feat(client/shopping): create custom editable shopping list cell element

client/src/main/java/client/scenes/shopping/ShoppingListCell.java

@@ -0,0 +1,67 @@
+package client.scenes.shopping;
+
+import client.scenes.recipe.OrderedEditableListCell;
+import commons.FormalIngredient;
+import javafx.scene.Node;
+import javafx.scene.control.Label;
+import javafx.scene.control.Spinner;
+import javafx.scene.control.SpinnerValueFactory;
+import javafx.scene.input.KeyCode;
+import javafx.scene.input.KeyEvent;
+import javafx.scene.layout.HBox;
+import javafx.util.Pair;
+
+import java.util.Optional;
+
+public class ShoppingListCell extends OrderedEditableListCell<Pair<FormalIngredient, Optional<String>>> {
+    private Node makeEditor() {
+        HBox editor = new HBox();
+        Spinner<Double> amountInput = new Spinner<>();
+        FormalIngredient ingredient = getItem().getKey();
+        amountInput.setEditable(true);
+        amountInput.setValueFactory(new SpinnerValueFactory.DoubleSpinnerValueFactory(0, Double.MAX_VALUE, ingredient.getAmount()));
+        Label textLabel = new Label(getItem().getKey().getUnitSuffix() + " of " + getItem().getKey().getIngredient().getName());
+        editor.getChildren().addAll(amountInput, textLabel);
+        editor.addEventHandler(KeyEvent.KEY_RELEASED, e -> {
+            if (e.getCode() != KeyCode.ENTER) {
+                return;
+            }
+            Pair<FormalIngredient, Optional<String>> pair = getItem();
+            pair.getKey().setAmount(amountInput.getValue());
+            commitEdit(pair);
+        });
+        return editor;
+    }
+    @Override
+    public void startEdit() {
+        super.startEdit();
+        this.setText("");
+        this.setGraphic(makeEditor());
+    }
+    @Override
+    protected void updateItem(Pair<FormalIngredient, Optional<String>> item, boolean empty) {
+        super.updateItem(item, empty);
+
+        if (empty) {
+            this.setText("");
+            return;
+        }
+
+        String display = item.getKey().toString() +
+                item.getValue().map(recipe -> {
+                    return " (" + recipe + ")";
+                }).orElse("");
+
+        this.setText(display);
+    }
+    @Override
+    public void cancelEdit() {
+        super.cancelEdit();
+    }
+
+    @Override
+    public void commitEdit(Pair<FormalIngredient, Optional<String>> newValue) {
+        super.commitEdit(newValue);
+    }
+
+}