extract xcode like scrollbars as a separate option

platform/platform-api/src/com/intellij/util/ui/ButtonlessScrollBarUI.java

@@ -692,7 +692,7 @@ public class ButtonlessScrollBarUI extends BasicScrollBarUI {
   }
 
   private void paintMacThumb(Graphics g, Rectangle thumbBounds) {
-    if (isMacScrollbarHiddenAndDistractionFreeEnabled()) return;
+    if (isMacScrollbarHiddenAndXcodeLikeScrollbar()) return;
 
     thumbBounds = getMacScrollBarBounds(thumbBounds, true);
     Graphics2D g2d = (Graphics2D)g;
@@ -837,12 +837,12 @@ public class ButtonlessScrollBarUI extends BasicScrollBarUI {
     return new EmptyButton();
   }
 
-  protected boolean isMacScrollbarHiddenAndDistractionFreeEnabled() {
-    return myMacScrollbarHidden && isMacOverlayScrollbarSupported() && isDistractionFreeMode();
+  protected boolean isMacScrollbarHiddenAndXcodeLikeScrollbar() {
+    return myMacScrollbarHidden && isMacOverlayScrollbarSupported() && xcodeLikeScrollbar();
   }
 
-  protected static boolean isDistractionFreeMode() {
-    return Registry.is("editor.distraction.free.mode");
+  protected static boolean xcodeLikeScrollbar() {
+    return Registry.is("editor.xcode.like.scrollbar");
   }
 
   public void registerRepaintCallback(ScrollbarRepaintCallback callback) {

platform/platform-impl/src/com/intellij/openapi/editor/impl/EditorMarkupModelImpl.java

@@ -520,8 +520,8 @@ public class EditorMarkupModelImpl extends MarkupModelImpl implements EditorMark
     }
 
     @Override
-    protected boolean isMacScrollbarHiddenAndDistractionFreeEnabled() {
-      return super.isMacScrollbarHiddenAndDistractionFreeEnabled() && isRealFileEditor(myEditor);
+    protected boolean isMacScrollbarHiddenAndXcodeLikeScrollbar() {
+      return super.isMacScrollbarHiddenAndXcodeLikeScrollbar() && isRealFileEditor(myEditor);
     }
 
     @Override
@@ -606,7 +606,7 @@ public class EditorMarkupModelImpl extends MarkupModelImpl implements EditorMark
 
     @Override
     protected boolean alwaysPaintThumb() {
-      if (scrollbar.getOrientation() == Adjustable.VERTICAL) return !(isDistractionFreeMode() && isRealFileEditor(myEditor));
+      if (scrollbar.getOrientation() == Adjustable.VERTICAL) return !(xcodeLikeScrollbar() && isRealFileEditor(myEditor));
       return super.alwaysPaintThumb();
     }
 
@@ -644,7 +644,7 @@ public class EditorMarkupModelImpl extends MarkupModelImpl implements EditorMark
 
     @Override
     protected void doPaintTrack(@NotNull Graphics g, @NotNull JComponent c, @NotNull Rectangle bounds) {
-      if (isMacScrollbarHiddenAndDistractionFreeEnabled()) {
+      if (isMacScrollbarHiddenAndXcodeLikeScrollbar()) {
         paintTrackBasement(g, bounds);
         return;
       }
@@ -876,7 +876,7 @@ public class EditorMarkupModelImpl extends MarkupModelImpl implements EditorMark
 
     @Override
     public void mouseMoved(@NotNull MouseEvent e) {
-      if (isMacScrollbarHiddenAndDistractionFreeEnabled()) return;
+      if (isMacScrollbarHiddenAndXcodeLikeScrollbar()) return;
       EditorImpl.MyScrollBar scrollBar = myEditor.getVerticalScrollBar();
       int buttonHeight = scrollBar.getDecScrollButtonHeight();
       int lineCount = getDocument().getLineCount() + myEditor.getSettings().getAdditionalLinesCount();

platform/util/resources/misc/registry.properties

@@ -489,3 +489,6 @@ editor.caret.width.description=Caret width
 editor.caret.width.restartRequired=true
 
 editor.transparent.scrollbar=true
+
+editor.xcode.like.scrollbar=false
+editor.xcode.like.scrollbar.description=Enables auto-hideable Xcode-like editor stripes