layout/generic/nsPageContentFrame.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either of the GNU General Public License Version 2 or later (the "GPL"),
  26  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37 #include "nsPageContentFrame.h"
  38 #include "nsPageFrame.h"
  39 #include "nsPlaceholderFrame.h"
  40 #include "nsCSSFrameConstructor.h"
  41 #include "nsHTMLContainerFrame.h"
  42 #include "nsHTMLParts.h"
  43 #include "nsIContent.h"
  44 #include "nsPresContext.h"
  45 #include "nsIRenderingContext.h"
  46 #include "nsGkAtoms.h"
  47 #include "nsIPresShell.h"
  48 #include "nsIDeviceContext.h"
  49 #include "nsReadableUtils.h"
  50 #include "nsSimplePageSequence.h"
  51 #include "nsDisplayList.h"
  52
  53 nsIFrame*
  54 NS_NewPageContentFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
  55 {
  56   return new (aPresShell) nsPageContentFrame(aContext);
  57 }
  58
  59 NS_IMPL_FRAMEARENA_HELPERS(nsPageContentFrame)
  60
  61 /* virtual */ nsSize
  62 nsPageContentFrame::ComputeSize(nsIRenderingContext *aRenderingContext,
  63                                 nsSize aCBSize, nscoord aAvailableWidth,
  64                                 nsSize aMargin, nsSize aBorder, nsSize aPadding,
  65                                 PRBool aShrinkWrap)
  66 {
  67   NS_ASSERTION(mPD, "Pages are supposed to have page data");
  68   nscoord height = (!mPD || mPD->mReflowSize.height == NS_UNCONSTRAINEDSIZE)
  69                    ? NS_UNCONSTRAINEDSIZE
  70                    : (mPD->mReflowSize.height - mPD->mReflowMargin.TopBottom());
  71   return nsSize(aAvailableWidth, height);
  72 }
  73
  74 NS_IMETHODIMP
  75 nsPageContentFrame::Reflow(nsPresContext*           aPresContext,
  76                            nsHTMLReflowMetrics&     aDesiredSize,
  77                            const nsHTMLReflowState& aReflowState,
  78                            nsReflowStatus&          aStatus)
  79 {
  80   DO_GLOBAL_REFLOW_COUNT("nsPageContentFrame");
  81   DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
  82   aStatus = NS_FRAME_COMPLETE;  // initialize out parameter
  83   nsresult rv = NS_OK;
  84
  85   if (GetPrevInFlow() && (GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
  86     nsresult rv = aPresContext->PresShell()->FrameConstructor()
  87                     ->ReplicateFixedFrames(this);
  88     NS_ENSURE_SUCCESS(rv, rv);
  89   }
  90
  91   // Set our size up front, since some parts of reflow depend on it
  92   // being already set.  Note that the computed height may be
  93   // unconstrained; that's ok.  Consumers should watch out for that.
  94   SetSize(nsSize(aReflowState.availableWidth, aReflowState.availableHeight));
  95
  96   // A PageContentFrame must always have one child: the canvas frame.
  97   // Resize our frame allowing it only to be as big as we are
  98   // XXX Pay attention to the page's border and padding...
  99   if (mFrames.NotEmpty()) {
 100     nsIFrame* frame = mFrames.FirstChild();
 101     nsSize  maxSize(aReflowState.availableWidth, aReflowState.availableHeight);
 102     nsHTMLReflowState kidReflowState(aPresContext, aReflowState, frame, maxSize);
 103     kidReflowState.SetComputedHeight(aReflowState.availableHeight);
 104
 105     mPD->mPageContentSize  = aReflowState.availableWidth;
 106
 107     // Reflow the page content area
 108     rv = ReflowChild(frame, aPresContext, aDesiredSize, kidReflowState, 0, 0, 0, aStatus);
 109     NS_ENSURE_SUCCESS(rv, rv);
 110
 111     // The document element's background should cover the entire canvas, so
 112     // take into account the combined area and any space taken up by
 113     // absolutely positioned elements
 114     nsMargin padding(0,0,0,0);
 115
 116     // XXXbz this screws up percentage padding (sets padding to zero
 117     // in the percentage padding case)
 118     kidReflowState.mStylePadding->GetPadding(padding);
 119
 120     // This is for shrink-to-fit, and therefore we want to use the
 121     // scrollable overflow, since the purpose of shrink to fit is to
 122     // make the content that ought to be reachable (represented by the
 123     // scrollable overflow) fit in the page.
 124     if (frame->HasOverflowAreas()) {
 125       // The background covers the content area and padding area, so check
 126       // for children sticking outside the child frame's padding edge
 127       nscoord xmost = aDesiredSize.ScrollableOverflow().XMost();
 128       if (xmost > aDesiredSize.width) {
 129         mPD->mPageContentXMost =
 130           xmost +
 131           kidReflowState.mStyleBorder->GetActualBorderWidth(NS_SIDE_RIGHT) +
 132           padding.right;
 133       }
 134     }
 135
 136     // Place and size the child
 137     FinishReflowChild(frame, aPresContext, &kidReflowState, aDesiredSize, 0, 0, 0);
 138
 139     NS_ASSERTION(aPresContext->IsDynamic() || !NS_FRAME_IS_FULLY_COMPLETE(aStatus) ||
 140                   !frame->GetNextInFlow(), "bad child flow list");
 141   }
 142   // Reflow our fixed frames
 143   nsReflowStatus fixedStatus = NS_FRAME_COMPLETE;
 144   mFixedContainer.Reflow(this, aPresContext, aReflowState, fixedStatus,
 145                          aReflowState.availableWidth,
 146                          aReflowState.availableHeight,
 147                          PR_FALSE, PR_TRUE, PR_TRUE, // XXX could be optimized
 148                          nsnull /* ignore overflow */);
 149   NS_ASSERTION(NS_FRAME_IS_COMPLETE(fixedStatus), "fixed frames can be truncated, but not incomplete");
 150
 151   // Return our desired size
 152   aDesiredSize.width = aReflowState.availableWidth;
 153   if (aReflowState.availableHeight != NS_UNCONSTRAINEDSIZE) {
 154     aDesiredSize.height = aReflowState.availableHeight;
 155   }
 156
 157   FinishAndStoreOverflow(&aDesiredSize);
 158
 159   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
 160   return NS_OK;
 161 }
 162
 163 nsIAtom*
 164 nsPageContentFrame::GetType() const
 165 {
 166   return nsGkAtoms::pageContentFrame;
 167 }
 168
 169 #ifdef DEBUG
 170 NS_IMETHODIMP
 171 nsPageContentFrame::GetFrameName(nsAString& aResult) const
 172 {
 173   return MakeFrameName(NS_LITERAL_STRING("PageContent"), aResult);
 174 }
 175 #endif
 176
 177 /* virtual */ PRBool
 178 nsPageContentFrame::IsContainingBlock() const
 179 {
 180   return PR_TRUE;
 181 }