Update Element API for CSSOM smooth scrolling to match the spec

Source/core/html/HTMLBodyElement.cpp

Index: Source/core/html/HTMLBodyElement.cpp
diff --git a/Source/core/html/HTMLBodyElement.cpp b/Source/core/html/HTMLBodyElement.cpp
index c855c82efd216db3f03ca1b4ffeb019dd2497f65..12da1cc61b113e9181561f8ca4acd93f7610f749 100644
--- a/Source/core/html/HTMLBodyElement.cpp
+++ b/Source/core/html/HTMLBodyElement.cpp
@@ -33,6 +33,7 @@
 #include "core/dom/Attribute.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
+#include "core/frame/ScrollToOptions.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/HTMLFrameElementBase.h"
 #include "core/html/parser/HTMLParserIdioms.h"
@@ -265,7 +266,7 @@ void HTMLBodyElement::setScrollLeft(double scrollLeft)
     FrameView* view = frame->view();
     if (!view)
         return;
-    view->setScrollPosition(DoublePoint(scrollLeft * frame->pageZoomFactor(), view->scrollY()));
+    view->setScrollPosition(DoublePoint(scrollLeft * frame->pageZoomFactor(), view->scrollY()), ScrollBehaviorAuto);
 }
 
 double HTMLBodyElement::scrollTop()
@@ -315,7 +316,7 @@ void HTMLBodyElement::setScrollTop(double scrollTop)
     FrameView* view = frame->view();
     if (!view)
         return;
-    view->setScrollPosition(DoublePoint(view->scrollX(), scrollTop * frame->pageZoomFactor()));
+    view->setScrollPosition(DoublePoint(view->scrollX(), scrollTop * frame->pageZoomFactor()), ScrollBehaviorAuto);
 }
 
 int HTMLBodyElement::scrollHeight()
@@ -336,4 +337,93 @@ int HTMLBodyElement::scrollWidth()
     return view ? adjustForZoom(view->contentsWidth(), &document) : 0;
 }
 
+void HTMLBodyElement::scrollBy(const ScrollToOptions& scrollToOptions)

[Ian Vollick, 2014/12/08 16:35:23]

nit: The similarity of these methods and those in Element is a little sad. Is it
possible to share code?

[ajuma, 2014/12/08 18:34:13]

Added helpers (scrollFrameBy, scrollFrameTo, scrollRenderBoxBy,
scrollRenderBoxTo) to Element so that code can be shared.

+{
+    Document& document = this->document();
+    document.updateLayoutIgnorePendingStylesheets();
+
+    double left = scrollToOptions.hasLeft() ? scrollToOptions.left() : 0.0;
+    double top = scrollToOptions.hasTop() ? scrollToOptions.top() : 0.0;
+    if (std::isnan(left) || std::isnan(top))
+        return;
+
+    ScrollBehavior scrollBehavior = ScrollBehaviorAuto;
+    ScrollableArea::scrollBehaviorFromString(scrollToOptions.behavior(), scrollBehavior);
+
+    if (RuntimeEnabledFeatures::scrollTopLeftInteropEnabled()) {
+        RenderBox* render = renderBox();
+        if (!render)
+            return;
+        if (render->hasOverflowClip()) {
+            double currentScaledLeft = render->scrollLeft();
+            double currentScaledTop = render->scrollTop();
+            double newScaledLeft = left * render->style()->effectiveZoom() + currentScaledLeft;
+            double newScaledTop = top * render->style()->effectiveZoom() + currentScaledTop;
+            // FIXME: Use scrollBehavior to decide whether to scroll smoothly or instantly.
+            render->scrollToOffset(DoubleSize(newScaledLeft, newScaledTop));
+            return;
+        }
+        if (!document.inQuirksMode())
+            return;
+    }
+
+    LocalFrame* frame = document.frame();
+    if (!frame)
+        return;
+    FrameView* view = frame->view();
+    if (!view)
+        return;
+
+    double newScaledLeft = left * frame->pageZoomFactor() + view->scrollX();
+    double newScaledTop = top * frame->pageZoomFactor() + view->scrollY();
+    view->setScrollPosition(DoublePoint(newScaledLeft, newScaledTop), scrollBehavior);
+}
+
+void HTMLBodyElement::scrollTo(const ScrollToOptions& scrollToOptions)
+{
+    Document& document = this->document();
+    document.updateLayoutIgnorePendingStylesheets();
+
+    if ((scrollToOptions.hasLeft() && std::isnan(scrollToOptions.left()))
+        || (scrollToOptions.hasTop() && std::isnan(scrollToOptions.top())))
+        return;
+
+    ScrollBehavior scrollBehavior = ScrollBehaviorAuto;
+    ScrollableArea::scrollBehaviorFromString(scrollToOptions.behavior(), scrollBehavior);
+
+    if (RuntimeEnabledFeatures::scrollTopLeftInteropEnabled()) {
+        RenderBox* render = renderBox();
+        if (!render)
+            return;
+        if (render->hasOverflowClip()) {
+            double scaledLeft = render->scrollLeft();
+            double scaledTop = render->scrollTop();
+            if (scrollToOptions.hasLeft())
+                scaledLeft = scrollToOptions.left() * render->style()->effectiveZoom();
+            if (scrollToOptions.hasTop())
+                scaledTop = scrollToOptions.top() * render->style()->effectiveZoom();
+            // FIXME: Use scrollBehavior to decide whether to scroll smoothly or instantly.
+            render->scrollToOffset(DoubleSize(scaledLeft, scaledTop));
+            return;
+        }
+        if (!document.inQuirksMode())
+            return;
+    }
+
+    LocalFrame* frame = document.frame();
+    if (!frame)
+        return;
+    FrameView* view = frame->view();
+    if (!view)
+        return;
+
+    double scaledLeft = view->scrollX();
+    double scaledTop = view->scrollY();
+    if (scrollToOptions.hasLeft())
+        scaledLeft = scrollToOptions.left() * frame->pageZoomFactor();
+    if (scrollToOptions.hasTop())
+        scaledTop = scrollToOptions.top() * frame->pageZoomFactor();
+    view->setScrollPosition(DoublePoint(scaledLeft, scaledTop), scrollBehavior);
+}
+
 } // namespace blink