Java tutorial
/* * Copyright 2000-2014 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.client.debug.internal; import java.util.HashSet; import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.Style; import com.google.gwt.dom.client.Style.Position; import com.google.gwt.dom.client.Style.Unit; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.ui.RootPanel; import com.google.gwt.user.client.ui.Widget; import com.vaadin.client.BrowserInfo; import com.vaadin.client.ComponentConnector; import com.vaadin.client.ServerConnector; import com.vaadin.client.ui.VWindow; /** * Highlights a widget in the UI by overlaying a semi-transparent colored div. * <p> * Multiple highlights can be added, then selectively removed with * {@link #hide(Element)} or all at once with {@link #hideAll()}. * </p> * <p> * Note that highlights are intended to be short-term; highlights do not move or * disappear with the highlighted widget, and it is also fairly likely that * someone else calls {@link #hideAll()} eventually. * </p> * * @since 7.1 * @author Vaadin Ltd */ public class Highlight { private static final String DEFAULT_COLOR = "red"; private static final double DEFAULT_OPACITY = 0.3; private static final int MIN_WIDTH = 3; private static final int MIN_HEIGHT = 3; static HashSet<Element> highlights; /** * Highlight the {@link Widget} for the given {@link ComponentConnector}. * <p> * Pass the returned {@link Element} to {@link #hide(Element)} to remove * this particular highlight. * </p> * * @param connector * ComponentConnector * @return Highlight element */ static Element show(ComponentConnector connector) { return show(connector, DEFAULT_COLOR); } /** * Highlight the {@link Widget} for the given connector if it is a * {@link ComponentConnector}. Hide any other highlight. * <p> * Pass the returned {@link Element} to {@link #hide(Element)} to remove * this particular highlight. * </p> * * @since 7.1 * * @param connector * the server connector to highlight * @return Highlight element, or <code>null</code> if the connector isn't a * component */ static Element showOnly(ServerConnector connector) { hideAll(); if (connector instanceof ComponentConnector) { return show((ComponentConnector) connector); } else { return null; } } /** * Highlights the {@link Widget} for the given {@link ComponentConnector} * using the given color. * <p> * Pass the returned {@link Element} to {@link #hide(Element)} to remove * this particular highlight. * </p> * * @param connector * ComponentConnector * @param color * Color of highlight * @return Highlight element */ static Element show(ComponentConnector connector, String color) { if (connector != null) { Widget w = connector.getWidget(); return show(w, color); } return null; } /** * Highlights the given {@link Widget}. * <p> * Pass the returned {@link Element} to {@link #hide(Element)} to remove * this particular highlight. * </p> * * @param widget * Widget to highlight * @return Highlight element */ static Element show(Widget widget) { return show(widget, DEFAULT_COLOR); } /** * Highlight the given {@link Widget} using the given color. * <p> * Pass the returned {@link Element} to {@link #hide(Element)} to remove * this particular highlight. * </p> * * @param widget * Widget to highlight * @param color * Color of highlight * @return Highlight element */ static Element show(Widget widget, String color) { if (widget != null) { show(widget.getElement(), color); } return null; } /** * Highlights the given {@link Element}. * <p> * Pass the returned {@link Element} to {@link #hide(Element)} to remove * this particular highlight. * </p> * * @param element * Element to highlight * @return Highlight element */ static Element show(Element element) { return show(element, DEFAULT_COLOR); } /** * Highlight the given {@link Element} using the given color. * <p> * Pass the returned highlight {@link Element} to {@link #hide(Element)} to * remove this particular highlight. * </p> * * @param element * Element to highlight * @param color * Color of highlight * @return Highlight element */ static Element show(Element element, String color) { if (element != null) { if (highlights == null) { highlights = new HashSet<Element>(); } Element highlight = DOM.createDiv(); Style style = highlight.getStyle(); style.setTop(element.getAbsoluteTop(), Unit.PX); style.setLeft(element.getAbsoluteLeft(), Unit.PX); int width = element.getOffsetWidth(); if (width < MIN_WIDTH) { width = MIN_WIDTH; } style.setWidth(width, Unit.PX); int height = element.getOffsetHeight(); if (height < MIN_HEIGHT) { height = MIN_HEIGHT; } style.setHeight(height, Unit.PX); RootPanel.getBodyElement().appendChild(highlight); style.setPosition(Position.ABSOLUTE); style.setZIndex(VWindow.Z_INDEX + 1000); style.setBackgroundColor(color); style.setOpacity(DEFAULT_OPACITY); if (BrowserInfo.get().isIE()) { style.setProperty("filter", "alpha(opacity=" + (DEFAULT_OPACITY * 100) + ")"); } highlights.add(highlight); return highlight; } return null; } /** * Hides the given highlight. * * @param highlight * Highlight to hide */ static void hide(Element highlight) { if (highlight != null && highlight.getParentElement() != null) { highlight.getParentElement().removeChild(highlight); highlights.remove(highlight); } } /** * Hides all highlights */ static void hideAll() { if (highlights != null) { for (Element highlight : highlights) { if (highlight.getParentElement() != null) { highlight.getParentElement().removeChild(highlight); } } highlights = null; } } }