Merge WebKit at r73109: Initial merge by git.

Change-Id: I61f1a66d9642e3d8405d3ac6ccab2a53421c75d8

1 files changed, 55 insertions, 13 deletions

diff --git a/WebCore/platform/ScrollView.cpp b/WebCore/platform/ScrollView.cpp
index 4a9d479..d6184e9 100644
--- a/WebCore/platform/ScrollView.cpp
+++ b/WebCore/platform/ScrollView.cpp
@@ -53,6 +53,7 @@ ScrollView::ScrollView()
     , m_drawPanScrollIcon(false)
     , m_useFixedLayout(false)
     , m_paintsEntireContents(false)
+    , m_delegatesScrolling(false)
 {
     platformInit();
 }
@@ -201,6 +202,11 @@ void ScrollView::setPaintsEntireContents(bool paintsEntireContents)
     m_paintsEntireContents = paintsEntireContents;
 }
 
+void ScrollView::setDelegatesScrolling(bool delegatesScrolling)
+{
+    m_delegatesScrolling = delegatesScrolling;
+}
+
 #if !PLATFORM(GTK)
 IntRect ScrollView::visibleContentRect(bool includeScrollbars) const
 {
@@ -302,9 +308,21 @@ int ScrollView::actualScrollY() const
 
 IntPoint ScrollView::maximumScrollPosition() const
 {
-    IntSize maximumOffset = contentsSize() - visibleContentRect().size();
+    IntPoint maximumOffset(contentsWidth() - visibleWidth() - m_scrollOrigin.x(), contentsHeight() - visibleHeight() - m_scrollOrigin.y());
     maximumOffset.clampNegativeToZero();
-    return IntPoint(maximumOffset.width(), maximumOffset.height());
+    return maximumOffset;
+}
+
+IntPoint ScrollView::minimumScrollPosition() const
+{
+    return IntPoint(-m_scrollOrigin.x(), -m_scrollOrigin.y());
+}
+
+IntPoint ScrollView::adjustScrollPositionWithinRange(const IntPoint& scrollPoint) const
+{
+    IntPoint newScrollPosition = scrollPoint.shrunkTo(maximumScrollPosition());
+    newScrollPosition = newScrollPosition.expandedTo(minimumScrollPosition());
+    return newScrollPosition;
 }
 
 int ScrollView::scrollSize(ScrollbarOrientation orientation) const
@@ -327,9 +345,9 @@ void ScrollView::valueChanged(Scrollbar* scrollbar)
     IntSize newOffset = m_scrollOffset;
     if (scrollbar) {
         if (scrollbar->orientation() == HorizontalScrollbar)
-            newOffset.setWidth(scrollbar->value());
+            newOffset.setWidth(scrollbar->value() - m_scrollOrigin.x());
         else if (scrollbar->orientation() == VerticalScrollbar)
-            newOffset.setHeight(scrollbar->value());
+            newOffset.setHeight(scrollbar->value() - m_scrollOrigin.y());
     }
 
     IntSize scrollDelta = newOffset - m_scrollOffset;
@@ -372,8 +390,7 @@ void ScrollView::setScrollPosition(const IntPoint& scrollPoint)
     }
 #endif
 
-    IntPoint newScrollPosition = scrollPoint.shrunkTo(maximumScrollPosition());
-    newScrollPosition.clampNegativeToZero();
+    IntPoint newScrollPosition = adjustScrollPositionWithinRange(scrollPoint);
 
     if (newScrollPosition == scrollPosition())
         return;
@@ -464,11 +481,15 @@ void ScrollView::updateScrollbars(const IntSize& desiredOffset)
             newHasHorizontalScrollbar = false;
 
         if (hasHorizontalScrollbar != newHasHorizontalScrollbar) {
+            if (m_scrollOrigin.y() && !newHasHorizontalScrollbar)
+                m_scrollOrigin.setY(m_scrollOrigin.y() - m_horizontalScrollbar->height());
             setHasHorizontalScrollbar(newHasHorizontalScrollbar);
             sendContentResizedNotification = true;
         }
 
         if (hasVerticalScrollbar != newHasVerticalScrollbar) {
+            if (m_scrollOrigin.x() && !newHasVerticalScrollbar)
+                m_scrollOrigin.setX(m_scrollOrigin.x() - m_verticalScrollbar->width());
             setHasVerticalScrollbar(newHasVerticalScrollbar);
             sendContentResizedNotification = true;
         }
@@ -494,10 +515,10 @@ void ScrollView::updateScrollbars(const IntSize& desiredOffset)
         return;
 
     m_inUpdateScrollbars = true;
-    IntSize maxScrollPosition(contentsWidth() - visibleWidth(), contentsHeight() - visibleHeight());
-    IntSize scroll = desiredOffset.shrunkTo(maxScrollPosition);
-    scroll.clampNegativeToZero();
- 
+
+    IntPoint scrollPoint = adjustScrollPositionWithinRange(IntPoint(desiredOffset.width(), desiredOffset.height()));
+    IntSize scroll(scrollPoint.x(), scrollPoint.y());
+
     if (m_horizontalScrollbar) {
         int clientWidth = visibleWidth();
         m_horizontalScrollbar->setEnabled(contentsWidth() > clientWidth);
@@ -515,7 +536,7 @@ void ScrollView::updateScrollbars(const IntSize& desiredOffset)
             m_horizontalScrollbar->setSuppressInvalidation(true);
         m_horizontalScrollbar->setSteps(Scrollbar::pixelsPerLineStep(), pageStep);
         m_horizontalScrollbar->setProportion(clientWidth, contentsWidth());
-        m_horizontalScrollbar->setValue(scroll.width(), Scrollbar::NotFromScrollAnimator);
+        m_horizontalScrollbar->setValue(scroll.width() + m_scrollOrigin.x(), Scrollbar::NotFromScrollAnimator);
         if (m_scrollbarsSuppressed)
             m_horizontalScrollbar->setSuppressInvalidation(false); 
     } 
@@ -537,7 +558,7 @@ void ScrollView::updateScrollbars(const IntSize& desiredOffset)
             m_verticalScrollbar->setSuppressInvalidation(true);
         m_verticalScrollbar->setSteps(Scrollbar::pixelsPerLineStep(), pageStep);
         m_verticalScrollbar->setProportion(clientHeight, contentsHeight());
-        m_verticalScrollbar->setValue(scroll.height(), Scrollbar::NotFromScrollAnimator);
+        m_verticalScrollbar->setValue(scroll.height() + m_scrollOrigin.y(), Scrollbar::NotFromScrollAnimator);
         if (m_scrollbarsSuppressed)
             m_verticalScrollbar->setSuppressInvalidation(false);
     }
@@ -1042,7 +1063,24 @@ void ScrollView::removePanScrollIcon()
     hostWindow()->invalidateContentsAndWindow(IntRect(m_panScrollIconPoint, IntSize(panIconSizeLength, panIconSizeLength)), true /*immediate*/);
 }
 
-#if !PLATFORM(WX) && !PLATFORM(GTK) && !PLATFORM(QT) && !PLATFORM(EFL)
+void ScrollView::setScrollOrigin(const IntPoint& origin, bool updatePosition)
+{
+    if (m_scrollOrigin == origin)
+        return;
+
+    m_scrollOrigin = origin;
+
+    if (platformWidget()) {
+        platformSetScrollOrigin(origin, updatePosition);
+        return;
+    }
+    
+    // Update if the scroll origin changes, since our position will be different if the content size did not change.
+    if (updatePosition)
+        updateScrollbars(scrollOffset());
+}
+
+#if !PLATFORM(WX) && !PLATFORM(GTK) && !PLATFORM(EFL)
 
 void ScrollView::platformInit()
 {
@@ -1072,6 +1110,10 @@ void ScrollView::platformSetScrollbarsSuppressed(bool)
 {
 }
 
+void ScrollView::platformSetScrollOrigin(const IntPoint&, bool updatePosition)
+{
+}
+
 #endif
 
 #if !PLATFORM(MAC) && !PLATFORM(WX)