gecko-dev/layout/generic/nsPageFrame.cpp

/* -*- 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.
 */
#include "nsPageFrame.h"
#include "nsIContent.h"
#include "nsIPresContext.h"
#include "nsIStyleContext.h"
#include "nsIReflowCommand.h"
#include "nsIRenderingContext.h"
#include "nsHTMLAtoms.h"
#include "nsHTMLIIDs.h"

nsPageFrame::nsPageFrame(nsIContent* aContent, nsIFrame* aParent)
  : nsContainerFrame(aContent, aParent)
{
}

NS_METHOD nsPageFrame::Reflow(nsIPresContext&          aPresContext,
                              nsHTMLReflowMetrics&     aDesiredSize,
                              const nsHTMLReflowState& aReflowState,
                              nsReflowStatus&          aStatus)
{
  aStatus = NS_FRAME_COMPLETE;  // initialize out parameter

  // XXX Do something sensible in page mode...
  if (eReflowReason_Incremental == aReflowState.reason) {
    // We don't expect the target of the reflow command to be page frame
#ifdef NS_DEUG
    NS_ASSERTION(nsnull != aReflowState.reflowCommand, "null reflow command");

    nsIFrame* target;
    aReflowState.reflowCommand->GetTarget(target);
    NS_ASSERTION(target != this, "page frame is reflow command target");
#endif
  
    // Verify the next reflow command frame is our one and only child frame
    nsIFrame* next;
    aReflowState.reflowCommand->GetNext(next);
    NS_ASSERTION(next == mFirstChild, "bad reflow frame");

    // Dispatch the reflow command to our content child. Allow it to be as high
    // as it wants
    nsSize            maxSize(aReflowState.maxSize.width, NS_UNCONSTRAINEDSIZE);
    nsHTMLReflowState kidReflowState(aPresContext, mFirstChild, aReflowState,
                                     maxSize);
  
    ReflowChild(mFirstChild, aPresContext, aDesiredSize, kidReflowState, aStatus);
  
    // Place and size the child. Make sure the child is at least as
    // tall as our max size (the containing window)
    if (aDesiredSize.height < aReflowState.maxSize.height) {
      aDesiredSize.height = aReflowState.maxSize.height;
    }

    nsRect  rect(0, 0, aDesiredSize.width, aDesiredSize.height);
    mFirstChild->SetRect(rect);

  } else {
    // Do we have any children?
    // XXX We should use the overflow list instead...
    if ((nsnull == mFirstChild) && (nsnull != mPrevInFlow)) {
      nsPageFrame*  prevPage = (nsPageFrame*)mPrevInFlow;

      nsIFrame* prevLastChild = prevPage->LastFrame(prevPage->mFirstChild);

      // Create a continuing child of the previous page's last child
      nsIStyleContext* kidSC;
      prevLastChild->GetStyleContext(kidSC);
      nsresult rv = prevLastChild->CreateContinuingFrame(aPresContext, this,
                                                         kidSC, mFirstChild);
      NS_RELEASE(kidSC);
    }

    // Resize our frame allowing it only to be as big as we are
    // XXX Pay attention to the page's border and padding...
    if (nsnull != mFirstChild) {
      nsHTMLReflowState kidReflowState(aPresContext, mFirstChild, aReflowState,
                                       aReflowState.maxSize);
      nsIHTMLReflow*    htmlReflow;

      if (NS_OK == mFirstChild->QueryInterface(kIHTMLReflowIID, (void**)&htmlReflow)) {
        // Get the child's desired size
        ReflowChild(mFirstChild, aPresContext, aDesiredSize, kidReflowState, aStatus);
  
        // Make sure the child is at least as tall as our max size (the containing window)
        if (aDesiredSize.height < aReflowState.maxSize.height) {
          aDesiredSize.height = aReflowState.maxSize.height;
        }
  
        // Place and size the child
        nsRect  rect(0, 0, aDesiredSize.width, aDesiredSize.height);
        mFirstChild->SetRect(rect);
        // XXX Should we be sending the DidReflow?
        htmlReflow->DidReflow(aPresContext, NS_FRAME_REFLOW_FINISHED);
  
        // Is the frame complete?
        if (NS_FRAME_IS_COMPLETE(aStatus)) {
          nsIFrame* childNextInFlow;
  
          mFirstChild->GetNextInFlow(childNextInFlow);
          NS_ASSERTION(nsnull == childNextInFlow, "bad child flow list");
        }
      }
    }

    // Return our desired size
    aDesiredSize.width = aReflowState.maxSize.width;
    aDesiredSize.height = aReflowState.maxSize.height;
  }

  return NS_OK;
}

NS_METHOD
nsPageFrame::CreateContinuingFrame(nsIPresContext&  aPresContext,
                                   nsIFrame*        aParent,
                                   nsIStyleContext* aStyleContext,
                                   nsIFrame*&       aContinuingFrame)
{
  nsPageFrame* cf = new nsPageFrame(mContent, aParent);
  if (nsnull == cf) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  PrepareContinuingFrame(aPresContext, aParent, aStyleContext, cf);
  aContinuingFrame = cf;
  return NS_OK;
}

NS_METHOD nsPageFrame::Paint(nsIPresContext&      aPresContext,
                           nsIRenderingContext& aRenderingContext,
                           const nsRect&        aDirtyRect)
{
  nsContainerFrame::Paint(aPresContext, aRenderingContext, aDirtyRect);

  // For the time being paint a border around the page so we know
  // where each page begins and ends
  aRenderingContext.SetColor(NS_RGB(0, 0, 0));
  aRenderingContext.DrawRect(0, 0, mRect.width, mRect.height);
  return NS_OK;
}

NS_METHOD nsPageFrame::ListTag(FILE* out) const
{
  fprintf(out, "*Page<");
  nsIAtom* atom;
  mContent->GetTag(atom);
  if (nsnull != atom) {
    nsAutoString tmp;
    atom->ToString(tmp);
    fputs(tmp, out);
  }
  fprintf(out, ">(%d)@%p", ContentIndexInContainer(this), this);
  return NS_OK;
}