java - JTable inside JScrollPane inside JPanel with GridBagLayout, doesn't look as it should -

first, hier code:

import java.awt.dimension; import java.awt.gridbagconstraints; import java.awt.gridbaglayout; import java.awt.insets;  import javax.swing.jcomponent;  import javax.swing.jbutton; import javax.swing.jtoolbar; import javax.swing.jframe; import javax.swing.jlabel; import javax.swing.jpanel; import javax.swing.jscrollpane; import javax.swing.jtable; import javax.swing.table.tablecolumn;  @suppresswarnings("serial") public class spielklasse extends jpanel{  private int ientries = 1;  public spielklasse(string strtitle){     setlayout(new gridbaglayout());      //dummy fill vertical space     gridbagconstraints c = new gridbagconstraints();     c.gridx = 0;     c.gridy = 1000;     c.fill = gridbagconstraints.both;     c.weightx=1;     c.weighty=1;     c.gridwidth = 2;     add(new jlabel(" "),c); }  public void addentry(jcomponent component){      gridbagconstraints c = new gridbagconstraints();     c.anchor = gridbagconstraints.northwest;     c.gridx = 1;     c.gridy = ientries;     c.weightx = 1;     c.insets = new insets(10, 20, 10, 20);     c.fill = gridbagconstraints.horizontal;     add(component, c);      ientries++;  }  public static jpanel addexampletablepanel() {     string[] columnnames = { "first", "second", "third", "fourth", "fifth", "sixth" };      string[][] strarr = new string[100][columnnames.length];      (int = 0; < strarr.length; i++) {         (int j = 0; j < strarr[0].length; j++) {             strarr[i][j] = + " xxxxx " + j;         }     }      jtable table = new jtable(strarr, columnnames) {         @override         public dimension getpreferredscrollableviewportsize() {             int headerheight = gettableheader().getpreferredsize().height;             int height = headerheight + (10 * getrowheight());             int width = getpreferredsize().width;             return new dimension(width, height);         }     };      jscrollpane scrollpane = new jscrollpane(table, jscrollpane.vertical_scrollbar_as_needed, jscrollpane.horizontal_scrollbar_as_needed);     table.setautoresizemode(jtable.auto_resize_off);      tablecolumn column = null;     (int = 0; < columnnames.length; i++) {         column = table.getcolumnmodel().getcolumn(i);         column.setpreferredwidth(50);         column.setmaxwidth(50);         column.setminwidth(50);     }      jtoolbar toolbar = new jtoolbar();     jbutton btn = new jbutton("test123");     toolbar.add(btn);      jpanel panel = new jpanel(new gridbaglayout());      gridbagconstraints c = new gridbagconstraints();      c.fill = gridbagconstraints.horizontal;     c.gridy = 0;     c.weightx = 1;     c.weighty = 1;     c.gridwidth = 1;     c.anchor = gridbagconstraints.line_start;      panel.add(toolbar, c);     c.gridy = 1;     panel.add(scrollpane, c);      return panel; }   public static void main(string[] args) {      spielklasse mainpanel = new spielklasse("test");     mainpanel.addentry(addexampletablepanel());     mainpanel.addentry(addexampletablepanel());     mainpanel.addentry(addexampletablepanel());      jframe frame = new jframe();     frame.setsize(300, 400);     frame.setdefaultcloseoperation(jframe.exit_on_close);     frame.getcontentpane().add(new jscrollpane(mainpanel));     frame.setvisible(true); }  } 

the class "spieklasse" should create jpanel multiple entries of different types tables, textboxes etc.

in example here, 3 jtable-containing panels should added.

this jtable inside jsrollpane , should have fixed column widths. jscrollpane inside jpanel, wich contains toolbar above table perform actions etc. jpanel added main panel of type "spielklasse". main panel inside jscrollpane.

here problem: - table-panel should have fixed height wich can set want. in code example, size fixed, dont know why , wrong size :-) - @ table horizontal scrollbar should appear, when size of frame smaller size of table (all columns together). when frame bigger, everying should stretched horizontal (works already)

i hope explanation enough , can me :-)

edit: updated improvement of camickr, vertical size problem solved.

the size fixed, dont know why , wrong size :-)

the size of scroll pane determined getpreferredscrollableviewportsize() method of jtable.

when table created following hardcoded in jtable:

setpreferredscrollableviewportsize(new dimension(450, 400)); 

so if want control default width/height of scroll pane need override getpreferredscrollableviewportsize() method return reasonable value. height should include column header number of rows in table wish display.

maybe like:

@override public dimension getpreferredscrollableviewportsize()  {     int headerheight = table.gettableheader().getpreferredsize().height;     int height = headerheight + (10 * getrowheight());     int width = getpreferredsize().width;     return new dimension(width, height); } 

edit:

to use scrollablepanel can change code to:

//public class table8 extends jpanel{ public class table8 extends scrollablepanel{  private int ientries = 1;  public table8(string strtitle){     setlayout(new gridbaglayout());     setscrollablewidth( scrollablepanel.scrollablesizehint.fit ); 

another problem gridbaglayout. if there not enough space display component @ preferred size, component snaps minimum size. causes problems scroll pane need add:

scrollpane.setminimumsize( scrollpane.getpreferredsize() ); 

or may easier use layout manager. maybe vertical boxlayout.