/*

 * This file is part of libbluray

 * Copyright (C) 2010  William Hahne

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library. If not, see

 * <http://www.gnu.org/licenses/>.

 */

package org.havi.ui;

import java.util.Enumeration;

import java.util.Vector;

public class HToggleGroup {

    public HToggleGroup() {

    }

    public HToggleButton getCurrent() {

        return current;

    }

    public void setCurrent(HToggleButton selection) {

        // Treat null as unselection

        if (selection == null) {

            HToggleButton tmp = getCurrent();

            if (tmp != null && getForcedSelection() && buttons.size() > 0) {

                // Enforce forced selection (reselect button!)

                tmp.setSwitchableState(true);

            } else {

                // General behavior

                current = null;

                if (tmp != null) tmp.setSwitchableState(false);

            }

        }

        // Set current only if part of this group

        // And isn't the current selection (stops infinite loop)

        else if (buttons.contains(selection) && getCurrent() != selection) {

            current = selection;

            selection.setSwitchableState(true);

            unswitch(selection); // Enforce single selection

        }

    }

    public void setForcedSelection(boolean forceSelection) {

        this.forceSelection = forceSelection;

        // Enforce new setting

        if (forceSelection && getCurrent() == null && buttons.size() > 0) {

            forceSelect();

        }

    }

    public boolean getForcedSelection() {

        return forceSelection;

    }

    public void setEnabled(boolean enable) {

        enabled = enable;

        for (Enumeration e = buttons.elements(); e.hasMoreElements();) {

            setEnabled((HToggleButton) e.nextElement(), enable);

        }

    }

    public boolean isEnabled() {

        return enabled;

    }

    protected void add(HToggleButton button) {

        // Only add if not already added

        if (!buttons.contains(button)) {

            buttons.addElement(button);

            setEnabled(button, isEnabled()); // Enforce enabled state

            // Enforce forced selection (if first addition)

            if (getForcedSelection() && buttons.size() == 1 && getCurrent() != button) {

                button.setSwitchableState(true);

                current = button;

                // Assume that if size()>=1 that it's already enforced!

            }

            // If currently selected, unselect all others!

            else if (button.getSwitchableState()) {

                current = button;

                if (buttons.size() > 1) unswitch(button); // Enforce single

                                                          // selection

            }

        }

    }

    protected void remove(HToggleButton button) {

        if (!buttons.removeElement(button)) {

            throw new IllegalArgumentException("Not a member of this HToggleGroup");

        } else {

            if (button == getCurrent()) {

                current = null;

                if (getForcedSelection() && buttons.size() > 0) {

                    current = null;

                    forceSelect();

                }

            }

        }

    }

    private void unswitch(HToggleButton button) {

        for (Enumeration e = buttons.elements(); e.hasMoreElements();) {

            HToggleButton b = (HToggleButton) e.nextElement();

            if (b != button) b.setSwitchableState(false);

        }

    }

    private void forceSelect() {

        // assert(getCurrent() == null);

        if (buttons.size() > 0) {

            HToggleButton b = (HToggleButton) buttons.elementAt(0);

            b.setSwitchableState(true);

            current = b;

        }

    }

    private void setEnabled(HToggleButton tb, boolean enable) {

        if (false) { // If HAVi 1.1

            tb.setEnabled(enable);

        } else {

            // HAVI 1.01beta

            int state = tb.getInteractionState();

            tb.setInteractionState(enable ? (state & ~HState.DISABLED_STATE_BIT) : (state | HState.DISABLED_STATE_BIT));

        }

    }

    /** Whether the buttons in this group are enabled or now. */

    private boolean enabled = true;

    /** Controls whether a selection must always be made or not. */

    private boolean forceSelection = false;

    /** The currently selected {@link HToggleButton}. */

    private HToggleButton current = null;

    /** The buttons currently added to this group. */

    private Vector buttons = new Vector();

}