java - Timeline animation JavaFX -

i know why screen not clearing after every move of chart. thats code :

mainclass, remove there "time" , put lambda expresion in drawing method updatescene, dont know yet how :/

import javafx.application.application; import javafx.scene.group; import javafx.scene.scene; import javafx.scene.paint.color; import javafx.stage.stage;   public class mainclass extends application{     private drawing draw;     private double time = 0;     public static void main(string[] args) {         launch(args);     }        @override         public void start(final stage stage) {            group root = new group();            root.setstyle("-fx-background-color: rgb(35, 39, 50);");             stage.setscene(new scene(root, 1000, 1000,  color.rgb(35, 39, 50)));           while(time < 2 ) {                draw = new drawing(root, time);                time+=0.1;                 draw.updatescene();                stage.show();                 }        } } 

axes class describing how should draw axes :

import javafx.beans.binding.bindings; import javafx.geometry.side; import javafx.scene.chart.numberaxis; import javafx.scene.layout.pane;  public class axes extends pane{     private numberaxis xaxis;     private numberaxis yaxis;      public axes(int width, int height,              double xmin, double xmax, double xtickunit,              double ymin, double ymax, double ytickunit) {         setminsize(pane.use_pref_size, pane.use_pref_size);         setprefsize(width, height);         setmaxsize(pane.use_pref_size, pane.use_pref_size);          xaxis = new numberaxis(xmin, xmax, xtickunit);         xaxis.setside(side.bottom);         xaxis.setminortickvisible(false);         xaxis.setprefwidth(width);         xaxis.setlayouty(height/2);          yaxis = new numberaxis(ymin, ymax, ytickunit);         yaxis.setside(side.left);         yaxis.setminortickvisible(false);         yaxis.setprefheight(height);         yaxis.layoutxproperty().bind(bindings.subtract((width / 2) + 1, yaxis.widthproperty()));          getchildren().setall(xaxis, yaxis);     }      public numberaxis getxaxis() {         return xaxis;     }      public numberaxis getyaxis() {         return yaxis;     }  } 

scaling , drawing need in chart.

import java.util.function.function; import javafx.scene.layout.pane; import javafx.scene.paint.color; import javafx.scene.shape.lineto; import javafx.scene.shape.moveto; import javafx.scene.shape.path; import javafx.scene.shape.rectangle;  public class chart extends pane {      public chart(function<double, double> f,             double xmin, double xmax, double xinc,             axes axes ) {         path path = new path();         path.setstroke(color.orange.derivecolor(0, 1, 1,0.5));         path.setstrokewidth(1);         path.setclip(new rectangle(0, 0, axes.getprefwidth(), axes.getprefheight()));           double x = xmin;         double y = f.apply(x);           path.getelements().add(new moveto(                 mapx(x, axes), mapy(y, axes)                 ));         x+=xinc;          while(x < xmax) {             if(x == xmax) {                  x = xmin;                 y = f.apply(x);                 path.getelements().add(new moveto(                         mapx(x, axes), mapy(y, axes)                         ));             }             y = f.apply(x);             path.getelements().add(new lineto(                     mapx(x, axes), mapy(y, axes)                     ));             x+=xinc;          }           setminsize(pane.use_pref_size, pane.use_pref_size);          setprefsize(axes.getprefwidth(), axes.getprefheight());          setmaxsize(pane.use_pref_size, pane.use_pref_size);           getchildren().setall(axes, path);     }        private double mapx(double x, axes axes) {         double fx = axes.getprefwidth() / 2;         double sx = axes.getprefwidth() /                  (axes.getxaxis().getupperbound() - axes.getxaxis().getlowerbound());          return x * fx + sx;     }      private double mapy(double y, axes axes) {         double fy = axes.getprefheight() / 2;         double sy = axes.getprefheight() /                  (axes.getyaxis().getupperbound() - axes.getyaxis().getlowerbound());          return -y * sy + fy;     }  } 

drawing class responsible making animation , drawing chart pattern want to.

import javafx.animation.keyframe; import javafx.animation.timeline; import javafx.scene.group; import javafx.util.duration;  public class drawing {     private double t = 0;     private double l = 1;     private group root;      public drawing(final group root, double t) {         this.root = root;         this.t = t;     }      public void updatescene() {          final chart chart = new chart(x -> math.exp(-(math.pow((x-t), 2)))*math.cos((2*math.pi*(x-t))/l),                 -1, 1, 0.01, new axes(1000, 1000,                         -1, 1, 0.1, -1, 1, 0.1)                 );         timeline timeline = new timeline(timeline.indefinite,                  new keyframe(new duration(1000),                 x -> {                               root.getchildren().add(chart);                 }));             timeline.setautoreverse(true);         timeline.play();      }    } 

screen showing got after compilation. question up, dunno causes not cleaning after each timeline stage.

1. if want reasonable answer question, should not throw code on instead boil down code essential reproduce problem.
2. the overall concept of program looks horribly wrong me. if want move chart move not create new one.
3. why call stage.show() in loop?
4. without having time @ code i'd problem constant recreation of charts.