Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>It's an old discussion ... but I had exactly the same problem and did not want a workaround solution as adding a "clear selection button". So, I wrote my own ButtonGroup that solves the original question (a button can be deselected, leaving the group with no button selected). It also adds the ability to be observed by a java.util.Observer that will be informed every time the selected button changes.</p> <p>Here is the code:</p> <pre><code>package net.yapbam.gui.util; import java.awt.event.*; import java.util.ArrayList; import java.util.List; import java.util.Observable; import java.io.Serializable; import javax.swing.JToggleButton; /** * This class is, like javax.swing.ButtonGroup, used to create a multiple-exclusion scope for * a set of buttons. Creating a set of buttons with the same &lt;code&gt;ButtonGroup&lt;/code&gt; object means that * turning "on" one of those buttons turns off all other buttons in the group. * &lt;p&gt; * The main difference of this group with the swing one is that you can deselected buttons by clicking on them * and have a group without no selected button.&lt;br&gt; * Another difference is that this class extends the java.util.Observable class and calls its observers update method * when the selected button changes. * &lt;/p&gt; */ public class ButtonGroup extends Observable implements Serializable { private static final long serialVersionUID = 1L; /** * The buttons list */ private List&lt;JToggleButton&gt; buttons; /** * The current selection. */ private JToggleButton selected; private ItemListener listener; /** * Constructor. */ public ButtonGroup() { this.buttons = new ArrayList&lt;JToggleButton&gt;(); this.selected = null; this.listener = new ItemListener() { @Override public void itemStateChanged(ItemEvent e) { JToggleButton b = (JToggleButton) e.getItem(); if (e.getStateChange()==ItemEvent.SELECTED) { setSelected(b); } else { if (selected==b) setSelected(null); } } }; } /** * Adds a button to this group. * @param b the button to be added * @exception NullPointerException if the button is null */ public void add(JToggleButton b) { if (b==null) throw new NullPointerException(); buttons.add(b); b.addItemListener(listener); if (b.isSelected()) setSelected(b); } /** * Removes a button from this group. * @param b the button to be removed * @exception IllegalArgumentException if the button is unknown in this group * @exception NullPointerException if the button is null */ public void remove(JToggleButton b) { if (b == null) throw new NullPointerException(); if (this.buttons.remove(b)) { b.removeItemListener(this.listener); if (this.selected==b) setSelected(null); } else { throw new IllegalArgumentException(); } } /** * Clears the selection such that none of the buttons in the * &lt;code&gt;ButtonGroup&lt;/code&gt; are selected. */ public void clearSelection() { if (selected != null) setSelected(null); } /** * Returns the selected button. * @return the selected button */ public JToggleButton getSelected() { return this.selected; } /** Changes the selected button. * @param b the button to be selected (null deselects all buttons) * @exception IllegalArgumentException if the button is not in this group */ public void setSelected(JToggleButton b) { if (b==this.selected) return; if ((b!=null) &amp;&amp; (!this.buttons.contains(b))) throw new IllegalArgumentException(); JToggleButton old = this.selected; this.selected = b; if (b!=null) b.setSelected(true); if (old!=null) old.setSelected(false); this.setChanged(); this.notifyObservers(this.selected); } } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POUncheck all checkboxes added as a group
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USJean-Marc Astesana
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload