fr.putnami.pwt.core.theme.client.DefaultThemeController.java Source code

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Here is the source code for fr.putnami.pwt.core.theme.client.DefaultThemeController.java

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/**
 * This file is part of pwt.
 *
 * pwt is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * pwt is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
 * General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with pwt. If not,
 * see <http://www.gnu.org/licenses/>.
 */
package fr.putnami.pwt.core.theme.client;

import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.HeadElement;
import com.google.gwt.dom.client.LinkElement;
import com.google.gwt.dom.client.NodeList;

import fr.putnami.pwt.core.widget.client.base.SimpleStyle;

/**
 * The DefaultThemeController is the default {@link ThemeController} implemenation. <br>
 * <strong>Note</strong>: IE8 use {@link DefaultIE8ThemeController}.
 * <p>
 * The DefaultThemeController inserts all style sheet in the root document header. It install first
 * all default theme css then the current theme ones.
 * </p>
 * <ol>
 * <li>Remove all the css in the &lt;head&gt; tag</li>
 * <li>Install all css of the default theme</li>
 * <li>Install all css of the current theme</li>
 * </ol>
 *
 * @since 1.0
 */
public class DefaultThemeController extends ThemeController {

    private HeadElement head;

    private final Theme defaultTheme = new Theme();
    private Theme currentTheme;
    private IconFont icons;

    private boolean isInit = false;

    /*
     * (non-Javadoc)
     *
     * @see fr.putnami.pwt.core.theme.client.ThemeController#getDefaultTheme()
     */
    @Override
    public Theme getDefaultTheme() {
        return this.defaultTheme;
    }

    /*
     * (non-Javadoc)
     * 
     * @see fr.putnami.pwt.core.theme.client.ThemeController#installTheme(
     * fr.putnami.pwt.core.theme.client * .Theme)
     */
    @Override
    public void installTheme(Theme theme) {
        this.removeCssLinks();
        if (this.currentTheme != null) {
            for (CssLink link : this.currentTheme.getLinks()) {
                link.getLink().removeFromParent();
            }
        }
        this.currentTheme = theme;
        this.resetTheme();
    }

    /*
     * (non-Javadoc)
     *
     * @see fr.putnami.pwt.core.theme.client.ThemeController#installDefaultTheme()
     */
    @Override
    public void installDefaultTheme() {
        this.installTheme(null);
    }

    /*
     * (non-Javadoc)
     *
     * @see fr.putnami.pwt.core.theme.client.ThemeController#resetTheme()
     */
    @Override
    public void resetTheme() {
        if (this.currentTheme != null && this.currentTheme.getIconFont() != null) {
            this.icons = this.currentTheme.getIconFont();
        } else if (this.defaultTheme.getIconFont() != null) {
            this.icons = this.defaultTheme.getIconFont();
        }
        if (this.icons != null) {
            this.getHead().appendChild(this.icons.getLink());
        }
        this.insertLinks(this.defaultTheme);
        this.insertLinks(this.currentTheme);
    }

    /**
     * Insert links in the document head tag.
     *
     * @param theme the theme
     */
    private void insertLinks(Theme theme) {
        if (theme != null) {
            for (CssLink link : theme.getLinks()) {
                this.getHead().appendChild(link.getLink());
            }
        }
    }

    /**
     * Removes all link tags in the head if not initialized.
     */
    private void removeCssLinks() {
        if (this.isInit) {
            return;
        }
        this.isInit = true;
        // Remove all existing link element
        NodeList<Element> links = this.getHead().getElementsByTagName(LinkElement.TAG);
        int size = links.getLength();
        for (int i = 0; i < size; i++) {
            LinkElement elem = LinkElement.as(links.getItem(0));
            if ("stylesheet".equals(elem.getRel())) {
                elem.removeFromParent();
            }
        }
    }

    /**
     * Gets the head tag element.
     *
     * @return the head tag element
     */
    protected HeadElement getHead() {
        if (this.head == null) {
            Element elt = Document.get().getElementsByTagName("head").getItem(0);
            assert elt != null : "The host HTML page does not have a <head> element"
                    + " which is required by this injector";
            this.head = HeadElement.as(elt);
        }
        return this.head;
    }

    /*
     * (non-Javadoc)
     *
     * @see fr.putnami.pwt.core.theme.client.ThemeController#getIconStyle(java.lang.String)
     */
    @Override
    public CssStyle getIconStyle(String iconName) {
        if (this.icons == null) {
            return SimpleStyle.EMPTY_STYLE;
        }
        return this.icons.getStyle(iconName);
    }

}