/*
 * Java-Gnome Bindings Library
 *
 * Copyright 1998-2004 the Java-Gnome Team, all rights reserved.
 *
 * The Java-Gnome bindings library is free software distributed under
 * the terms of the GNU Library General Public License version 2.
 */

package org.gnu.gtk;

import java.util.Vector;

import org.gnu.glib.EventMap;
import org.gnu.glib.EventType;
import org.gnu.glib.Type;
import org.gnu.gtk.event.ToggleEvent;
import org.gnu.gtk.event.ToggleListener;
import org.gnu.glib.Handle;

/**
 * A ToggleButton is a button that changes and retains its on or off state each
 * time it is selected with the mouse. When in the on state, it will appear to
 * be pressed in.
 * 
 * @see CheckButton
 * @see RadioButton
 * @see Button
 */
public class ToggleButton extends Button {
    /**
     * Creates a new toggle button.
     */
    public ToggleButton() {
        super(gtk_toggle_button_new());
    }

    /**
     * Construct a toggle button using a handle to a native resource.
     */
    public ToggleButton(Handle handle) {
        super(handle);
    }

    /**
     * Internal static factory method to be used by Java-Gnome only.
     */
    public static ToggleButton getToggleButton(Handle handle) {
        if (handle == null)
            return null;

        ToggleButton obj = (ToggleButton) getGObjectFromHandle(handle);
        if (obj == null)
            obj = new ToggleButton(handle);

        return obj;
    }

    /**
     * Creates a new toggle button with a text label. If the hasMnemonic Label
     * is set, the button is assumes to contain mnemonic characters; that is
     * characters which are preceeded by an underscore. These will appear
     * underlined and will be used as keyboard accelerators.
     * 
     * @param label
     *            The text to be displayed on the button
     * @param hasMnemonic
     *            If true, keyboeard accelerators will be interpreted.
     */
    public ToggleButton(String label, boolean hasMnemonic) {
        super(init(label, hasMnemonic));
    }

    private static Handle init(String label, boolean hasMnemonic) {
        if (hasMnemonic) {
            return gtk_toggle_button_new_with_mnemonic(label);
        } else {
            return gtk_toggle_button_new_with_label(label);
        }
    }

    /**
     * Modifies the state of the toggle button
     * 
     * @param state
     *            If true, the button is in the 'on', or 'pressed in' state.
     */
    public void setState(boolean state) {
        gtk_toggle_button_set_active(getHandle(), state);
    }

    /**
     * Returns the state of the toggle button
     * 
     * @return True if the button is on or 'pressed in'.
     */
    public boolean getState() {
        return gtk_toggle_button_get_active(getHandle());
    }

    /**
     * Determines whether the toggle button should be in the half-on, or
     * inconsistent state. This is envirely a visual setting - changes to this
     * will not affect the state of the button as returned by {@link
     * #getState()}.
     * 
     * @param isInconsistent
     *            If true, the button will appear in the in-between state.
     */
    public void setInconsistent(boolean isInconsistent) {
        gtk_toggle_button_set_inconsistent(getHandle(), isInconsistent);
    }

    /**
     * Return whether this is in the inconsistent state
     * 
     * @see #setInconsistent(boolean)
     * @return True if the 'inbetween' state is in use
     */
    public boolean getInconsistent() {
        return gtk_toggle_button_get_inconsistent(getHandle());
    }

    /***************************************************************************
     * Event Handler Related code
     **************************************************************************/

    /**
     * Listeners for handling toggle events
     */
    private Vector toggleListeners = null;

    /**
     * Register an object to handle button events.
     * 
     * @see org.gnu.gtk.event.ToggleListener
     */
    public void addListener(ToggleListener listener) {
        // Don't add the listener a second time if it is in the Vector.
        int i = findListener(toggleListeners, listener);
        if (i == -1) {
            if (null == toggleListeners) {
                evtMap.initialize(this, ToggleEvent.Type.TOGGLED);
                toggleListeners = new Vector();
            }
            toggleListeners.addElement(listener);
        }
    }

    /**
     * Removes a listener
     * 
     * @see #addListener(ToggleListener)
     */
    public void removeListener(ToggleListener listener) {
        int i = findListener(toggleListeners, listener);
        if (i > -1) {
            toggleListeners.remove(i);
        }
        if (0 == toggleListeners.size()) {
            evtMap.uninitialize(this, ToggleEvent.Type.TOGGLED);
            toggleListeners = null;
        }
    }

    protected void fireToggleEvent(ToggleEvent event) {
        if (null == toggleListeners) {
            return;
        }
        int size = toggleListeners.size();
        int i = 0;
        while (i < size) {
            ToggleListener tl = (ToggleListener) toggleListeners.elementAt(i);
            tl.toggleEvent(event);
            i++;
        }
    }

    private void handleToggled() {
        fireToggleEvent(new ToggleEvent(this));
    }

    public Class getEventListenerClass(String signal) {
        Class cls = evtMap.getEventListenerClass(signal);
        if (cls == null)
            cls = super.getEventListenerClass(signal);
        return cls;
    }

    public EventType getEventType(String signal) {
        EventType et = evtMap.getEventType(signal);
        if (et == null)
            et = super.getEventType(signal);
        return et;
    }

    private static EventMap evtMap = new EventMap();
    static {
        addEvents(evtMap);
    }

    /**
     * Implementation method to build an EventMap for this widget class. Not
     * useful (or supported) for application use.
     */
    private static void addEvents(EventMap anEvtMap) {
        anEvtMap.addEvent("toggled", "handleToggled", ToggleEvent.Type.TOGGLED,
                ToggleListener.class);
    }

    /**
     * Retrieve the runtime type used by the GLib library.
     */
    public static Type getType() {
        return new Type(gtk_toggle_button_get_type());
    }

    native static final protected int gtk_toggle_button_get_type();

    native static final protected Handle gtk_toggle_button_new();

    native static final protected Handle gtk_toggle_button_new_with_label(
            String label);

    native static final protected Handle gtk_toggle_button_new_with_mnemonic(
            String label);

    native static final protected void gtk_toggle_button_set_mode(
            Handle toggle_button, boolean drawIndicator);

    native static final protected boolean gtk_toggle_button_get_mode(
            Handle toggle_button);

    native static final protected void gtk_toggle_button_set_active(
            Handle toggle_button, boolean isActive);

    native static final protected boolean gtk_toggle_button_get_active(
            Handle toggle_button);

    native static final protected void gtk_toggle_button_toggled(
            Handle toggle_button);

    native static final protected void gtk_toggle_button_set_inconsistent(
            Handle toggle_button, boolean setting);

    native static final protected boolean gtk_toggle_button_get_inconsistent(
            Handle toggle_button);
}