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Diffstat (limited to 'src/com/itmill/toolkit/demo/features/FeatureServerEvents.java')
| -rw-r--r-- | src/com/itmill/toolkit/demo/features/FeatureServerEvents.java | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/src/com/itmill/toolkit/demo/features/FeatureServerEvents.java b/src/com/itmill/toolkit/demo/features/FeatureServerEvents.java new file mode 100644 index 0000000000..cdf371a91d --- /dev/null +++ b/src/com/itmill/toolkit/demo/features/FeatureServerEvents.java @@ -0,0 +1,132 @@ +/* ************************************************************************* + + IT Mill Toolkit + + Development of Browser User Intarfaces Made Easy + + Copyright (C) 2000-2006 IT Mill Ltd + + ************************************************************************* + + This product is distributed under commercial license that can be found + from the product package on license/license.txt. Use of this product might + require purchasing a commercial license from IT Mill Ltd. For guidelines + on usage, see license/licensing-guidelines.html + + ************************************************************************* + + For more information, contact: + + IT Mill Ltd phone: +358 2 4802 7180 + Ruukinkatu 2-4 fax: +358 2 4802 7181 + 20540, Turku email: info@itmill.com + Finland company www: www.itmill.com + + Primary source for information and releases: www.itmill.com + + ********************************************************************** */ + +package com.itmill.toolkit.demo.features; + +import java.net.MalformedURLException; +import java.net.URL; + +import com.itmill.toolkit.terminal.ExternalResource; +import com.itmill.toolkit.ui.*; + +public class FeatureServerEvents extends Feature { + + protected String getTitle() { + return "Server Events"; + } + + protected Component getDemoComponent() { + OrderedLayout l = new OrderedLayout(); + + l.addComponent( + new Label( + "<h3>Multiplayer GO-Game</h3><p>For demonstration, see GO-Game example application. The application implements a " + + "multi-player board game, where the moved by one player are immediately reflected to " + + "another player.</p>" + + "<p>Updating another players screen is totally automatic, and the programmed " + + "does not need to be avare when the refresh requests are sent to screen by the server. In " + + "web adapter the requests are passed through open HTTP-connection as java-script fragments " + + "that update the windows that need repainting.</p>", + Label.CONTENT_UIDL)); + + URL goUrl = null; + try { + goUrl = new URL(getApplication().getURL(), "../go/"); + } catch (MalformedURLException e) { + } + + if (goUrl != null) { + Link link = new Link("Start GO-Game", new ExternalResource(goUrl)); + link.setTargetName("gogame"); + link.setTargetBorder(Link.TARGET_BORDER_NONE); + l.addComponent(link); + } + + l.addComponent( + new Label( + "<h3>Chat example</h3><p>For some purposes it might be better to create your own "+ + "stream. The easiest way of creating a continuous stream for "+ + "simple purposes is to use StreamResource-class. See chat "+ + "example below, how this technique can be used for creation "+ + "of simple chat program.</p>", + Label.CONTENT_UIDL)); + + URL chatUrl = null; + try { + chatUrl = new URL(getApplication().getURL(), "../chat/"); + } catch (MalformedURLException e) { + } + + if (goUrl != null) { + Link link = new Link("Start chat", new ExternalResource(chatUrl)); + link.setTargetName("chat"); + link.setTargetBorder(Link.TARGET_BORDER_NONE); + l.addComponent(link); + } + + return l; + } + + protected String getDescriptionXHTML() { + return "<p>Millstone component framework supports both transactional and " + + "continuous terminals. This means that either the events from the " + + "terminal are sent together as transactions or the events are " + + "passed immediately when the user initiates them through the user " + + "interface. </p>" + + "<p>WebAdapter converts the Millstone applications to web-environment " + + "by transferring the events as HTTP-parameters and drawing the " + + "pages after the components have received and handled the events. " + + "In the web-environment the web browser is always the active party that " + + "starts the transaction. This is problematic when the server should " + + "notify the user about changes without HTTP-request initiated by the " + + "user.</p>" + + "<h3>WebAdapter Solution</h3>" + + "<p>Millstone solves the problem by combining component frameworks " + + "ability to automatically notify terminal adapter about all visual " + + "changes to HTTP-protocols ability to handle very long and slow " + + "page downloads. WebAdapter provides the web browser with " + + "possibility to keep special server command stream open all the time. " + + "All the visual updates that happen in components causes the " + + "WebAdapter to automatically creates JavaScript that updates the " + + "corresponding web browser window and to send the script immediately " + + "to browser for execution.</p>" + + "<p>The mechanism is fairly complicated, but using the mechanism in " + + "any Millstone application is trivial. Application just needs " + + "to make sure that WebBrowser opens a hidden iframe to location: " + + "<code>?SERVER_COMMANDS=1</code>.</p>" + + "<p>See the example of the usage on Demo-tab to get better understanding " + + "of the mechanism. If you read the example's source code, you will notice that " + + "the program does not contain any support for sending events to client, as " + + "it is completely automatic.</p>"; + } + + protected String getImage() { + return "serverevents.jpg"; + } + +} |