OO-2191: add the delete button in the upload of tiny to remove a file

src/main/java/org/olat/core/commons/modules/bc/FileUploadController.java

@@ -57,6 +57,7 @@ import org.olat.core.gui.components.form.flexible.impl.Form;
 import org.olat.core.gui.components.form.flexible.impl.FormBasicController;
 import org.olat.core.gui.components.form.flexible.impl.FormEvent;
 import org.olat.core.gui.components.form.flexible.impl.FormLayoutContainer;
+import org.olat.core.gui.components.form.flexible.impl.elements.FileElementEvent;
 import org.olat.core.gui.control.Controller;
 import org.olat.core.gui.control.Event;
 import org.olat.core.gui.control.WindowControl;
@@ -303,7 +304,11 @@ public class FileUploadController extends FormBasicController {
 	@Override
 	protected void formInnerEvent(UserRequest ureq, FormItem source, FormEvent event) {
 		if(fileEl == source) {
-			if(metaDataCtr != null) {
+			if(FileElementEvent.DELETE.equals(event.getCommand())) {
+				fileEl.reset();
+				fileEl.setDeleteEnabled(false);
+				fileEl.clearError();
+			} else if(metaDataCtr != null) {
 				String filename = fileEl.getUploadFileName();
 				if(!FileUtils.validateFilename(filename)) {
 					String suffix = FileUtils.getFileSuffix(filename);
@@ -879,9 +884,10 @@ public class FileUploadController extends FormBasicController {
 		String filename = fileEl.getUploadFileName();
 		
 		boolean allOk = validateFilename(filename, fileEl);
-		List<ValidationStatus> status = new ArrayList<>();
-		fileEl.validate(status);//revalidate because we clear the errors
-		return allOk && status.isEmpty();
+		List<ValidationStatus> fileStatus = new ArrayList<>();
+		fileEl.validate(fileStatus);//revalidate because we clear the error
+		fileEl.setDeleteEnabled(fileStatus.size() > 0);
+		return allOk && fileStatus.isEmpty();
 	}
 	
 	private boolean validateFilename(String filename, FormItem itemEl) {