ImageViewerDialog.java

package com.kartoflane.superluminal2.ui;

import java.awt.Desktop;
import java.io.File;
import java.io.IOException;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.events.ControlListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;

import com.kartoflane.superluminal2.Superluminal;
import com.kartoflane.superluminal2.mvc.views.Preview;
import com.kartoflane.superluminal2.utils.IOUtils;
import com.kartoflane.superluminal2.utils.Utils;

public class ImageViewerDialog {
	private static ImageViewerDialog instance = null;

	private Preview preview = null;
	private Shell shell = null;
	private Canvas canvas;
	private Button btnClose;
	private Button btnShow;

	public ImageViewerDialog(Shell parent) {
		if (instance != null)
			throw new IllegalStateException("Previous instance has not been disposed!");
		instance = this;

		shell = new Shell(parent, SWT.DIALOG_TRIM | SWT.RESIZE | SWT.APPLICATION_MODAL);
		shell.setText(Superluminal.APP_NAME + " - Image Viewer");
		shell.setLayout(new GridLayout(2, false));

		canvas = new Canvas(shell, SWT.DOUBLE_BUFFERED);
		canvas.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1));

		RGB rgb = canvas.getBackground().getRGB();
		preview = new Preview();
		preview.setBackgroundColor((int) (0.9 * rgb.red), (int) (0.9 * rgb.green), (int) (0.9 * rgb.blue));
		preview.setDrawBackground(true);
		canvas.addPaintListener(preview);

		canvas.addControlListener(new ControlListener() {
			@Override
			public void controlMoved(ControlEvent e) {
			}

			@Override
			public void controlResized(ControlEvent e) {
				updatePreview();
				canvas.redraw();
			}
		});

		btnShow = new Button(shell, SWT.NONE);
		GridData gd_btnShow = new GridData(SWT.LEFT, SWT.CENTER, true, false, 1, 1);
		gd_btnShow.widthHint = 80;
		btnShow.setLayoutData(gd_btnShow);
		btnShow.setText("Show File");

		btnClose = new Button(shell, SWT.NONE);
		GridData gd_btnClose = new GridData(SWT.RIGHT, SWT.CENTER, false, false, 1, 1);
		gd_btnClose.widthHint = 80;
		btnClose.setLayoutData(gd_btnClose);
		btnClose.setText("Close");

		btnShow.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				String path = preview.getImagePath();
				if (path == null)
					return;

				File file = new File(IOUtils.trimProtocol(path));
				if (file.exists()) {
					if (Desktop.isDesktopSupported()) {
						Desktop desktop = Desktop.getDesktop();
						if (desktop != null) {
							try {
								desktop.open(file.getParentFile());
							} catch (IOException ex) {
							}
						}
					} else {
						Superluminal.log.error("Unable to open file location - AWT Desktop not supported.");
					}
				} else {
					Superluminal.log.error(String.format("Unable to open file location - file could not be found: '%s'", path));
				}
			}
		});

		btnClose.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				dispose();
			}
		});

		shell.addListener(SWT.Close, new Listener() {
			@Override
			public void handleEvent(Event e) {
				btnClose.notifyListeners(SWT.Selection, null);
				e.doit = false;
			}
		});

		shell.setMinimumSize(200, 200);
		shell.pack();
		Point size = shell.getSize();
		shell.setSize(size.x + 5, size.y);
		Point parSize = parent.getSize();
		Point parLoc = parent.getLocation();
		shell.setLocation(parLoc.x + parSize.x / 3 - size.x / 2, parLoc.y + parSize.y / 3 - size.y / 2);
	}

	public static ImageViewerDialog getInstance() {
		return instance;
	}

	private void updatePreview() {
		Point iSize = preview.getImageSize();
		Point cSize = canvas.getSize();

		double ratio = (double) iSize.y / iSize.x;
		int w = (int) (cSize.y / ratio);
		int h = (int) (cSize.x * ratio);
		preview.setSize(Utils.min(w, cSize.x, iSize.x), Utils.min(h, cSize.y, iSize.y));
		preview.setLocation(cSize.x / 2, cSize.y / 2);
	}

	public void open(String path) {
		preview.setImage(path == null ? "db:img/nullResource.png" : path);
		updatePreview();
		canvas.redraw();

		btnShow.setEnabled(IOUtils.getProtocol(path).equals("file:"));
		shell.open();
	}

	public void dispose() {
		preview.dispose();
		shell.dispose();
		instance = null;
	}

	public boolean isVisible() {
		return shell.isVisible();
	}
}