JavaFX ListView 带有用于上下滚动的触摸事件 [英] JavaFX ListView with touch events for scrolling up and down

问题描述

我想用手势实现一个可滚动的 ListView，就像在手机和平​​板电脑中一样，用手指上下滚动我的列表.但是，只要我点击列表，我当前的列表就会选择一个项目.我怎样才能做到这一点?我在 Oracle 教程中找不到任何示例.

I would like to implement a scrollable ListView with gestures, just like in mobiles and tablets, to scroll up and down my list with a finger. But my current list selects an item as soon as I click down on the list. How can I achieve this? I couldn't find any example at the Oracle tutorials.

private ObservableList<Document> items = FXCollections.observableArrayList();
@FXML ListView<Document> listView;

{
    ...

    listView.setItems(items);
    listView.getStylesheets().add("style/listview.css");
    listView.setStyle("-fx-background-insets: 0 ;"); // remove 1px border of listview container

    listView.setCellFactory(new Callback<ListView<Document>, ListCell<Document>>() {
        @Override
        public ListCell<Document> call(ListView<Document> listView) {
            return new DocumentArrayAdapter();
        }
    });  

    ...
}

public void loadListView(List<Document> ldoc){
    if (!ldoc.isEmpty()){
        items.addAll(ldoc);
    }
}

推荐答案

这就是我所做的

public class CustomListCell extends ListCell<Document>{

private double lastYposition = 0;

public CustomListCell(){

    setOnMousePressed(new EventHandler<MouseEvent>() {
        @Override
        public void handle(MouseEvent event) {
            lastYposition = event.getSceneY();
        }
    });

    setOnMouseDragged(new EventHandler<MouseEvent>() {
        @Override
        public void handle(MouseEvent event) {
            double newYposition = event.getSceneY();
            double diff = newYposition - lastYposition;
            lastYposition = newYposition;
            CustomScrollEvent cse = new CustomScrollEvent();
            cse.fireVerticalScroll((int)diff, DocumentArrayAdapter.this, (EventTarget) event.getSource());
        }
    });  

和

package myproject.utils;

import javafx.event.Event;
import javafx.event.EventTarget;
import javafx.scene.input.ScrollEvent;

public class CustomScrollEvent {

public void fireVerticalScroll(int deltaY, Object source, EventTarget target){

    ScrollEvent newScrollEvent = null;
    newScrollEvent = new ScrollEvent(source,
               target,
               ScrollEvent.SCROLL,
               0,
               0,
               0,
               0,
               false,
               false,
               false,
               false,
               false,
               false,
               0,
               deltaY,
               0,
               0,
               ScrollEvent.HorizontalTextScrollUnits.CHARACTERS,
               0,
               ScrollEvent.VerticalTextScrollUnits.NONE,
               deltaY,
               0,
               null);

        Event.fireEvent(target, newScrollEvent);
}
}

虽然我已经在自己的 ListCell 中实现了监听器，但我想它也可以直接在 ListView 上实现监听器，使用 listView.setOnMousePressed 和 listView.setOnMouseDragged

Although I've implemented the listener in my own ListCell, I guess it would also work implementing the listeners directly at the ListView, with listView.setOnMousePressed and listView.setOnMouseDragged

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