Using a TopComponent's Lookup

/* * To change this template, choose Tools | Templates * and open the template in the editor. */ package org.myorg.MyViewer; import java.io.Serializable; import java.util.Collection; import java.util.logging.Logger; import org.myorg.myapi.APIObject; import org.openide.util.Lookup; import org.openide.util.LookupEvent; import org.openide.util.LookupListener; import org.openide.util.NbBundle; import org.openide.windows.TopComponent; import org.openide.windows.WindowManager; import org.openide.util.Utilities; /** * Top component which displays something. */ final class MyViewerTopComponent extends TopComponent implements LookupListener { private static MyViewerTopComponent instance; /** path to the icon used by the component and its open action */ static final String ICON_PATH = "org/myorg/MyViewer/HaoSc32_1320_200525152611580.gif"; private static final String PREFERRED_ID = "MyViewerTopComponent"; private Lookup.Result result = null; private MyViewerTopComponent() { initComponents(); setName(NbBundle.getMessage(MyViewerTopComponent.class, "CTL_MyViewerTopComponent")); setToolTipText(NbBundle.getMessage(MyViewerTopComponent.class, "HINT_MyViewerTopComponent")); setIcon(Utilities.loadImage(ICON_PATH, true)); } /** This method is called from within the constructor to * initialize the form. * WARNING: Do NOT modify this code. The content of this method is * always regenerated by the Form Editor. */ // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents private void initComponents() { jLabel1 = new javax.swing.JLabel(); jLabel2 = new javax.swing.JLabel(); org.openide.awt.Mnemonics.setLocalizedText(jLabel1, org.openide.util.NbBundle.getMessage(MyViewerTopComponent.class, "MyViewerTopComponent.jLabel1.text")); // NOI18N org.openide.awt.Mnemonics.setLocalizedText(jLabel2, org.openide.util.NbBundle.getMessage(MyViewerTopComponent.class, "MyViewerTopComponent.jLabel2.text")); // NOI18N javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this); this.setLayout(layout); layout.setHorizontalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(110, 110, 110) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 164, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 186, javax.swing.GroupLayout.PREFERRED_SIZE)) .addContainerGap(104, Short.MAX_VALUE)) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(67, 67, 67) .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(jLabel2) .addContainerGap(179, Short.MAX_VALUE)) ); }// </editor-fold>//GEN-END:initComponents // Variables declaration - do not modify//GEN-BEGIN:variables private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; // End of variables declaration//GEN-END:variables /** * Gets default instance. Do not use directly: reserved for *.settings files only, * i.e. deserialization routines; otherwise you could get a non-deserialized instance. * To obtain the singleton instance, use {@link #findInstance}. */ public static synchronized MyViewerTopComponent getDefault() { if (instance == null) { instance = new MyViewerTopComponent(); } return instance; } /** * Obtain the MyViewerTopComponent instance. Never call {@link #getDefault} directly! */ public static synchronized MyViewerTopComponent findInstance() { TopComponent win = WindowManager.getDefault().findTopComponent(PREFERRED_ID); if (win == null) { Logger.getLogger(MyViewerTopComponent.class.getName()).warning( "Cannot find " + PREFERRED_ID + " component. It will not be located properly in the window system."); return getDefault(); } if (win instanceof MyViewerTopComponent) { return (MyViewerTopComponent) win; } Logger.getLogger(MyViewerTopComponent.class.getName()).warning( "There seem to be multiple components with the '" + PREFERRED_ID + "' ID. That is a potential source of errors and unexpected behavior."); return getDefault(); } @Override public int getPersistenceType() { return TopComponent.PERSISTENCE_ALWAYS; } /** * componentOpened() is called whenever the component is made visible by the window system; */ @Override public void componentOpened() { Lookup.Template tpl = new Lookup.Template(APIObject.class); result = Utilities.actionsGlobalContext().lookup(tpl); result.addLookupListener(this); } @Override public void componentClosed() { result.removeLookupListener(this); result = null; } /** replaces this in object stream */ @Override public Object writeReplace() { return new ResolvableHelper(); } @Override protected String preferredID() { return PREFERRED_ID; } /** * The resultChanged() method is your implementation of LookupListener. * Whenever the selected APIObject changes, it will update the two JLabels you put on the form. * @param arg0 */ public void resultChanged(LookupEvent arg0) { Lookup.Result r = (Lookup.Result) arg0.getSource(); Collection c = r.allInstances(); if (!c.isEmpty()) { APIObject o = (APIObject) c.iterator().next(); jLabel1.setText(Integer.toString(o.getIndex())); jLabel2.setText(o.getDate().toString()); } else { jLabel1.setText("[no selection]"); jLabel2.setText(""); } //throw new UnsupportedOperationException("Not supported yet."); } final static class ResolvableHelper implements Serializable { private static final long serialVersionUID = 1L; public Object readResolve() { return MyViewerTopComponent.getDefault(); } } }