com.pietschy.gwt.pectin.client.components.ComboBox.java Source code

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Here is the source code for com.pietschy.gwt.pectin.client.components.ComboBox.java

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/*
 * Copyright 2009 Andrew Pietsch 
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you 
 * may not use this file except in compliance with the License. You may 
 * obtain a copy of the License at 
 *      
 *      http://www.apache.org/licenses/LICENSE-2.0 
 *
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 
 * implied. See the License for the specific language governing permissions 
 * and limitations under the License. 
 */

package com.pietschy.gwt.pectin.client.components;

import com.google.gwt.event.dom.client.*;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Focusable;
import com.google.gwt.user.client.ui.HasValue;
import com.pietschy.gwt.pectin.client.form.metadata.HasEnabled;
import com.pietschy.gwt.pectin.client.form.validation.ValidationResult;
import com.pietschy.gwt.pectin.client.form.validation.component.ValidationDisplay;
import com.pietschy.gwt.pectin.client.form.validation.component.ValidationStyles;
import com.pietschy.gwt.pectin.client.list.ArrayListModel;
import com.pietschy.gwt.pectin.client.list.ListModel;
import com.pietschy.gwt.pectin.client.list.ListModelChangedEvent;
import com.pietschy.gwt.pectin.client.list.ListModelChangedHandler;

import java.util.Arrays;
import java.util.List;

/**
 * Created by IntelliJ IDEA.
 * User: andrew
 * Date: Jun 17, 2008
 * Time: 2:41:00 PM
 * To change this template use File | Settings | File Templates.
 */
public class ComboBox<T> extends Composite
        implements HasValue<T>, HasEnabled, Focusable, HasFocusHandlers, HasBlurHandlers, ValidationDisplay {
    public static Renderer<Object> DEFAULT_RENDERER = new Renderer<Object>() {
        public String toDisplayString(Object value) {
            return value != null ? value.toString() : "<null>";
        }
    };

    private ListBoxWorkAroundBug2689 listBox = new ListBoxWorkAroundBug2689();
    private ListModel<T> valueList;
    private ListBoxMonitor listBoxMonitor = new ListBoxMonitor();
    private Renderer<? super T> renderer = DEFAULT_RENDERER;

    public ComboBox(T[] values) {
        this(values, DEFAULT_RENDERER);
    }

    public ComboBox(T[] values, Renderer<? super T> renderer) {
        this(Arrays.asList(values), renderer);
    }

    public ComboBox(List<T> values) {
        this(values, DEFAULT_RENDERER);
    }

    public ComboBox(List<T> values, Renderer<? super T> renderer) {
        ArrayListModel<T> model = new ArrayListModel<T>();
        model.setElements(values);
        init(model, renderer);
    }

    public ComboBox(ListModel<T> values) {
        init(values, DEFAULT_RENDERER);
    }

    public ComboBox(ListModel<T> values, Renderer<? super T> renderer) {
        init(values, renderer);
    }

    private void init(ListModel<T> values, Renderer<? super T> renderer) {
        if (values == null) {
            throw new NullPointerException("values is null");
        }

        if (renderer == null) {
            throw new NullPointerException("renderer is null");
        }

        valueList = values;
        this.renderer = renderer;
        rebuildListBox();
        listBox.addChangeHandler(listBoxMonitor);
        valueList.addListModelChangedHandler(new ListModelChangedHandler<T>() {
            public void onListDataChanged(ListModelChangedEvent<T> event) {
                rebuildListBox();
            }
        });

        initWidget(listBox);
    }

    private void rebuildListBox() {
        listBoxMonitor.setIgnoreEvents(true);
        try {
            listBox.clear();
            for (int i = 0; i < valueList.size(); i++) {
                T value = valueList.get(i);
                listBox.addItem(renderer.toDisplayString(value), Integer.toString(i));
            }
        } finally {
            listBoxMonitor.setIgnoreEvents(false);
        }
    }

    public void setRenderer(Renderer<? super T> renderer) {
        if (renderer == null) {
            throw new NullPointerException("renderer is null");
        }

        this.renderer = renderer;
        rebuildListBox();
    }

    public void setEnabled(boolean enabled) {
        listBox.setEnabled(enabled);
    }

    public boolean isEnabled() {
        return listBox.isEnabled();
    }

    public T getValue() {
        String indexAsString = listBox.getSelectedValue();

        if (indexAsString == null) {
            return null;
        }

        return valueList.get(Integer.parseInt(indexAsString));
    }

    public void setValue(T value) {
        setValue(value, false);
    }

    public void setValue(T value, boolean fireEvents) {
        listBoxMonitor.setIgnoreEvents(true);
        try {
            if (value == null) {
                listBox.setSelectedValue(null);
            } else {
                listBox.setSelectedValue(Integer.toString(valueList.indexOf(value)));
            }

            if (fireEvents) {
                fireValueChanged(value);
            }
        } finally {
            listBoxMonitor.setIgnoreEvents(false);
        }
    }

    public void setValidationResult(ValidationResult result) {
        ValidationStyles.defaultInstance().applyStyle(listBox, result);
    }

    private void fireValueChanged(T value) {
        ValueChangeEvent.fire(this, value);
    }

    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<T> handler) {
        return addHandler(handler, ValueChangeEvent.getType());
    }

    public HandlerRegistration addFocusHandler(FocusHandler handler) {
        return listBox.addFocusHandler(handler);
    }

    public HandlerRegistration addBlurHandler(BlurHandler handler) {
        return listBox.addBlurHandler(handler);
    }

    public int getTabIndex() {
        return listBox.getTabIndex();
    }

    public void setAccessKey(char key) {
        listBox.setAccessKey(key);
    }

    public void setFocus(boolean focused) {
        listBox.setFocus(focused);
    }

    public void setTabIndex(int index) {
        listBox.setTabIndex(index);
    }

    public static interface Renderer<T> {
        String toDisplayString(T value);
    }

    private class ListBoxMonitor implements ChangeHandler {
        private boolean ignoreEvents = false;

        public void onChange(ChangeEvent event) {
            if (!ignoreEvents) {
                fireValueChanged(getValue());
            }
        }

        public void setIgnoreEvents(boolean ignoreEvents) {
            this.ignoreEvents = ignoreEvents;
        }
    }
}