com.bearsoft.gwt.ui.widgets.StyledListBox.java Source code

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Here is the source code for com.bearsoft.gwt.ui.widgets.StyledListBox.java

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package com.bearsoft.gwt.ui.widgets;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.google.gwt.dom.client.OptionElement;
import com.google.gwt.dom.client.SelectElement;
import com.google.gwt.event.dom.client.ChangeEvent;
import com.google.gwt.event.dom.client.ChangeHandler;
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.i18n.client.HasDirection;
import com.google.gwt.user.client.ui.HasValue;
import com.google.gwt.user.client.ui.ListBox;

/**
 * 
 * @author mg
 */
public class StyledListBox<T> extends ListBox implements HasValue<T> {

    protected List<T> associatedValues = new ArrayList<>();
    protected Map<T, Integer> indicies;
    protected T value;

    public StyledListBox() {
        this(false);
    }

    public StyledListBox(boolean isMultipleSelect) {
        super();
        setMultipleSelect(isMultipleSelect);
        addChangeHandler(new ChangeHandler() {

            @Override
            public void onChange(ChangeEvent event) {
                if (!isMultipleSelect()) {
                    int selected = getSelectedIndex();
                    if (selected == -1) {
                        setValue(null, true);
                    } else {
                        setValue(associatedValues.get(selected), true);
                    }
                }
            }

        });
    }

    public void addItem(String aLabel, String aKey, T aAssociatedValue, String aClassName) {
        super.addItem(aLabel != null ? aLabel : "", aKey);
        associatedValues.set(getItemCount() - 1, aAssociatedValue);
        setItemStyleName(getItemCount() - 1, aClassName);
    }

    public void addItem(String aLabel, HasDirection.Direction dir, String aKey, T aAssociatedValue,
            String aClassName) {
        super.addItem(aLabel != null ? aLabel : "", dir, aKey);
        associatedValues.set(getItemCount() - 1, aAssociatedValue);
        setItemStyleName(getItemCount() - 1, aClassName);
    }

    @Override
    public void insertItem(String aLabel, HasDirection.Direction dir, String aKey, int index) {
        boolean wasUnselected = getSelectedIndex() == -1;
        super.insertItem(aLabel != null ? aLabel : "", dir, aKey, index);
        if (wasUnselected)
            super.setSelectedIndex(-1);
        if (index == -1)// crazy gwt ListBox treats -1 as adding to the end
            associatedValues.add(null);
        else
            associatedValues.add(index, null);
        indicies = null;
    }

    @Override
    public void removeItem(int index) {
        super.removeItem(index);
        associatedValues.remove(index);
        indicies = null;
    }

    private void checkIndex(int index) {
        if (index < 0 || index >= getItemCount()) {
            throw new IndexOutOfBoundsException();
        }
    }

    public OptionElement getItem(int aIndex) {
        checkIndex(aIndex);
        return getElement().<SelectElement>cast().getOptions().getItem(aIndex);
    }

    public T getAssociatedValue(int aIndex) {
        checkIndex(aIndex);
        return associatedValues.get(aIndex);
    }

    public void setAssociatedValue(int aIndex, T aValue) {
        checkIndex(aIndex);
        associatedValues.set(aIndex, aValue);
        indicies = null;
    }

    public String getKey(int aIndex) {
        OptionElement option = getItem(aIndex);
        return option.getValue();
    }

    public String getItemStyleName(int aIndex) {
        checkIndex(aIndex);
        OptionElement option = getElement().<SelectElement>cast().getOptions().getItem(aIndex);
        return option.getClassName();
    }

    public void setItemStyleName(int aIndex, String aValue) {
        checkIndex(aIndex);
        OptionElement option = getElement().<SelectElement>cast().getOptions().getItem(aIndex);
        option.setClassName(aValue);
    }

    @Override
    public void clear() {
        super.clear();
        associatedValues.clear();
        indicies = null;
    }

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

    @Override
    public T getValue() {
        return value;
    }

    @Override
    public void setValue(T aValue) {
        setValue(aValue, false);
    }

    public String getText() {
        int idx = indexOf(value);
        if (idx != -1) {
            return getItemText(idx);
        } else {
            return null;
        }
    }

    public String getText(T aValue) {
        validateLocator();
        Integer idx = indicies.get(aValue);
        if (idx != null) {
            return getItemText(idx);
        } else {
            return null;
        }
    }

    public int indexOf(T aValue) {
        validateLocator();
        Integer idx = indicies.get(aValue);
        if (idx != null) {
            return idx;
        } else {
            return -1;
        }
    }

    @Override
    public void setSelectedIndex(int index) {
        super.setSelectedIndex(index);
    }

    @Override
    public void setValue(T aValue, boolean fireEvents) {
        if (value != aValue) {
            value = aValue;
            int index = indexOf(aValue);
            setSelectedIndex(index);
            if (fireEvents) {
                ValueChangeEvent.fire(StyledListBox.this, value);
            }
        }
    }

    private void validateLocator() {
        if (indicies == null) {
            indicies = new HashMap<>();
            for (int i = 0; i < associatedValues.size(); i++) {
                T association = associatedValues.get(i);
                indicies.put(association, i);
            }
        }
    }
}