Java Swing - ImageViewer

 Java Swing - ImageViewer

package jlib5.app;

import jlib5.swing.Dock;
import jlib5.swing.Drop;
import jlib5.swing.ImageView;
import com.formdev.flatlaf.FlatLightLaf;
import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.io.File;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JToolBar;
import javax.swing.SwingUtilities;
import net.infonode.docking.View;


public final class ImageViewer {
    
    Dock dock;
    javax.swing.JFrame frame;
    String imageTitle = "imageView";
    ImageView imageView;
    
    public static void main(String[] args) throws Exception {
        FlatLightLaf.setup();
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new ImageViewer();
            }
        });
    }
    
    ImageViewer() {
        createViews();
        showFrame();
    }
    
    final void createViews() {
        dock = new Dock();
        imageView = new ImageView();
        View imgview = dock.addToViewMap(imageTitle, null, imageView.getLayout());
        dock.createRootWindow();
        dock.getRootWindow().setWindow(dock.getTab(imgview));
        imageView.getCtrl().setTransferHandler(new Drop(this::fileDropHandler) );
    }
    
    void showFrame() {
        frame = new JFrame("ImageViewer");
        frame.getContentPane().add(createToolBar(), BorderLayout.NORTH);
        frame.getContentPane().add(dock.getRootWindow(), BorderLayout.CENTER);
        frame.getContentPane().add(new JLabel("Ready"), BorderLayout.SOUTH);
        frame.setJMenuBar(createMenuBar());
        frame.setSize(900, 700);
        frame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);  
    }    

   //---------------------------------------------------------------------------
    boolean fileDropHandler(Object...obj)  {
        java.util.List<File> files = (java.util.List<File>) obj[0];
        imageView.loadImage(files.get(0));    
        return true;
    }
    void fileOpen() {
        imageView.loadImage(fileOpenDialog(frame));
    } 

   //---------------------------------------------------------------------------
    public File fileOpenDialog(Frame frame) {
        JFileChooser fileChooser = new JFileChooser();
        fileChooser.setCurrentDirectory(new File(System.getProperty("user.home")));
        int result = fileChooser.showOpenDialog(frame);
        if (result == JFileChooser.APPROVE_OPTION) {
            return fileChooser.getSelectedFile();
        }
        return null;
    }
    
    JButton getButton(String text, Image image, Runnable handler) {
        JButton button = new JButton();
        if( text    != null ) { button.setText(text); }
        if( image   != null ) { button.setIcon(new ImageIcon(image)); }
        if( handler != null ) { button.addActionListener( (e) -> handler.run() ); }
        return button;
    }  
        
    JToolBar createToolBar() {
        JToolBar toolBar = new JToolBar();
        toolBar.add( getButton("Open",null,this::fileOpen) );
        toolBar.add( getButton("(0)",null,() -> { imageView.updateImage("original"); } ) );
        toolBar.add( getButton("(+)",null,() -> { imageView.updateImage("increase"); } ) );
        toolBar.add( getButton("(-)",null,() -> { imageView.updateImage("decrease"); } ) );
        toolBar.add( getButton("(F)",null,() -> { imageView.updateImage("fit"); } ) );
        toolBar.add( getButton("(W)",null,() -> { imageView.updateImage("width"); } ) );
        toolBar.add( getButton("(H)",null,() -> { imageView.updateImage("height"); } ) );
        return toolBar;
    }    
    
    JMenuBar createMenuBar() {
      JMenuBar menu = new JMenuBar();
      menu.add(createFileMenu());
      return menu;
    }

    JMenu createFileMenu() {
        JMenu menu = new JMenu("File");
        JMenuItem item = new JMenuItem("Exit");
        menu.add(item).addActionListener((ActionEvent e) -> {
            System.exit(0);
        });
        return menu;
    }

}