ListView vs. Flowless

FlowlessBenchmark.java

import javafx.application.Application;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.layout.Region;
import javafx.stage.Stage;

import org.fxmisc.flowless.Cell;
import org.fxmisc.flowless.VirtualFlow;

import com.sun.javafx.tk.Toolkit;

public class FlowlessBenchmark extends Application {

    public static void main(String[] args) {
        launch(args);
    }

    private int counter = 0;
    private int layoutCounter = 0;

    @Override
    public void start(Stage primaryStage) {
        ObservableList<String> items = FXCollections.observableArrayList();
        for(int i = 0; i < 20; ++i) {
            items.addAll("red", "green", "blue", "purple");
        }
        VirtualFlow<String, ?> flow = VirtualFlow.createVertical(
                items,
                color -> reg(color));
        Scene scene = new Scene(flow, 200, 400);
        primaryStage.setScene(scene);
        primaryStage.show();

        Platform.runLater(() -> {
            Toolkit.getToolkit().firePulse();
            System.out.println("Number of cell creations/layouts when:");

            counter = 0;
            layoutCounter = 0;
            items.set(10, "yellow");
            Toolkit.getToolkit().firePulse();
            System.out.println(" - updating an item in the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            items.set(30, "yellow");
            Toolkit.getToolkit().firePulse();
            System.out.println(" - updating an item outside the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            items.remove(12);
            Toolkit.getToolkit().firePulse();
            System.out.println(" - deleting an item in the middle of the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            items.add(12, "yellow");
            Toolkit.getToolkit().firePulse();
            System.out.println(" - adding an item in the middle of the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            flow.showAsFirst(5);
            Toolkit.getToolkit().firePulse();
            System.out.println(" - scrolling 5 items down: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            flow.showAsFirst(55);
            Toolkit.getToolkit().firePulse();
            System.out.println(" - scrolling 50 items down: " + counter + "/" + layoutCounter);
        });
    }

    private Cell<String, Region> reg(String color) {
        counter += 1;
        Region reg = new Region() {
            @Override
            protected void layoutChildren() {
                layoutCounter += 1;
                super.layoutChildren();
            }
        };
        reg.setPrefHeight(16);
        reg.setStyle("-fx-background-color: " + color);
        return Cell.wrapNode(reg);
    }
}

ListViewBenchmark.java

import javafx.application.Application;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.layout.Region;
import javafx.stage.Stage;

import com.sun.javafx.tk.Toolkit;

public class ListViewBenchmark extends Application {

    public static void main(String[] args) {
        launch(args);
    }

    private int counter = 0;
    private int layoutCounter = 0;

    @Override
    public void start(Stage primaryStage) {
        ObservableList<String> items = FXCollections.observableArrayList();
        for(int i = 0; i < 20; ++i) {
            items.addAll("red", "green", "blue", "purple");
        }
        ListView<String> listView = new ListView<>(items);
        listView.setFixedCellSize(16.0);
        listView.setCellFactory(lv -> rect());
        Scene scene = new Scene(listView, 200, 400);
        primaryStage.setScene(scene);
        primaryStage.show();

        Platform.runLater(() -> {
            Toolkit.getToolkit().firePulse();
            System.out.println("Number of updateItems/layouts when:");

            counter = 0;
            layoutCounter = 0;
            items.set(10, "yellow");
            Toolkit.getToolkit().firePulse();
            System.out.println(" - updating an item in the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            items.set(30, "yellow");
            Toolkit.getToolkit().firePulse();
            System.out.println(" - updating an item outside the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            items.remove(12);
            Toolkit.getToolkit().firePulse();
            System.out.println(" - deleting an item in the middle of the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            items.add(12, "yellow");
            Toolkit.getToolkit().firePulse();
            System.out.println(" - adding an item in the middle of the viewport: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            listView.scrollTo(5);
            Toolkit.getToolkit().firePulse();
            System.out.println(" - scrolling 5 items down: " + counter + "/" + layoutCounter);

            counter = 0;
            layoutCounter = 0;
            listView.scrollTo(55);
            Toolkit.getToolkit().firePulse();
            System.out.println(" - scrolling 50 items down: " + counter + "/" + layoutCounter);
        });
    }

    private ListCell<String> rect() {
        return new ListCell<String> () {
            { setStyle("-fx-padding: 0"); }

            @Override
            protected void updateItem(String color, boolean empty) {
                super.updateItem(color, empty);
                setText(null);
                if(empty) {
                    setGraphic(null);
                } else {
                    counter += 1;
                    Region reg = new Region() {
                        @Override
                        protected void layoutChildren() {
                            layoutCounter += 1;
                            super.layoutChildren();
                        }
                    };
                    reg.setPrefHeight(16);
                    reg.setStyle("-fx-background-color: " + color);
                    setGraphic(reg);
                }
            }
        };
    }
}

output.md

Tested with JDK 8u40.

ListViewBenchmark:

Number of updateItems/layouts when:
 - updating an item in the viewport: 1/1
 - updating an item outside the viewport: 0/0
 - deleting an item in the middle of the viewport: 38/25
 - adding an item in the middle of the viewport: 38/25
 - scrolling 5 items down: 5/5
 - scrolling 50 items down: 25/25

FlowlessBenchmark:

Number of cell creations/layouts when:
 - updating an item in the viewport: 1/1
 - updating an item outside the viewport: 0/0
 - deleting an item in the middle of the viewport: 1/1
 - adding an item in the middle of the viewport: 1/1
 - scrolling 5 items down: 5/5
 - scrolling 50 items down: 25/25