Java tutorial
/***************************************************************** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. ****************************************************************/ package org.apache.cayenne.modeler.util; import java.awt.Component; import java.awt.Dimension; import java.awt.Point; import java.awt.Window; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.beans.PropertyChangeListener; import java.beans.PropertyChangeSupport; import java.util.prefs.Preferences; import javax.swing.JComponent; import javax.swing.JDialog; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.KeyStroke; import org.apache.cayenne.modeler.Application; import org.apache.cayenne.modeler.pref.FSPath; import org.apache.cayenne.swing.BoundComponent; import org.apache.cayenne.util.Util; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A superclass of CayenneModeler controllers. */ public abstract class CayenneController implements BoundComponent { private static Log logObj = LogFactory.getLog(CayenneController.class); protected CayenneController parent; protected Application application; protected PropertyChangeSupport propertyChangeSupport; public CayenneController() { } public CayenneController(CayenneController parent) { this.application = (parent != null) ? parent.getApplication() : null; this.parent = parent; } public CayenneController(Application application) { this.application = application; } public Application getApplication() { return application; } public CayenneController getParent() { return parent; } /** * Returns the vie wassociated with this Controller. */ public abstract Component getView(); /** * Returns last file system directory visited by user for this component. If there is * no such directory set up in the preferences, creates a new object, setting its path * to the parent last directory or to the user HOME directory. */ public FSPath getLastDirectory() { // find start directory in preferences FSPath path = (FSPath) application.getCayenneProjectPreferences().getProjectDetailObject(FSPath.class, getViewPreferences().node("lastDir")); if (path.getPath() == null) { String pathString = (getParent() != null) ? getParent().getLastDirectory().getPath() : System.getProperty("user.home"); path.setPath(pathString); } return path; } /** * Returns preference for this component view. */ protected Preferences getViewPreferences() { if (getApplication().getProject() == null) { return getApplication().getPreferencesNode(getView().getClass(), ""); } Preferences pref = getApplication().getMainPreferenceForProject(); String pathToProject = pref.absolutePath(); String path = pathToProject + "/" + getView().getClass().getName().replace(".", "/"); return pref.node(path); } /** * Utility method to provide a visual indication an execution error. This * implementation logs an error and pops up a dialog window with error message. */ protected void reportError(String title, Throwable th) { th = Util.unwindException(th); logObj.info("Error in " + getClass().getName(), th); th.printStackTrace(); JOptionPane.showMessageDialog(getView(), th.getMessage(), title, JOptionPane.ERROR_MESSAGE); } /** * Centers view on parent window. */ protected void centerView() { Window parentWindow = parent.getWindow(); Dimension parentSize = parentWindow.getSize(); Dimension windowSize = getView().getSize(); Point parentLocation = new Point(0, 0); if (parentWindow.isShowing()) { parentLocation = parentWindow.getLocationOnScreen(); } int x = parentLocation.x + parentSize.width / 2 - windowSize.width / 2; int y = parentLocation.y + parentSize.height / 2 - windowSize.height / 2; getView().setLocation(x, y); } /** * If this view or a parent view is a JDialog, makes it closeable on ESC hit. Dialog * "defaultCloseOperation" property is taken into account when processing ESC button * click. */ protected void makeCloseableOnEscape() { Window window = getWindow(); if (!(window instanceof JDialog)) { return; } final JDialog dialog = (JDialog) window; KeyStroke escReleased = KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0, true); ActionListener closeAction = new ActionListener() { public void actionPerformed(ActionEvent e) { if (dialog.isVisible()) { switch (dialog.getDefaultCloseOperation()) { case JDialog.HIDE_ON_CLOSE: dialog.setVisible(false); break; case JDialog.DISPOSE_ON_CLOSE: dialog.setVisible(false); dialog.dispose(); break; case JDialog.DO_NOTHING_ON_CLOSE: default: break; } } } }; dialog.getRootPane().registerKeyboardAction(closeAction, escReleased, JComponent.WHEN_IN_FOCUSED_WINDOW); } /** * Finds a Window in the view hierarchy. */ public Window getWindow() { Component view = getView(); while (view != null) { if (view instanceof Window) { return (Window) view; } view = view.getParent(); } return null; } /** * Finds a JFrame in the view hierarchy. */ public JFrame getFrame() { Component view = getView(); while (view != null) { if (view instanceof JFrame) { return (JFrame) view; } view = view.getParent(); } return null; } /** * Fires property change event. Exists for the benefit of subclasses. */ protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) { if (propertyChangeSupport != null) { propertyChangeSupport.firePropertyChange(propertyName, oldValue, newValue); } } /** * Adds a listener for property change events. */ public void addPropertyChangeListener(String expression, PropertyChangeListener listener) { if (propertyChangeSupport == null) { propertyChangeSupport = new PropertyChangeSupport(this); } propertyChangeSupport.addPropertyChangeListener(expression, listener); } /** * Default implementation is a noop. Override to handle parent binding updates. */ public void bindingUpdated(String expression, Object newValue) { // do nothing... } }