JavaFX ScrollPane on Android - Too Slow

问题

I have just coded a simple example of using a scrolling pane in JavaFX. Just one ScrollPane placed in the Scene, and the ScrollPane holds a Label component with a large text. Using gradle I have uploaded the app on a Nexus 4 android device. As you can see from the video I have uploaded, the scrolling is way too slow. I am sure others have experienced this. Any suggestion of how this can be changed to the native speed scroll is really much appreciated.

Source code of the app can be downloaded from here.

AndroidFX.java

public class AndroidFX extends Application{

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

    @Override
    public void start(Stage primaryStage) throws Exception {
        Parent mySearchListFXML = getFXMLPane("/fxml/ScrollPaneWithLabel.fxml");
        primaryStage.setScene(new Scene(mySearchListFXML));
        primaryStage.setWidth(Screen.getPrimary().getVisualBounds().getWidth()); primaryStage.setHeight(Screen.getPrimary().getVisualBounds().getHeight());     
        primaryStage.show();
    }

    public static Parent getFXMLPane(String url) throws IOException {
        URL location = AndroidFX.class.getResource(url);
        FXMLLoader fxmlLoader = new FXMLLoader();
        fxmlLoader.setLocation(location);
        Parent pane = fxmlLoader.load();
        return pane;
    }
}

ScrollPaneWithLabel.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>

<ScrollPane fx:id="scrollPane" fitToWidth="true" hbarPolicy="NEVER" pannable="true" style="-fx-background: white;" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
   <content>
      <Label text="<VERY LARGE TEXT HERE>" wrapText="true" />
   </content>
</ScrollPane>

回答1:

Faced similar issues. The problem is worse on hidpi devices, disabling the hipdpi setting in the properties file helps but you will have to do any scaling your self for hidpi screens.

Another thing that might help is caching the fonts. I believe the end result of a javafx ported application is more like a big image with hot spots. Scrolling I think is just telling the application to redraw the whole image every time. Just a theory really. Caching does help but can make your text look kinda fuzzy. Although I had some success in scaling the font large, setting the cache to true and then scale down, normally x2 and .5 gives pretty good results. Using em for the fonts helps the fuzzy text too.

If you need to show a huge amount of text and it must be scrolled, you will probably get much better results displaying it through a webview. I haven't ever really used it to be honest, but I would imagine that it is replaced when ported with the native browser window so performance should be pretty good I think. I guess it is possible they wrote a html renderer in javafx and then you would run into the same pitfalls.

http://www.gluonhq.com is offering something called the charm, down, and connect package that is supposed to mimic native apps. It sounds promising and I am currently trying to get more info to see if they have solutions to these types of issues. I will add to the post if I receive any more info about charm.

来源：https://stackoverflow.com/questions/30111061/javafx-scrollpane-on-android-too-slow