java - Creating Vertical Scrollable Pane for JPanels -

i trying make jscrollpane contains jpanels have charts jfreechart api. generatechartpanel method return charts in jpanel can make bunch of them. far have in main:

 public static void main (string[] args){      jframe main = new jframe();     main.setlayout(new borderlayout());     main.setpreferredsize(new dimension(500,500));      //creates specframe     jscrollpane specscrollpane = new jscrollpane();     jpanel container = new jpanel();     container.setlayout(new gridlayout());      container.add(generatespecpanelfromsmiles("c"));     container.add(generatespecpanelfromsmiles("cc"));     container.add(generatespecpanelfromsmiles("ccc"));      container.setvisible(true);     specscrollpane.setvisible(true);     specscrollpane.add(container);     main.add(specscrollpane);      refineryutilities.centerframeonscreen(main);     main.setvisible(true); 

when run this, nothing shows up. apparently can't pack, setcloseop, setlayout, or center these panes commented them out. missing?

edit: getting dimensions

 specpanel.addcomponentlistener(new java.awt.event.componentadapter() {         @override         public void componentresized(componentevent event) {             specpanel.setsize(math.min(specpanel.getpreferredsize().width, specpanel.getwidth()),                     math.min(specpanel.getpreferredsize().height, specpanel.getheight()));         }     }); 

thanks

• jscrollpane designated nest 1 jcomponent

• you have put jpanel jscrollpane, jpanel can add 3 components

• have change default layout manager (flowlayout) parent jpanel (contains 3 components), 1 depends of components, how returns preferredsize, maybe start gridlayout(all childs has same size on screen)

edit

whatever generatespecpanelfromsmiles it, must returns preferredsize parentpanel, e.g. (playing preferredsize gridlayout , boxlayout - box accepting min, max , preferred size)

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import java.awt.borderlayout; import java.awt.color; import java.awt.dimension; import java.awt.graphics; import java.awt.gridlayout; import java.awt.layoutmanager; import java.awt.event.actionevent; import java.awt.event.actionlistener; import javax.swing.boxlayout; import javax.swing.jbutton; import javax.swing.jframe; import javax.swing.jpanel; import javax.swing.jscrollpane;  public class jpanelsinsidejscrollpane {      private jframe frame = new jframe("jpanels inside jscrollpane");     private jscrollpane scrollpane = new jscrollpane();     private jpanel parentpanel, childone, childtwo, childthree;     private jbutton button = new jbutton("change, switch layout manager boxlayout");      public jpanelsinsidejscrollpane() {         parentpanel = new jpanel() {             @override             public dimension getpreferredsize() {                 return new dimension(new dimension(800, 600));             }              @override             public void paintcomponent(graphics g) {                 int margin = 10;                 dimension dim = getsize();                 super.paintcomponent(g);                 g.setcolor(color.dark_gray);                 g.fillrect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);             }         };         parentpanel.setlayout(new gridlayout(0, 1));         childone = new jpanel() {             @override             public dimension getminimumsize() {                 return new dimension(100, 100);             }              @override             public dimension getpreferredsize() {                 return new dimension(200, 300);             }              @override             public dimension getmaximumsize() {                 return new dimension(500, 300);             }              @override             public void paintcomponent(graphics g) {                 int margin = 10;                 dimension dim = getsize();                 super.paintcomponent(g);                 g.setcolor(color.green);                 g.fillrect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);             }         };         childtwo = new jpanel() {             @override             public dimension getminimumsize() {                 return new dimension(100, 100);             }              @override             public dimension getpreferredsize() {                 return new dimension(400, 300);             }              @override             public dimension getmaximumsize() {                 return new dimension(600, 400);             }              @override             public void paintcomponent(graphics g) {                 int margin = 10;                 dimension dim = getsize();                 super.paintcomponent(g);                 g.setcolor(color.blue);                 g.fillrect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);             }         };         childthree = new jpanel() {             @override             public dimension getminimumsize() {                 return new dimension(100, 100);             }              @override             public dimension getpreferredsize() {                 return new dimension(400, 300);             }              @override             public dimension getmaximumsize() {                 return new dimension(800, 600);             }              @override             public void paintcomponent(graphics g) {                 int margin = 10;                 dimension dim = getsize();                 super.paintcomponent(g);                 g.setcolor(color.orange);                 g.fillrect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);             }         };         parentpanel.add(childone);         parentpanel.add(childtwo);         parentpanel.add(childthree);         scrollpane.setviewportview(parentpanel);         scrollpane.getverticalscrollbar().setunitincrement(30);         scrollpane.gethorizontalscrollbar().setunitincrement(30);         button.addactionlistener(new actionlistener() {             @override             public void actionperformed(actionevent e) {                 layoutmanager manager = parentpanel.getlayout();                 if ((manager != null) && (manager instanceof boxlayout)) {                     parentpanel.setlayout(new gridlayout(0, 1));                     button.settext("change, switch layout manager boxlayout");                 } else if ((manager != null) && (manager instanceof gridlayout)) {                     parentpanel.setlayout(new boxlayout(parentpanel, boxlayout.page_axis));                     button.settext("change, switch layout manager gridlayout");                 }                 parentpanel.revalidate();                 parentpanel.repaint();             }         });         frame.add(scrollpane);         frame.add(button, borderlayout.south);         frame.setsize(400, 300);         frame.setvisible(true);         frame.setdefaultcloseoperation(jframe.exit_on_close);     }      public static void main(string args[]) {         javax.swing.swingutilities.invokelater(new runnable() {             @override             public void run() {                 new jpanelsinsidejscrollpane();             }         });     } }