com.databasepreservation.visualization.client.common.search.Dropdown.java Source code

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Here is the source code for com.databasepreservation.visualization.client.common.search.Dropdown.java

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/**
 * The contents of this file are based on those found at https://github.com/keeps/roda
 * and are subject to the license and copyright detailed in https://github.com/keeps/roda
 */
package com.databasepreservation.visualization.client.common.search;

import java.util.HashMap;
import java.util.Map;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
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.FocusPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.VerticalPanel;

/**
 * @author Bruno Ferreira <bferreira@keep.pt>
 */
public class Dropdown extends Composite implements HasValueChangeHandlers<String> {
    private FocusPanel focusPanel;
    private SimplePanel panel;
    private Label selectedLabel;
    private PopupPanel popup;
    private VerticalPanel popupPanel;
    private boolean popupShowing = false;

    private Map<String, String> popupValues;

    public Dropdown() {
        focusPanel = new FocusPanel();
        panel = new SimplePanel();
        selectedLabel = new Label();
        popup = new PopupPanel(true);
        popupPanel = new VerticalPanel();
        popupValues = new HashMap<String, String>();

        panel.add(selectedLabel);
        focusPanel.add(panel);

        focusPanel.addClickHandler(new ClickHandler() {

            @Override
            public void onClick(ClickEvent event) {
                popup();
            }
        });

        popup.addCloseHandler(new CloseHandler<PopupPanel>() {

            @Override
            public void onClose(CloseEvent<PopupPanel> event) {
                panel.removeStyleName("open");
            }
        });

        initWidget(focusPanel);

        focusPanel.addStyleName("dropdown");
        panel.addStyleName("dropdown-panel");
        selectedLabel.addStyleName("dropdown-label");
        popup.addStyleName("dropdown-popup");
    }

    public void addItem(final String label, final String value) {
        popupValues.put(label, value);
        Label item = new Label(label);
        popupPanel.add(item);
        item.addStyleName("dropdown-item");

        item.addClickHandler(new ClickHandler() {

            @Override
            public void onClick(ClickEvent event) {
                selectedLabel.setText(label);
                onChange();
                popup();
            }
        });

        popup.setWidget(popupPanel);
        setPanelWidth();
    }

    public void setLabel(String text) {
        selectedLabel.setText(text);
    }

    public void popup() {
        if (popupShowing) {
            popup.hide();
            popupShowing = popup.isShowing();
        } else {
            popup.showRelativeTo(panel);
            popupShowing = popup.isShowing();
            panel.addStyleName("open");
        }
    }

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

    protected void onChange() {
        ValueChangeEvent.fire(this, getSelectedValue());
    }

    public String getSelectedValue() {
        return popupValues.get(selectedLabel.getText());
    }

    public void setPanelWidth() {
        boolean visible = popup.isVisible();
        popup.setVisible(true);
        focusPanel.getElement().setAttribute("min-width", popup.getOffsetWidth() + "px");
        popup.setVisible(visible);
    }

    public void addPopupStyleName(String styleName) {
        popup.addStyleName(styleName);
    }
}