com.cedarsolutions.client.gwt.custom.table.SwitchableSelectionModel Maven / Gradle / Ivy

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Utility code for use with GWT and Mvp4g.
There is a newer version: 5.8.4
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *
 *              C E D A R
 *          S O L U T I O N S       "Software done right."
 *           S O F T W A R E
 *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *
 * Copyright (c) 2013 Kenneth J. Pronovici.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the Apache License, Version 2.0.
 * See LICENSE for more information about the licensing terms.
 *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *
 * Author   : Kenneth J. Pronovici 
 * Language : Java 6
 * Project  : Common Java Functionality
 *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
package com.cedarsolutions.client.gwt.custom.table;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import com.google.gwt.view.client.ProvidesKey;
import com.google.gwt.view.client.SelectionChangeEvent;
import com.google.gwt.view.client.SelectionModel.AbstractSelectionModel;
import com.google.gwt.view.client.SetSelectionModel;

/**
 * Selection model that allows switching the selection type, for use with DataTable.
 *
 * 
 * Code Source
 * 
 *
 * 
 * This code was initially copied from GWT under the terms of its license, and
 * was later modified to allow both single and multiple selection types.
 * 
 *
 * 
 *    
 *       
 *          
 *             
 *             
 *          
 *          
 *             
 *             
 *          
 *          
 *             
 *             
 *          
 *       
 *    Source: {@link com.google.gwt.view.client.MultiSelectionModel}
Version: GWT 2.5.1
Date: December, 2013
 * 
 *
 * @param  Type of the associated table.
 * @author Kenneth J. Pronovici 
 */
public class SwitchableSelectionModel extends AbstractSelectionModel implements SetSelectionModel {

    private SelectionType selectionType;
    private Map selectedSet;
    private Map> selectionChanges;

    public SwitchableSelectionModel(ProvidesKey keyProvider, SelectionType selectionType) {
        super(keyProvider);
        this.selectionType = selectionType;
        this.selectedSet = new HashMap();
        this.selectionChanges = new HashMap>();
    }

    public void setSelectionType(SelectionType selectionType) {
        this.selectionType = selectionType;
        this.selectedSet.clear();
        this.selectionChanges.clear();
    }

    public SelectionType getSelectionType() {
        return this.selectionType;
    }

    @Override
    public void clear() {
        this.selectionChanges.clear();
        this.unselectAll();
        this.scheduleSelectionChangeEvent();
    }

    /** Unselect all items. */
    private void unselectAll() {
        for (T value : this.selectedSet.values()) {
            this.selectionChanges.put(getKey(value), new SelectionChange(value, false));
        }
    }

    @Override
    public Set getSelectedSet() {
        this.resolveChanges();
        return new HashSet(this.selectedSet.values());
    }

    /** Get the the selected object, really only makes sense when SelectionType.SINGLE. */
    public T getSelectedObject() {
        this.resolveChanges();
        if (this.selectedSet.isEmpty()) {
            return null;
        } else {
            return new ArrayList(this.selectedSet.values()).get(0);
        }
    }

    @Override
    public boolean isSelected(T object) {
        this.resolveChanges();
        return this.selectedSet.containsKey(getKey(object));
    }

    @Override
    public void setSelected(T object, boolean selected) {
        if (this.selectionType == SelectionType.MULTI) {
            this.selectionChanges.put(getKey(object), new SelectionChange(object, selected));
            this.scheduleSelectionChangeEvent();
        } else {
            if (object == null) {
                this.unselectAll();
                this.scheduleSelectionChangeEvent();
            } else {
                if (selected) {
                    this.unselectAll();
                    this.selectionChanges.put(getKey(object), new SelectionChange(object, true));
                    this.scheduleSelectionChangeEvent();
                } else {
                    if (isSelected(object)) {
                        this.selectionChanges.put(getKey(object), new SelectionChange(object, false));
                        this.scheduleSelectionChangeEvent();
                    }
                }
            }
        }
    }

    @Override
    protected void fireSelectionChangeEvent() {
        if (isEventScheduled()) {
            setEventCancelled(true);
        }

        this.resolveChanges();
    }

    private void resolveChanges() {
        if (this.selectionChanges.isEmpty()) {
            return;
        }

        boolean changed = false;
        for (Map.Entry> entry : this.selectionChanges.entrySet()) {
            Object key = entry.getKey();
            SelectionChange value = entry.getValue();
            boolean selected = value.isSelected;

            T oldValue = this.selectedSet.get(key);
            if (selected) {
                this.selectedSet.put(key, value.item);
                Object oldKey = getKey(oldValue);
                if (!changed) {
                    changed = (oldKey == null) ? (key != null) : !oldKey.equals(key);
                }
            } else {
                if (oldValue != null) {
                    this.selectedSet.remove(key);
                    changed = true;
                }
            }
        }

        this.selectionChanges.clear();

        if (changed) {
            SelectionChangeEvent.fire(this);
        }
    }

    /** Available selection types. */
    public enum SelectionType {
        SINGLE,
        MULTI,
    }

    /** Stores an item and its pending selection state. */
    private static class SelectionChange {
        private final T item;
        private final boolean isSelected;

        SelectionChange(T item, boolean isSelected) {
            this.item = item;
            this.isSelected = isSelected;
        }
    }

}
Source:	{@link com.google.gwt.view.client.MultiSelectionModel}
Version:	GWT 2.5.1
Date:	December, 2013
com.cedarsolutions.client.gwt.custom.table.SwitchableSelectionModel Maven / Gradle / Ivy

* Code Source *
