desktopdemo.java

java tutorial.sun公司官方出品。java入门书籍。最新版

        fileHGroup.addComponent(btnFile);
        txtFieldsHGroup.addGroup(fileHGroup);
        
        GroupLayout.ParallelGroup btnHGroup =
                layout.createParallelGroup(GroupLayout.Alignment.LEADING);
        btnHGroup.addComponent(btnLaunchBrowser);
        btnHGroup.addComponent(btnLaunchEmail);
        btnHGroup.addComponent(btnLaunchApplication);
        
        majorHGroup.addGroup(lblHGroup);
        majorHGroup.addGroup(txtFieldsHGroup);
        majorHGroup.addGroup(btnHGroup);
        
        layout.setHorizontalGroup(majorHGroup);
        
        // Vertical group
        
        GroupLayout.SequentialGroup majorVGroup = layout.createSequentialGroup();
        
        GroupLayout.ParallelGroup uriVGroup =
                layout.createParallelGroup(GroupLayout.Alignment.BASELINE);
        uriVGroup.addComponent(lblBrowserUri);
        uriVGroup.addComponent(txtBrowserURI);
        uriVGroup.addComponent(btnLaunchBrowser);
        
        GroupLayout.ParallelGroup mailVGroup =
                layout.createParallelGroup(GroupLayout.Alignment.BASELINE);
        mailVGroup.addComponent(lblMailRecipient);
        mailVGroup.addComponent(txtMailTo);
        mailVGroup.addComponent(btnLaunchEmail);
        
        GroupLayout.ParallelGroup rbVGroup =
                layout.createParallelGroup(GroupLayout.Alignment.BASELINE);
        rbVGroup.addComponent(rbOpen);
        rbVGroup.addComponent(rbEdit);
        rbVGroup.addComponent(rbPrint);
        
        GroupLayout.ParallelGroup fileVGroup =
                layout.createParallelGroup(GroupLayout.Alignment.BASELINE);
        fileVGroup.addComponent(lblFile);
        fileVGroup.addComponent(btnLaunchApplication);
        fileVGroup.addComponent(txtFile);
        fileVGroup.addComponent(btnFile);
        
        majorVGroup.addGroup(uriVGroup);
        majorVGroup.addGroup(mailVGroup);
        majorVGroup.addGroup(rbVGroup);
        majorVGroup.addGroup(fileVGroup);
        
        layout.setVerticalGroup(majorVGroup);
        
        pack();
    }
    
    /**
     * Load the "desktop" icon into our frame window.
     */
    private void loadFrameIcon() {
        URL imgUrl = null;
        ImageIcon imgIcon = null;
        
        imgUrl = DesktopDemo.class.getResource("images/desk32.gif");
        imgIcon = new ImageIcon(imgUrl);
        Image img = imgIcon.getImage();
        this.setIconImage(img);
    }
    
    /*
     * Set the Desktop.Action to PRINT before invoking
     * the default application.
     */
    private void onPrintAction(ActionEvent evt) {
        action = Desktop.Action.PRINT;
    }
    
    /**
     * Set the Desktop.Action to EDIT before invoking
     * the default application.
     */
    private void onEditAction(ActionEvent evt) {
        action = Desktop.Action.EDIT;
    }
    
    /**
     * Set the Desktop.Action to OPEN before invoking
     * the default application.
     */
    private void onOpenAction(ActionEvent evt) {
        action = Desktop.Action.OPEN;
    }
    
    /**
     * Launch the default application associated with a specific
     * filename using the preset Desktop.Action.
     *
     */
    private void onLaunchDefaultApplication(ActionEvent evt) {
        String fileName = txtFile.getText();
        File file = new File(fileName);
        
        try {
            switch(action) {
                case OPEN:
                    desktop.open(file);
                    break;
                case EDIT:
                    desktop.edit(file);
                    break;
                case PRINT:
                    desktop.print(file);
                    break;
            }
        } catch (IOException ioe) {
            //ioe.printStackTrace();
            System.out.println("Cannot perform the given operation to the " + file + " file");
        }
    }
    
    /**
     * Launch the default email client using the "mailto"
     * protocol and the text supplied by the user.
     *
     */
    private void onLaunchMail(ActionEvent evt) {
        String mailTo = txtMailTo.getText();
        URI uriMailTo = null;
        try {
            if (mailTo.length() > 0) {
                uriMailTo = new URI("mailto", mailTo, null);
                desktop.mail(uriMailTo);
            } else {
                desktop.mail();
            }
        } catch(IOException ioe) {
            ioe.printStackTrace();
        } catch(URISyntaxException use) {
            use.printStackTrace();
        }
    }
    
    /**
     * Launch the default browser with the text provided by the
     * user.
     *
     */
    private void onLaunchBrowser(ActionEvent evt) {
        URI uri = null;
        try {
            uri = new URI(txtBrowserURI.getText());
            desktop.browse(uri);
        } catch(IOException ioe) {
            System.out.println("The system cannot find the " + uri + " file specified");
            //ioe.printStackTrace();
        } catch(URISyntaxException use) {
            System.out.println("Illegal character in path");
            //use.printStackTrace();
        }
    }
    
    private void onChooseFile(ActionEvent evt) {
        if (evt.getSource() == btnFile) {
            int returnVal = fc.showOpenDialog(DesktopDemo.this);
            if (returnVal == JFileChooser.APPROVE_OPTION){
                file = fc.getSelectedFile();
                txtFile.setText(file.getAbsolutePath());
            }
        }
    }
    
    /**
     * Enable actions that are supported on this host.
     * The actions are: open browser, open email client, and
     * open, edit, and print files using their associated application
     */
    
    private void enableSupportedActions() {
        if (desktop.isSupported(Desktop.Action.BROWSE)) {
            txtBrowserURI.setEnabled(true);
            btnLaunchBrowser.setEnabled(true);
        }
        if (desktop.isSupported(Desktop.Action.MAIL)) {
            txtMailTo.setEnabled(true);
            btnLaunchEmail.setEnabled(true);
        }
        if (desktop.isSupported(Desktop.Action.OPEN)) {
            rbOpen.setEnabled(true);
        }
        if (desktop.isSupported(Desktop.Action.EDIT)) {
            rbEdit.setEnabled(true);
        }
        if (desktop.isSupported(Desktop.Action.PRINT)) {
            rbPrint.setEnabled(true);
        }
        if (rbEdit.isEnabled() || rbOpen.isEnabled() || rbPrint.isEnabled()) {
            txtFile.setEnabled(true);
            btnLaunchApplication.setEnabled(true);
            btnFile.setEnabled(true);
        }
    }
    
    /**
     * Disable all graphical components until we know
     * whether their functionality is supported.
     */
    private void disableActions() {
        txtBrowserURI.setEnabled(false);
        btnLaunchBrowser.setEnabled(false);
        
        txtMailTo.setEnabled(false);
        btnLaunchEmail.setEnabled(false);
        
        rbEdit.setEnabled(false);
        rbOpen.setEnabled(false);
        rbPrint.setEnabled(false);
        
        txtFile.setEnabled(false);
        btnLaunchApplication.setEnabled(false);
        btnFile.setEnabled(false);
    }
}