C++11: Replace 0 with nullptr where applicable in layout code.

Source/core/layout/LayoutObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 141 matching lines @@
     LayoutObject* parent() const { return m_parent; }
     bool isDescendantOf(const LayoutObject*) const;
 
     LayoutObject* previousSibling() const { return m_previous; }
     LayoutObject* nextSibling() const { return m_next; }
 
     LayoutObject* slowFirstChild() const
     {
         if (const LayoutObjectChildList* children = virtualChildren())
             return children->firstChild();
-        return 0;
+        return nullptr;
     }
     LayoutObject* slowLastChild() const
     {
         if (const LayoutObjectChildList* children = virtualChildren())
             return children->lastChild();
-        return 0;
+        return nullptr;
     }
 
-    virtual LayoutObjectChildList* virtualChildren() { return 0; }
-    virtual const LayoutObjectChildList* virtualChildren() const { return 0; }
+    virtual LayoutObjectChildList* virtualChildren() { return nullptr; }
+    virtual const LayoutObjectChildList* virtualChildren() const { return nullptr; }
 
     LayoutObject* nextInPreOrder() const;
     LayoutObject* nextInPreOrder(const LayoutObject* stayWithin) const;
     LayoutObject* nextInPreOrderAfterChildren() const;
     LayoutObject* nextInPreOrderAfterChildren(const LayoutObject* stayWithin) const;
     LayoutObject* previousInPreOrder() const;
     LayoutObject* previousInPreOrder(const LayoutObject* stayWithin) const;
     LayoutObject* childAt(unsigned) const;
 
     LayoutObject* lastLeafChild() const;
@@ skipping 14 matching lines @@
     LayoutBox* enclosingBox() const;
     LayoutBoxModelObject* enclosingBoxModelObject() const;
 
     LayoutBox* enclosingScrollableBox() const;
 
     // Function to return our enclosing flow thread if we are contained inside one. This
     // function follows the containing block chain.
     LayoutFlowThread* flowThreadContainingBlock() const
     {
         if (!isInsideFlowThread())
-            return 0;
+            return nullptr;
         return locateFlowThreadContainingBlock();
     }
 
 #if ENABLE(ASSERT)
     void setHasAXObject(bool flag) { m_hasAXObject = flag; }
     bool hasAXObject() const { return m_hasAXObject; }
 
     // Helper class forbidding calls to setNeedsLayout() during its lifetime.
     class SetLayoutNeededForbiddenScope {
     public:
@@ skipping 44 matching lines @@
     }
 
     // Obtains the nearest enclosing block (including this block) that contributes a first-line style to our inline
     // children.
     virtual LayoutBlock* firstLineBlock() const;
 
     // LayoutObject tree manipulation
     //////////////////////////////////////////
     virtual bool canHaveChildren() const { return virtualChildren(); }
     virtual bool isChildAllowed(LayoutObject*, const ComputedStyle&) const { return true; }
-    virtual void addChild(LayoutObject* newChild, LayoutObject* beforeChild = 0);
-    virtual void addChildIgnoringContinuation(LayoutObject* newChild, LayoutObject* beforeChild = 0) { return addChild(newChild, beforeChild); }
+    virtual void addChild(LayoutObject* newChild, LayoutObject* beforeChild = nullptr);
+    virtual void addChildIgnoringContinuation(LayoutObject* newChild, LayoutObject* beforeChild = nullptr) { return addChild(newChild, beforeChild); }
     virtual void removeChild(LayoutObject*);
     virtual bool createsAnonymousWrapper() const { return false; }
     //////////////////////////////////////////
 
 protected:
     //////////////////////////////////////////
     // Helper functions. Dangerous to use!
     void setPreviousSibling(LayoutObject* previous) { m_previous = previous; }
     void setNextSibling(LayoutObject* next) { m_next = next; }
     void setParent(LayoutObject* parent)
@@ skipping 27 matching lines @@
 public:
 #ifndef NDEBUG
     void showTreeForThis() const;
     void showLayoutTreeForThis() const;
     void showLineTreeForThis() const;
 
     void showLayoutObject() const;
     // We don't make printedCharacters an optional parameter so that
     // showLayoutObject can be called from gdb easily.
     void showLayoutObject(int printedCharacters) const;
-    void showLayoutTreeAndMark(const LayoutObject* markedObject1 = 0, const char* markedLabel1 = 0, const LayoutObject* markedObject2 = 0, const char* markedLabel2 = 0, int depth = 0) const;
+    void showLayoutTreeAndMark(const LayoutObject* markedObject1 = nullptr, const char* markedLabel1 = nullptr, const LayoutObject* markedObject2 = nullptr, const char* markedLabel2 = nullptr, int depth = 0) const;
 #endif
 
     static LayoutObject* createObject(Element*, const ComputedStyle&);
     static unsigned instanceCount() { return s_instanceCount; }
 
     // LayoutObjects are allocated out of the rendering partition.
     void* operator new(size_t);
     void operator delete(void*);
 
 public:
@@ skipping 166 matching lines @@
         // This function is kept in sync with anonymous block creation conditions in
         // LayoutBlock::createAnonymousBlock(). This includes creating an anonymous
         // LayoutBlock having a BLOCK or BOX display. Other classes such as LayoutTextFragment
         // are not LayoutBlocks and will return false. See https://bugs.webkit.org/show_bug.cgi?id=56709.
         return isAnonymous() && (style()->display() == BLOCK || style()->display() == BOX) && style()->styleType() == NOPSEUDO && isLayoutBlock() && !isListMarker() && !isLayoutFlowThread() && !isLayoutMultiColumnSet()
             && !isLayoutFullScreen()
             && !isLayoutFullScreenPlaceholder();
     }
     bool isElementContinuation() const { return node() && node()->layoutObject() != this; }
     bool isInlineElementContinuation() const { return isElementContinuation() && isInline(); }
-    virtual LayoutBoxModelObject* virtualContinuation() const { return 0; }
+    virtual LayoutBoxModelObject* virtualContinuation() const { return nullptr; }
 
     bool isFloating() const { return m_bitfields.floating(); }
 
     bool isOutOfFlowPositioned() const { return m_bitfields.isOutOfFlowPositioned(); } // absolute or fixed positioning
     bool isRelPositioned() const { return m_bitfields.isRelPositioned(); } // relative positioning
     bool isPositioned() const { return m_bitfields.isPositioned(); }
 
     bool isText() const  { return m_bitfields.isText(); }
     bool isBox() const { return m_bitfields.isBox(); }
     bool isInline() const { return m_bitfields.isInline(); } // inline object
@@ skipping 59 matching lines @@
     bool hasHiddenBackface() const { return style() && style()->backfaceVisibility() == BackfaceVisibilityHidden; }
 
     bool hasFilter() const { return style() && style()->hasFilter(); }
 
     bool hasShapeOutside() const { return style() && style()->shapeOutside(); }
 
     inline bool preservesNewline() const;
 
     // The pseudo element style can be cached or uncached.  Use the cached method if the pseudo element doesn't respect
     // any pseudo classes (and therefore has no concept of changing state).
-    ComputedStyle* getCachedPseudoStyle(PseudoId, const ComputedStyle* parentStyle = 0) const;
-    PassRefPtr<ComputedStyle> getUncachedPseudoStyle(const PseudoStyleRequest&, const ComputedStyle* parentStyle = 0, const ComputedStyle* ownStyle = 0) const;
+    ComputedStyle* getCachedPseudoStyle(PseudoId, const ComputedStyle* parentStyle = nullptr) const;
+    PassRefPtr<ComputedStyle> getUncachedPseudoStyle(const PseudoStyleRequest&, const ComputedStyle* parentStyle = nullptr, const ComputedStyle* ownStyle = nullptr) const;
 
     virtual void updateDragState(bool dragOn);
 
     LayoutView* view() const { return document().layoutView(); };
     FrameView* frameView() const { return document().view(); };
 
     bool isRooted() const;
 
     Node* node() const
     {
         return isAnonymous() ? 0 : m_node;
     }
 
     Node* nonPseudoNode() const
     {
         return isPseudoElement() ? 0 : node();
     }
 
     void clearNode() { m_node = nullptr; }
 
     // Returns the styled node that caused the generation of this layoutObject.
     // This is the same as node() except for layoutObjects of :before, :after and
     // :first-letter pseudo elements for which their parent node is returned.
     Node* generatingNode() const { return isPseudoElement() ? node()->parentOrShadowHostNode() : node(); }
 
     Document& document() const { return m_node->document(); }
     LocalFrame* frame() const { return document().frame(); }
 
-    virtual LayoutMultiColumnSpannerPlaceholder* spannerPlaceholder() const { return 0; }
+    virtual LayoutMultiColumnSpannerPlaceholder* spannerPlaceholder() const { return nullptr; }
     bool isColumnSpanAll() const { return style()->columnSpan() == ColumnSpanAll && spannerPlaceholder(); }
 
     // Returns the object containing this one. Can be different from parent for positioned elements.
     // If paintInvalidationContainer and paintInvalidationContainerSkipped are not null, on return *paintInvalidationContainerSkipped
     // is true if the layoutObject returned is an ancestor of paintInvalidationContainer.
-    LayoutObject* container(const LayoutBoxModelObject* paintInvalidationContainer = 0, bool* paintInvalidationContainerSkipped = 0) const;
-    LayoutBlock* containerForFixedPosition(const LayoutBoxModelObject* paintInvalidationContainer = 0, bool* paintInvalidationContainerSkipped = 0) const;
+    LayoutObject* container(const LayoutBoxModelObject* paintInvalidationContainer = nullptr, bool* paintInvalidationContainerSkipped = nullptr) const;
+    LayoutBlock* containerForFixedPosition(const LayoutBoxModelObject* paintInvalidationContainer = nullptr, bool* paintInvalidationContainerSkipped = nullptr) const;
 
     virtual LayoutObject* hoverAncestor() const { return parent(); }
 
     Element* offsetParent() const;
 
-    void markContainerChainForLayout(bool scheduleRelayout = true, LayoutObject* newRoot = 0, SubtreeLayoutScope* = 0);
-    void setNeedsLayout(LayoutInvalidationReasonForTracing, MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = 0);
-    void setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReasonForTracing, MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = 0);
+    void markContainerChainForLayout(bool scheduleRelayout = true, LayoutObject* newRoot = nullptr, SubtreeLayoutScope* = nullptr);
+    void setNeedsLayout(LayoutInvalidationReasonForTracing, MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = nullptr);
+    void setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReasonForTracing, MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = nullptr);
     void clearNeedsLayout();
-    void setChildNeedsLayout(MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = 0);
+    void setChildNeedsLayout(MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = nullptr);
     void setNeedsPositionedMovementLayout();
     void setPreferredLogicalWidthsDirty(MarkingBehavior = MarkContainerChain);
     void clearPreferredLogicalWidthsDirty();
 
     void setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReasonForTracing reason)
     {
         setNeedsLayout(reason);
         setPreferredLogicalWidthsDirty();
     }
     void setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReasonForTracing reason)
@@ skipping 98 matching lines @@
     {
         return isLayoutView() || (hasTransformRelatedProperty() && isLayoutBlock()) || isSVGForeignObject();
     }
 
     // Convert the given local point to absolute coordinates
     // FIXME: Temporary. If UseTransforms is true, take transforms into account. Eventually localToAbsolute() will always be transform-aware.
     FloatPoint localToAbsolute(const FloatPoint& localPoint = FloatPoint(), MapCoordinatesFlags = 0) const;
     FloatPoint absoluteToLocal(const FloatPoint&, MapCoordinatesFlags = 0) const;
 
     // Convert a local quad to absolute coordinates, taking transforms into account.
-    FloatQuad localToAbsoluteQuad(const FloatQuad& quad, MapCoordinatesFlags mode = 0, bool* wasFixed = 0) const
+    FloatQuad localToAbsoluteQuad(const FloatQuad& quad, MapCoordinatesFlags mode = 0, bool* wasFixed = nullptr) const
     {
         return localToContainerQuad(quad, 0, mode, wasFixed);
     }
     // Convert an absolute quad to local coordinates.
     FloatQuad absoluteToLocalQuad(const FloatQuad&, MapCoordinatesFlags mode = 0) const;
 
     // Convert a local quad into the coordinate system of container, taking transforms into account.
-    FloatQuad localToContainerQuad(const FloatQuad&, const LayoutBoxModelObject* paintInvalidatinoContainer, MapCoordinatesFlags = 0, bool* wasFixed = 0) const;
-    FloatPoint localToContainerPoint(const FloatPoint&, const LayoutBoxModelObject* paintInvalidationContainer, MapCoordinatesFlags = 0, bool* wasFixed = 0, const PaintInvalidationState* = 0) const;
+    FloatQuad localToContainerQuad(const FloatQuad&, const LayoutBoxModelObject* paintInvalidationContainer, MapCoordinatesFlags = 0, bool* wasFixed = nullptr) const;
+    FloatPoint localToContainerPoint(const FloatPoint&, const LayoutBoxModelObject* paintInvalidationContainer, MapCoordinatesFlags = 0, bool* wasFixed = nullptr, const PaintInvalidationState* = nullptr) const;
 
     // Convert a local point into the coordinate system of backing coordinates. Also returns the backing layer if needed.
     FloatPoint localToInvalidationBackingPoint(const LayoutPoint&, DeprecatedPaintLayer** backingLayer = nullptr);
 
     // Return the offset from the container() layoutObject (excluding transforms). In multi-column layout,
     // different offsets apply at different points, so return the offset that applies to the given point.
-    virtual LayoutSize offsetFromContainer(const LayoutObject*, const LayoutPoint&, bool* offsetDependsOnPoint = 0) const;
+    virtual LayoutSize offsetFromContainer(const LayoutObject*, const LayoutPoint&, bool* offsetDependsOnPoint = nullptr) const;
     // Return the offset from an object up the container() chain. Asserts that none of the intermediate objects have transforms.
     LayoutSize offsetFromAncestorContainer(const LayoutObject*) const;
 
     virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint&) const { }
 
     FloatRect absoluteBoundingBoxFloatRect() const;
     // This returns an IntRect enclosing this object. If this object has an
     // integral size and the position has fractional values, the resultant
     // IntRect can be larger than the integral size.
     IntRect absoluteBoundingBoxRect() const;
     // FIXME: This function should go away eventually
     IntRect absoluteBoundingBoxRectIgnoringTransforms() const;
 
     // Build an array of quads in absolute coords for line boxes
-    virtual void absoluteQuads(Vector<FloatQuad>&, bool* /*wasFixed*/ = 0) const { }
+    virtual void absoluteQuads(Vector<FloatQuad>&, bool* /* wasFixed */ = nullptr) const { }
 
     virtual IntRect absoluteFocusRingBoundingBoxRect() const;
 
     static FloatRect absoluteBoundingBoxRectForRange(const Range*);
 
     // the rect that will be painted if this object is passed as the paintingRoot
     IntRect paintingRootRect(IntRect& topLevelRect);
 
     virtual LayoutUnit minPreferredLogicalWidth() const { return 0; }
     virtual LayoutUnit maxPreferredLogicalWidth() const { return 0; }
@@ skipping 47 matching lines @@
 
     const LayoutBoxModelObject* adjustCompositedContainerForSpecialAncestors(const LayoutBoxModelObject* paintInvalidationContainer) const;
     bool isPaintInvalidationContainer() const;
 
     LayoutRect computePaintInvalidationRect()
     {
         return computePaintInvalidationRect(containerForPaintInvalidation());
     }
 
     // Returns the paint invalidation rect for this LayoutObject in the coordinate space of the paint backing (typically a GraphicsLayer) for |paintInvalidationContainer|.
-    LayoutRect computePaintInvalidationRect(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = 0) const;
+    LayoutRect computePaintInvalidationRect(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = nullptr) const;
 
     // Returns the rect bounds needed to invalidate the paint of this object, in the coordinate space of the layoutObject backing of |paintInvalidationContainer|
-    LayoutRect boundsRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = 0) const;
+    LayoutRect boundsRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = nullptr) const;
 
     // Actually do the paint invalidate of rect r for this object which has been computed in the coordinate space
     // of the GraphicsLayer backing of |paintInvalidationContainer|. Note that this coordinaten space is not the same
     // as the local coordinate space of |paintInvalidationContainer| in the presence of layer squashing.
     void invalidatePaintUsingContainer(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason) const;
 
     // Invalidate the paint of a specific subrectangle within a given object. The rect |r| is in the object's coordinate space.
     void invalidatePaintRectangle(const LayoutRect&) const;
     void invalidatePaintRectangleNotInvalidatingDisplayItemClients(const LayoutRect& r) const { invalidatePaintRectangleInternal(r); }
 
     // Walk the tree after layout issuing paint invalidations for layoutObjects that have changed or moved, updating bounds that have changed, and clearing paint invalidation state.
     virtual void invalidateTreeIfNeeded(PaintInvalidationState&);
 
     virtual void invalidatePaintForOverflow();
     void invalidatePaintForOverflowIfNeeded();
 
     void invalidatePaintIncludingNonCompositingDescendants();
     void setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
 
     // Returns the rect that should have paint invalidated whenever this object changes. The rect is in the view's
     // coordinate space. This method deals with outlines and overflow.
     virtual LayoutRect absoluteClippedOverflowRect() const;
-    virtual LayoutRect clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = 0) const;
-    virtual LayoutRect rectWithOutlineForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, LayoutUnit outlineWidth, const PaintInvalidationState* = 0) const;
+    virtual LayoutRect clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = nullptr) const;
+    virtual LayoutRect rectWithOutlineForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, LayoutUnit outlineWidth, const PaintInvalidationState* = nullptr) const;
 
     // Given a rect in the object's coordinate space, compute a rect suitable for invalidating paints of
     // that rect in the coordinate space of paintInvalidationContainer.
     virtual void mapRectToPaintInvalidationBacking(const LayoutBoxModelObject* paintInvalidationContainer, LayoutRect&, const PaintInvalidationState*) const;
 
     // Return the offset to the column in which the specified point (in flow-thread coordinates)
     // lives. This is used to convert a flow-thread point to a visual point.
     virtual LayoutSize columnOffset(const LayoutPoint&) const { return LayoutSize(); }
 
     virtual unsigned length() const { return 1; }
@@ skipping 38 matching lines @@
 
     // Whether or not a given block needs to paint selection gaps.
     virtual bool shouldPaintSelectionGaps() const { return false; }
 
     /**
      * Returns the local coordinates of the caret within this layout object.
      * @param caretOffset zero-based offset determining position within the layout object.
      * @param extraWidthToEndOfLine optional out arg to give extra width to end of line -
      * useful for character range rect computations
      */
-    virtual LayoutRect localCaretRect(InlineBox*, int caretOffset, LayoutUnit* extraWidthToEndOfLine = 0);
+    virtual LayoutRect localCaretRect(InlineBox*, int caretOffset, LayoutUnit* extraWidthToEndOfLine = nullptr);
 
     // When performing a global document tear-down, the layoutObject of the document is cleared. We use this
     // as a hook to detect the case of document destruction and don't waste time doing unnecessary work.
     bool documentBeingDestroyed() const;
 
     void destroyAndCleanupAnonymousWrappers();
 
     // While the destroy() method is virtual, this should only be overriden in very rare circumstances.
     // You want to override willBeDestroyed() instead unless you explicitly need to stop this object
     // from being destroyed (for example, LayoutPart overrides destroy() for this purpose).
@@ skipping 12 matching lines @@
 
     virtual bool isCombineText() const { return false; }
 
     virtual int caretMinOffset() const;
     virtual int caretMaxOffset() const;
 
     virtual int previousOffset(int current) const;
     virtual int previousOffsetForBackwardDeletion(int current) const;
     virtual int nextOffset(int current) const;
 
-    virtual void imageChanged(ImageResource*, const IntRect* = 0) override final;
-    virtual void imageChanged(WrappedImagePtr, const IntRect* = 0) { }
+    virtual void imageChanged(ImageResource*, const IntRect* = nullptr) override final;
+    virtual void imageChanged(WrappedImagePtr, const IntRect* = nullptr) { }
     virtual bool willRenderImage(ImageResource*) override final;
     virtual bool getImageAnimationPolicy(ImageResource*, ImageAnimationPolicy&) override final;
 
     void selectionStartEnd(int& spos, int& epos) const;
 
     void remove()
     {
         if (parent())
             parent()->removeChild(this);
     }
 
     bool visibleToHitTestRequest(const HitTestRequest& request) const { return style()->visibility() == VISIBLE && (request.ignorePointerEventsNone() || style()->pointerEvents() != PE_NONE) && !isInert(); }
 
     bool visibleToHitTesting() const { return style()->visibility() == VISIBLE && style()->pointerEvents() != PE_NONE && !isInert(); }
 
     // Map points and quads through elements, potentially via 3d transforms. You should never need to call these directly; use
     // localToAbsolute/absoluteToLocal methods instead.
-    virtual void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0, const PaintInvalidationState* = 0) const;
+    virtual void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = nullptr, const PaintInvalidationState* = nullptr) const;
     virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const;
 
     // Pushes state onto LayoutGeometryMap about how to map coordinates from this layoutObject to its container, or ancestorToStopAt (whichever is encountered first).
     // Returns the layoutObject which was mapped to (container or ancestorToStopAt).
     virtual const LayoutObject* pushMappingToContainer(const LayoutBoxModelObject* ancestorToStopAt, LayoutGeometryMap&) const;
 
     bool shouldUseTransformFromContainer(const LayoutObject* container) const;
     void getTransformFromContainer(const LayoutObject* container, const LayoutSize& offsetInContainer, TransformationMatrix&) const;
 
     bool createsGroup() const { return isTransparent() || hasMask() || hasFilter() || style()->hasBlendMode(); }
@@ skipping 661 matching lines @@
 void showTree(const blink::LayoutObject*);
 void showLineTree(const blink::LayoutObject*);
 void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 void showLayoutTree(const blink::LayoutObject* object1, const blink::LayoutObject* object2);
 
 #endif
 
 #endif // LayoutObject_h