/*MujMail - Simple mail client for J2MECopyright (C) 2008 David Hauzar <david.hauzar.mujmail@gmail.com>This program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */package mujmail.ui;import javax.microedition.lcdui.CommandListener;import javax.microedition.lcdui.Displayable;import mujmail.MujMail;import mujmail.util.StartupModes;/** * Class for creating user interface elements. * * Represents one screen. It assumes model, view and controller in one class so * it is good for not so complex screens with no so complex models and controllers. * For complex ones, use rather MVC design pattern. *   * @author David Hauzar */public abstract class MVCComponent implements CommandListener {    private boolean initialized = false;        /**     * Gets the display that should be used to paint to the screen.     * @return the display that should be used to paint to the screen.     */    protected MujMail.MyDisplay getDisplay() {        return MujMail.mujmail.getDisplay();    }        /**     * Gets displayable screen.     * @return the screen that should be displayed.     * @throws java.lang.Exception     */    private Displayable getScreen() {        if (!initialized) {            initModel();            createView();            initialized = true;        } else {            updateView();        }        Displayable view = getView();        view.setCommandListener(this);                return view;    }    /**     * Shows screen of this user interface element.     * @param startupMode the mode in that this method should be executed.     */    public void showScreen(StartupModes startupMode) {        if (startupMode == StartupModes.IN_THE_SAME_THREAD) {            showScreen();        } else {            // start in the new thread            Thread t = new Thread() {                public void run() {                    showScreen();                }            };            t.start();        }    }            /**     * Shows screen of this element.     */    public void showScreen() {        try {            getDisplay().setCurrent(getScreen());        } catch (Exception e) {            e.printStackTrace();            // TODO: show allert        }    }            /**     * Gets the screen object.     * Before first calling of this method, method {@link mujmail.ui.MVCComponent#createView()}.     * will is always called. Before furthre calling of this method, method     * {@link mujmail.ui.MVCComponent#updateView() } is called.     *     * @return the screen object.     */    protected abstract Displayable getView();    /**     * Initializes the model. This method is called before first calling of     * method {@link mujmail.ui.MVCComponent#getView() }     */    protected abstract void initModel();    /**     * Creates the view. This method is called before first calling of method     * {@link mujmail.ui.MVCComponent#getView() } and after calling of method     * {@link mujmail.ui.MVCComponent#initModel() }.     */    protected abstract void createView();    /**     * Updates the view. Called in method {@link mujmail.ui.MVCComponent#showScreen() }     * before calling of method getView when this calling is not first time.     */    protected abstract void updateView();    }