Viewer: Disable scrollbar hotkeys if no scrollbars

... or if keyboard grabbing is enabled. Fixes #348
TurboVNC · Nov 22, 2022 · ccb77c5 · ccb77c5
1 parent dda6375
commit ccb77c5
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Showing 3 changed files with 55 additions and 24 deletions.
diff --git a/ChangeLog.md b/ChangeLog.md
@@ -38,6 +38,12 @@ sequence, Mac users sometimes attempt to use Command-V with TurboVNC out of
 habit, which caused view-only mode to be activated accidentally because of
 3.0 beta1[28].  CTRL-ALT-SHIFT-V can still be used to toggle view-only mode.
 
+8. The TurboVNC Viewer normally reserves CTRL-ALT-SHIFT-{arrow keys} as hotkeys
+to move the horizontal and vertical scrollbars.  However, those key sequences
+are also used by Emacs and GNOME.  Thus, the TurboVNC Viewer now sends those
+key sequences to the server if no scrollbars are visible or if keyboard
+grabbing is enabled.
+
 
 3.0.1
 =====

diff --git a/java/com/turbovnc/vncviewer/DesktopWindow.java b/java/com/turbovnc/vncviewer/DesktopWindow.java
@@ -684,7 +684,11 @@ public void keyPressed(KeyEvent e) {
         case KeyEvent.VK_PAGE_DOWN:
         case KeyEvent.VK_HOME:
         case KeyEvent.VK_END:
-          return;
+          if (cc.viewport != null &&
+              (cc.viewport.sp.getHorizontalScrollBar().isVisible() ||
+               cc.viewport.sp.getVerticalScrollBar().isVisible()) &&
+              !VncViewer.isKeyboardGrabbed(cc.viewport))
+            return;
       }
     }
     if ((e.getModifiersEx() & InputEvent.META_DOWN_MASK) ==

diff --git a/java/com/turbovnc/vncviewer/Viewport.java b/java/com/turbovnc/vncviewer/Viewport.java
@@ -1,4 +1,4 @@
-/* Copyright (C) 2012-2013, 2015-2021 D. R. Commander.  All Rights Reserved.
+/* Copyright (C) 2012-2013, 2015-2022 D. R. Commander.  All Rights Reserved.
  * Copyright (C) 2011-2013 Brian P. Hinz
  * Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
  *
@@ -49,28 +49,7 @@ public Viewport(CConn cc_) {
     sp.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
     sp.setViewportBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
     sp.getViewport().setBackground(Color.BLACK);
-    InputMap im = sp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
-    int ctrlAltShiftMask = InputEvent.SHIFT_DOWN_MASK |
-                           InputEvent.CTRL_DOWN_MASK |
-                           InputEvent.ALT_DOWN_MASK;
-    if (im != null) {
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, ctrlAltShiftMask),
-             "unitScrollUp");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, ctrlAltShiftMask),
-             "unitScrollDown");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, ctrlAltShiftMask),
-             "unitScrollLeft");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, ctrlAltShiftMask),
-             "unitScrollRight");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_UP, ctrlAltShiftMask),
-             "scrollUp");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_DOWN, ctrlAltShiftMask),
-             "scrollDown");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_HOME, ctrlAltShiftMask),
-             "scrollLeft");
-      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_END, ctrlAltShiftMask),
-             "scrollRight");
-    }
+    setScrollBarHotkeysEnabled(true);
     tb = new Toolbar(cc);
     add(tb, BorderLayout.PAGE_START);
     getContentPane().add(sp);
@@ -179,6 +158,9 @@ public void actionPerformed(ActionEvent e) {
             ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
           sp.validate();
         }
+        setScrollBarHotkeysEnabled((sp.getHorizontalScrollBar().isVisible() ||
+                                    sp.getVerticalScrollBar().isVisible()) &&
+                                   !VncViewer.isKeyboardGrabbed(cc.viewport));
         if (cc.desktop.cursor != null) {
           Cursor cursor = cc.desktop.cursor;
           if (cursor.hotspot != null)
@@ -219,6 +201,42 @@ public void componentMoved(ComponentEvent e) {
     lastEvent.deviceID = -1;
   }
 
+  private void setScrollBarHotkeysEnabled(boolean enable) {
+    InputMap im = sp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
+    int ctrlAltShiftMask = InputEvent.SHIFT_DOWN_MASK |
+                           InputEvent.CTRL_DOWN_MASK |
+                           InputEvent.ALT_DOWN_MASK;
+    if (im == null) return;
+    if (enable) {
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, ctrlAltShiftMask),
+             "unitScrollUp");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, ctrlAltShiftMask),
+             "unitScrollDown");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, ctrlAltShiftMask),
+             "unitScrollLeft");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, ctrlAltShiftMask),
+             "unitScrollRight");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_UP, ctrlAltShiftMask),
+             "scrollUp");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_DOWN, ctrlAltShiftMask),
+             "scrollDown");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_HOME, ctrlAltShiftMask),
+             "scrollLeft");
+      im.put(KeyStroke.getKeyStroke(KeyEvent.VK_END, ctrlAltShiftMask),
+             "scrollRight");
+    } else {
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_UP, ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_UP, ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_DOWN,
+                                       ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_HOME, ctrlAltShiftMask));
+      im.remove(KeyStroke.getKeyStroke(KeyEvent.VK_END, ctrlAltShiftMask));
+    }
+  }
+
   public Dimension getAvailableSize() {
     Dimension availableSize = getSize();
     if (!cc.opts.fullScreen) {
@@ -438,6 +456,9 @@ public void grabKeyboardHelper(boolean on, boolean force) {
           return;
         grabKeyboard(on, Params.grabPointer.getValue());
         VncViewer.setGrabOwner(on ? this : null);
+        setScrollBarHotkeysEnabled((sp.getHorizontalScrollBar().isVisible() ||
+                                    sp.getVerticalScrollBar().isVisible()) &&
+                                   !on);
       } catch (UnsatisfiedLinkError e) {
         vlog.info("WARNING: Could not invoke grabKeyboard() from TurboVNC Helper.");
         vlog.info("  Keyboard grabbing will be disabled.");