com.dimdim.conference.ui.dialogues.client.common.helper.CheckBoxSet.java Source code

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Here is the source code for com.dimdim.conference.ui.dialogues.client.common.helper.CheckBoxSet.java

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/*
 **************************************************************************
 *                                                                        *
 *               DDDDD   iii             DDDDD   iii                      *
 *               DD  DD      mm mm mmmm  DD  DD      mm mm mmmm           *
 *               DD   DD iii mmm  mm  mm DD   DD iii mmm  mm  mm          *
 *               DD   DD iii mmm  mm  mm DD   DD iii mmm  mm  mm          *
 *               DDDDDD  iii mmm  mm  mm DDDDDD  iii mmm  mm  mm          *
 *                                                                        *
 **************************************************************************
 **************************************************************************
 *                                                                        *
 * Part of the DimDim V 1.0 Codebase (http://www.dimdim.com)             *
 *                                                                        *
 * Copyright (c) 2006 Communiva Inc. All Rights Reserved.                 *
 *                                                                        *
 *                                                                        *
 * This code is licensed under the DimDim License                         *
 * For details please visit http://www.dimdim.com/license                 *
 *                                                                        *
 **************************************************************************
 */

package com.dimdim.conference.ui.dialogues.client.common.helper;

import java.util.Vector;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.CheckBox;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.Widget;

/**
 * @author Jayant Pandit
 * @email Jayant.Pandit@communiva.com
 * 
 * This set enforces that within the given group of checkboxes only a fixed
 * number will be enabled at a time.
 * 
 * 1.   The set itself will not change the state of the checkboxes, this is
 *       strictly a helper to manager ui.
 * 2.   The set is constructed only with the max enabled number. This can be
 *       changed during the lifetime of the set, 0 is allowed to mean that the
 *       whole set of boxes are simply disabled.
 * 3.   Through the click listeners the set will keep track of the enabled
 *       boxes. When the maximum number of boxes are checked, the set will
 *       disable the other unchecked boxes.
 * 4.   When at least of the checked boxes is unchecked, the other unchecked
 *       boxes will be enabled.
 * 5.   The set will also accept an optional label to put a message about
 *       why the checkboxes are disabled.
 */

public class CheckBoxSet implements ClickListener {
    protected int maxChecked;
    protected int currentlyChecked;
    protected Vector boxes;
    protected Label messageLabel;

    public CheckBoxSet(int maxChecked, Label messageLabel) {
        this.maxChecked = maxChecked;
        this.currentlyChecked = 0;
        this.messageLabel = messageLabel;
        this.boxes = new Vector();
    }

    public void addCheckBox(CheckBox cb) {
        if (!this.boxes.contains(cb)) {
            this.boxes.addElement(cb);
            if (cb.isChecked()) {
                incrementCheckedCount();
            } else {
                this.setSpaceAvailability();
            }
            cb.addClickListener(this);
        }
    }

    public void removeCheckBox(CheckBox cb) {
        if (this.boxes.contains(cb)) {
            this.boxes.remove(cb);
            if (cb.isChecked()) {
                decrementCheckedCount();
            }
            cb.removeClickListener(this);
        }
    }

    public void onClick(Widget w) {
        CheckBox cb = (CheckBox) w;
        if (cb.isChecked()) {
            this.incrementCheckedCount();
        } else {
            this.decrementCheckedCount();
        }
    }

    public boolean hasSpace() {
        return (this.currentlyChecked < this.maxChecked);
    }

    public int getCurrentlyChecked() {
        return this.currentlyChecked;
    }

    protected void setSpaceAvailability() {
        if (this.currentlyChecked < this.maxChecked) {
            this.setAllEnabled(true);
        } else {
            this.setAllEnabled(false);
        }
    }

    protected void setAllEnabled(boolean b) {
        int sz = this.boxes.size();
        for (int i = 0; i < sz; i++) {
            CheckBox cb = (CheckBox) this.boxes.elementAt(i);
            if (!cb.isChecked()) {
                cb.setEnabled(b);
            }
        }
    }

    protected void incrementCheckedCount() {
        this.currentlyChecked++;
        this.setSpaceAvailability();
    }

    protected void decrementCheckedCount() {
        this.currentlyChecked--;
        this.setSpaceAvailability();
    }

    public int getMaxChecked() {
        return maxChecked;
    }

    public void setMaxChecked(int maxChecked) {
        this.maxChecked = maxChecked;
    }

    public Label getMessageLabel() {
        return messageLabel;
    }

    public void setMessageLabel(Label messageLabel) {
        this.messageLabel = messageLabel;
    }
}