@Override public Insets getBorderInsets(final Component c) { if (myProject == null) return new Insets(0, 0, 0, 0); ToolWindowManager toolWindowManager = ToolWindowManager.getInstance(myProject); if (!(toolWindowManager instanceof ToolWindowManagerImpl) || !((ToolWindowManagerImpl) toolWindowManager).isToolWindowRegistered(myInfo.getId()) || myWindow.getType() == ToolWindowType.FLOATING) { return new Insets(0, 0, 0, 0); } ToolWindowAnchor anchor = myWindow.getAnchor(); Component component = myWindow.getComponent(); Container parent = component.getParent(); while (parent != null) { if (parent instanceof Splitter) { Splitter splitter = (Splitter) parent; boolean isFirst = splitter.getFirstComponent() == component; boolean isVertical = splitter.isVertical(); return new Insets( 0, anchor == ToolWindowAnchor.RIGHT || (!isVertical && !isFirst) ? 1 : 0, (isVertical && isFirst) ? 1 : 0, anchor == ToolWindowAnchor.LEFT || (!isVertical && isFirst) ? 1 : 0); } component = parent; parent = component.getParent(); } return new Insets( 0, anchor == ToolWindowAnchor.RIGHT ? 1 : 0, anchor == ToolWindowAnchor.TOP ? 1 : 0, anchor == ToolWindowAnchor.LEFT ? 1 : 0); }