pjs/layout/generic/nsPlaceholderFrame.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or 
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the NPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */
#include "nsPlaceholderFrame.h"
#include "nsLineLayout.h"
#include "nsIContent.h"
#include "nsIPresContext.h"
#include "nsIRenderingContext.h"
#include "nsLayoutAtoms.h"

nsresult
NS_NewPlaceholderFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame)
{
  NS_PRECONDITION(aNewFrame, "null OUT ptr");
  if (nsnull == aNewFrame) {
    return NS_ERROR_NULL_POINTER;
  }
  nsPlaceholderFrame* it = new (aPresShell) nsPlaceholderFrame;
  if (nsnull == it) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  *aNewFrame = it;
  return NS_OK;
}

// These are useful for debugging
nsPlaceholderFrame::nsPlaceholderFrame()
{
}

nsPlaceholderFrame::~nsPlaceholderFrame()
{
}

NS_IMETHODIMP
nsPlaceholderFrame::Reflow(nsIPresContext*          aPresContext,
                           nsHTMLReflowMetrics&     aDesiredSize,
                           const nsHTMLReflowState& aReflowState,
                           nsReflowStatus&          aStatus)
{
  DO_GLOBAL_REFLOW_COUNT("nsPlaceholderFrame", aReflowState.reason);
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
  aDesiredSize.width = 0;
  aDesiredSize.height = 0;
  aDesiredSize.ascent = 0;
  aDesiredSize.descent = 0;
  if (aDesiredSize.mComputeMEW) {
    aDesiredSize.mMaxElementWidth = 0;
  }

  aStatus = NS_FRAME_COMPLETE;
  NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
  return NS_OK;
}

nsIAtom*
nsPlaceholderFrame::GetType() const
{
  return nsLayoutAtoms::placeholderFrame; 
}

/* virtual */ PRBool
nsPlaceholderFrame::IsEmpty()
{
  return PR_TRUE;
}

#ifdef DEBUG
NS_IMETHODIMP
nsPlaceholderFrame::Paint(nsIPresContext*      aPresContext,
                          nsIRenderingContext& aRenderingContext,
                          const nsRect&        aDirtyRect,
                          nsFramePaintLayer    aWhichLayer,
                          PRUint32             aFlags)
{
  if ((NS_FRAME_PAINT_LAYER_DEBUG == aWhichLayer) && GetShowFrameBorders()) {
    float p2t;
    aPresContext->GetPixelsToTwips(&p2t);
    aRenderingContext.SetColor(NS_RGB(0, 255, 255));
    nscoord x = NSIntPixelsToTwips(-5, p2t);
    aRenderingContext.FillRect(x, 0, NSIntPixelsToTwips(13, p2t),
                               NSIntPixelsToTwips(3, p2t));
    nscoord y = NSIntPixelsToTwips(-10, p2t);
    aRenderingContext.FillRect(0, y, NSIntPixelsToTwips(3, p2t),
                               NSIntPixelsToTwips(10, p2t));
  }
  DO_GLOBAL_REFLOW_COUNT_DSP("nsPlaceholderFrame", &aRenderingContext);
  return NS_OK;
}

NS_IMETHODIMP
nsPlaceholderFrame::GetFrameName(nsAString& aResult) const
{
  return MakeFrameName(NS_LITERAL_STRING("Placeholder"), aResult);
}

NS_IMETHODIMP
nsPlaceholderFrame::List(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent) const
{
  IndentBy(out, aIndent);
  ListTag(out);
#ifdef DEBUG_waterson
  fprintf(out, " [parent=%p]", NS_STATIC_CAST(void*, mParent));
#endif
  if (HasView()) {
    fprintf(out, " [view=%p]", (void*)GetView());
  }
  fprintf(out, " {%d,%d,%d,%d}", mRect.x, mRect.y, mRect.width, mRect.height);
  if (0 != mState) {
    fprintf(out, " [state=%08x]", mState);
  }
  if (mOutOfFlowFrame) {
    fprintf(out, " outOfFlowFrame=");
    nsFrame::ListTag(out, mOutOfFlowFrame);
  }
  fputs("\n", out);
  return NS_OK;
}
#endif