Fixed drag-and-drop into text fields: files are now inserted at the text caret position instead of where the mouse was dropped

CHANGELOG.md

@@ -1,3 +1,4 @@
+- Fixed drag-and-drop into text fields: files are now inserted at the text caret position instead of where the mouse was dropped
 - Fixed Accept/Decline and Yes/No button colors to respect the IDE Look and Feel theme (dark themes no longer show clashing hardcoded colors)
 - Added session management when opening a session from the toolbar and when closing a tab via the Close button
 - Added configurable session mode: choose to resume the last session or start a new one

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>io.github.nbclaudecodegui</groupId>
     <artifactId>netbeans-claude-code-gui</artifactId>
-    <version>0.21.14-SNAPSHOT</version>
+    <version>0.21.18-SNAPSHOT</version>
     <packaging>nbm</packaging>
     <name>Netbeans Claude Code GUI</name>
     <description>NetBeans plugin that provides a GUI for Claude Code CLI — run claude code sessions directly inside the IDE.</description>

src/main/java/io/github/nbclaudecodegui/ui/common/FileDropHandler.java

@@ -198,7 +198,20 @@ public boolean importData(TransferSupport support) {
         LOG.fine("importData: component=" + support.getComponent().getClass().getSimpleName());
         Transferable t = support.getTransferable();
         JTextComponent textComponent = findTextComponent(support.getComponent());
-        return doImport(t, textComponent);
+        int insertPos = textComponent != null ? textComponent.getCaretPosition() : 0;
+        return doImport(t, textComponent, insertPos);
+    }
+
+    /**
+     * Called by our custom {@link java.awt.dnd.DropTargetAdapter} in place of the standard
+     * Swing drop pipeline.  Because our adapter never calls {@code setDropLocation}, the caret
+     * stays at the position the user left it — so we can read it here and insert there.
+     */
+    void handleDrop(java.awt.dnd.DropTargetDropEvent dtde, JTextComponent tc) {
+        dtde.acceptDrop(java.awt.dnd.DnDConstants.ACTION_COPY_OR_MOVE);
+        int insertPos = tc.getCaretPosition();
+        boolean ok = doImport(dtde.getTransferable(), tc, insertPos);
+        dtde.dropComplete(ok);
     }
 
     // -------------------------------------------------------------------------
@@ -223,27 +236,27 @@ public boolean importFromClipboard(JTextComponent textComponent) {
         boolean hasText  = t.isDataFlavorSupported(DataFlavor.stringFlavor);
         LOG.fine("importFromClipboard: hasFiles=" + hasFiles + " hasImage=" + hasImage + " hasText=" + hasText);
         if (!hasFiles && !hasImage && !hasText) return false;
-        return doImport(t, textComponent);
+        return doImport(t, textComponent, textComponent.getCaretPosition());
     }
 
     // -------------------------------------------------------------------------
     // Shared import logic
     // -------------------------------------------------------------------------
 
-    private boolean doImport(Transferable t, JTextComponent textComponent) {
+    private boolean doImport(Transferable t, JTextComponent textComponent, int insertPos) {
         try {
             Node[] nodes = extractNodes(t);
             if (nodes != null && nodes.length > 0) {
                 LOG.fine("doImport: nodes branch, count=" + nodes.length);
-                return importNodes(nodes, textComponent);
+                return importNodes(nodes, textComponent, insertPos);
             }
             if (t.isDataFlavorSupported(DataFlavor.imageFlavor)) {
                 Image img = (Image) t.getTransferData(DataFlavor.imageFlavor);
                 if (img != null) {
                     LOG.fine("doImport: image branch");
                     File tmp = writeTempPng(img);
                     if (textComponent != null) {
-                        insertAtCaret(textComponent, "@" + tmp.getAbsolutePath());
+                        insertAtCaret(textComponent, "@" + tmp.getAbsolutePath(), insertPos);
                     }
                     return true;
                 }
@@ -265,14 +278,14 @@ private boolean doImport(Transferable t, JTextComponent textComponent) {
                 }
 
                 if (paths.length() > 0 && textComponent != null) {
-                    insertAtCaret(textComponent, paths.toString());
+                    insertAtCaret(textComponent, paths.toString(), insertPos);
                 }
                 return true;
             }
             if (t.isDataFlavorSupported(DataFlavor.stringFlavor)) {
                 LOG.fine("doImport: string branch");
                 String s = (String) t.getTransferData(DataFlavor.stringFlavor);
-                if (s != null && textComponent != null) { insertAtCaret(textComponent, s); return true; }
+                if (s != null && textComponent != null) { insertAtCaret(textComponent, s, insertPos); return true; }
             }
         } catch (Exception ex) {
             // Import failed; fall through to return false
@@ -297,6 +310,11 @@ private boolean doImport(Transferable t, JTextComponent textComponent) {
      * </ul>
      */
     boolean importNodes(Node[] nodes, JTextComponent textComponent) {
+        int pos = textComponent != null ? textComponent.getCaretPosition() : 0;
+        return importNodes(nodes, textComponent, pos);
+    }
+
+    private boolean importNodes(Node[] nodes, JTextComponent textComponent, int insertPos) {
         LOG.fine("importNodes: entry, count=" + (nodes == null ? 0 : nodes.length));
         if (nodes == null || nodes.length == 0) return false;
         String wdStr = workingDirSupplier.get();
@@ -393,7 +411,7 @@ boolean importNodes(Node[] nodes, JTextComponent textComponent) {
         }
 
         if (inlineText.length() > 0 && textComponent != null) {
-            insertAtCaret(textComponent, inlineText.toString());
+            insertAtCaret(textComponent, inlineText.toString(), insertPos);
         }
         LOG.fine("importNodes: returning " + (inlineText.length() > 0) + ", text='" + inlineText + "'");
         return inlineText.length() > 0;
@@ -438,9 +456,8 @@ private File writeTempPng(Image img) throws IOException {
         return tmp;
     }
 
-    private static void insertAtCaret(JTextComponent textComponent, String text) {
+    private static void insertAtCaret(JTextComponent textComponent, String text, int pos) {
         javax.swing.SwingUtilities.invokeLater(() -> {
-            int pos = textComponent.getCaretPosition();
             try {
                 String before = textComponent.getText(0, pos);
                 String toInsert = (!before.isEmpty() && !before.endsWith(" ") && !before.endsWith("\n"))

src/main/java/io/github/nbclaudecodegui/ui/common/TextComponentDecorator.java

@@ -54,6 +54,31 @@ public void setup() {
         dropHandler = new FileDropHandler(wdSupplier, tc.getTransferHandler());
         tc.setTransferHandler(dropHandler);
 
+        // Replace Swing's SwingDropTarget with our own that never calls setDropLocation,
+        // so the caret stays frozen at its original position during the entire drag.
+        tc.setDropTarget(new java.awt.dnd.DropTarget(tc,
+                java.awt.dnd.DnDConstants.ACTION_COPY_OR_MOVE,
+                new java.awt.dnd.DropTargetAdapter() {
+                    @Override
+                    public void dragEnter(java.awt.dnd.DropTargetDragEvent e) {
+                        if (dropHandler.canImportTransferable(e.getTransferable()))
+                            e.acceptDrag(java.awt.dnd.DnDConstants.ACTION_COPY_OR_MOVE);
+                        else
+                            e.rejectDrag();
+                    }
+                    @Override
+                    public void dragOver(java.awt.dnd.DropTargetDragEvent e) {
+                        if (dropHandler.canImportTransferable(e.getTransferable()))
+                            e.acceptDrag(java.awt.dnd.DnDConstants.ACTION_COPY_OR_MOVE);
+                        else
+                            e.rejectDrag();
+                    }
+                    @Override
+                    public void drop(java.awt.dnd.DropTargetDropEvent e) {
+                        dropHandler.handleDrop(e, tc);
+                    }
+                }, true));
+
         // 2. @-completion
         AtCompletionPopup.install(tc, wdSupplier);
 

src/test/java/io/github/nbclaudecodegui/ui/common/FileDropHandlerTest.java

@@ -782,6 +782,61 @@ void importNodesFilesWindowNodeInsideWorkDirInsertsRelativePath() throws Excepti
         });
     }
 
+    // -------------------------------------------------------------------------
+    // Tests: insert at explicit position (DnD caret-save fix)
+    // -------------------------------------------------------------------------
+
+    /**
+     * Verifies that doImport(Transferable, JTextComponent, int) inserts at the
+     * given position, NOT at the text component's current caret position.
+     * This is the core of the DnD caret-save fix: the drag-hover caret movement
+     * must be ignored; insertion must happen where the caret was before the drag.
+     */
+    @Test
+    void dropFileInsertsAtExplicitPositionIgnoringCurrentCaret() throws Exception {
+        File inside = new File(workDir, "file.txt");
+        inside.createNewFile();
+
+        SwingUtilities.invokeAndWait(() -> {
+            area.setText("hello world");
+            // Simulate Swing moving the caret to the drop location (end of text)
+            area.setCaretPosition(11);
+            // Call doImport with insertPos=5 (the saved pre-drag caret position)
+            java.awt.datatransfer.Transferable t = fileListTransferable(List.of(inside));
+            callDoImportAt(handler, t, area, 5);
+        });
+
+        SwingUtilities.invokeAndWait(() -> {
+            String text = area.getText();
+            assertTrue(text.contains("file.txt"), "path must appear in text, got: '" + text + "'");
+            // The path must be inserted inside "hello world", not appended at the end
+            assertTrue(text.startsWith("hello"),
+                    "text must start with 'hello' (insertion at pos 5), got: '" + text + "'");
+            int pathIdx = text.indexOf("file.txt");
+            assertTrue(pathIdx > 0 && pathIdx < text.indexOf("world"),
+                    "path must be inserted between 'hello' and 'world', got: '" + text + "'");
+        });
+    }
+
+    /**
+     * Calls the package-private {@code doImport(Transferable, JTextComponent, int)} via reflection.
+     */
+    private static boolean callDoImportAt(FileDropHandler handler,
+                                          java.awt.datatransfer.Transferable t,
+                                          JTextArea area, int insertPos) {
+        try {
+            java.lang.reflect.Method m = FileDropHandler.class.getDeclaredMethod(
+                    "doImport",
+                    java.awt.datatransfer.Transferable.class,
+                    javax.swing.text.JTextComponent.class,
+                    int.class);
+            m.setAccessible(true);
+            return (boolean) m.invoke(handler, t, area, insertPos);
+        } catch (Exception ex) {
+            throw new RuntimeException("Could not invoke FileDropHandler.doImport(t, tc, pos)", ex);
+        }
+    }
+
     // -------------------------------------------------------------------------
     // Tests: Cut/Copy — export delegation to original TransferHandler
     // -------------------------------------------------------------------------
@@ -845,7 +900,8 @@ void canImportBlankAbstractNodeReturnsFalse() throws Exception {
     }
 
     /**
-     * Calls the package-private {@code doImport(Transferable, JTextComponent)} via reflection.
+     * Calls the package-private {@code doImport(Transferable, JTextComponent, int)} via reflection,
+     * using the current caret position as the insert position.
      */
     private static boolean callDoImport(FileDropHandler handler,
                                         java.awt.datatransfer.Transferable t,
@@ -854,9 +910,10 @@ private static boolean callDoImport(FileDropHandler handler,
             java.lang.reflect.Method m = FileDropHandler.class.getDeclaredMethod(
                     "doImport",
                     java.awt.datatransfer.Transferable.class,
-                    javax.swing.text.JTextComponent.class);
+                    javax.swing.text.JTextComponent.class,
+                    int.class);
             m.setAccessible(true);
-            return (boolean) m.invoke(handler, t, area);
+            return (boolean) m.invoke(handler, t, area, area.getCaretPosition());
         } catch (Exception ex) {
             throw new RuntimeException("Could not invoke FileDropHandler.doImport", ex);
         }