JavaFX的字幕動畫

Question

你也許已經看到了一些應用程序，當在一個選項卡中的String不能完全那麼表明它是動畫，並會前後，使用戶可以看到字符串的標籤contains.Android就是幹這個是當您的手機顯示屏不足以顯示整個標籤時的設置。

下面是使用Service在JavaFX中實現它的代碼，但它不是一個好方法。

問題是： 下面是我可以如何使用動畫或JavaFX類中的其他構建？

代碼：

import javafx.application.Platform; 
import javafx.concurrent.Service; 
import javafx.concurrent.Task; 
import javafx.scene.control.Label; 
import javafx.scene.paint.Color; 
import javafx.scene.text.Font; 
import javafx.scene.text.FontWeight; 
import tools.InfoTool; 

public class MoveTitleService extends Service<Void>{ 
    private String title; 
    volatile boolean doAnimation; 
    private int counter; 
    public Label movingText = new Label("A reallyyy big teeeeexxxxxxxxxxxxxxxxxxxxxxxt"); 


    /** 
    *Constructor 
    */ 
    public MoveTitleService() { 
     movingText.setFont(Font.font("null",FontWeight.BOLD,14)); 
     movingText.setTextFill(Color.WHITE); 

     setOnSucceeded(s ->{ 
      movingText.setText(""); 
     }); 
    } 

    //Start the Service 
    public void startTheService(String title) { 
     this.title = title; 
     doAnimation = true; 

     restart(); 
    } 


    //Stop the Service 
    public void stopService(){ 
     doAnimation=false; 
    } 

    @Override 
    protected Task<Void> createTask() { 
     return new Task<Void>() { 
      @Override 
      protected Void call() throws Exception { 

       while (doAnimation) { 
        //System.out.println("MoveTitleService is Running..."); 

        // One letter at a time 
        for (int m = 0; m <= title.length(); m++) { 
         counter=m; 

         Platform.runLater(() ->{ 
          movingText.setText(title.substring(0, counter) + addSpaces(title.length() - counter));  
         }); 

         if(!doAnimation) break; 
         Thread.sleep(150); 
        } 

        // Disappearing to back 
        for (int m = 0; m < title.length(); m++) { 
         counter=m; 

         Platform.runLater(() ->{ 
          movingText.setText(title.substring(counter)); 
         }); 

         if(!doAnimation) break; 
         Thread.sleep(150); 
        } 

        // Appearing to front 
        for (int m = 1; m <= title.length(); m++) { 
         counter=m; 

         Platform.runLater(() ->{ 
          movingText.setText(title.substring(title.length() - counter)); 
         }); 

         if(!doAnimation) break; 
         Thread.sleep(150); 
        } 

        if(!doAnimation) break; 
        for(int i=0; i<3000/150; i++) 
         Thread.sleep(150); 
        Thread.sleep(3000); 

       } 

       return null; 
      } 

      private String addSpaces(int spaces) { 
       String z = ""; 
       for (int i = 0; i <= spaces; i++) 
        z += " "; 

       return z; 
      } 

     }; 
    } 

} 

Answer 1

你可以使用這個Timeline：

// min distance to Pane bounds 
private static final double OFFSET = 25; 

@Override 
public void start(Stage primaryStage) { 
    Text text = new Text("A reallyyy big teeeeexxxxxxxxxxxxxxxxxxxxxxxt!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 
    text.setLayoutY(25); 
    text.setManaged(false); 
    text.setLayoutX(OFFSET); 

    Pane pane = new Pane(text); 
    pane.setMinHeight(50); 

    Timeline timeline = new Timeline(); 

    KeyFrame updateFrame = new KeyFrame(Duration.seconds(1/60d), new EventHandler<ActionEvent>() { 

     private boolean rightMovement; 

     @Override 
     public void handle(ActionEvent event) { 
      double tW = text.getLayoutBounds().getWidth(); 
      double pW = pane.getWidth(); 
      double layoutX = text.getLayoutX(); 

      if (2 * OFFSET + tW <= pW && layoutX >= OFFSET) { 
       // stop, if the pane is large enough and the position is correct 
       text.setLayoutX(OFFSET); 
       timeline.stop(); 
      } else { 
       if ((rightMovement && layoutX >= OFFSET) || (!rightMovement && layoutX + tW + OFFSET <= pW)) { 
        // invert movement, if bounds are reached 
        rightMovement = !rightMovement; 
       } 

       // update position 
       if (rightMovement) { 
        layoutX += 1; 
       } else { 
        layoutX -= 1; 
       } 
       text.setLayoutX(layoutX); 
      } 
     } 
    }); 

    timeline.getKeyFrames().add(updateFrame); 
    timeline.setCycleCount(Animation.INDEFINITE); 

    // listen to bound changes of the elements to start/stop the animation 
    InvalidationListener listener = o -> { 
     double textWidth = text.getLayoutBounds().getWidth(); 
     double paneWidth = pane.getWidth(); 
     if (textWidth + 2 * OFFSET > paneWidth 
       && timeline.getStatus() != Animation.Status.RUNNING) { 
      timeline.play(); 
     } 
    }; 

    text.layoutBoundsProperty().addListener(listener); 
    pane.widthProperty().addListener(listener); 

    Scene scene = new Scene(pane); 

    primaryStage.setScene(scene); 
    primaryStage.show(); 
} 

注意repeadedly更新自己需要做的事情，因爲運行時Animation s不能進行調整的位置，所以對於任何大小調整到動畫中生效，你需要反覆更新...