Java tutorial
/* * This is part of Geomajas, a GIS framework, http://www.geomajas.org/. * * Copyright 2008-2013 Geosparc nv, http://www.geosparc.com/, Belgium. * * The program is available in open source according to the GNU Affero * General Public License. All contributions in this program are covered * by the Geomajas Contributors License Agreement. For full licensing * details, see LICENSE.txt in the project root. */ package org.geomajas.gwt.client.util; import java.util.LinkedList; import java.util.List; import org.geomajas.command.CommandResponse; import org.geomajas.gwt.client.command.AbstractCommandCallback; import org.geomajas.gwt.client.handler.NotificationHandler; import org.geomajas.gwt.client.i18n.GlobalMessages; import com.google.gwt.core.client.GWT; import com.google.gwt.user.client.Timer; import com.smartgwt.client.types.AnimationEffect; import com.smartgwt.client.types.Positioning; import com.smartgwt.client.widgets.AnimationCallback; import com.smartgwt.client.widgets.Canvas; import com.smartgwt.client.widgets.HTMLFlow; /** * Shows an error message as a croc eye, visible for an amount of time. The position of the notification can be set * unsing {@link WidgetLayout}. This also implements commandcallback, so it can also be attached to * {@link GwtCommandDispatcher}. * * @author Oliver May * @author Kristof Heirwegh */ public final class CrocEyeNotificationHandler extends AbstractCommandCallback<CommandResponse> implements NotificationHandler { private static final int TIMEOUT = 10000; // millisec private static final String INFOMESSAGE_STYLE = "infoMessage"; private static final String ERRORMESSAGE_STYLE = "errorMessage"; private static final GlobalMessages MESSAGES = GWT.create(GlobalMessages.class); private static CrocEyeNotificationHandler instance; private CrocEyeNotificationHandler() { } @Override public void handleInfo(String message) { showInfoMessage(message); } @Override public void handleError(String message) { showErrorMessage(message); } /** * Get the singleton instance of the notificationHandler. * * @return the instance. */ public static CrocEyeNotificationHandler getInstance() { if (instance == null) { instance = new CrocEyeNotificationHandler(); } return instance; } /** * Show info message in the croceye. * @param message the message to show */ public static void showInfoMessage(String message) { getInstance().addMessage(message, INFOMESSAGE_STYLE); } /** * Show error message in the croceye. * @param message the message to show */ public static void showErrorMessage(String message) { getInstance().addMessage(message, ERRORMESSAGE_STYLE); } /** * Clear all messages currently displayed in the croceye. */ public static void clearMessages() { getInstance().hideInfoPanel(); } // ---------------------------------------------------------- @Override public void onCommunicationException(Throwable error) { addMessage(MESSAGES.commandCommunicationError() + error.getMessage(), ERRORMESSAGE_STYLE); } @Override public void onCommandException(CommandResponse response) { String message = ""; List<String> msgs = response.getErrorMessages(); for (int i = 0; i < msgs.size(); i++) { if (i == 0) { message += msgs.get(i); } else { message += "- " + msgs.get(i); } if (i < msgs.size() - 1) { message += "<br />"; } } addMessage(message, ERRORMESSAGE_STYLE); } // ---------------------------------------------------------- private int timeout = TIMEOUT; private int width = 200; private int maxItems = 5; private Canvas parent; private HTMLFlow infoPanel; private List<String> messages = new LinkedList<String>(); private void addMessage(String message, String style) { messages.add("<div class=\"" + style + "\">" + message + "</div>"); // SafeHtmlUtils.htmlEscape(message) if (messages.size() > maxItems) { messages.remove(0); } showInfoPanel(buildHtml()); Timer timer = new Timer() { public void run() { if (messages.size() > 0) { messages.remove(0); } if (messages.size() > 0) { showInfoPanel(buildHtml()); } else { hideInfoPanel(); } } }; timer.schedule(timeout); } private String buildHtml() { String html = ""; for (int i = 0; i < messages.size(); i++) { html += messages.get(i); if (i < (messages.size() - 1)) { html += "<div class=\"infoWindowBreak\"></div>"; } } return html; } private void showInfoPanel(String contents) { if (infoPanel == null) { int left = WidgetLayout.crocEyePositionLeft; int top = WidgetLayout.crocEyePositionTop; infoPanel = new HTMLFlow(contents); infoPanel.setWidth(width); infoPanel.setAutoHeight(); if (parent != null) { infoPanel.setParentElement(parent); } infoPanel.setPosition(Positioning.ABSOLUTE); infoPanel.setShowEdges(true); infoPanel.setEdgeSize(1); infoPanel.setPadding(3); infoPanel.setTop(top); infoPanel.setLeft(left); infoPanel.setBackgroundColor("#FFFFFF"); infoPanel.bringToFront(); infoPanel.setZIndex(2000000); infoPanel.setKeepInParentRect(true); infoPanel.setAnimateTime(500); infoPanel.animateShow(AnimationEffect.FADE); } else { infoPanel.setContents(contents); } infoPanel.bringToFront(); infoPanel.setZIndex(2000000); } private void hideInfoPanel() { if (infoPanel != null) { infoPanel.animateFade(0, new AnimationCallback() { public void execute(boolean earlyFinish) { HTMLFlow temp = infoPanel; infoPanel = null; temp.destroy(); } }); } } // ---------------------------------------------------------- /** * Set the timeout, how long the message is displayed. */ public int getTimeout() { return timeout; } /** * Get the timeout, how long the message is displayed. */ public void setTimeout(int timeout) { this.timeout = timeout; } /** * Hook the croceye to a parent widget. */ public void init(Canvas parent) { this.parent = parent; } /** * Get the width of the croceye. */ public int getWidth() { return width; } /** * Set the width of the croceye. */ public void setWidth(int width) { this.width = width; } /** * Get the maximum messages displayed. */ public int getMaxItems() { return maxItems; } /** * Set the maximum messages displayed. */ public void setMaxItems(int maxItems) { this.maxItems = maxItems; } @Override public void execute(CommandResponse response) { } }