asquare.gwt.sb.client.ui.StreamPanel.java Source code

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Here is the source code for asquare.gwt.sb.client.ui.StreamPanel.java

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/*
 * Copyright 2007 Mat Gessel <mat.gessel@gmail.com>
 * 
 * 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 asquare.gwt.sb.client.ui;

import java.util.Stack;

import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.ui.ComplexPanel;
import com.google.gwt.user.client.ui.UIObject;
import com.google.gwt.user.client.ui.Widget;

/**
 * A {@link com.google.gwt.user.client.ui.ComplexPanel ComplexPanel} which keeps
 * in internal "cursor" enabling you to construct HTML fragments like writing to
 * a stream. Allows customization of the root element and <code>display</code>
 * style of added children.
 * <p>
 * TODO: 
 * <ul>
 * <li>optional strict checking; prevent tables in spans and such</li>
 * </ul>
 * 
 * <h3>CSS Style Rules</h3>
 * <ul class='css'>
 * <li>.tk-StreamPanel { }</li>
 * </ul>
 */
public class StreamPanel extends ComplexPanel {
    private Stack<Element> m_elementTreePath = new Stack<Element>();
    private Stack<Widget> m_widgetTreePath = new Stack<Widget>();
    private String m_display = null;

    /**
     * Constructs a panel with a <code>DIV</code> element and default children
     * display property.
     */
    public StreamPanel() {
        this("div", null);
    }

    /**
     * Constructs a panel with the specified element and the default display
     * style.
     * 
     * @param element a html element tag
     */
    public StreamPanel(String element) {
        this(element, null);
    }

    /**
     * Constructs a panel with the specified element and display style.
     * 
     * @param element a html element tag
     * @param display a css <code>display</code> style value to apply
     *            to added children
     */
    public StreamPanel(String element, String display) {
        setElement(DOM.createElement(element));
        setStyleName("tk-StreamPanel");
        m_elementTreePath.push(getElement());
        m_widgetTreePath.push(this);
        m_display = display;
    }

    public void close() {
        m_elementTreePath.pop();
        m_widgetTreePath.pop();
    }

    public void top() {
        while (m_elementTreePath.size() > 1) {
            m_elementTreePath.pop();
            m_widgetTreePath.pop();
        }
    }

    public Widget currentWidget() {
        return m_widgetTreePath.peek();
    }

    /**
     * Appends an element to the current node. 
     * 
     * @param type
     */
    public Element element(String type) {
        Element element = DOM.createElement(type);
        if (m_display != null)
            DOM.setStyleAttribute(element, "display", m_display);
        DOM.appendChild(m_elementTreePath.peek(), element);
        return element;
    }

    /**
     * Appends an element to the current node and makes the new element the
     * current node.
     * 
     * @param type
     */
    public Element elementOpen(String type) {
        Element element = element(type);
        m_elementTreePath.push(element);
        m_widgetTreePath.push(null);
        return element;
    }

    public Widget widget(Widget w) {
        if (m_display != null)
            DOM.setStyleAttribute(w.getElement(), "display", m_display);
        add(w, m_elementTreePath.peek());
        return w;
    }

    public Widget widgetOpen(Widget w) {
        widget(w);
        m_elementTreePath.push(w.getElement());
        m_widgetTreePath.push(w);
        return w;
    }

    public void attr(String attributeName, String value) {
        DOM.setElementProperty(m_elementTreePath.peek(), attributeName, value);
    }

    public void text(String text) {
        Element e = m_elementTreePath.peek();
        DOM.setInnerText(e, DOM.getInnerText(e) + text);
    }

    public void html(String html) {
        Element e = m_elementTreePath.peek();
        DOM.setInnerHTML(e, DOM.getInnerHTML(e) + html);
    }

    public void styleName(String styleName) {
        UIObject.setStyleName(m_elementTreePath.peek(), styleName, true);
    }

    /**
     * Sets the display style value which will be applied to subsequently added
     * children.
     * 
     * @param display a css <code>display</code> style value to apply
     *            to added children
     */
    public void setDisplay(String display) {
        m_display = display;
    }

    /**
     * Not supported 
     * 
     * @throws UnsupportedOperationException if called
     * @deprecated not supported
     */
    @Override
    public boolean remove(Widget w) {
        throw new UnsupportedOperationException();
    }
}