Start adding support for drag and drop and multi attachment upload

git-svn-id: https://svn.research-infrastructures.eu/d4science/gcube/trunk/portlets/user/share-updates@122210 82a268e6-3cf1-43bd-a215-b396298e98cf

.settings/com.google.gdt.eclipse.core.prefs

@@ -1,5 +1,5 @@
 eclipse.preferences.version=1
 jarsExcludedFromWebInfLib=
-lastWarOutDir=/Users/massi/Documents/workspace/share-updates/target/share-updates-1.6.1-SNAPSHOT
+lastWarOutDir=/home/costantino/workspace/share-updates/target/share-updates-1.8.2-SNAPSHOT
 warSrcDir=src/main/webapp
 warSrcDirIsOutput=false

.settings/org.eclipse.wst.common.component

@@ -4,10 +4,7 @@
     <wb-resource deploy-path="/" source-path="/src/main/webapp" tag="defaultRootSource"/>
     <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/>
         <wb-resource deploy-path="/WEB-INF/classes" source-path="/target/generated-sources/gwt"/>
-        <dependent-module archiveName="gcube-widgets-1.9.1-SNAPSHOT.jar" deploy-path="/WEB-INF/lib" handle="module:/resource/gcube-widgets/gcube-widgets">
+        <dependent-module archiveName="fileupload-progress-bar-1.3.0-SNAPSHOT.jar" deploy-path="/WEB-INF/lib" handle="module:/resource/fileupload-progress-bar/fileupload-progress-bar">
-            <dependency-type>uses</dependency-type>
-        </dependent-module>
-        <dependent-module archiveName="pickitem-widget-1.1.0-SNAPSHOT.jar" deploy-path="/WEB-INF/lib" handle="module:/resource/pickitem-widget/pickitem-widget">
             <dependency-type>uses</dependency-type>
         </dependent-module>
         <dependent-module archiveName="fileupload-progress-bar-1.3.0-SNAPSHOT.jar" deploy-path="/WEB-INF/lib" handle="module:/resource/fileupload-progress-bar/fileupload-progress-bar">

pom.xml

@@ -48,6 +48,11 @@
 		</dependencies>
 	</dependencyManagement>
 	<dependencies>
+		<dependency>
+			<groupId>xerces</groupId>
+			<artifactId>xercesImpl</artifactId>
+			<version>2.9.1</version>
+		</dependency>
 		<dependency>
 			<groupId>com.google.gwt</groupId>
 			<artifactId>gwt-user</artifactId>

src/main/java/org/gcube/portlets/user/shareupdates/client/ShareUpdates.java

@@ -4,16 +4,33 @@ import org.gcube.portlets.user.gcubewidgets.client.ClientScopeHelper;
 import org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm;
 
 import com.google.gwt.core.client.EntryPoint;
+import com.google.gwt.core.client.ScriptInjector;
+import com.google.gwt.core.shared.GWT;
 import com.google.gwt.user.client.Window.Location;
 import com.google.gwt.user.client.rpc.AsyncCallback;
 import com.google.gwt.user.client.ui.RootPanel;
 
 /**
  * Entry point classes define <code>onModuleLoad()</code>.
+ * @author Massimiliano Assante at ISTI CNR
+ * @author Costantino Perciante at ISTI CNR
  */
 public class ShareUpdates implements EntryPoint {
 
 	public void onModuleLoad() {
+
+		// check if jQuery is available
+		boolean jQueryLoaded = isjQueryLoaded();
+
+		if(jQueryLoaded)
+			GWT.log("Injecting : http://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js");
+		else{
+			ScriptInjector.fromUrl("http://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js")
+			.setWindow(ScriptInjector.TOP_WINDOW)
+			.inject();
+		}
+
+		// start UI and related stuff
 		ClientScopeHelper.getService().setScope(Location.getHref(), new AsyncCallback<Boolean>() {
 			@Override
 			public void onSuccess(Boolean result) {
@@ -24,4 +41,15 @@ public class ShareUpdates implements EntryPoint {
 			}
 		});
 	}
+
+	/**
+	 * Checks if jQuery is loaded.
+	 *
+	 * @return true, if jQuery is loaded, false otherwise
+	 */
+	private native boolean isjQueryLoaded() /*-{
+
+		return (typeof $wnd['jQuery'] !== 'undefined');
+
+	}-*/;
 }

src/main/java/org/gcube/portlets/user/shareupdates/client/view/AttachedFile.java

@@ -0,0 +1,50 @@
+package org.gcube.portlets.user.shareupdates.client.view;
+
+public class AttachedFile {
+	
+	private String fileName;
+	private String fileAbsolutePathOnServer;
+	private AttachmentPreviewer atPrev;
+	private boolean correctlyUploaded;
+	
+	/**
+	 * 
+	 * @param fileName name of the file
+	 * @param fileAbsolutePathOnServer path on the server 
+	 * @param atPrev object that shows such attachment
+	 * @param uploaded has been it correctly uploaded on the server?
+	 */
+	public AttachedFile(String fileName, String fileAbsolutePathOnServer,
+			AttachmentPreviewer atPrev, boolean uploaded) {
+		super();
+		this.fileName = fileName;
+		this.fileAbsolutePathOnServer = fileAbsolutePathOnServer;
+		this.atPrev = atPrev;
+		this.correctlyUploaded = uploaded;
+	}
+	public String getFileName() {
+		return fileName;
+	}
+	public void setFileName(String fileName) {
+		this.fileName = fileName;
+	}
+	public String getFileAbsolutePathOnServer() {
+		return fileAbsolutePathOnServer;
+	}
+	public void setFileAbsolutePathOnServer(String fileAbsolutePathOnServer) {
+		this.fileAbsolutePathOnServer = fileAbsolutePathOnServer;
+	}
+	public AttachmentPreviewer getAtPrev() {
+		return atPrev;
+	}
+	public void setAtPrev(AttachmentPreviewer atPrev) {
+		this.atPrev = atPrev;
+	}
+	public boolean isCorrectlyUploaded() {
+		return correctlyUploaded;
+	}
+	public void setCorrectlyUploaded(boolean correctlyUploaded) {
+		this.correctlyUploaded = correctlyUploaded;
+	}
+	
+}

src/main/java/org/gcube/portlets/user/shareupdates/client/view/AttachmentPreviewer.java

@@ -0,0 +1,126 @@
+package org.gcube.portlets.user.shareupdates.client.view;
+
+import com.google.gwt.core.client.GWT;
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.uibinder.client.UiBinder;
+import com.google.gwt.uibinder.client.UiField;
+import com.google.gwt.uibinder.client.UiHandler;
+import com.google.gwt.user.client.Window;
+import com.google.gwt.user.client.ui.Composite;
+import com.google.gwt.user.client.ui.HTML;
+import com.google.gwt.user.client.ui.Image;
+import com.google.gwt.user.client.ui.Label;
+import com.google.gwt.user.client.ui.Widget;
+
+public class AttachmentPreviewer extends Composite {	
+
+	private static AttachmentPreviewerUiBinder uiBinder = GWT
+			.create(AttachmentPreviewerUiBinder.class);
+
+	interface AttachmentPreviewerUiBinder extends
+	UiBinder<Widget, AttachmentPreviewer> {
+	}
+
+	public AttachmentPreviewer() {
+		initWidget(uiBinder.createAndBindUi(this));
+	}
+	
+	private static final String DELETE_ATTACHMENT = "The attachment won't be saved. Would you like to continue?";
+
+	@UiField 
+	HTML deleteAttachment;
+
+	@UiField
+	Image imagePreview;
+
+	@UiField
+	Label fileName;
+
+	@UiField
+	Label resultLabel;
+
+	@UiField
+	Image resultImage;
+	
+	// Parent of this AttachmentPreviewer object
+	private Placeholder parent;
+	
+	// the ShareUpdateForm 
+	private ShareUpdateForm shareUpdateForm;
+	
+	public AttachmentPreviewer(String fileName, String urlImagePreview, Placeholder parent, ShareUpdateForm shareUpdateForm) {
+
+		initWidget(uiBinder.createAndBindUi(this));
+
+		// set filename and temp attachment url
+		this.fileName.setText(fileName);
+		this.imagePreview.setUrl(urlImagePreview);
+
+		// style the delete button
+		this.deleteAttachment.setStyleName("su-deleteAttachment");
+		this.deleteAttachment.setTitle("Cancel");
+		
+		// save parent
+		this.parent = parent;
+		
+		// save the shareUpdateForm object, since it maintains the list of attached files
+		this.shareUpdateForm = shareUpdateForm;
+	}
+
+	@UiHandler("deleteAttachment")
+	void onClick(ClickEvent e) {
+		
+		// alert the user
+		boolean confirm = Window.confirm(DELETE_ATTACHMENT);
+
+		if(!confirm)
+			return;
+		
+		// we have to remove the AttachmentPreview object (that is, this object) and
+		// remove the file from the List of AttachedFiles
+		parent.remove(this);
+		shareUpdateForm.removeAttachedFile(this);
+		
+	}
+
+	/**
+	 * set the label and the that shows if the file has been saved or not 
+	 * @param result
+	 * @param urlImageResult
+	 */
+	public void setResultAttachment(String result, String urlImageResult){
+		this.resultLabel.setText(result);
+		this.resultImage.setUrl(urlImageResult);
+	}
+
+	/**
+	 * Change the image preview of the attachment from the default one
+	 * @param urlImagePreview
+	 */
+	public void setImagePreview(String urlImagePreview){
+		this.imagePreview.setUrl(urlImagePreview);
+	}
+
+	/**
+	 * Change style of part of this object to allow the user to retry to upload the file
+	 * @param tooltip
+	 * @param retryToAttachImageUrl
+	 */
+	public void setImagePreviewToRetry(String tooltip, String retryToAttachImageUrl) {
+		
+		this.imagePreview.setUrl(retryToAttachImageUrl);
+		this.imagePreview.setTitle(tooltip);
+		
+		// add the handler on the icon
+		this.imagePreview.addClickHandler(new ClickHandler() {
+			
+			@Override
+			public void onClick(ClickEvent event) {
+				Window.alert("Retry to attach handler to be implemented...");
+			}
+		});
+		
+	}
+
+}

src/main/java/org/gcube/portlets/user/shareupdates/client/view/AttachmentPreviewer.ui.xml

@@ -0,0 +1,48 @@
+<!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
+<ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
+	xmlns:g="urn:import:com.google.gwt.user.client.ui">
+	<ui:style>
+	.image-preview {
+		align: left;
+		margin-right: 5px;
+		margin-left: 2px;
+		display: inline;
+		margin-top: 5px;
+		height: 40px;
+	}
+	
+	.attach-result {
+		vertical-align: top;
+		display: inline-block;
+		font-size: 10px;
+		font-weight: bold;
+	}
+	
+	.image-result {
+		margin-left: 4px;
+		width: 10px;
+		vertical-align: middle;
+	}
+	
+	.container-style {
+		border-style: solid;
+		background-color: #DCDCDC;
+		border-width: thin;
+		margin-left: 30px;
+		margin-top: 1px;
+		width: 565px;
+	}
+
+	</ui:style>
+	<g:HTMLPanel styleName="{style.container-style}">
+		<g:Image styleName="{style.image-preview}" ui:field="imagePreview"></g:Image>
+		<g:VerticalPanel styleName="{style.attach-result}">
+			<g:Label ui:field="fileName"></g:Label>
+			<g:HorizontalPanel ui:field="attachmentResult">
+				<g:Label ui:field="resultLabel"></g:Label>
+				<g:Image styleName="{style.image-result}" ui:field="resultImage"></g:Image>
+			</g:HorizontalPanel>
+		</g:VerticalPanel>
+		<g:HTML ui:field="deleteAttachment"></g:HTML>
+	</g:HTMLPanel>
+</ui:UiBinder> 

src/main/java/org/gcube/portlets/user/shareupdates/client/view/LinkPreviewer.java

@@ -26,8 +26,6 @@ public class LinkPreviewer extends Composite {
 	
 	private LinkPreview toShow;
 	
-	private SaveInWorkspaceBox saveCopy;
-	
 	private boolean showImage = true;
 	
 	@UiField 
@@ -44,10 +42,8 @@ public class LinkPreviewer extends Composite {
 	CheckBox hideCheckBox;
 	@UiField
 	CheckBox hideImageCheckBox;
-	@UiField
-	Placeholder uploadInWS;
 
-	public LinkPreviewer(ShareUpdateForm parent, LinkPreview toShow, boolean isFilePreview) {
+	public LinkPreviewer(ShareUpdateForm parent, LinkPreview toShow) {
 		initWidget(uiBinder.createAndBindUi(this));
 		closeImage.setStyleName("su-closeImage");
 		closeImage.setTitle("Cancel");
@@ -67,10 +63,6 @@ public class LinkPreviewer extends Composite {
 		urlText.setHTML((url.length() > 80) ? url.substring(0, 80)+"..." : url);
 		
 		switcher.setImages(toShow.getImageUrls());
-		if (isFilePreview) {
-			saveCopy = new SaveInWorkspaceBox();
-			uploadInWS.add(saveCopy);
-		} 
 	}
 
 	public ImageSwitcher getSwitcher() {
@@ -79,7 +71,7 @@ public class LinkPreviewer extends Composite {
 	
 	@UiHandler("closeImage") 
 	void onDeleteFeedClick(ClickEvent e) {
-		parent.cancelPreview();
+		parent.cancelLinkPreview();
 	}	
 	
 	@UiHandler("hideImageCheckBox") 
@@ -109,10 +101,4 @@ public class LinkPreviewer extends Composite {
 			return null;
 		return switcher.getSelectedImageURL();
 	}
-	protected boolean isSharingFile() {
-		return (saveCopy != null);
-	}
-	protected boolean isSaveCopySelected() {
-		return isSharingFile() ? saveCopy.getValue() : false;		
-	}
 }

src/main/java/org/gcube/portlets/user/shareupdates/client/view/Placeholder.java

@@ -1,11 +1,13 @@
 package org.gcube.portlets.user.shareupdates.client.view;
 
-import com.google.gwt.user.client.ui.SimplePanel;
+
+import com.google.gwt.user.client.ui.VerticalPanel;
 /**
- * 
+ * This panel will contain the attachments/previews
- * @author massi
+ * @author Massimiliano Assante at ISTI CNR
+ * @author Costantino Perciante at ISTI CNR
  *
  */
-public class Placeholder extends SimplePanel {
+public class Placeholder extends VerticalPanel {
 
 }

src/main/java/org/gcube/portlets/user/shareupdates/client/view/ShareUpdateForm.java

@@ -1,6 +1,8 @@
 package org.gcube.portlets.user.shareupdates.client.view;
 
 import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
 
 import net.eliasbalasis.tibcopagebus4gwt.client.PageBusAdapter;
 import net.eliasbalasis.tibcopagebus4gwt.client.PageBusAdapterException;
@@ -16,17 +18,24 @@ import org.gcube.portlets.user.shareupdates.shared.LinkPreview;
 import org.gcube.portlets.user.shareupdates.shared.UserSettings;
 import org.gcube.portlets.widgets.fileupload.client.events.FileUploadCompleteEvent;
 import org.gcube.portlets.widgets.fileupload.client.events.FileUploadCompleteEventHandler;
+import org.gcube.portlets.widgets.fileupload.client.view.FileSubmit;
 import org.gcube.portlets.widgets.fileupload.client.view.UploadProgressPanel;
 import org.jsonmaker.gwt.client.Jsonizer;
 
+import com.github.gwtbootstrap.client.ui.Button;
 import com.google.gwt.core.client.GWT;
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
+import com.google.gwt.dom.client.Style.BorderStyle;
 import com.google.gwt.dom.client.Style.Display;
+import com.google.gwt.dom.client.Style.FontWeight;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.dom.client.Style.Visibility;
 import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.event.dom.client.DragLeaveEvent;
+import com.google.gwt.event.dom.client.DragLeaveHandler;
+import com.google.gwt.event.dom.client.DragOverEvent;
+import com.google.gwt.event.dom.client.DragOverHandler;
 import com.google.gwt.event.shared.HandlerManager;
 import com.google.gwt.uibinder.client.UiBinder;
 import com.google.gwt.uibinder.client.UiFactory;
@@ -34,67 +43,84 @@ import com.google.gwt.uibinder.client.UiField;
 import com.google.gwt.uibinder.client.UiHandler;
 import com.google.gwt.user.client.Window;
 import com.google.gwt.user.client.rpc.AsyncCallback;
-import com.github.gwtbootstrap.client.ui.Button;
 import com.google.gwt.user.client.ui.Composite;
 import com.google.gwt.user.client.ui.FileUpload;
-import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.HTMLPanel;
-import com.google.gwt.user.client.ui.HasAlignment;
-import com.google.gwt.user.client.ui.HorizontalPanel;
 import com.google.gwt.user.client.ui.Image;
 import com.google.gwt.user.client.ui.ListBox;
+import com.google.gwt.user.client.ui.ValueBoxBase.TextAlignment;
 import com.google.gwt.user.client.ui.Widget;
 /**
  * 	
- * @author Massimiliano Assante
+ * @author Massimiliano Assante at ISTI CNR
+ * @author Costantino Perciante at ISTI CNR
  *
  */
 public class ShareUpdateForm extends Composite {
-	/**
+
-	 * Create a remote service proxy to talk to the server-side Greeting service.
+	//Create a remote service proxy to talk to the server-side Greeting service.
-	 */
 	private final ShareUpdateServiceAsync shareupdateService = GWT
 			.create(ShareUpdateService.class);
 
 	final PageBusAdapter pageBusAdapter = new PageBusAdapter();
+
 	// the label for all Vres/channels
 	private final static String ALL_VRES = "Share with: your Virtual Research Environments";
 
+	// Labels
 	protected final static String SHARE_UPDATE_TEXT = "Share an update or a link, use “@” to mention and “#” to add a topic";
 	protected final static String ERROR_UPDATE_TEXT = "Looks like empty to me!";
 	public final static String NO_TEXT_FILE_SHARE = "_N0_73X7_SH4R3_";
 	private final static String LISTBOX_LEVEL = " - ";
+	public static final String DROP_FILE_HERE_TEXT  = "Drop your file(s) here!";
+	public static final String ATTACHMENT_LOADED = "Attachment loaded!";
+	public static final String ATTACHMENT_NOT_LOADED = "Attachment not loaded!";
+	private static final String RETRY_TO_ATTACH_MESSAGE = "Retry to attach this file";
+	private static final String DELETE_LINK_PREVIEW = "The link preview will be removed. Would you like to continue?";
+	private static final String DELETE_ATTACHMENTS = "The attachment(s) will be removed. Would you like to continue?";
 
-
+	// image urls
 	public static final String loading = GWT.getModuleBaseURL() + "../images/avatarLoader.gif";
 	public static final String avatar_default = GWT.getModuleBaseURL() + "../images/Avatar_default.png";
 	public static final String attach = GWT.getModuleBaseURL() + "../images/attach.png";
+	public static final String attachedDefault = GWT.getModuleBaseURL() + "../images/attachment_default.png";
+	public static final String loadedAttachment = GWT.getModuleBaseURL() + "../images/load.png";
+	public static final String notLoadedAttachment = GWT.getModuleBaseURL() + "../images/not_load.png";
+	public static final String retryToAttach = GWT.getModuleBaseURL() + "../images/reload.png";
 
-	/**
+	// maximum number of files that can be attached!
-	 * needed to know where to find the (possible) uploaded file 
+	private static final int MAX_NUMBER_ATTACHMENTS = 10;
-	 */
+
-	private String uploadedFilePathOnServer;
+	// remember the previous text in the textarea (while handling drag and drop)
-	private String uploadedFileNameOnServer;
+	private static String previousText;
+
+	// list of attachedFiles (both correctly or not correctly uploaded)
+	private List<AttachedFile> listOfAttachedFiles = new ArrayList<>();
 
 	private HandlerManager eventBus = new HandlerManager(null);
 
 	private static ShareUpdateFormUiBinder uiBinder = GWT
 			.create(ShareUpdateFormUiBinder.class);
 
+	// The link previewer
 	private LinkPreviewer myLinkPreviewer;
 
+	// panel that show the in progress upload of an attachment
 	private UploadProgressPanel uploadProgress;
 
 	interface ShareUpdateFormUiBinder extends UiBinder<Widget, ShareUpdateForm> {
 	}
 
+	// this instance
 	private static ShareUpdateForm singleton;
 
 	public static ShareUpdateForm get() {
 		return singleton;
 	}
+
 	@UiField
 	HTMLPanel mainPanel;
+
 	@UiField
 	Placeholder preview;
 
@@ -107,7 +133,8 @@ public class ShareUpdateForm extends Composite {
 	@UiField
 	Image avatarImage;
 
-	@UiField SuperPosedTextArea shareTextArea; 
+	@UiField 
+	SuperPosedTextArea shareTextArea; 
 
 	@UiField 
 	ListBox privacyLevel = new ListBox();
@@ -115,23 +142,12 @@ public class ShareUpdateForm extends Composite {
 	@UiField
 	ListBox notifyListbox = new ListBox();
 
+	// requested user's information
 	private UserInfo myUserInfo;
 
-
+	/**
-	private void bind() {
+	 * Constructor
-		/**
+	 */
-		 * get the uploaded file result
-		 */
-		eventBus.addHandler(FileUploadCompleteEvent.TYPE, new FileUploadCompleteEventHandler() {
-			@Override
-			public void onUploadComplete(FileUploadCompleteEvent event) {
-				String absolutePathOnServer = event.getUploadedFileInfo().getAbsolutePath();
-				GWT.log("uploaded on Server here: " + absolutePathOnServer);
-				checkFile(event.getUploadedFileInfo().getFilename(), absolutePathOnServer);
-			}
-		});
-	}
-
 	public ShareUpdateForm() {
 		initWidget(uiBinder.createAndBindUi(this));
 		singleton = this;
@@ -140,9 +156,8 @@ public class ShareUpdateForm extends Composite {
 		shareTextArea.setText(SHARE_UPDATE_TEXT);
 
 		attachButton.getElement().getStyle().setDisplay(Display.INLINE);
-	//	attachButton.setHTML("<span style=\"padding: 5px 1px; background: url('"+attach+"') 50% 50% no-repeat;\">&nbsp;&nbsp;&nbsp;&nbsp;</span>");
 		attachButton.addStyleName("upload-btn-m");
-		
+
 		shareupdateService.getUserSettings(new AsyncCallback<UserSettings>() {
 			public void onFailure(Throwable caught) {
 				avatarImage.setUrl(avatar_default);
@@ -167,9 +182,9 @@ public class ShareUpdateForm extends Composite {
 						privacyLevel.addItem(LISTBOX_LEVEL +  "Share with: " + singleVREName, vreId);						
 					}
 
-				//privacyLevel.addItem("My Connections", PrivacyLevel.CONNECTION.toString());
 				if (myUserInfo.isAdmin())
 					privacyLevel.addItem("Share with: Everyone", PrivacyLevel.PORTAL.toString());
+
 				//change css if deployed in VRE scope
 				if (!userSettings.isInfrastructure()) {
 					mainPanel.addStyleName("framed");	
@@ -184,6 +199,84 @@ public class ShareUpdateForm extends Composite {
 					privacyLevel.setVisible(true);
 				attachButton.setVisible(true);
 				submitButton.setVisible(true);
+
+				// check if DND can be activated and enable it if it's possible
+				if(checkDNDAvailability()){
+
+					// add drag over handler on shareTextArea
+					shareTextArea.addDragOverHandler(new DragOverHandler() {
+
+						@Override
+						public void onDragOver(DragOverEvent event) {
+
+							GWT.log("Drag over handler");
+
+							// save current text (note that the DragOverEvent event can be fired several times)
+							boolean conditionToSave = !shareTextArea.getText().equals(DROP_FILE_HERE_TEXT) &&  !shareTextArea.getText().equals(SHARE_UPDATE_TEXT);
+							previousText =  conditionToSave ? shareTextArea.getText() : previousText;
+
+							// change border properties
+							shareTextArea.getElement().getStyle().setBorderStyle(BorderStyle.DASHED);
+							shareTextArea.getElement().getStyle().setBorderColor("rgba(82, 168, 236, 0.6)");
+							shareTextArea.getElement().getStyle().setBorderWidth(2.5, Unit.PX);
+
+							// change background color
+							shareTextArea.getElement().getStyle().setBackgroundColor("rgba(82, 168, 236, 0.2)");
+
+							// enlarge the window
+							Document.get().getElementById("highlighterContainer").getStyle().setHeight(52, Unit.PX);
+							Document.get().getElementById("highlighter").getStyle().setHeight(52, Unit.PX);
+							Document.get().getElementById("postTextArea").getStyle().setHeight(52, Unit.PX);
+
+							// add "Drop file here" text 
+							shareTextArea.setText(DROP_FILE_HERE_TEXT);
+							shareTextArea.setAlignment(TextAlignment.CENTER);
+							shareTextArea.getElement().getStyle().setFontWeight(FontWeight.BOLD);
+							shareTextArea.getElement().getStyle().setPaddingTop(
+									(Double.parseDouble(shareTextArea.getElement().getStyle().getHeight().replace("px", "")) + 20)/2.0, Unit.PX);
+
+							// set the color of the text if needed to gray
+							if(!previousText.equals(SHARE_UPDATE_TEXT))
+								shareTextArea.getElement().getStyle().setColor("#999"); 
+
+						}
+					});
+
+					// clear drag over effect
+					shareTextArea.addDragLeaveHandler(new DragLeaveHandler() {
+
+						@Override
+						public void onDragLeave(DragLeaveEvent event) {
+
+							GWT.log("Drag leave handler");
+
+							// remove style changes
+							resetTextArea();
+
+						}
+
+					});
+
+					// enable shareTextArea as drop target (using native javascript)
+					addNativeDropHandler(singleton, FileSubmit.URL);
+
+				}
+			}
+		});
+	}
+
+	/**
+	 * Bind events to manage
+	 */
+	private void bind() {
+
+		//get the uploaded file result
+		eventBus.addHandler(FileUploadCompleteEvent.TYPE, new FileUploadCompleteEventHandler() {
+			@Override
+			public void onUploadComplete(FileUploadCompleteEvent event) {
+				String absolutePathOnServer = event.getUploadedFileInfo().getAbsolutePath();
+				GWT.log("uploaded on Server here: " + absolutePathOnServer);
+				checkFile(event.getUploadedFileInfo().getFilename(), absolutePathOnServer);
 			}
 		});
 	}
@@ -208,15 +301,28 @@ public class ShareUpdateForm extends Composite {
 
 	@UiHandler("attachButton")
 	void onAttachClick(ClickEvent e) {	
-		if (myLinkPreviewer == null) {
+
-			FileUpload up = uploadProgress.initialize();
+		// check if there is a linkpreview
-			up.setVisible(false);
+		if(myLinkPreviewer != null){
-			fileBrowse(up.getElement());
+
-			uploadProgress.setVisible(true);			
+			// in this case let the user choose what to do
-		} else {
+			boolean confirm = Window.confirm(DELETE_LINK_PREVIEW);
-			Window.alert("You cannot post two files, please remove the previous one first.");
+
+			if(!confirm)
+				return;
+
+			// remove preview
+			cancelLinkPreview();
 		}
+
+		// proceed with the upload
+		FileUpload up = uploadProgress.initialize();
+		up.setVisible(false);
+		fileBrowse(up.getElement());
+		uploadProgress.setVisible(true);
+
 	}
+
 	/**
 	 * this simulates the click on the hidden native GWT FileUpload Button
 	 * @param el
@@ -228,7 +334,10 @@ public class ShareUpdateForm extends Composite {
 
 	@UiHandler("submitButton")
 	void onClick(ClickEvent e) {	
-		attachButton.getElement().getStyle().setVisibility(Visibility.VISIBLE); //beacuse otherwise it looses the other properties setting
+
+		//because otherwise it looses the other properties setting
+		attachButton.getElement().getStyle().setVisibility(Visibility.VISIBLE); 
+
 		shareupdateService.getUserSettings(new AsyncCallback<UserSettings>() {
 			public void onFailure(Throwable caught) {
 				Window.alert("Ops! we encountered some problems delivering your message, server is not responding, please try again in a short while.");
@@ -242,7 +351,7 @@ public class ShareUpdateForm extends Composite {
 				String toShare = shareTextArea.getText().trim();
 
 				//We allow to post a file without writing nothing in the sharing textarea
-				if (myLinkPreviewer != null && myLinkPreviewer.isSharingFile() && (toShare.equals(SHARE_UPDATE_TEXT) || toShare.equals(ERROR_UPDATE_TEXT) || toShare.equals("")) ) {
+				if (myLinkPreviewer != null && (toShare.equals(SHARE_UPDATE_TEXT) || toShare.equals(ERROR_UPDATE_TEXT) || toShare.equals("")) ) {
 					toShare = NO_TEXT_FILE_SHARE;
 				}
 				if (toShare.equals(SHARE_UPDATE_TEXT) || toShare.equals(ERROR_UPDATE_TEXT) || toShare.equals("")) {
@@ -284,10 +393,11 @@ public class ShareUpdateForm extends Composite {
 			linkUrl = myLinkPreviewer.getUrl();
 			linkUrlThumbnail = myLinkPreviewer.getUrlThumbnail();
 			linkHost = myLinkPreviewer.getHost();
-			if (myLinkPreviewer.isSaveCopySelected()) {
+			// TODO handle attachments
-				fileName = uploadedFileNameOnServer;
+			//			if (myLinkPreviewer.isSaveCopySelected()) {
-				filePath = uploadedFilePathOnServer;
+			//				fileName = uploadedFileNameOnServer;
-			}
+			//				filePath = uploadedFilePathOnServer;
+			//			}
 		}
 		LinkPreview preview2Share = new LinkPreview(linkTitle, linkDescription, linkUrl, linkHost, null);
 		boolean notifyGroup = notifyListbox.getSelectedIndex() > 0;  
@@ -362,6 +472,22 @@ public class ShareUpdateForm extends Composite {
 			// Attempt to convert each item into an URL.   
 			for( String item : parts ) {
 				if (item.startsWith("http") || item.startsWith("www")) {
+
+					// check if there are attachments and inform the user that they will be lost
+					if(!listOfAttachedFiles.isEmpty()){
+
+						// in this case let the user to choose what to do
+						boolean confirm = Window.confirm(DELETE_ATTACHMENTS);
+
+						if(!confirm)
+							return;
+
+						// else... remove attachments and continue
+						listOfAttachedFiles.clear();
+						preview.clear();
+
+					}
+
 					preview.add(new LinkLoader());
 					submitButton.setEnabled(false);
 					//GWT.log("It's http link:" + linkToCheck);
@@ -374,7 +500,7 @@ public class ShareUpdateForm extends Composite {
 						public void onSuccess(LinkPreview result) {
 							preview.clear();
 							if (result != null) 
-								addPreview(result, false);
+								addPreviewLink(result);
 							submitButton.setEnabled(true);
 						}
 					});
@@ -393,14 +519,26 @@ public class ShareUpdateForm extends Composite {
 	 * @param absolutePathOnServer the path of the file ending with its name on the server temp
 	 */
 	protected void checkFile(final String fileName, final String absolutePathOnServer) {		
-		preview.add(new LinkLoader());
+
+		// create temp view of the attached file and add to the previewer
+		final AttachmentPreviewer atPrev = new AttachmentPreviewer(fileName, attachedDefault, preview, this);
+		preview.add(atPrev);
+		
+		// disable the submit button till we know the result of the upload process
 		submitButton.setEnabled(false);
+
 		shareupdateService.checkUploadedFile(fileName, absolutePathOnServer, new AsyncCallback<LinkPreview>() {
 			public void onFailure(Throwable caught) {
-				GWT.log("Failed");
+				GWT.log("Upload of the file failed!");
 				uploadProgress.showRegisteringResult(false);
-				preview.clear();
+				uploadProgress.setVisible(false);
+
+				addPreviewAttachment(null, atPrev);
+				listOfAttachedFiles.add(new AttachedFile(fileName, absolutePathOnServer, atPrev, false));
 				submitButton.setEnabled(true);
+
+				/*preview.clear();
+
 				final HorizontalPanel hp = new HorizontalPanel();
 				final Button close = new Button("Try Again"); 
 				final HTML reportIssue = new HTML("<a href=\"https://support.d4science.research-infrastructures.eu\" target=\"_blank\">"
@@ -417,24 +555,23 @@ public class ShareUpdateForm extends Composite {
 				hp.setVerticalAlignment(HasAlignment.ALIGN_MIDDLE);
 				hp.add(close);				
 				hp.add(reportIssue);				
-				preview.add(hp);
+				preview.add(hp);*/
 			}
 
-			public void onSuccess(LinkPreview result) {			
+			public void onSuccess(LinkPreview result) {	
-				preview.clear();
+
+				if(result == null)
+					return;
+
 				uploadProgress.setVisible(false);
-				if (result != null) 
+				addPreviewAttachment(result, atPrev);	
-					addPreview(result, true);	
+				listOfAttachedFiles.add(new AttachedFile(fileName, absolutePathOnServer, atPrev, true));
-				attachButton.getElement().getStyle().setVisibility(Visibility.HIDDEN); //beacuse otherwise it looses the other properties setting
-				uploadedFilePathOnServer = absolutePathOnServer;
-				uploadedFileNameOnServer = fileName;
 				submitButton.setEnabled(true);
 
 			}
 		});
 	}
 
-
 	/**
 	 * called when pasting. it tries to avoid pasting long non spaced strings
 	 * @param linkToCheck
@@ -456,17 +593,326 @@ public class ShareUpdateForm extends Composite {
 	 * add the link preview in the view
 	 * @param result
 	 */
-	private void addPreview(LinkPreview result, boolean isFilePreview) {
+	private void addPreviewLink(LinkPreview result) {
+		preview.clear();
 		uploadProgress.setVisible(false);
-		myLinkPreviewer = new LinkPreviewer(this, result, isFilePreview);
+		myLinkPreviewer = new LinkPreviewer(this, result);
 		preview.add(myLinkPreviewer);
 	}
+
+	/**
+	 * Call it to show attachment(s)
+	 */
+	private void addPreviewAttachment(LinkPreview result, AttachmentPreviewer atPrev){
+
+		uploadProgress.setVisible(false);
+
+		// check the result
+		if(result == null){
+			// failed upload
+			atPrev.setResultAttachment(ATTACHMENT_NOT_LOADED, notLoadedAttachment);
+
+			// change the preview image to reload icon to let the user retry 
+			atPrev.setImagePreviewToRetry(RETRY_TO_ATTACH_MESSAGE, retryToAttach);
+		}
+		else{
+			// set the preview information (the first image is the one related to attachments)
+			atPrev.setResultAttachment(ATTACHMENT_LOADED, loadedAttachment);
+			atPrev.setImagePreview(result.getImageUrls().get(0));
+		}
+
+		preview.add(atPrev);
+	}
 	/**
 	 * 
 	 */
-	protected void cancelPreview() {
+	protected void cancelLinkPreview() {
 		preview.clear();
 		myLinkPreviewer = null;
 		attachButton.getElement().getStyle().setVisibility(Visibility.VISIBLE); //beacuse otherwise it looses the other properties setting	
 	}
+
+	/**
+	 * Handle drop of files within shareTextArea (native javascript code)
+	 * @param instance
+	 */
+	private static native void addNativeDropHandler(ShareUpdateForm instance,
+			String servletUrl)/*-{
+
+		console.log("Adding drop handler to text area");
+
+		// retrieve textArea by id
+		var drop = $wnd.$('#postTextArea')[0];			
+		console.log("drop is " + drop);
+
+		// check if this file is a folder
+		function isFolder(file) {
+
+			if (file != null && !file.type && file.size % 4096 == 0) {
+				return true;
+			}
+			return false;
+		}
+
+		// function used to add the handler
+		function addEventHandler(obj, evt, handler) {
+			if (obj.addEventListener) {
+				// W3C method
+				obj.addEventListener(evt, handler, false);
+			} else if (obj.attachEvent) {
+				// IE method.
+				obj.attachEvent('on' + evt, handler);
+			} else {
+				// Old school method.
+				obj['on' + evt] = handler;
+			}
+		}
+
+		// The real drop handler
+		addEventHandler(
+				drop,
+				'drop',
+				function(e) {
+
+					// get window.event if e argument missing (in IE)
+					e = e || window.event; 
+
+					 // stops the browser from redirecting off to the image.
+					if (e.preventDefault) {
+
+						e.preventDefault();
+
+					}
+
+					// opts for the remote call
+					var opts = {
+
+						url : servletUrl,
+						type : "POST",
+						processData : false
+
+					};
+
+					// get the file(s)
+					var dt = e.dataTransfer;
+					var files = dt.files;
+
+					// check limit for number of files 
+					var numberOfAlreadyAttachedFiles = instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::numberOfAttachments()();
+					numberOfAlreadyAttachedFiles += files.length;
+					var limitExceeded = (files.length > @org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::MAX_NUMBER_ATTACHMENTS);
+
+					if(limitExceeded){
+
+						var msg = "Too much files attached!"
+						instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::showAlert(Ljava/lang/String;)(msg);
+						console.log(msg);
+
+						// reset text area
+						instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::resetTextArea()();
+						return;
+					}
+
+					// reset if no file was dropped (??)
+					if (files.length == 0) {
+
+						// reset text area
+						instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::resetTextArea()();
+						return;
+
+					}
+
+					console.log("Number of dropped file(s): " + files.length);
+
+					var numFolder = 0;
+					
+					// save maximum allowed size
+					var maximumSize = @org.gcube.portlets.widgets.fileupload.client.view.FileSubmit::MAX_SIZE_ATTACHED_FILE_MB;
+					
+					// msg for ignored (too big files)
+					var ignoredFilesAlert = " file(s) ignored because larger than " + maximumSize + "MB"; 
+					
+					// number of ignored files
+					var numberIgnoredFiles = 0;
+
+					// for each dropped file
+					for (var i = 0; i < files.length; i++) {
+
+						var file = files[i];
+						var fileSelected = file.name + ";";
+
+						// be sure it is not a folder
+						if (!isFolder(file)) {
+							console.log("filesSelected: " + fileSelected);
+							console.log("files: " + files);
+							
+							// check its size
+							var fileSize = file.size / 1024 / 1024;
+							
+							console.log("File size is " + fileSize);
+							
+							if(fileSize > maximumSize){
+								numberIgnoredFiles ++;
+								continue;
+							}
+
+							// create new progress bar
+							instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::showProgressDND()();
+
+							// create request
+							var xhr = new XMLHttpRequest();
+							xhr.open(opts.type, opts.url, true);
+							var formdata = new FormData(); 
+
+							// append the file
+							formdata.append("fileUpload", file);
+
+							// send data
+							xhr.send(formdata);
+
+							console.log("File " + file.name + " sent at " + servletUrl);
+
+						}else{ 
+
+							// increment the number of skipped folders
+							numFolder++;
+
+						}
+					}
+
+					// alert the user that folder(s) can't be uploaded
+					if(numFolder > 0){
+						var msg;
+
+						if(numFolder == files.length){
+
+							msg = "Sorry but it's not possible to upload a folder!";
+							instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::showAlert(Ljava/lang/String;)(msg);
+
+							// reset text area
+							instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::resetTextArea()();
+							return;
+
+						}
+
+                        // print ignored folders, if any
+						var msg = "Ignored ";
+						msg += numFolder > 1? numFolder+" folders": numFolder+" folder";
+						msg+= " during upload.";
+						console.log(msg);
+						instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::showAlert(Ljava/lang/String;)(msg);
+					}
+					
+					// alert for too large files
+					if(numberIgnoredFiles > 0){
+						var msg = numberIgnoredFiles + ignoredFilesAlert;
+						
+						if(numberIgnoredFiles == files.length){
+
+							msg = file.name + " can't be uploaded since it is too large!";
+							instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::showAlert(Ljava/lang/String;)(msg);
+
+							// reset text area
+							instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::resetTextArea()();
+							return;
+
+						}
+						
+						var msg = numberIgnoredFiles + ignoredFilesAlert;
+						console.log(msg);
+						instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::showAlert(Ljava/lang/String;)(msg);
+					}
+
+					// reset text area
+					instance.@org.gcube.portlets.user.shareupdates.client.view.ShareUpdateForm::resetTextArea()();
+				});
+
+	}-*/;
+
+	/**
+	 * Check if DND could be enabled (i.e, it's supported by the browser)
+	 * @return
+	 */
+	public static native boolean checkDNDAvailability()/*-{
+
+		return window.FileReader;
+
+	}-*/;
+
+	/**
+	 * On dragLeave reset changes on the text area
+	 */
+	private void resetTextArea() {
+
+		// remove border properties
+		shareTextArea.getElement().getStyle().setBorderStyle(BorderStyle.SOLID);
+		shareTextArea.getElement().getStyle().setBorderColor("#333");
+		shareTextArea.getElement().getStyle().setBorderWidth(1, Unit.PX);
+
+		// change back background color
+		shareTextArea.getElement().getStyle().setBackgroundColor("transparent");
+
+		// remove text "Drop file here" and reput the old text
+		shareTextArea.setText(previousText);
+		shareTextArea.setAlignment(TextAlignment.LEFT);
+
+		// rechange text color if needed
+		if(!previousText.equals(DROP_FILE_HERE_TEXT) && !previousText.equals(SHARE_UPDATE_TEXT))
+			shareTextArea.getElement().getStyle().setColor("#333"); 
+
+		// reset padding top
+		shareTextArea.getElement().getStyle().setPaddingTop(4, Unit.PX);
+
+		// reset font weight
+		shareTextArea.getElement().getStyle().setFontWeight(FontWeight.NORMAL);
+	}
+
+	/**
+	 * Alert the user about something.
+	 *
+	 * @param msg the msg to show
+	 */
+	private void showAlert(String msg){
+
+		Window.alert(msg);
+
+	}
+
+	/**
+	 * Show progress bar and start the ProgressController
+	 * @param e
+	 */
+	private void showProgressDND() {	
+		uploadProgress.initializeDND();
+		uploadProgress.setVisible(true);
+	}
+
+	/**
+	 * Remove an attached file from the listOfAttachedFiles
+	 * @param attachmentPreviewer
+	 */
+	public void removeAttachedFile(AttachmentPreviewer attachmentPreviewer) {
+
+		Iterator<AttachedFile> iterator = listOfAttachedFiles.iterator();
+
+		while (iterator.hasNext()) {
+			AttachedFile attachedFile = (AttachedFile) iterator.next();
+			if(attachedFile.getAtPrev().equals(attachedFile)){
+				iterator.remove();
+				return;
+			}
+
+		}
+
+	}
+	
+	/**
+	 * Get the number of attached files
+	 * @return number of attached files
+	 */
+	public int numberOfAttachments(){
+		
+		return listOfAttachedFiles.size();
+		
+	}
 }

src/main/java/org/gcube/portlets/user/shareupdates/shared/LinkPreview.java

@@ -4,6 +4,11 @@ import java.io.Serializable;
 import java.util.ArrayList;
 
 @SuppressWarnings("serial")
+/**
+ * This class is used for link preview (both actual links and attachments)
+ * @author Costantino Perciante at ISTI-CNR
+ *
+ */
 public class LinkPreview implements Serializable {
 	
 	private String title;

src/main/webapp/ShareUpdates.css

@@ -1,4 +1,4 @@
-td > form {
+td>form {
 	margin-top: 5px !important;
 	margin-bottom: 0px !important;
 }
@@ -9,7 +9,7 @@ fieldset {
 }
 
 fieldset .control-group {
-    margin-bottom: 0px;
+	margin-bottom: 0px;
 }
 
 fieldset select {
@@ -135,7 +135,7 @@ fieldset select {
 	padding: 5px 15px;
 }
 
-.shareButton:hover,.shareButton:focus {
+.shareButton:hover, .shareButton:focus {
 	background-color: #019AD3;
 	background-image: linear-gradient(#33BCEF, #019AD3);
 	border-color: #057ED0;
@@ -220,6 +220,21 @@ fieldset select {
 	cursor: hand;
 }
 
+.su-deleteAttachment {
+	background: url(images/close.png) 0px 0px no-repeat;
+	height: 15px;
+	width: 15px;
+	display: inline;
+	float: right;
+	vertical-align: top;
+}
+
+.su-deleteAttachment:hover {
+	background: url(images/close.png) 0px -16px no-repeat;
+	cursor: pointer;
+	cursor: hand;
+}
+
 .su-closeImage:active {
 	background: url(images/close.png) 0px -32px no-repeat;
 }
@@ -242,7 +257,7 @@ fieldset select {
 	cursor: hand;
 }
 
-a.link,a.link:active,a.link:visited {
+a.link, a.link:active, a.link:visited {
 	font-family: 'Lucida Grande', Verdana, 'Bitstream Vera Sans', Arial,
 		sans-serif;
 	font-size: 12px;