Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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.vaadin.ui; import org.jsoup.nodes.Element; import com.vaadin.shared.ui.AbstractLayoutState; import com.vaadin.shared.ui.MarginInfo; import com.vaadin.ui.declarative.DesignAttributeHandler; import com.vaadin.ui.declarative.DesignContext; /** * An abstract class that defines default implementation for the {@link Layout} * interface. * * @author Vaadin Ltd. * @since 5.0 */ public abstract class AbstractLayout extends AbstractComponentContainer implements Layout { @Override protected AbstractLayoutState getState() { return (AbstractLayoutState) super.getState(); } @Override protected AbstractLayoutState getState(boolean markAsDirty) { return (AbstractLayoutState) super.getState(markAsDirty); } /** * Reads margin attributes from a design into a MarginInfo object. This * helper method should be called from the * {@link #readDesign(Element, DesignContext) readDesign} method of layouts * that implement {@link MarginHandler}. * * @since 7.5 * * @param design * the design from which to read * @param defMargin * the default margin state for edges that are not set in the * design * @param context * the DesignContext instance used for parsing the design * @return the margin info */ protected MarginInfo readMargin(Element design, MarginInfo defMargin, DesignContext context) { if (design.hasAttr("margin")) { boolean margin = DesignAttributeHandler.readAttribute("margin", design.attributes(), boolean.class); return new MarginInfo(margin); } else { boolean left = DesignAttributeHandler.readAttribute("margin-left", design.attributes(), defMargin.hasLeft(), boolean.class); boolean right = DesignAttributeHandler.readAttribute("margin-right", design.attributes(), defMargin.hasRight(), boolean.class); boolean top = DesignAttributeHandler.readAttribute("margin-top", design.attributes(), defMargin.hasTop(), boolean.class); boolean bottom = DesignAttributeHandler.readAttribute("margin-bottom", design.attributes(), defMargin.hasBottom(), boolean.class); return new MarginInfo(top, right, bottom, left); } } /** * Writes margin attributes from a MarginInfo object to a design. This * helper method should be called from the * {@link #readDesign(Element, DesignContext) writeDesign} method of layouts * that implement {@link MarginHandler}. * * * @since 7.5 * * @param design * the design to write to * @param margin * the margin state to write * @param defMargin * the default margin state to compare against * @param context * the DesignContext instance used for parsing the design */ protected void writeMargin(Element design, MarginInfo margin, MarginInfo defMargin, DesignContext context) { if (defMargin.getBitMask() == margin.getBitMask()) { // Default, no need to write } else if (margin.hasNone()) { // Write "margin='false'" DesignAttributeHandler.writeAttribute("margin", design.attributes(), false, true, boolean.class, context); } else if (margin.hasAll()) { // Write "margin" DesignAttributeHandler.writeAttribute("margin", design.attributes(), true, false, boolean.class, context); } else { DesignAttributeHandler.writeAttribute("margin-left", design.attributes(), margin.hasLeft(), defMargin.hasLeft(), boolean.class, context); DesignAttributeHandler.writeAttribute("margin-right", design.attributes(), margin.hasRight(), defMargin.hasRight(), boolean.class, context); DesignAttributeHandler.writeAttribute("margin-top", design.attributes(), margin.hasTop(), defMargin.hasTop(), boolean.class, context); DesignAttributeHandler.writeAttribute("margin-bottom", design.attributes(), margin.hasBottom(), defMargin.hasBottom(), boolean.class, context); } } }