Implement Element.scrollIntoView for scroll-behavior: smooth.

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index 36834df69780f4e1f97da8ac9f49a34cb58bb91e..48d8e5ba1844ce6f4698ec352609922556f2bb84 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -26,10 +26,12 @@
 
 #include "core/dom/Element.h"
 
+#include <memory>
 #include "bindings/core/v8/DOMDataStore.h"
 #include "bindings/core/v8/Dictionary.h"
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/ScrollIntoViewOptionsOrBoolean.h"
 #include "bindings/core/v8/V8DOMActivityLogger.h"
 #include "bindings/core/v8/V8DOMWrapper.h"
 #include "bindings/core/v8/V8PerContextData.h"
@@ -97,6 +99,7 @@
 #include "core/frame/HostsUsingFeatures.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
+#include "core/frame/ScrollIntoViewOptions.h"
 #include "core/frame/ScrollToOptions.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
@@ -131,6 +134,7 @@
 #include "core/page/scrolling/ScrollCustomizationCallbacks.h"
 #include "core/page/scrolling/ScrollState.h"
 #include "core/page/scrolling/ScrollStateCallback.h"
+#include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/page/scrolling/TopDocumentRootScrollerController.h"
 #include "core/paint/PaintLayer.h"
 #include "core/svg/SVGAElement.h"
@@ -140,13 +144,13 @@
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/CompositorMutableProperties.h"
 #include "platform/graphics/CompositorMutation.h"
+#include "platform/scroll/ProgrammaticScrollCoordinator.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "wtf/BitVector.h"
 #include "wtf/HashFunctions.h"
 #include "wtf/text/CString.h"
 #include "wtf/text/StringBuilder.h"
 #include "wtf/text/TextPosition.h"
-#include <memory>
 
 namespace blink {
 
@@ -428,7 +432,51 @@ bool Element::shouldIgnoreAttributeCase() const {
   return isHTMLElement() && document().isHTMLDocument();
 }
 
+void Element::scrollIntoView(ExceptionState& exception) {
+  ScrollIntoViewOptions options;
+  options.setBlock("start");
+  options.setInlinePosition("nearest");
+  scrollIntoViewWithOptions(options);
+}
+
+void Element::scrollIntoView(ScrollIntoViewOptionsOrBoolean arg,
+                             ExceptionState& exception) {
+  ScrollIntoViewOptions options;
+  if (arg.isBoolean()) {
+    if (arg.getAsBoolean())
+      options.setBlock("start");
+    else
+      options.setBlock("end");
+    options.setInlinePosition("nearest");
+  } else if (arg.isScrollIntoViewOptions()) {
+    options = arg.getAsScrollIntoViewOptions();
+    if (!RuntimeEnabledFeatures::cssomSmoothScrollEnabled() &&
+        options.behavior() == "smooth") {
+      exception.throwTypeError(
+          "Smooth ScrollIntoView is an Experimental Web"

[bokan, 2017/03/28 16:29:53]

I don't think we usually throw for a feature being off. I think we should just
ignore the behavior option silently if the REF isn't on (but still
scrollIntoView).

[sunyunjia, 2017/04/07 13:53:20]

Done.

+          " Platform Feature, go to chrome://flags to enable it.");
+      return;
+    }
+  } else {
+    exception.throwTypeError(
+        "ScrollIntoView only supports bool or"
+        " ScrollIntoViewOptions as argument.");
+    return;
+  }
+  scrollIntoViewWithOptions(options);
+}
+
 void Element::scrollIntoView(bool alignToTop) {
+  ScrollIntoViewOptions options;
+  if (alignToTop)
+    options.setBlock("start");
+  else
+    options.setBlock("end");
+  options.setInlinePosition("nearest");
+  scrollIntoViewWithOptions(options);
+}
+
+void Element::scrollIntoViewWithOptions(const ScrollIntoViewOptions& options) {
   document().updateStyleAndLayoutIgnorePendingStylesheetsForNode(this);
 
   if (!layoutObject())
@@ -437,18 +485,40 @@ void Element::scrollIntoView(bool alignToTop) {
   bool makeVisibleInVisualViewport =
       !document().page()->settings().getInertVisualViewport();
 
+  ScrollBehavior behavior = ScrollBehaviorAuto;
+  if (options.behavior() == "smooth") {
+    behavior = ScrollBehaviorSmooth;
+  }
+  // Block Alignment to the top / bottom and to the closest edge.
+  ScrollAlignment blockAlignment = ScrollAlignment::alignTopAlways;
+  if (options.block() == "center")
+    blockAlignment = ScrollAlignment::alignCenterAlways;
+  else if (options.block() == "end")
+    blockAlignment = ScrollAlignment::alignBottomAlways;
+  else if (options.block() == "nearest")
+    blockAlignment = ScrollAlignment::alignToEdgeIfNeeded;
+
+  // Inline Alignment to the top / bottom and to the closest edge.
+  ScrollAlignment inlineAlignment = ScrollAlignment::alignToEdgeIfNeeded;
+  if (options.inlinePosition() == "start")
+    inlineAlignment = ScrollAlignment::alignLeftAlways;
+  else if (options.inlinePosition() == "center")
+    inlineAlignment = ScrollAlignment::alignCenterAlways;
+  else if (options.inlinePosition() == "end")
+    inlineAlignment = ScrollAlignment::alignRightAlways;
+
   LayoutRect bounds = boundingBox();
-  // Align to the top / bottom and to the closest edge.
-  if (alignToTop)
-    layoutObject()->scrollRectToVisible(
-        bounds, ScrollAlignment::alignToEdgeIfNeeded,
-        ScrollAlignment::alignTopAlways, ProgrammaticScroll,
-        makeVisibleInVisualViewport);
-  else
-    layoutObject()->scrollRectToVisible(
-        bounds, ScrollAlignment::alignToEdgeIfNeeded,
-        ScrollAlignment::alignBottomAlways, ProgrammaticScroll,
-        makeVisibleInVisualViewport);
+  layoutObject()->scrollRectToVisible(bounds, inlineAlignment, blockAlignment,
+                                      ProgrammaticScroll,
+                                      makeVisibleInVisualViewport, behavior);
+
+  if (document().page()->scrollingCoordinator()) {
+    document()
+        .page()
+        ->scrollingCoordinator()
+        ->programmaticScrollCoordinator()
+        ->runQueuedAnimations();
+  }
 
   document().setSequentialFocusNavigationStartingPoint(this);
 }