gecko-dev/layout/tables/nsTableColGroupFrame.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */
#ifndef nsTableColGroupFrame_h__
#define nsTableColGroupFrame_h__

#include "nscore.h"
#include "nsContainerFrame.h"


/**
 * nsTableColGroupFrame
 * data structure to maintain information about a single table cell's frame
 *
 * @author  sclark
 */
class nsTableColGroupFrame : public nsContainerFrame
{
public:
  /** instantiate a new instance of nsTableColGroupFrame.
    * @param aResult    the new object is returned in this out-param
    * @param aContent   the table object to map
    * @param aParent    the parent of the new frame
    *
    * @return  NS_OK if the frame was properly allocated, otherwise an error code
    */
  friend nsresult 
  NS_NewTableColGroupFrame(nsIContent* aContent,
                           nsIFrame*   aParentFrame,
                           nsIFrame*&  aResult);

  NS_IMETHOD Init(nsIPresContext& aPresContext, nsIFrame* aChildList);

  NS_IMETHOD Paint(nsIPresContext& aPresContext,
                   nsIRenderingContext& aRenderingContext,
                   const nsRect& aDirtyRect);

  /** reflow of a column group is a trivial matter of reflowing
    * the col group's children (columns), and setting this frame
    * to 0-size.  Since tables are row-centric, column group frames
    * don't play directly in the rendering game.  They do however
    * maintain important state that effects table and cell layout.
    */
  NS_IMETHOD Reflow(nsIPresContext&      aPresContext,
                    nsReflowMetrics&     aDesiredSize,
                    const nsReflowState& aReflowState,
                    nsReflowStatus&      aStatus);

  /** returns the number of columns represented by this group.
    * if there are col children, count them (taking into account the span of each)
    * else, check my own span attribute.
    */
  virtual PRInt32 GetColumnCount ();

  virtual PRInt32 GetStartColumnIndex ();
  
  virtual void SetStartColumnIndex (PRInt32 aIndex);

  /** helper method to get the span attribute for this colgroup */
  PRInt32 GetSpan();

  NS_IMETHOD  List(FILE* out = stdout, PRInt32 aIndent = 0, nsIListFilter *aFilter = nsnull) const;

protected:

  nsTableColGroupFrame(nsIContent* aContent, nsIFrame* aParentFrame);

  ~nsTableColGroupFrame();

  /** Hook for style post processing.  
    * Since we need to know the full column structure before the COLS attribute
    * can be interpreted, we can't just use DidSetStyleContext
    */
  NS_METHOD SetStyleContextForFirstPass(nsIPresContext* aPresContext);

  nsresult InitNewFrames(nsIPresContext& aPresContext, nsIFrame* aChildList);
  nsresult AppendNewFrames(nsIPresContext& aPresContext, nsIFrame* aChildList);
  
  PRInt32 mColCount;

  /** the starting column index this col group represents. Must be >= 0. */
  PRInt32 mStartColIndex;

};

inline int nsTableColGroupFrame::GetStartColumnIndex ()
{  return mStartColIndex;}
  
inline void nsTableColGroupFrame::SetStartColumnIndex (int aIndex)
{
  if (aIndex != mStartColIndex)
    mColCount = 0;  // our index is being changed, trigger reset of col indicies, don't propogate back to table
  mStartColIndex = aIndex;
}

#endif