DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Untracked file

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla 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/MPL/
 *
 * 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 Communicator client 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):
 *   Steve Clark <buster@netscape.com>
 *   Robert O'Callahan <roc+moz@cs.cmu.edu>
 *   L. David Baron <dbaron@dbaron.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of 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 MPL, 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 MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef nsBlockReflowState_h__
#define nsBlockReflowState_h__

#include "nsBlockBandData.h"
#include "nsLineBox.h"
#include "nsFrameList.h"

class nsBlockFrame;

  // block reflow state flags
#define BRS_UNCONSTRAINEDWIDTH    0x00000001
#define BRS_UNCONSTRAINEDHEIGHT   0x00000002
#define BRS_SHRINKWRAPWIDTH       0x00000004
#define BRS_NEEDRESIZEREFLOW      0x00000008
#define BRS_ISTOPMARGINROOT       0x00000020  // Is this frame a root for top/bottom margin collapsing?
#define BRS_ISBOTTOMMARGINROOT    0x00000040
#define BRS_APPLYTOPMARGIN        0x00000080  // See ShouldApplyTopMargin
#define BRS_COMPUTEMAXELEMENTWIDTH 0x00000100
#define BRS_COMPUTEMAXWIDTH       0x00000200
#define BRS_ISFIRSTINFLOW         0x00000400
#define BRS_LASTFLAG              BRS_ISFIRSTINFLOW

class nsBlockReflowState {
public:
  nsBlockReflowState(const nsHTMLReflowState& aReflowState,
                     nsPresContext* aPresContext,
                     nsBlockFrame* aFrame,
                     const nsHTMLReflowMetrics& aMetrics,
                     PRBool aTopMarginRoot, PRBool aBottomMarginRoot);

  ~nsBlockReflowState();

  // Set up a property on the block that points to our temporary mOverflowPlaceholders
  // list, if that list is or could become non-empty during this reflow. Must be
  // called after the block has done DrainOverflowLines because DrainOverflowLines
  // can setup mOverflowPlaceholders even if the block is in unconstrained height
  // reflow (it may have previously been reflowed with constrained height).
  void SetupOverflowPlaceholdersProperty();

  /**
   * Get the available reflow space for the current y coordinate. The
   * available space is relative to our coordinate system (0,0) is our
   * upper left corner.
   */
  void GetAvailableSpace() { GetAvailableSpace(mY, PR_FALSE); }
  void GetAvailableSpace(nscoord aY, PRBool aRelaxHeightConstraint);

  /*
   * The following functions all return PR_TRUE if they were able to
   * place the float, PR_FALSE if the float did not fit in available
   * space.
   */
  PRBool InitFloat(nsLineLayout&       aLineLayout,
                   nsPlaceholderFrame* aPlaceholderFrame,
                   nsReflowStatus&     aReflowStatus);
  PRBool AddFloat(nsLineLayout&       aLineLayout,
                  nsPlaceholderFrame* aPlaceholderFrame,
                  PRBool              aInitialReflow,
                  nsReflowStatus&     aReflowStatus);
  PRBool CanPlaceFloat(const nsSize& aFloatSize, PRUint8 aFloats, PRBool aForceFit);
  PRBool FlowAndPlaceFloat(nsFloatCache*   aFloatCache,
                           PRBool*         aIsLeftFloat,
                           nsReflowStatus& aReflowStatus,
                           PRBool          aForceFit);
  PRBool PlaceBelowCurrentLineFloats(nsFloatCacheList& aFloats, PRBool aForceFit);

  // Returns the first coordinate >= aY that clears the
  // indicated floats.
  nscoord ClearFloats(nscoord aY, PRUint8 aBreakType);

  PRBool IsAdjacentWithTop() const {
    return mY ==
      ((mFlags & BRS_ISFIRSTINFLOW) ? mReflowState.mComputedBorderPadding.top : 0);
  }

  /**
   * Adjusts the border/padding to return 0 for the top if
   * we are no the first in flow.
   */
  nsMargin BorderPadding() const {
    nsMargin result = mReflowState.mComputedBorderPadding;
    if (!(mFlags & BRS_ISFIRSTINFLOW)) {
      result.top = 0;
    }
    return result;
  }

  // XXX maybe we should do the same adjustment for continuations here
  const nsMargin& Margin() const {
    return mReflowState.mComputedMargin;
  }

  void UpdateMaxElementWidth(nscoord aMaxElementWidth);

  void UpdateMaximumWidth(nscoord aMaximumWidth);

  // Reconstruct the previous bottom margin that goes above |aLine|.
  void ReconstructMarginAbove(nsLineList::iterator aLine);

  void ComputeBlockAvailSpace(nsIFrame* aFrame,
                              nsSplittableType aSplitType,
                              const nsStyleDisplay* aDisplay,
                              nsRect& aResult);

protected:
  void RecoverFloats(nsLineList::iterator aLine, nscoord aDeltaY);

public:
  void RecoverStateFrom(nsLineList::iterator aLine, nscoord aDeltaY);

  void AdvanceToNextLine() {
    mLineNumber++;
  }

  PRBool IsImpactedByFloat() const;

  nsLineBox* NewLineBox(nsIFrame* aFrame, PRInt32 aCount, PRBool aIsBlock);

  void FreeLineBox(nsLineBox* aLine);

  //----------------------------------------

  // This state is the "global" state computed once for the reflow of
  // the block.

  // The block frame that is using this object
  nsBlockFrame* mBlock;

  nsPresContext* mPresContext;

  const nsHTMLReflowState& mReflowState;

  nsSpaceManager* mSpaceManager;

  // The coordinates within the spacemanager where the block is being
  // placed <b>after</b> taking into account the blocks border and
  // padding. This, therefore, represents the inner "content area" (in
  // spacemanager coordinates) where child frames will be placed,
  // including child blocks and floats.
  nscoord mSpaceManagerX, mSpaceManagerY;

  // XXX get rid of this
  nsReflowStatus mReflowStatus;

  nscoord mBottomEdge;

  // The content area to reflow child frames within. The x/y
  // coordinates are known to be mBorderPadding.left and
  // mBorderPadding.top. The width/height may be NS_UNCONSTRAINEDSIZE
  // if the container reflowing this frame has given the frame an
  // unconstrained area.
  nsSize mContentArea;

  // Placeholders for continuation out-of-flow frames that need to
  // move to our next in flow are placed here during reflow. At the end of reflow
  // they move to the end of the overflow lines.
  // Their out-of-flows are not in any child list during reflow, but are added
  // to the overflow-out-of-flow list when the placeholders are appended to
  // the overflow lines.
  nsFrameList mOverflowPlaceholders;

  //----------------------------------------

  // This state is "running" state updated by the reflow of each line
  // in the block. This same state is "recovered" when a line is not
  // dirty and is passed over during incremental reflow.

  // The current line being reflowed
  // If it is mBlock->end_lines(), then it is invalid.
  nsLineList::iterator mCurrentLine;

  // The current Y coordinate in the block
  nscoord mY;

  // The available space within the current band.
  nsRect mAvailSpaceRect;

  // The maximum x-most of each line
  nscoord mKidXMost;

  // The combined area of all floats placed so far
  nsRect mFloatCombinedArea;

  nsFloatCacheFreeList mFloatCacheFreeList;

  // Previous child. This is used when pulling up a frame to update
  // the sibling list.
  nsIFrame* mPrevChild;

  // The previous child frames collapsed bottom margin value.
  nsCollapsingMargin mPrevBottomMargin;

  // The current next-in-flow for the block. When lines are pulled
  // from a next-in-flow, this is used to know which next-in-flow to
  // pull from. When a next-in-flow is emptied of lines, we advance
  // this to the next next-in-flow.
  nsBlockFrame* mNextInFlow;

  // The current band data for the current Y coordinate
  nsBlockBandData mBand;

  //----------------------------------------

  // Temporary line-reflow state. This state is used during the reflow
  // of a given line, but doesn't have meaning before or after.

  // The list of floats that are "current-line" floats. These are
  // added to the line after the line has been reflowed, to keep the
  // list fiddling from being N^2.
  nsFloatCacheFreeList mCurrentLineFloats;

  // The list of floats which are "below current-line"
  // floats. These are reflowed/placed after the line is reflowed
  // and placed. Again, this is done to keep the list fiddling from
  // being N^2.
  nsFloatCacheFreeList mBelowCurrentLineFloats;

  nscoord mMaxElementWidth;

  // maximum width includes the left border/padding but not the right
  nscoord mMaximumWidth;

  nscoord mMinLineHeight;

  PRInt32 mLineNumber;

  PRInt16 mFlags;
 
  PRUint8 mFloatBreakType;

  void SetFlag(PRUint32 aFlag, PRBool aValue)
  {
    NS_ASSERTION(aFlag<=BRS_LASTFLAG, "bad flag");
    NS_ASSERTION(aValue==PR_FALSE || aValue==PR_TRUE, "bad value");
    if (aValue) { // set flag
      mFlags |= aFlag;
    }
    else {        // unset flag
      mFlags &= ~aFlag;
    }
  }

  PRBool GetFlag(PRUint32 aFlag) const
  {
    NS_ASSERTION(aFlag<=BRS_LASTFLAG, "bad flag");
    PRBool result = (mFlags & aFlag);
    if (result) return PR_TRUE;
    return PR_FALSE;
  }
};

#endif // nsBlockReflowState_h__