com.google.gwt.sample.expenses.client.SortableHeader.java Source code

Introduction

Here is the source code for com.google.gwt.sample.expenses.client.SortableHeader.java

Source

/*
 * Copyright 2010 Google Inc.
 *
 * 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.google.gwt.sample.expenses.client;

import com.google.gwt.cell.client.Cell.Context;
import com.google.gwt.cell.client.ClickableTextCell;
import com.google.gwt.core.client.GWT;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.cellview.client.Header;
import com.google.gwt.user.client.ui.AbstractImagePrototype;

/**
 * A {@link Header} subclass that maintains sorting state and displays an icon
 * to indicate the sort direction.
 */
public class SortableHeader extends Header<String> {

    interface Template extends SafeHtmlTemplates {
        @Template("<div style=\"position:relative;cursor:hand;cursor:pointer;"
                + "padding-right:{0}px;\">{1}<div>{2}</div></div>")
        SafeHtml sorted(int imageWidth, SafeHtml arrow, String text);

        @Template("<div style=\"position:relative;cursor:hand;cursor:pointer;"
                + "padding-right:{0}px;\"><div style=\"position:absolute;display:none;"
                + "\"></div><div>{1}</div></div>")
        SafeHtml unsorted(int imageWidth, String text);
    }

    private static Template template;

    /**
     * Image resources.
     */
    public static interface Resources extends ClientBundle {

        ImageResource downArrow();

        ImageResource upArrow();
    }

    private static final Resources RESOURCES = GWT.create(Resources.class);
    private static final int IMAGE_WIDTH = 16;
    private static final SafeHtml DOWN_ARROW = makeImage(RESOURCES.downArrow());
    private static final SafeHtml UP_ARROW = makeImage(RESOURCES.upArrow());

    private static SafeHtml makeImage(ImageResource resource) {
        AbstractImagePrototype proto = AbstractImagePrototype.create(resource);
        String html = proto.getHTML().replace("style='", "style='position:absolute;right:0px;top:0px;");
        return SafeHtmlUtils.fromTrustedString(html);
    }

    private boolean reverseSort = false;
    private boolean sorted = false;
    private String text;

    SortableHeader(String text) {
        super(new ClickableTextCell());
        if (template == null) {
            template = GWT.create(Template.class);
        }
        this.text = text;
    }

    public boolean getReverseSort() {
        return reverseSort;
    }

    @Override
    public String getValue() {
        return text;
    }

    @Override
    public void render(Context context, SafeHtmlBuilder sb) {
        if (sorted) {
            sb.append(template.sorted(IMAGE_WIDTH, reverseSort ? DOWN_ARROW : UP_ARROW, text));
        } else {
            sb.append(template.unsorted(IMAGE_WIDTH, text));
        }
    }

    public void setReverseSort(boolean reverseSort) {
        this.reverseSort = reverseSort;
    }

    public void setSorted(boolean sorted) {
        this.sorted = sorted;
    }

    public void toggleReverseSort() {
        this.reverseSort = !this.reverseSort;
    }
}