EXT-3159 Mouse-wheel scrolling down causes unexpected side-scrolling

If vertical scroll bar is visible, give it the scroll events and
don't scroll horizontally.  Eliminated extraneous folder view item
scroll handler.  Reviewed with Richard.

4 files changed, 36 insertions, 17 deletions

diff --git a/indra/llui/llscrollcontainer.cpp b/indra/llui/llscrollcontainer.cpp
index f6caed4617..a5e47e8547 100644
--- a/indra/llui/llscrollcontainer.cpp
+++ b/indra/llui/llscrollcontainer.cpp
@@ -235,18 +235,37 @@ BOOL LLScrollContainer::handleKeyHere(KEY key, MASK mask)
 
 BOOL LLScrollContainer::handleScrollWheel( S32 x, S32 y, S32 clicks )
 {
-	if(LLUICtrl::handleScrollWheel(x,y,clicks))
+	// Give event to my child views - they may have scroll bars
+	// (Bad UI design, but technically possible.)
+	if (LLUICtrl::handleScrollWheel(x,y,clicks))
 		return TRUE;
-	for( S32 i = 0; i < SCROLLBAR_COUNT; i++ )
-	{
-		// Note: tries vertical and then horizontal
 
+	// When the vertical scrollbar is visible, scroll wheel
+	// only affects vertical scrolling.  It's confusing to have
+	// scroll wheel perform both vertical and horizontal in a
+	// single container.
+	LLScrollbar* vertical = mScrollbar[VERTICAL];
+	if (vertical->getVisible()
+		&& vertical->getEnabled())
+	{
 		// Pretend the mouse is over the scrollbar
-		if( mScrollbar[i]->handleScrollWheel( 0, 0, clicks ) )
+		if (vertical->handleScrollWheel( 0, 0, clicks ) )
 		{
 			updateScroll();
-			return TRUE;
 		}
+		// Always eat the event
+		return TRUE;
+	}
+
+	LLScrollbar* horizontal = mScrollbar[HORIZONTAL];
+	// Test enablement and visibility for consistency with
+	// LLView::childrenHandleScrollWheel().
+	if (horizontal->getVisible()
+		&& horizontal->getEnabled()
+		&& horizontal->handleScrollWheel( 0, 0, clicks ) )
+	{
+		updateScroll();
+		return TRUE;
 	}
 	return FALSE;
 }
diff --git a/indra/newview/llfolderviewitem.cpp b/indra/newview/llfolderviewitem.cpp
index 63511301b3..fdc5c053fc 100644
--- a/indra/newview/llfolderviewitem.cpp
+++ b/indra/newview/llfolderviewitem.cpp
@@ -735,15 +735,6 @@ BOOL LLFolderViewItem::handleDoubleClick( S32 x, S32 y, MASK mask )
 	return TRUE;
 }
 
-BOOL LLFolderViewItem::handleScrollWheel(S32 x, S32 y, S32 clicks)
-{
-	if (getParent())
-	{
-		return getParent()->handleScrollWheel(x, y, clicks);
-	}
-	return FALSE;
-}
-
 BOOL LLFolderViewItem::handleMouseUp( S32 x, S32 y, MASK mask )
 {
 	if (LLView::childrenHandleMouseUp(x, y, mask))
diff --git a/indra/newview/llfolderviewitem.h b/indra/newview/llfolderviewitem.h
index f6264ec968..9683d17096 100644
--- a/indra/newview/llfolderviewitem.h
+++ b/indra/newview/llfolderviewitem.h
@@ -319,7 +319,6 @@ public:
 	virtual BOOL handleHover( S32 x, S32 y, MASK mask );
 	virtual BOOL handleMouseUp( S32 x, S32 y, MASK mask );
 	virtual BOOL handleDoubleClick( S32 x, S32 y, MASK mask );
-	virtual BOOL handleScrollWheel(S32 x, S32 y, S32 clicks);
 
 	//	virtual void handleDropped();
 	virtual void draw();
diff --git a/indra/newview/skins/default/xui/en/floater_test_text_editor.xml b/indra/newview/skins/default/xui/en/floater_test_text_editor.xml
index b0aa5c7c4f..8be0c28c5c 100644
--- a/indra/newview/skins/default/xui/en/floater_test_text_editor.xml
+++ b/indra/newview/skins/default/xui/en/floater_test_text_editor.xml
@@ -9,7 +9,6 @@
   <text_editor
    height="50"
    follows="top|left|bottom"
-   layout="topleft"
    left="10"
    name="test_text_editor"
    tool_tip="text editor"
@@ -17,4 +16,15 @@
    width="200">
     Text Editor
   </text_editor>
+  <text_editor
+   height="50"
+   follows="top|left|bottom"
+   font="SansSerif" 
+   left="10"
+   name="test_text_editor"
+   tool_tip="text editor"
+   top_pad="10"
+   width="200">
+    This contains long text and should scroll horizontally to the right
+  </text_editor>
 </floater>