Implement Element.scrollIntoView for scroll-behavior: smooth.

third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 1192 matching lines @@
       element, pseudo_id, rules_to_include);
 }
 
 double LocalDOMWindow::devicePixelRatio() const {
   if (!GetFrame())
     return 0.0;
 
   return GetFrame()->DevicePixelRatio();
 }
 
+void LocalDOMWindow::scrollHelper(ScrollableArea* viewport,

[bokan, 2017/05/19 18:37:14]

This name is too generic. Maybe "scrollViewportTo"?

[sunyunjia, 2017/05/19 22:30:41]

Done.

+                                  const ScrollOffset& offset,
+                                  ScrollBehavior scroll_behavior) const {
+  if (SmoothScrollSequencer* sequencer =
+          GetFrame()->GetPage()->GetSmoothScrollSequencer()) {
+    sequencer->AbortAnimations();
+    if (scroll_behavior == kScrollBehaviorInstant) {
+      viewport->SetScrollOffset(offset, kProgrammaticScroll, scroll_behavior);
+    } else {
+      sequencer->QueueAnimation(viewport, offset);
+      sequencer->RunQueuedAnimations();
+    }
+  }
+}
+
 void LocalDOMWindow::scrollBy(double x,
                               double y,
                               ScrollBehavior scroll_behavior) const {
   if (!IsCurrentlyDisplayedInFrame())
     return;
 
   document()->UpdateStyleAndLayoutIgnorePendingStylesheets();
 
   FrameView* view = GetFrame()->View();
   if (!view)
     return;
 
   Page* page = GetFrame()->GetPage();
   if (!page)
     return;
 
   x = ScrollableArea::NormalizeNonFiniteScroll(x);
   y = ScrollableArea::NormalizeNonFiniteScroll(y);
 
   ScrollableArea* viewport = page->GetSettings().GetInertVisualViewport()
                                  ? view->LayoutViewportScrollableArea()
                                  : view->GetScrollableArea();
 
   ScrollOffset current_offset = viewport->GetScrollOffset();
   ScrollOffset scaled_delta(x * GetFrame()->PageZoomFactor(),
                             y * GetFrame()->PageZoomFactor());
 
-  viewport->SetScrollOffset(current_offset + scaled_delta, kProgrammaticScroll,
-                            scroll_behavior);
+  scrollHelper(viewport, current_offset + scaled_delta, scroll_behavior);
 }
 
 void LocalDOMWindow::scrollBy(const ScrollToOptions& scroll_to_options) const {
   double x = 0.0;
   double y = 0.0;
   if (scroll_to_options.hasLeft())
     x = scroll_to_options.left();
   if (scroll_to_options.hasTop())
     y = scroll_to_options.top();
   ScrollBehavior scroll_behavior = kScrollBehaviorAuto;
@@ skipping 20 matching lines @@
   // It is only necessary to have an up-to-date layout if the position may be
   // clamped, which is never the case for (0, 0).
   if (x || y)
     document()->UpdateStyleAndLayoutIgnorePendingStylesheets();
 
   ScrollOffset layout_offset(x * GetFrame()->PageZoomFactor(),
                              y * GetFrame()->PageZoomFactor());
   ScrollableArea* viewport = page->GetSettings().GetInertVisualViewport()
                                  ? view->LayoutViewportScrollableArea()
                                  : view->GetScrollableArea();
-  viewport->SetScrollOffset(layout_offset, kProgrammaticScroll,
-                            kScrollBehaviorAuto);
+  scrollHelper(viewport, layout_offset, kScrollBehaviorAuto);
 }
 
 void LocalDOMWindow::scrollTo(const ScrollToOptions& scroll_to_options) const {
   if (!IsCurrentlyDisplayedInFrame())
     return;
 
   FrameView* view = GetFrame()->View();
   if (!view)
     return;
 
@@ skipping 26 matching lines @@
 
   if (scroll_to_options.hasTop())
     scaled_y =
         ScrollableArea::NormalizeNonFiniteScroll(scroll_to_options.top()) *
         GetFrame()->PageZoomFactor();
 
   ScrollBehavior scroll_behavior = kScrollBehaviorAuto;
   ScrollableArea::ScrollBehaviorFromString(scroll_to_options.behavior(),
                                            scroll_behavior);
 
-  viewport->SetScrollOffset(ScrollOffset(scaled_x, scaled_y),
-                            kProgrammaticScroll, scroll_behavior);
+  scrollHelper(viewport, ScrollOffset(scaled_x, scaled_y), scroll_behavior);
 }
 
 void LocalDOMWindow::moveBy(int x, int y) const {
   if (!GetFrame() || !GetFrame()->IsMainFrame())
     return;
 
   Page* page = GetFrame()->GetPage();
   if (!page)
     return;
 
@@ skipping 362 matching lines @@
   DOMWindow::Trace(visitor);
   Supplementable<LocalDOMWindow>::Trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(LocalDOMWindow) {
   visitor->TraceWrappers(custom_elements_);
   DOMWindow::TraceWrappers(visitor);
 }
 
 }  // namespace blink