoveButton(vendor, vendorRefresh));
+    }
+
+    private Button getRemoveButton(TransactionVendor transactionVendor, Runnable vendorRefresh) {
+        Button removeButton = new Button("Remove");
+        removeButton.setOnAction(event -> {
+            boolean confirm = Popups.confirm(removeButton, "Are you sure you want to remove this vendor? Any transactions assigned to this vendor will have their vendor field cleared. This cannot be undone.");
+            if (confirm) {
+                Profile.getCurrent().dataSource().useRepo(
+                        TransactionVendorRepository.class,
+                        repo -> repo.deleteById(transactionVendor.id)
+                );
+                vendorRefresh.run();
+            }
+        });
+        return removeButton;
+    }
+}

src/main/resources/categories-view.fxml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.layout.BorderPane?>
+<?import javafx.scene.control.Label?>
+<?import javafx.scene.layout.VBox?>
+<?import javafx.scene.layout.HBox?>
+<?import javafx.scene.control.Button?>
+<?import javafx.scene.control.ScrollPane?>
+<BorderPane xmlns="http://javafx.com/javafx"
+            xmlns:fx="http://javafx.com/fxml"
+            fx:controller="com.andrewlalis.perfin.control.CategoriesViewController"
+>
+    <top>
+        <Label text="Transaction Categories" styleClass="large-font,bold-text,std-padding"/>
+    </top>
+    <center>
+        <VBox>
+            <HBox styleClass="std-padding, std-spacing" VBox.vgrow="NEVER">
+                <Button text="Add Category"/>
+            </HBox>
+            <ScrollPane styleClass="tile-container-scroll" VBox.vgrow="ALWAYS">
+                <VBox fx:id="categoriesVBox" styleClass="tile-container"/>
+            </ScrollPane>
+        </VBox>
+    </center>
+</BorderPane>

src/main/resources/edit-category.fxml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import com.andrewlalis.perfin.view.component.PropertiesPane?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+<BorderPane xmlns="http://javafx.com/javafx"
+            xmlns:fx="http://javafx.com/fxml"
+            fx:controller="com.andrewlalis.perfin.control.EditCategoryController"
+>
+    <top>
+        <Label text="Edit Transaction Category" styleClass="bold-text,large-font,std-padding"/>
+    </top>
+    <center>
+        <VBox>
+            <PropertiesPane hgap="5" vgap="5" styleClass="std-padding" maxWidth="500">
+                <columnConstraints>
+                    <ColumnConstraints hgrow="NEVER" halignment="LEFT" minWidth="150"/>
+                    <ColumnConstraints hgrow="ALWAYS" halignment="RIGHT"/>
+                </columnConstraints>
+
+                <Label text="Name" labelFor="${nameField}"/>
+                <TextField fx:id="nameField"/>
+
+                <Label text="Color" labelFor="${colorPicker}"/>
+                <ColorPicker fx:id="colorPicker"/>
+            </PropertiesPane>
+            <HBox styleClass="std-padding, std-spacing">
+                <Button text="Save" fx:id="saveButton" onAction="#save"/>
+                <Button text="Cancel" onAction="#cancel"/>
+            </HBox>
+        </VBox>
+    </center>
+</BorderPane>

src/main/resources/edit-transaction.fxml

@@ -68,13 +68,13 @@
 
                     <VBox>
                         <Label text="Category" labelFor="${categoryComboBox}" styleClass="bold-text"/>
-                        <Hyperlink text="Manage categories" styleClass="small-font"/>
+                        <Hyperlink fx:id="categoriesHyperlink" text="Manage categories" styleClass="small-font"/>
                     </VBox>
                     <ComboBox fx:id="categoryComboBox" editable="true" maxWidth="Infinity"/>
 
                     <VBox>
                         <Label text="Tags" labelFor="${tagsComboBox}" styleClass="bold-text"/>
-                        <Hyperlink text="Manage tags" styleClass="small-font"/>
+                        <Hyperlink fx:id="tagsHyperlink" text="Manage tags" styleClass="small-font"/>
                     </VBox>
                     <VBox maxWidth="Infinity">
                         <HBox styleClass="std-spacing">

src/main/resources/vendors-view.fxml

@@ -3,10 +3,7 @@
 <?import javafx.scene.control.Button?>
 <?import javafx.scene.control.Label?>
 <?import javafx.scene.control.ScrollPane?>
-<?import javafx.scene.layout.BorderPane?>
-<?import javafx.scene.layout.HBox?>
-<?import javafx.scene.layout.VBox?>
-<?import javafx.scene.text.Text?>
+<?import javafx.scene.layout.*?>
 <BorderPane xmlns="http://javafx.com/javafx"
             xmlns:fx="http://javafx.com/fxml"
             fx:controller="com.andrewlalis.perfin.control.VendorsViewController"