menu system compiles
[nikiroo-utils.git] / src / jexer / TApplication.java
index 3f748036ff670ab45339b09689bc6f22da02e7d8..b2ee5071a74284b42a6068efed531c4dc3c90039 100644 (file)
@@ -1,16 +1,11 @@
 /**
- * Jexer - Java Text User Interface - demonstration program
- *
- * Version: $Id$
- *
- * Author: Kevin Lamonte, <a href="mailto:kevin.lamonte@gmail.com">kevin.lamonte@gmail.com</a>
+ * Jexer - Java Text User Interface
  *
  * License: LGPLv3 or later
  *
- * Copyright: This module is licensed under the GNU Lesser General
- * Public License Version 3.  Please see the file "COPYING" in this
- * directory for more information about the GNU Lesser General Public
- * License Version 3.
+ * This module is licensed under the GNU Lesser General Public License
+ * Version 3.  Please see the file "COPYING" in this directory for more
+ * information about the GNU Lesser General Public License Version 3.
  *
  *     Copyright (C) 2015  Kevin Lamonte
  *
  * http://www.gnu.org/licenses/, or write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
+ *
+ * @author Kevin Lamonte [kevin.lamonte@gmail.com]
+ * @version 1
  */
 package jexer;
 
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+import jexer.bits.CellAttributes;
+import jexer.bits.ColorTheme;
+import jexer.bits.GraphicsChars;
+import jexer.event.TCommandEvent;
+import jexer.event.TInputEvent;
+import jexer.event.TKeypressEvent;
+import jexer.event.TMenuEvent;
+import jexer.event.TMouseEvent;
+import jexer.event.TResizeEvent;
+import jexer.backend.Backend;
+import jexer.backend.ECMA48Backend;
+import jexer.io.Screen;
+import jexer.menu.TMenu;
+import jexer.menu.TMenuItem;
+import static jexer.TCommand.*;
+import static jexer.TKeypress.*;
+
 /**
  * TApplication sets up a full Text User Interface application.
  */
 public class TApplication {
 
     /**
-     * Run this application until it exits, using stdin and stdout
+     * Access to the physical screen, keyboard, and mouse.
+     */
+    private Backend backend;
+
+    /**
+     * Get the Screen.
+     *
+     * @return the Screen
+     */
+    public final Screen getScreen() {
+        return backend.getScreen();
+    }
+
+    /**
+     * Actual mouse coordinate X.
+     */
+    private int mouseX;
+
+    /**
+     * Actual mouse coordinate Y.
+     */
+    private int mouseY;
+
+    /**
+     * Event queue that will be drained by either primary or secondary Fiber.
+     */
+    private List<TInputEvent> eventQueue;
+
+    /**
+     * Top-level menus in this application.
+     */
+    private List<TMenu> menus;
+
+    /**
+     * Stack of activated sub-menus in this application.
+     */
+    private List<TMenu> subMenus;
+
+    /**
+     * The currently acive menu.
+     */
+    private TMenu activeMenu = null;
+
+    /**
+     * Windows and widgets pull colors from this ColorTheme.
+     */
+    private ColorTheme theme;
+
+    /**
+     * Get the color theme.
+     *
+     * @return the theme
+     */
+    public final ColorTheme getTheme() {
+        return theme;
+    }
+
+    /**
+     * The top-level windows (but not menus).
+     */
+    private List<TWindow> windows;
+
+    /**
+     * When true, exit the application.
+     */
+    private boolean quit = false;
+
+    /**
+     * When true, repaint the entire screen.
+     */
+    private boolean repaint = true;
+
+    /**
+     * Request full repaint on next screen refresh.
+     */
+    public final void setRepaint() {
+        repaint = true;
+    }
+
+    /**
+     * When true, just flush updates from the screen.
+     */
+    private boolean flush = false;
+
+    /**
+     * Y coordinate of the top edge of the desktop.  For now this is a
+     * constant.  Someday it would be nice to have a multi-line menu or
+     * toolbars.
+     */
+    private static final int desktopTop = 1;
+
+    /**
+     * Get Y coordinate of the top edge of the desktop.
+     *
+     * @return Y coordinate of the top edge of the desktop
+     */
+    public final int getDesktopTop() {
+        return desktopTop;
+    }
+
+    /**
+     * Y coordinate of the bottom edge of the desktop.
+     */
+    private int desktopBottom;
+
+    /**
+     * Get Y coordinate of the bottom edge of the desktop.
+     *
+     * @return Y coordinate of the bottom edge of the desktop
+     */
+    public final int getDesktopBottom() {
+        return desktopBottom;
+    }
+
+    /**
+     * Public constructor.
+     *
+     * @param input an InputStream connected to the remote user, or null for
+     * System.in.  If System.in is used, then on non-Windows systems it will
+     * be put in raw mode; shutdown() will (blindly!) put System.in in cooked
+     * mode.  input is always converted to a Reader with UTF-8 encoding.
+     * @param output an OutputStream connected to the remote user, or null
+     * for System.out.  output is always converted to a Writer with UTF-8
+     * encoding.
+     * @throws UnsupportedEncodingException if an exception is thrown when
+     * creating the InputStreamReader
+     */
+    public TApplication(final InputStream input,
+        final OutputStream output) throws UnsupportedEncodingException {
+
+        backend       = new ECMA48Backend(input, output);
+        theme         = new ColorTheme();
+        desktopBottom = getScreen().getHeight() - 1;
+        eventQueue    = new LinkedList<TInputEvent>();
+        windows       = new LinkedList<TWindow>();
+        menus         = new LinkedList<TMenu>();
+        subMenus      = new LinkedList<TMenu>();
+    }
+
+    /**
+     * Invert the cell at the mouse pointer position.
+     */
+    private void drawMouse() {
+        CellAttributes attr = getScreen().getAttrXY(mouseX, mouseY);
+        attr.setForeColor(attr.getForeColor().invert());
+        attr.setBackColor(attr.getBackColor().invert());
+        getScreen().putAttrXY(mouseX, mouseY, attr, false);
+        flush = true;
+
+        if (windows.size() == 0) {
+            repaint = true;
+        }
+    }
+
+    /**
+     * Draw everything.
+     */
+    public final void drawAll() {
+        if ((flush) && (!repaint)) {
+            backend.flushScreen();
+            flush = false;
+            return;
+        }
+
+        if (!repaint) {
+            return;
+        }
+
+        // If true, the cursor is not visible
+        boolean cursor = false;
+
+        // Start with a clean screen
+        getScreen().clear();
+
+        // Draw the background
+        CellAttributes background = theme.getColor("tapplication.background");
+        getScreen().putAll(GraphicsChars.HATCH, background);
+
+        // Draw each window in reverse Z order
+        List<TWindow> sorted = new LinkedList<TWindow>(windows);
+        Collections.sort(sorted);
+        Collections.reverse(sorted);
+        for (TWindow window: sorted) {
+            window.drawChildren();
+        }
+
+        // Draw the blank menubar line - reset the screen clipping first so
+        // it won't trim it out.
+        getScreen().resetClipping();
+        getScreen().hLineXY(0, 0, getScreen().getWidth(), ' ',
+            theme.getColor("tmenu"));
+        // Now draw the menus.
+        int x = 1;
+        for (TMenu menu: menus) {
+            CellAttributes menuColor;
+            CellAttributes menuMnemonicColor;
+            if (menu.getActive()) {
+                menuColor = theme.getColor("tmenu.highlighted");
+                menuMnemonicColor = theme.getColor("tmenu.mnemonic.highlighted");
+            } else {
+                menuColor = theme.getColor("tmenu");
+                menuMnemonicColor = theme.getColor("tmenu.mnemonic");
+            }
+            // Draw the menu title
+            getScreen().hLineXY(x, 0, menu.getTitle().length() + 2, ' ',
+                menuColor);
+            getScreen().putStrXY(x + 1, 0, menu.getTitle(), menuColor);
+            // Draw the highlight character
+            getScreen().putCharXY(x + 1 + menu.getMnemonic().getShortcutIdx(),
+                0, menu.getMnemonic().getShortcut(), menuMnemonicColor);
+
+            if (menu.getActive()) {
+                menu.drawChildren();
+                // Reset the screen clipping so we can draw the next title.
+                getScreen().resetClipping();
+            }
+            x += menu.getTitle().length() + 2;
+        }
+
+        for (TMenu menu: subMenus) {
+            // Reset the screen clipping so we can draw the next sub-menu.
+            getScreen().resetClipping();
+            menu.drawChildren();
+        }
+
+        // Draw the mouse pointer
+        drawMouse();
+
+        // Place the cursor if it is visible
+        TWidget activeWidget = null;
+        if (sorted.size() > 0) {
+            activeWidget = sorted.get(sorted.size() - 1).getActiveChild();
+            if (activeWidget.visibleCursor()) {
+                getScreen().putCursor(true, activeWidget.getCursorAbsoluteX(),
+                    activeWidget.getCursorAbsoluteY());
+                cursor = true;
+            }
+        }
+
+        // Kill the cursor
+        if (!cursor) {
+            getScreen().hideCursor();
+        }
+
+        // Flush the screen contents
+        backend.flushScreen();
+
+        repaint = false;
+        flush = false;
+    }
+
+    /**
+     * Run this application until it exits.
+     */
+    public final void run() {
+        List<TInputEvent> events = new LinkedList<TInputEvent>();
+
+        while (!quit) {
+            // Timeout is in milliseconds, so default timeout after 1 second
+            // of inactivity.
+            int timeout = getSleepTime(1000);
+
+            if (eventQueue.size() > 0) {
+                // Do not wait if there are definitely events waiting to be
+                // processed or a screen redraw to do.
+                timeout = 0;
+            }
+
+            // Pull any pending input events
+            backend.getEvents(events, timeout);
+            metaHandleEvents(events);
+            events.clear();
+
+            // Process timers and call doIdle()'s
+            doIdle();
+
+            // Update the screen
+            drawAll();
+        }
+
+        /*
+
+        // Shutdown the fibers
+        eventQueue.length = 0;
+        if (secondaryEventFiber !is null) {
+            assert(secondaryEventReceiver !is null);
+            secondaryEventReceiver = null;
+            if (secondaryEventFiber.state == Fiber.State.HOLD) {
+                // Wake up the secondary handler so that it can exit.
+                secondaryEventFiber.call();
+            }
+        }
+
+        if (primaryEventFiber.state == Fiber.State.HOLD) {
+            // Wake up the primary handler so that it can exit.
+            primaryEventFiber.call();
+        }
+         */
+
+        backend.shutdown();
+    }
+
+    /**
+     * Peek at certain application-level events, add to eventQueue, and wake
+     * up the consuming Fiber.
+     *
+     * @param events the input events to consume
+     */
+    private void metaHandleEvents(final List<TInputEvent> events) {
+
+        for (TInputEvent event: events) {
+
+            /*
+            System.err.printf(String.format("metaHandleEvents event: %s\n",
+                    event)); System.err.flush();
+             */
+
+            if (quit) {
+                // Do no more processing if the application is already trying
+                // to exit.
+                return;
+            }
+
+            // DEBUG
+            if (event instanceof TKeypressEvent) {
+                TKeypressEvent keypress = (TKeypressEvent) event;
+                if (keypress.equals(kbAltX)) {
+                    quit = true;
+                    return;
+                }
+            }
+            // DEBUG
+
+            // Special application-wide events -------------------------------
+
+            // Abort everything
+            if (event instanceof TCommandEvent) {
+                TCommandEvent command = (TCommandEvent) event;
+                if (command.getCmd().equals(cmAbort)) {
+                    quit = true;
+                    return;
+                }
+            }
+
+            // Screen resize
+            if (event instanceof TResizeEvent) {
+                TResizeEvent resize = (TResizeEvent) event;
+                getScreen().setDimensions(resize.getWidth(),
+                    resize.getHeight());
+                desktopBottom = getScreen().getHeight() - 1;
+                repaint = true;
+                mouseX = 0;
+                mouseY = 0;
+                continue;
+            }
+
+            // Peek at the mouse position
+            if (event instanceof TMouseEvent) {
+                TMouseEvent mouse = (TMouseEvent) event;
+                if ((mouseX != mouse.getX()) || (mouseY != mouse.getY())) {
+                    mouseX = mouse.getX();
+                    mouseY = mouse.getY();
+                    drawMouse();
+                }
+            }
+
+            // TODO: change to two separate threads
+            primaryHandleEvent(event);
+
+            /*
+
+            // Put into the main queue
+            addEvent(event);
+
+            // Have one of the two consumer Fibers peel the events off
+            // the queue.
+            if (secondaryEventFiber !is null) {
+                assert(secondaryEventFiber.state == Fiber.State.HOLD);
+
+                // Wake up the secondary handler for these events
+                secondaryEventFiber.call();
+            } else {
+                assert(primaryEventFiber.state == Fiber.State.HOLD);
+
+                // Wake up the primary handler for these events
+                primaryEventFiber.call();
+            }
+             */
+
+        } // for (TInputEvent event: events)
+
+    }
+
+    /**
+     * Dispatch one event to the appropriate widget or application-level
+     * event handler.  This is the primary event handler, it has the normal
+     * application-wide event handling.
+     *
+     * @param event the input event to consume
+     * @see #secondaryHandleEvent(TInputEvent event)
      */
-    final public void run() {
+    private void primaryHandleEvent(final TInputEvent event) {
+
+        // System.err.printf("Handle event: %s\n", event);
+
+        // Special application-wide events -----------------------------------
 
-       /*
-       while (quit == false) {
+        // Peek at the mouse position
+        if (event instanceof TMouseEvent) {
+            // See if we need to switch focus to another window or the menu
+            checkSwitchFocus((TMouseEvent) event);
+        }
 
-           // Timeout is in milliseconds, so default timeout after 1
-           // second of inactivity.
-           uint timeout = getSleepTime(1000);
-           // std.stdio.stderr.writefln("poll() timeout: %d", timeout);
+        // Handle menu events
+        if ((activeMenu != null) && !(event instanceof TCommandEvent)) {
+            TMenu menu = activeMenu;
 
-           if (eventQueue.length > 0) {
-               // Do not wait if there are definitely events waiting to be
-               // processed or a screen redraw to do.
-               timeout = 0;
-           }
+            if (event instanceof TMouseEvent) {
+                TMouseEvent mouse = (TMouseEvent) event;
 
-           // Pull any pending input events
-           TInputEvent [] events = backend.getEvents(timeout);
-           metaHandleEvents(events);
+                while (subMenus.size() > 0) {
+                    TMenu subMenu = subMenus.get(subMenus.size() - 1);
+                    if (subMenu.mouseWouldHit(mouse)) {
+                        break;
+                    }
+                    if ((mouse.getType() == TMouseEvent.Type.MOUSE_MOTION)
+                        && (!mouse.getMouse1())
+                        && (!mouse.getMouse2())
+                        && (!mouse.getMouse3())
+                        && (!mouse.getMouseWheelUp())
+                        && (!mouse.getMouseWheelDown())
+                    ) {
+                        break;
+                    }
+                    // We navigated away from a sub-menu, so close it
+                    closeSubMenu();
+                }
 
-           // Process timers and call doIdle()'s
-           doIdle();
+                // Convert the mouse relative x/y to menu coordinates
+                assert (mouse.getX() == mouse.getAbsoluteX());
+                assert (mouse.getY() == mouse.getAbsoluteY());
+                if (subMenus.size() > 0) {
+                    menu = subMenus.get(subMenus.size() - 1);
+                }
+                mouse.setX(mouse.getX() - menu.getX());
+                mouse.setY(mouse.getY() - menu.getY());
+            }
+            menu.handleEvent(event);
+            return;
+        }
 
-           // Update the screen
-           drawAll();
-       }
+        /*
+         TODO
 
-       // Shutdown the fibers
-       eventQueue.length = 0;
-       if (secondaryEventFiber !is null) {
-           assert(secondaryEventReceiver !is null);
-           secondaryEventReceiver = null;
-           if (secondaryEventFiber.state == Fiber.State.HOLD) {
-               // Wake up the secondary handler so that it can exit.
-               secondaryEventFiber.call();
-           }
-       }
+        if (event instanceof TKeypressEvent) {
+            TKeypressEvent keypress = (TKeypressEvent) event;
+            // See if this key matches an accelerator, and if so dispatch the
+            // menu event.
+            TKeypress keypressLowercase = keypress.getKey().toLowerCase();
+            TMenuItem item = accelerators.get(keypressLowercase);
+            if (item != null) {
+                // Let the menu item dispatch
+                item.dispatch();
+                return;
+            } else {
+                // Handle the keypress
+                if (onKeypress(keypress)) {
+                    return;
+                }
+            }
+        }
+         */
 
-       if (primaryEventFiber.state == Fiber.State.HOLD) {
-           // Wake up the primary handler so that it can exit.
-           primaryEventFiber.call();
-       }
+        if (event instanceof TCommandEvent) {
+            if (onCommand((TCommandEvent) event)) {
+                return;
+            }
+        }
 
-       backend.shutdown();
-        */
+        if (event instanceof TMenuEvent) {
+            if (onMenu((TMenuEvent) event)) {
+                return;
+            }
+        }
+
+        // Dispatch events to the active window -------------------------------
+        for (TWindow window: windows) {
+            if (window.getActive()) {
+                if (event instanceof TMouseEvent) {
+                    TMouseEvent mouse = (TMouseEvent) event;
+                    // Convert the mouse relative x/y to window coordinates
+                    assert (mouse.getX() == mouse.getAbsoluteX());
+                    assert (mouse.getY() == mouse.getAbsoluteY());
+                    mouse.setX(mouse.getX() - window.getX());
+                    mouse.setY(mouse.getY() - window.getY());
+                }
+                // System.err("TApplication dispatch event: %s\n", event);
+                window.handleEvent(event);
+                break;
+            }
+        }
+    }
+    /**
+     * Dispatch one event to the appropriate widget or application-level
+     * event handler.  This is the secondary event handler used by certain
+     * special dialogs (currently TMessageBox and TFileOpenBox).
+     *
+     * @param event the input event to consume
+     * @see #primaryHandleEvent(TInputEvent event)
+     */
+    private void secondaryHandleEvent(final TInputEvent event) {
+        // TODO
+    }
+
+    /**
+     * Do stuff when there is no user input.
+     */
+    private void doIdle() {
+        /*
+         TODO
+        // Now run any timers that have timed out
+        auto now = Clock.currTime;
+        TTimer [] keepTimers;
+        foreach (t; timers) {
+            if (t.nextTick < now) {
+                t.tick();
+                if (t.recurring == true) {
+                    keepTimers ~= t;
+                }
+            } else {
+                keepTimers ~= t;
+            }
+        }
+        timers = keepTimers;
 
-       System.out.println("Hello");
+        // Call onIdle's
+        foreach (w; windows) {
+            w.onIdle();
+        }
+         */
     }
+
+    /**
+     * Get the amount of time I can sleep before missing a Timer tick.
+     *
+     * @param timeout = initial (maximum) timeout
+     * @return number of milliseconds between now and the next timer event
+     */
+    protected int getSleepTime(final int timeout) {
+        /*
+        auto now = Clock.currTime;
+        auto sleepTime = dur!("msecs")(timeout);
+        foreach (t; timers) {
+            if (t.nextTick < now) {
+                return 0;
+            }
+            if ((t.nextTick > now) &&
+                ((t.nextTick - now) < sleepTime)
+            ) {
+                sleepTime = t.nextTick - now;
+            }
+        }
+        assert(sleepTime.total!("msecs")() >= 0);
+        return cast(uint)sleepTime.total!("msecs")();
+         */
+        // TODO: fix timers.  Until then, come back after 250 millis.
+        return 250;
+    }
+
+    /**
+     * Close window.  Note that the window's destructor is NOT called by this
+     * method, instead the GC is assumed to do the cleanup.
+     *
+     * @param window the window to remove
+     */
+    public final void closeWindow(final TWindow window) {
+        int z = window.getZ();
+        window.setZ(-1);
+        Collections.sort(windows);
+        windows.remove(0);
+        TWindow activeWindow = null;
+        for (TWindow w: windows) {
+            if (w.getZ() > z) {
+                w.setZ(w.getZ() - 1);
+                if (w.getZ() == 0) {
+                    w.setActive(true);
+                    assert (activeWindow == null);
+                    activeWindow = w;
+                } else {
+                    w.setActive(false);
+                }
+            }
+        }
+
+        // Perform window cleanup
+        window.onClose();
+
+        // Refresh screen
+        repaint = true;
+
+        /*
+         TODO
+
+
+        // Check if we are closing a TMessageBox or similar
+        if (secondaryEventReceiver !is null) {
+            assert(secondaryEventFiber !is null);
+
+            // Do not send events to the secondaryEventReceiver anymore, the
+            // window is closed.
+            secondaryEventReceiver = null;
+
+            // Special case: if this is called while executing on a
+            // secondaryEventFiber, call it so that widgetEventHandler() can
+            // terminate.
+            if (secondaryEventFiber.state == Fiber.State.HOLD) {
+                secondaryEventFiber.call();
+            }
+            secondaryEventFiber = null;
+
+            // Unfreeze the logic in handleEvent()
+            if (primaryEventFiber.state == Fiber.State.HOLD) {
+                primaryEventFiber.call();
+            }
+        }
+         */
+    }
+
+    /**
+     * Switch to the next window.
+     *
+     * @param forward if true, then switch to the next window in the list,
+     * otherwise switch to the previous window in the list
+     */
+    public final void switchWindow(final boolean forward) {
+        // Only switch if there are multiple windows
+        if (windows.size() < 2) {
+            return;
+        }
+
+        // Swap z/active between active window and the next in the list
+        int activeWindowI = -1;
+        for (int i = 0; i < windows.size(); i++) {
+            if (windows.get(i).getActive()) {
+                activeWindowI = i;
+                break;
+            }
+        }
+        assert (activeWindowI >= 0);
+
+        // Do not switch if a window is modal
+        if (windows.get(activeWindowI).isModal()) {
+            return;
+        }
+
+        int nextWindowI;
+        if (forward) {
+            nextWindowI = (activeWindowI + 1) % windows.size();
+        } else {
+            if (activeWindowI == 0) {
+                nextWindowI = windows.size() - 1;
+            } else {
+                nextWindowI = activeWindowI - 1;
+            }
+        }
+        windows.get(activeWindowI).setActive(false);
+        windows.get(activeWindowI).setZ(windows.get(nextWindowI).getZ());
+        windows.get(nextWindowI).setZ(0);
+        windows.get(nextWindowI).setActive(true);
+
+        // Refresh
+        repaint = true;
+    }
+
+    /**
+     * Add a window to my window list and make it active.
+     *
+     * @param window new window to add
+     */
+    public final void addWindow(final TWindow window) {
+        // Do not allow a modal window to spawn a non-modal window
+        if ((windows.size() > 0) && (windows.get(0).isModal())) {
+            assert (window.isModal());
+        }
+        for (TWindow w: windows) {
+            w.setActive(false);
+            w.setZ(w.getZ() + 1);
+        }
+        windows.add(window);
+        window.setActive(true);
+        window.setZ(0);
+    }
+
+    /**
+     * Check if there is a system-modal window on top.
+     *
+     * @return true if the active window is modal
+     */
+    private boolean modalWindowActive() {
+        if (windows.size() == 0) {
+            return false;
+        }
+        return windows.get(windows.size() - 1).isModal();
+    }
+
+    /**
+     * Check if a mouse event would hit either the active menu or any open
+     * sub-menus.
+     *
+     * @param mouse mouse event
+     * @return true if the mouse would hit the active menu or an open
+     * sub-menu
+     */
+    private boolean mouseOnMenu(final TMouseEvent mouse) {
+        assert (activeMenu != null);
+        List<TMenu> menus = new LinkedList<TMenu>(subMenus);
+        Collections.reverse(menus);
+        for (TMenu menu: menus) {
+            if (menu.mouseWouldHit(mouse)) {
+                return true;
+            }
+        }
+        return activeMenu.mouseWouldHit(mouse);
+    }
+
+    /**
+     * See if we need to switch window or activate the menu based on
+     * a mouse click.
+     *
+     * @param mouse mouse event
+     */
+    private void checkSwitchFocus(final TMouseEvent mouse) {
+
+        if ((mouse.getType() == TMouseEvent.Type.MOUSE_DOWN)
+            && (activeMenu != null)
+            && (mouse.getAbsoluteY() != 0)
+            && (!mouseOnMenu(mouse))
+        ) {
+            // They clicked outside the active menu, turn it off
+            activeMenu.setActive(false);
+            activeMenu = null;
+            for (TMenu menu: subMenus) {
+                menu.setActive(false);
+            }
+            subMenus.clear();
+            // Continue checks
+        }
+
+        // See if they hit the menu bar
+        if ((mouse.getType() == TMouseEvent.Type.MOUSE_DOWN)
+            && (mouse.getMouse1())
+            && (!modalWindowActive())
+            && (mouse.getAbsoluteY() == 0)
+        ) {
+
+            for (TMenu menu: subMenus) {
+                menu.setActive(false);
+            }
+            subMenus.clear();
+
+            // They selected the menu, go activate it
+            for (TMenu menu: menus) {
+                if ((mouse.getAbsoluteX() >= menu.getX())
+                    && (mouse.getAbsoluteX() < menu.getX()
+                        + menu.getTitle().length() + 2)
+                ) {
+                    menu.setActive(true);
+                    activeMenu = menu;
+                } else {
+                    menu.setActive(false);
+                }
+            }
+            repaint = true;
+            return;
+        }
+
+        // See if they hit the menu bar
+        if ((mouse.getType() == TMouseEvent.Type.MOUSE_MOTION)
+            && (mouse.getMouse1())
+            && (activeMenu != null)
+            && (mouse.getAbsoluteY() == 0)
+        ) {
+
+            TMenu oldMenu = activeMenu;
+            for (TMenu menu: subMenus) {
+                menu.setActive(false);
+            }
+            subMenus.clear();
+
+            // See if we should switch menus
+            for (TMenu menu: menus) {
+                if ((mouse.getAbsoluteX() >= menu.getX())
+                    && (mouse.getAbsoluteX() < menu.getX()
+                        + menu.getTitle().length() + 2)
+                ) {
+                    menu.setActive(true);
+                    activeMenu = menu;
+                }
+            }
+            if (oldMenu != activeMenu) {
+                // They switched menus
+                oldMenu.setActive(false);
+            }
+            repaint = true;
+            return;
+        }
+
+        // Only switch if there are multiple windows
+        if (windows.size() < 2) {
+            return;
+        }
+
+        // Switch on the upclick
+        if (mouse.getType() != TMouseEvent.Type.MOUSE_UP) {
+            return;
+        }
+
+        Collections.sort(windows);
+        if (windows.get(0).isModal()) {
+            // Modal windows don't switch
+            return;
+        }
+
+        for (TWindow window: windows) {
+            assert (!window.isModal());
+            if (window.mouseWouldHit(mouse)) {
+                if (window == windows.get(0)) {
+                    // Clicked on the same window, nothing to do
+                    return;
+                }
+
+                // We will be switching to another window
+                assert (windows.get(0).getActive());
+                assert (!window.getActive());
+                windows.get(0).setActive(false);
+                windows.get(0).setZ(window.getZ());
+                window.setZ(0);
+                window.setActive(true);
+                repaint = true;
+                return;
+            }
+        }
+
+        // Clicked on the background, nothing to do
+        return;
+    }
+
+    /**
+     * Turn off the menu.
+     */
+    public final void closeMenu() {
+        if (activeMenu != null) {
+            activeMenu.setActive(false);
+            activeMenu = null;
+            for (TMenu menu: subMenus) {
+                menu.setActive(false);
+            }
+            subMenus.clear();
+        }
+        repaint = true;
+    }
+
+    /**
+     * Turn off a sub-menu.
+     */
+    public final void closeSubMenu() {
+        assert (activeMenu != null);
+        TMenu item = subMenus.get(subMenus.size() - 1);
+        assert (item != null);
+        item.setActive(false);
+        subMenus.remove(subMenus.size() - 1);
+        repaint = true;
+    }
+
+    /**
+     * Switch to the next menu.
+     *
+     * @param forward if true, then switch to the next menu in the list,
+     * otherwise switch to the previous menu in the list
+     */
+    public final void switchMenu(final boolean forward) {
+        assert (activeMenu != null);
+
+        for (TMenu menu: subMenus) {
+            menu.setActive(false);
+        }
+        subMenus.clear();
+
+        for (int i = 0; i < menus.size(); i++) {
+            if (activeMenu == menus.get(i)) {
+                if (forward) {
+                    if (i < menus.size() - 1) {
+                        i++;
+                    }
+                } else {
+                    if (i > 0) {
+                        i--;
+                    }
+                }
+                activeMenu.setActive(false);
+                activeMenu = menus.get(i);
+                activeMenu.setActive(true);
+                repaint = true;
+                return;
+            }
+        }
+    }
+
+    /**
+     * Method that TApplication subclasses can override to handle menu or
+     * posted command events.
+     *
+     * @param command command event
+     * @return if true, this event was consumed
+     */
+    protected boolean onCommand(final TCommandEvent command) {
+        /*
+         TODO
+        // Default: handle cmExit
+        if (command.equals(cmExit)) {
+            if (messageBox("Confirmation", "Exit application?",
+                    TMessageBox.Type.YESNO).result == TMessageBox.Result.YES) {
+                quit = true;
+            }
+            repaint = true;
+            return true;
+        }
+
+        if (command.equals(cmShell)) {
+            openTerminal(0, 0, TWindow.Flag.RESIZABLE);
+            repaint = true;
+            return true;
+        }
+
+        if (command.equals(cmTile)) {
+            tileWindows();
+            repaint = true;
+            return true;
+        }
+        if (command.equals(cmCascade)) {
+            cascadeWindows();
+            repaint = true;
+            return true;
+        }
+        if (command.equals(cmCloseAll)) {
+            closeAllWindows();
+            repaint = true;
+            return true;
+        }
+         */
+        return false;
+    }
+
+    /**
+     * Method that TApplication subclasses can override to handle menu
+     * events.
+     *
+     * @param menu menu event
+     * @return if true, this event was consumed
+     */
+    protected boolean onMenu(final TMenuEvent menu) {
+
+        /*
+         TODO
+        // Default: handle MID_EXIT
+        if (menu.id == TMenu.MID_EXIT) {
+            if (messageBox("Confirmation", "Exit application?",
+                    TMessageBox.Type.YESNO).result == TMessageBox.Result.YES) {
+                quit = true;
+            }
+            // System.err.printf("onMenu MID_EXIT result: quit = %s\n", quit);
+            repaint = true;
+            return true;
+        }
+
+        if (menu.id == TMenu.MID_SHELL) {
+            openTerminal(0, 0, TWindow.Flag.RESIZABLE);
+            repaint = true;
+            return true;
+        }
+
+        if (menu.id == TMenu.MID_TILE) {
+            tileWindows();
+            repaint = true;
+            return true;
+        }
+        if (menu.id == TMenu.MID_CASCADE) {
+            cascadeWindows();
+            repaint = true;
+            return true;
+        }
+        if (menu.id == TMenu.MID_CLOSE_ALL) {
+            closeAllWindows();
+            repaint = true;
+            return true;
+        }
+        */
+        return false;
+    }
+
+    /**
+     * Method that TApplication subclasses can override to handle keystrokes.
+     *
+     * @param keypress keystroke event
+     * @return if true, this event was consumed
+     */
+    protected boolean onKeypress(final TKeypressEvent keypress) {
+        // Default: only menu shortcuts
+
+        // Process Alt-F, Alt-E, etc. menu shortcut keys
+        if (!keypress.getKey().getIsKey()
+            && keypress.getKey().getAlt()
+            && !keypress.getKey().getCtrl()
+            && (activeMenu == null)
+        ) {
+
+            assert (subMenus.size() == 0);
+
+            for (TMenu menu: menus) {
+                if (Character.toLowerCase(menu.getMnemonic().getShortcut())
+                    == Character.toLowerCase(keypress.getKey().getCh())
+                ) {
+                    activeMenu = menu;
+                    menu.setActive(true);
+                    repaint = true;
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Add a keyboard accelerator to the global hash.
+     *
+     * @param item menu item this accelerator relates to
+     * @param keypress keypress that will dispatch a TMenuEvent
+     */
+    public final void addAccelerator(final TMenuItem item,
+        final TKeypress keypress) {
+        /*
+         TODO
+        assert((keypress in accelerators) is null);
+        accelerators[keypress] = item;
+         */
+    }
+
+    /**
+     * Recompute menu x positions based on their title length.
+     */
+    public final void recomputeMenuX() {
+        int x = 0;
+        for (TMenu menu: menus) {
+            menu.setX(x);
+            x += menu.getTitle().length() + 2;
+        }
+    }
+
+    /**
+     * Post an event to process and turn off the menu.
+     *
+     * @param event new event to add to the queue
+     */
+    public final void addMenuEvent(final TInputEvent event) {
+        /*
+         TODO - synchronize correctly
+        eventQueue ~= event;
+         */
+        closeMenu();
+    }
+
+    /**
+     * Add a sub-menu to the list of open sub-menus.
+     *
+     * @param menu sub-menu
+     */
+    public final void addSubMenu(final TMenu menu) {
+        subMenus.add(menu);
+    }
+
 }