Move to Commons Base

[lgpl/argeo-commons.git] / base / runtime / org.argeo.eclipse.ui.rap / src / main / java / org / argeo / eclipse / ui / specific / FileHandler.java

diff --git a/base/runtime/org.argeo.eclipse.ui.rap/src/main/java/org/argeo/eclipse/ui/specific/FileHandler.java b/base/runtime/org.argeo.eclipse.ui.rap/src/main/java/org/argeo/eclipse/ui/specific/FileHandler.java
new file mode 100644 (file)
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+++ b/base/runtime/org.argeo.eclipse.ui.rap/src/main/java/org/argeo/eclipse/ui/specific/FileHandler.java
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+/*
+ * Copyright (C) 2007-2012 Mathieu Baudier
+ *
+ * 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 org.argeo.eclipse.ui.specific;
+
+import java.net.URL;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.eclipse.rwt.RWT;
+import org.eclipse.rwt.service.IServiceHandler;
+import org.eclipse.rwt.service.IServiceManager;
+import org.eclipse.ui.PlatformUI;
+
+/**
+ * RAP SPECIFIC handler to enable the opening of a download dialog box triggered
+ * by whatever action in the UI
+ * 
+ * Manages the registration of the effective DownloadServiceHandler at
+ * instantiation time.
+ * 
+ * Manages the process of forwarding the request to the handler at runtime to
+ * open the dialog box
+ * 
+ */
+public class FileHandler {
+       public final static String FORCED_DOWNLOAD_URL_BASE_PROPERTY = "argeo.rap.specific.forcedDownloadUrlBase";
+
+       private final static Log log = LogFactory.getLog(FileHandler.class);
+
+       public FileHandler(FileProvider provider) {
+               // Instantiate and register the DownloadServicHandler.
+               IServiceManager manager = RWT.getServiceManager();
+               IServiceHandler handler = new DownloadServiceHandler(provider);
+               manager.registerServiceHandler("downloadServiceHandler", handler);
+       }
+
+       public void openFile(String fileName, String fileId) {
+
+               // See RAP FAQ:
+               // http://wiki.eclipse.org/RAP/FAQ#How_to_provide_download_link.3F
+               // And forum discussion :
+               // http://www.eclipse.org/forums/index.php?t=msg&th=205487&start=0&S=43d85dacc88b505402420592109c7240
+
+               try {
+                       if (log.isTraceEnabled())
+                               log.trace("URL : " + createFullDownloadUrl(fileName, fileId));
+
+                       URL url = new URL(createFullDownloadUrl(fileName, fileId));
+                       PlatformUI.getWorkbench().getBrowserSupport()
+                                       .createBrowser("DownloadDialog").openURL(url);
+               } catch (Exception e) {
+                       e.printStackTrace();
+               }
+
+               // These lines are useless in the current use case but might be
+               // necessary with new browsers. Stored here for memo
+               // response.setContentType("application/force-download");
+               // response.setHeader("Content-Disposition", contentDisposition);
+               // response.setHeader("Content-Transfer-Encoding", "binary");
+               // response.setHeader("Pragma", "no-cache");
+               // response.setHeader("Cache-Control", "no-cache, must-revalidate");
+       }
+
+       private String createFullDownloadUrl(String fileName, String fileId) {
+               StringBuilder url = new StringBuilder();
+               // in case RAP is proxied we need to specify the actual base URL
+               // TODO find a cleaner way
+               String forcedDownloadUrlBase = System
+                               .getProperty(FORCED_DOWNLOAD_URL_BASE_PROPERTY);
+               if (forcedDownloadUrlBase != null)
+                       url.append(forcedDownloadUrlBase);
+               else
+                       url.append(RWT.getRequest().getRequestURL());
+               url.append(createParamUrl(fileName, fileId));
+               return url.toString();
+       }
+
+       private String createParamUrl(String filename, String fileId) {
+               StringBuilder url = new StringBuilder();
+               url.append("?");
+               url.append(IServiceHandler.REQUEST_PARAM);
+               url.append("=downloadServiceHandler");
+               url.append("&filename=");
+               url.append(filename);
+               url.append("&fileid=");
+               url.append(fileId);
+               String encodedURL = RWT.getResponse().encodeURL(url.toString());
+               return encodedURL;
+       }
+}