/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.jface.window;

import java.lang.reflect.InvocationTargetException;

import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.jface.action.CoolBarManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.StatusLineManager;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.operation.IRunnableContext;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.operation.ModalContext;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.CoolBar;
import org.eclipse.swt.widgets.Decorations;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;

/**
 * An application window is a high-level "main window", with built-in
 * support for an optional menu bar with standard menus, an optional toolbar,
 * and an optional status line.
 * <p>
 * Creating an application window involves the following steps:
 * <ul>
 *   <li>creating an instance of <code>ApplicationWindow</code>
 *   </li>
 *   <li>assigning the window to a window manager (optional)
 *   </li>
 *   <li>opening the window by calling <code>open</code>
 *   </li>
 * </ul>
 * Only on the last step, when the window is told to open, are
 * the window's shell and widget tree created. When the window is
 * closed, the shell and widget tree are disposed of and are no longer
 * referenced, and the window is automatically removed from its window
 * manager. Like all windows, an application window may be reopened.
 * </p>
 * <p>
 * An application window is also a suitable context in which to perform 
 * long-running operations (that is, it implements <code>IRunnableContext</code>).
 * </p>
 */
public class ApplicationWindow extends Window implements IRunnableContext {

    /**
     * Menu bar manager, or <code>null</code> if none (default).
     *
     * @see #addMenuBar
     */
    private MenuManager menuBarManager = null;

    /**
     * Tool bar manager, or <code>null</code> if none (default).
     *
     * @see #addToolBar
     */
    private ToolBarManager toolBarManager = null;

    /**
     * Status line manager, or <code>null</code> if none (default).
     *
     * @see #addStatusLine
     */
    private StatusLineManager statusLineManager = null;

    /**
     * Cool bar manager, or <code>null</null> if none (default).
     * 
     * @see #addCoolBar
     * @since 3.0
     */
    private CoolBarManager coolBarManager = null;

    /**
     * The seperator between the menu bar and the rest of the window.
     */
    protected Label seperator1;

    /**
     * A flag indicating that an operation is running.
     */
    private boolean operationInProgress = false;

    /**
     * Internal application window layout class.
     * This vertical layout supports a tool bar area (fixed size),
     * a separator line, the content area (variable size), and a 
     * status line (fixed size).
     */
    /*package*/class ApplicationWindowLayout extends Layout {

        static final int VGAP = 2;

        static final int BAR_SIZE = 23;

        protected Point computeSize(Composite composite, int wHint, int hHint,
                boolean flushCache) {
            if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT)
                return new Point(wHint, hHint);

            Point result = new Point(0, 0);
            Control[] ws = composite.getChildren();
            for (int i = 0; i < ws.length; i++) {
                Control w = ws[i];

                boolean hide = false;
                if (getToolBarControl() == w) {
                    if (!toolBarChildrenExist()) {
                        hide = true;
                        result.y += BAR_SIZE; // REVISIT
                    }
                } else if (getCoolBarControl() == w) {
                    if (!coolBarChildrenExist()) {
                        hide = true;
                        result.y += BAR_SIZE;
                    }
                } else if (statusLineManager != null
                        && statusLineManager.getControl() == w) {
                } else if (i > 0) { /* we assume this window is contents */
                    hide = false;
                }

                if (!hide) {
                    Point e = w.computeSize(wHint, hHint, flushCache);
                    result.x = Math.max(result.x, e.x);
                    result.y += e.y + VGAP;
                }
            }

            if (wHint != SWT.DEFAULT)
                result.x = wHint;
            if (hHint != SWT.DEFAULT)
                result.y = hHint;
            return result;
        }

        protected void layout(Composite composite, boolean flushCache) {
            Rectangle clientArea = composite.getClientArea();

            Control[] ws = composite.getChildren();

            for (int i = 0; i < ws.length; i++) {
                Control w = ws[i];

                if (i == 0) { // Separator
                    Point e = w.computeSize(SWT.DEFAULT, SWT.DEFAULT,
                            flushCache);
                    w.setBounds(clientArea.x, clientArea.y, clientArea.width,
                            e.y);
                    clientArea.y += e.y;
                    clientArea.height -= e.y;
                } else if (getToolBarControl() == w) {
                    if (toolBarChildrenExist()) {
                        Point e = w.computeSize(SWT.DEFAULT, SWT.DEFAULT,
                                flushCache);
                        w.setBounds(clientArea.x, clientArea.y,
                                clientArea.width, e.y);
                        clientArea.y += e.y + VGAP;
                        clientArea.height -= e.y + VGAP;
                    }
                } else if (getCoolBarControl() == w) {
                    if (coolBarChildrenExist()) {
                        Point e = w.computeSize(clientArea.width, SWT.DEFAULT,
                                flushCache);
                        w.setBounds(clientArea.x, clientArea.y,
                                clientArea.width, e.y);
                        clientArea.y += e.y + VGAP;
                        clientArea.height -= e.y + VGAP;
                    }
                } else if (statusLineManager != null
                        && statusLineManager.getControl() == w) {
                    Point e = w.computeSize(SWT.DEFAULT, SWT.DEFAULT,
                            flushCache);
                    w.setBounds(clientArea.x, clientArea.y + clientArea.height
                            - e.y, clientArea.width, e.y);
                    clientArea.height -= e.y + VGAP;
                } else {
                    w.setBounds(clientArea.x, clientArea.y + VGAP,
                            clientArea.width, clientArea.height - VGAP);
                }
            }
        }
    }

    /**
     * Return the top seperator.
     * @return Label
     */
    protected Label getSeperator1() {
        return seperator1;
    }

    /**
     * Create an application window instance, whose shell will be created under the
     * given parent shell.
     * Note that the window will have no visual representation (no widgets)
     * until it is told to open. By default, <code>open</code> does not block.
     *
     * @param parentShell the parent shell, or <code>null</code> to create a top-level shell
     */
    public ApplicationWindow(Shell parentShell) {
        super(parentShell);
    }

    /**
     * Configures this window to have a menu bar.
     * Does nothing if it already has one.
     * This method must be called before this window's shell is created.
     */
    protected void addMenuBar() {
        if ((getShell() == null) && (menuBarManager == null)) {
            menuBarManager = createMenuManager();
        }
    }

    /**
     * Configures this window to have a status line.
     * Does nothing if it already has one.
     * This method must be called before this window's shell is created.
     */
    protected void addStatusLine() {
        if ((getShell() == null) && (statusLineManager == null)) {
            statusLineManager = createStatusLineManager();
        }
    }

    /**
     * Configures this window to have a tool bar.
     * Does nothing if it already has one.
     * This method must be called before this window's shell is created.
     */
    protected void addToolBar(int style) {
        if ((getShell() == null) && (toolBarManager == null)
                && (coolBarManager == null)) {
            toolBarManager = createToolBarManager(style);
        }
    }

    /**
     * Configures this window to have a cool bar.
     * Does nothing if it already has one.
     * This method must be called before this window's shell is created.
     * 
     * @param style the cool bar style
     * @since 3.0
     */
    protected void addCoolBar(int style) {
        if ((getShell() == null) && (toolBarManager == null)
                && (coolBarManager == null)) {
            coolBarManager = createCoolBarManager(style);
        }
    }

    /* (non-Javadoc)
     * Method declared on Window.
     */
    protected boolean canHandleShellCloseEvent() {
        return super.canHandleShellCloseEvent() && !operationInProgress;
    }

    /* (non-Javadoc)
     * Method declared on Window.
     */
    public boolean close() {
        if (operationInProgress)
            return false;

        if (super.close()) {
            if (menuBarManager != null) {
                menuBarManager.dispose();
                menuBarManager = null;
            }
            if (toolBarManager != null) {
                toolBarManager.dispose();
                toolBarManager = null;
            }
            if (statusLineManager != null) {
                statusLineManager.dispose();
                statusLineManager = null;
            }
            if (coolBarManager != null) {
                coolBarManager.dispose();
                coolBarManager = null;
            }
            return true;
        }
        return false;
    }

    /**
     * Extends the super implementation by creating the trim widgets using <code>createTrimWidgets</code>. 
     */
    protected void configureShell(Shell shell) {

        super.configureShell(shell);

        createTrimWidgets(shell);
    }

    /**
     * Creates the trim widgets around the content area.
     * 
     * @param shell the shell
     * @since 3.0
     */
    protected void createTrimWidgets(Shell shell) {
        if (menuBarManager != null) {
            menuBarManager.updateAll(true);
            shell.setMenuBar(menuBarManager.createMenuBar((Decorations) shell));
        }

        if (showTopSeperator())
            seperator1 = new Label(shell, SWT.SEPARATOR | SWT.HORIZONTAL);

        // will create either a cool bar or a tool bar
        createToolBarControl(shell);
        createCoolBarControl(shell);
        createStatusLine(shell);
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.window.Window#getLayout()
     */
    protected Layout getLayout() {
        return new ApplicationWindowLayout();
    }

    /**
     * Returns whether to show a top separator line between the menu bar
     * and the rest of the window contents.  On some platforms such as the Mac,
     * the menu is separated from the main window already, so a separator line
     * is not desired. 
     * 
     * @return <code>true</code> to show the top separator, <code>false</code>
     *   to not show it
     * @since 3.0
     */
    protected boolean showTopSeperator() {
        return !"carbon".equals(SWT.getPlatform()); //$NON-NLS-1$
    }

    /**
     * Create the status line if required.
     * @param shell
     */
    protected void createStatusLine(Shell shell) {
        if (statusLineManager != null) {
            statusLineManager.createControl(shell, SWT.NONE);
        }
    }

    /**
     * Returns a new menu manager for the window.
     * <p>
     * Subclasses may override this method to customize the menu manager.
     * </p>
     * @return a menu manager
     */
    protected MenuManager createMenuManager() {
        return new MenuManager();
    }

    /**
     * Returns a new status line manager for the window.
     * <p>
     * Subclasses may override this method to customize the status line manager.
     * </p>
     * @return a status line manager
     */
    protected StatusLineManager createStatusLineManager() {
        return new StatusLineManager();
    }

    /**
     * Returns a new tool bar manager for the window.
     * <p>
     * Subclasses may override this method to customize the tool bar manager.
     * </p>
     * @return a tool bar manager
     */
    protected ToolBarManager createToolBarManager(int style) {
        return new ToolBarManager(style);
    }

    /**
     * Returns a new cool bar manager for the window.
     * <p>
     * Subclasses may override this method to customize the cool bar manager.
     * </p>
     * 
     * @return a cool bar manager
     * @since 3.0
     */
    protected CoolBarManager createCoolBarManager(int style) {
        return new CoolBarManager(style);
    }

    /**
     * Creates the control for the tool bar manager.
     * <p>
     * Subclasses may override this method to customize the tool bar manager.
     * </p>
     * @return a Control
     */
    protected Control createToolBarControl(Composite parent) {
        if (toolBarManager != null) {
            return toolBarManager.createControl(parent);
        }
        return null;
    }

    /**
     * Creates the control for the cool bar manager.
     * <p>
     * Subclasses may override this method to customize the cool bar manager.
     * </p>
     * 
     * @return an instance of <code>CoolBar</code>
     * @since 3.0
     */
    protected Control createCoolBarControl(Composite composite) {
        if (coolBarManager != null) {
            return coolBarManager.createControl(composite);
        }
        return null;
    }

    /**
     * Returns the default font used for this window.
     * <p>
     * The default implementation of this framework method
     * obtains the symbolic name of the font from the
     * <code>getSymbolicFontName</code> framework method
     * and retrieves this font from JFace's font
     * registry using <code>JFaceResources.getFont</code>.
     * Subclasses may override to use a different registry,
     * etc.
     * </p>
     *
     * @return the default font, or <code>null</code> if none
     */
    protected Font getFont() {
        return JFaceResources.getFont(getSymbolicFontName());
    }

    /**
     * Returns the menu bar manager for this window (if it has one).
     *
     * @return the menu bar manager, or <code>null</code> if
     *   this window does not have a menu bar
     * @see #addMenuBar()
     */
    public MenuManager getMenuBarManager() {
        return menuBarManager;
    }

    /**
     * Returns the status line manager for this window (if it has one).
     *
     * @return the status line manager, or <code>null</code> if
     *   this window does not have a status line
     * @see #addStatusLine
     */
    protected StatusLineManager getStatusLineManager() {
        return statusLineManager;
    }

    /**
     * Returns the symbolic font name of the font to be
     * used to display text in this window.
     * This is not recommended and is included for backwards
     * compatability.
     * It is recommended to use the default font provided by
     * SWT (that is, do not set the font).
     * 
     * @return the symbolic font name
     */
    public String getSymbolicFontName() {
        return JFaceResources.TEXT_FONT;
    }

    /**
     * Returns the tool bar manager for this window (if it has one).
     *
     * @return the tool bar manager, or <code>null</code> if
     *   this window does not have a tool bar
     * @see #addToolBar(int)
     */
    public ToolBarManager getToolBarManager() {
        return toolBarManager;
    }

    /**
     * Returns the cool bar manager for this window.
     *
     * @return the cool bar manager, or <code>null</code> if
     *   this window does not have a cool bar
     * @see #addCoolBar(int)
     * @since 3.0
     */
    public CoolBarManager getCoolBarManager() {
        return coolBarManager;
    }

    /**
     * Returns the control for the window's toolbar.
     * <p>
     * Subclasses may override this method to customize the tool bar manager.
     * </p>
     * @return a Control
     */
    protected Control getToolBarControl() {
        if (toolBarManager != null) {
            return toolBarManager.getControl();
        }
        return null;
    }

    /**
     * Returns the control for the window's cool bar.
     * <p>
     * Subclasses may override this method to customize the cool bar manager.
     * </p>
     * 
     * @return an instance of <code>CoolBar</code>
     * @since 3.0
     */
    protected Control getCoolBarControl() {
        if (coolBarManager != null) {
            return coolBarManager.getControl();
        }
        return null;
    }

    /**
     * This implementation of IRunnableContext#run(boolean, boolean,
     * IRunnableWithProgress) blocks until the runnable has been run,
     * regardless of the value of <code>fork</code>.
     * It is recommended that <code>fork</code> is set to
     * true in most cases. If <code>fork</code> is set to <code>false</code>,
     * the runnable will run in the UI thread and it is the runnable's
     * responsibility to call <code>Display.readAndDispatch()</code>
     * to ensure UI responsiveness.
     */
    public void run(final boolean fork, boolean cancelable,
            final IRunnableWithProgress runnable)
            throws InvocationTargetException, InterruptedException {
        try {
            operationInProgress = true;
            final StatusLineManager mgr = getStatusLineManager();
            if (mgr == null) {
                runnable.run(new NullProgressMonitor());
                return;
            }
            boolean cancelWasEnabled = mgr.isCancelEnabled();

            final Control contents = getContents();
            final Display display = contents.getDisplay();
            Shell shell = getShell();
            boolean contentsWasEnabled = contents.getEnabled();
            MenuManager manager = getMenuBarManager();
            Menu menuBar = null;
            if (manager != null) {
                menuBar = manager.getMenu();
                manager = null;
            }
            boolean menuBarWasEnabled = false;
            if (menuBar != null)
                menuBarWasEnabled = menuBar.isEnabled();

            Control toolbarControl = getToolBarControl();
            boolean toolbarWasEnabled = false;
            if (toolbarControl != null)
                toolbarWasEnabled = toolbarControl.getEnabled();

            Control coolbarControl = getCoolBarControl();
            boolean coolbarWasEnabled = false;
            if (coolbarControl != null)
                coolbarWasEnabled = coolbarControl.getEnabled();

            // Disable the rest of the shells on the current display
            Shell[] shells = display.getShells();
            boolean[] enabled = new boolean[shells.length];
            for (int i = 0; i < shells.length; i++) {
                Shell current = shells[i];
                if (current == shell)
                    continue;
                if (current != null && !current.isDisposed()) {
                    enabled[i] = current.getEnabled();
                    current.setEnabled(false);
                }
            }

            Control currentFocus = display.getFocusControl();
            try {
                contents.setEnabled(false);
                if (menuBar != null)
                    menuBar.setEnabled(false);
                if (toolbarControl != null)
                    toolbarControl.setEnabled(false);
                if (coolbarControl != null)
                    coolbarControl.setEnabled(false);
                mgr.setCancelEnabled(cancelable);
                final Exception[] holder = new Exception[1];
                BusyIndicator.showWhile(display, new Runnable() {
                    public void run() {
                        try {
                            ModalContext.run(runnable, fork, mgr
                                    .getProgressMonitor(), display);
                        } catch (InvocationTargetException ite) {
                            holder[0] = ite;
                        } catch (InterruptedException ie) {
                            holder[0] = ie;
                        }
                    }
                });

                if (holder[0] != null) {
                    if (holder[0] instanceof InvocationTargetException) {
                        throw (InvocationTargetException) holder[0];
                    } else if (holder[0] instanceof InterruptedException) {
                        throw (InterruptedException) holder[0];
                    }
                }
            } finally {
                operationInProgress = false;
                // Enable the rest of the shells on the current display
                for (int i = 0; i < shells.length; i++) {
                    Shell current = shells[i];
                    if (current == shell)
                        continue;
                    if (current != null && !current.isDisposed()) {
                        current.setEnabled(enabled[i]);
                    }
                }
                if (!contents.isDisposed())
                    contents.setEnabled(contentsWasEnabled);
                if (menuBar != null && !menuBar.isDisposed())
                    menuBar.setEnabled(menuBarWasEnabled);
                if (toolbarControl != null && !toolbarControl.isDisposed())
                    toolbarControl.setEnabled(toolbarWasEnabled);
                if (coolbarControl != null && !coolbarControl.isDisposed())
                    coolbarControl.setEnabled(coolbarWasEnabled);
                mgr.setCancelEnabled(cancelWasEnabled);
                if (currentFocus != null && !currentFocus.isDisposed()) {
                    // It's necessary to restore focus after reenabling the controls
                    // because disabling them causes focus to jump elsewhere.
                    // Use forceFocus rather than setFocus to avoid SWT's
                    // search for children which can take focus, so focus
                    // ends up back on the actual control that previously had it.
                    currentFocus.forceFocus();
                }
            }
        } finally {
            operationInProgress = false;
        }
    }

    /**
     * Sets or clears the message displayed in this window's status
     * line (if it has one). This method has no effect if the
     * window does not have a status line.
     *
     * @param message the status message, or <code>null</code> to clear it
     */
    public void setStatus(String message) {
        if (statusLineManager != null) {
            statusLineManager.setMessage(message);
        }
    }

    /**
     * Returns whether or not children exist for the Application Window's
     * toolbar control.
     * <p>
     * @return boolean true if children exist, false otherwise
     */
    protected boolean toolBarChildrenExist() {
        Control toolControl = getToolBarControl();
        if (toolControl instanceof ToolBar) {
            return ((ToolBar) toolControl).getItemCount() > 0;
        }
        return false;
    }

    /**
     * Returns whether or not children exist for this application window's
     * cool bar control.
     * 
     * @return boolean true if children exist, false otherwise
     * @since 3.0
     */
    protected boolean coolBarChildrenExist() {
        Control coolControl = getCoolBarControl();
        if (coolControl instanceof CoolBar) {
            return ((CoolBar) coolControl).getItemCount() > 0;
        }
        return false;
    }

}