Add drag-n-drop for Split'n'merge tab. Fix minor issues.

src/main/java/nsusbloader/Controllers/FrontController.java

@@ -292,7 +292,7 @@ public class FrontController implements Initializable {
      * */
     @FXML
     private void handleDragOver(DragEvent event){
-        if (event.getDragboard().hasFiles())
+        if (event.getDragboard().hasFiles() && ! MediatorControl.getInstance().getTransferActive())
             event.acceptTransferModes(TransferMode.ANY);
         event.consume();
     }
@@ -301,10 +301,6 @@ public class FrontController implements Initializable {
      * */
     @FXML
     private void handleDrop(DragEvent event){
-        if (MediatorControl.getInstance().getTransferActive()) {
-            event.setDropCompleted(true);
-            return;
-        }
         List<File> filesDropped = event.getDragboard().getFiles();
 
         if (getSelectedProtocol().equals("TinFoil") && MediatorControl.getInstance().getContoller().getSettingsCtrlr().getTfXciNszXczSupport())

src/main/java/nsusbloader/Controllers/RcmController.java

@@ -231,7 +231,10 @@ public class RcmController implements Initializable {
         );
 
         File payloadFile = fileChooser.showOpenDialog(payloadFPathLbl1.getScene().getWindow());
-        if (payloadFile != null) {
+
+        if (payloadFile == null)
+            return;
+
         final String fullFileName = payloadFile.getAbsolutePath();
         final Node btn = (Node)event.getSource();
 
@@ -252,7 +255,6 @@ public class RcmController implements Initializable {
                 setPayloadFile(5, fullFileName);
         }
     }
-    }
     @FXML
     private void bntResetPayloader(ActionEvent event){
         final Node btn = (Node)event.getSource();

src/main/java/nsusbloader/Controllers/SplitMergeController.java

@@ -3,7 +3,10 @@ package nsusbloader.Controllers;
 import javafx.concurrent.Task;
 import javafx.fxml.FXML;
 import javafx.fxml.Initializable;
+import javafx.scene.Node;
 import javafx.scene.control.*;
+import javafx.scene.input.DragEvent;
+import javafx.scene.input.TransferMode;
 import javafx.scene.layout.Region;
 import javafx.scene.layout.VBox;
 import javafx.stage.DirectoryChooser;
@@ -101,7 +104,6 @@ public class SplitMergeController implements Initializable {
                 if (fileFile == null)
                     return;
                 fileFolderActualPathLbl.setText(fileFile.getAbsolutePath());
-                convertBtn.setDisable(false);
             }
             else{
                 DirectoryChooser dc = new DirectoryChooser();
@@ -120,14 +122,14 @@ public class SplitMergeController implements Initializable {
                 if (folderFile == null)
                     return;
                 fileFolderActualPathLbl.setText(folderFile.getAbsolutePath());
-                convertBtn.setDisable(false);
             }
+            convertBtn.setDisable(false);
         });
 
         convertBtn.setOnAction(actionEvent -> setConvertBtnAction());
     }
 
-    public void notifySmThreadStarted(boolean isStart, EModule type){
+    public void notifySmThreadStarted(boolean isStart, EModule type){ // todo: refactor: remove everything, place to separate container and just disable.
         if (! type.equals(EModule.SPLIT_MERGE_TOOL)){
             smToolPane.setDisable(isStart);
             return;
@@ -176,7 +178,10 @@ public class SplitMergeController implements Initializable {
     private void setConvertBtnAction(){
         statusLbl.setText("");
         if (MediatorControl.getInstance().getTransferActive()) {
-            ServiceWindow.getErrorNotification(resourceBundle.getString("windowTitleError"), resourceBundle.getString("windowBodyPleaseFinishTransfersFirst"));
+            ServiceWindow.getErrorNotification(
+                    resourceBundle.getString("windowTitleError"),
+                    resourceBundle.getString("windowBodyPleaseFinishTransfersFirst")
+            );
             return;
         }
 
@@ -195,6 +200,32 @@ public class SplitMergeController implements Initializable {
         smThread.setDaemon(true);
         smThread.start();
     }
+    /**
+     * Drag-n-drop support (dragOver consumer)
+     * */
+    @FXML
+    private void handleDragOver(DragEvent event){
+        if (event.getDragboard().hasFiles() && ! MediatorControl.getInstance().getTransferActive())
+            event.acceptTransferModes(TransferMode.ANY);
+        event.consume();
+    }
+    /**
+     * Drag-n-drop support (drop consumer)
+     * */
+    @FXML
+    private void handleDrop(DragEvent event) {
+        Node sourceNode = (Node) event.getSource();
+        File fileDrpd = event.getDragboard().getFiles().get(0);
+
+        if (fileDrpd.isDirectory())
+            mergeRad.fire();
+        else
+            splitRad.fire();
+        fileFolderActualPathLbl.setText(fileDrpd.getAbsolutePath());
+        convertBtn.setDisable(false);
+        event.setDropCompleted(true);
+        event.consume();
+    }
     /**
      * Save application settings on exit
      * */

src/main/java/nsusbloader/Utilities/SplitMergeTool.java

@@ -183,7 +183,7 @@ class MergeTask extends Task<Boolean> {
 
         File[] chunkFiles = folder.listFiles((file, s) -> s.matches("^[0-9][0-9]$"));
 
-        if (chunkFiles == null){
+        if (chunkFiles == null || chunkFiles.length == 0){
             logPrinter.print("Selected folder doesn't have any chunks. Nothing to do here.", EMsgType.FAIL);
             logPrinter.close();
             return false;

src/main/resources/SplitMergeTab.fxml

@@ -14,7 +14,7 @@
 <?import javafx.scene.layout.VBox?>
 <?import javafx.scene.text.Font?>
 
-<VBox fx:id="smToolPane" spacing="20.0" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="nsusbloader.Controllers.SplitMergeController">
+<VBox fx:id="smToolPane" onDragDropped="#handleDrop" onDragOver="#handleDragOver" spacing="20.0" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="nsusbloader.Controllers.SplitMergeController">
    <VBox spacing="15.0">
       <children>
          <Pane minHeight="-Infinity" prefHeight="10.0" style="-fx-background-color: linear-gradient(from 41px 34px to 50px 50px, reflect,  #00c8fc 40%, transparent  45%);" />