layout/base/nsChangeHint.h

   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
  38 /* constants for what needs to be recomputed in response to style changes */
  39
  40 #ifndef nsChangeHint_h___
  41 #define nsChangeHint_h___
  42
  43 #include "prtypes.h"
  44
  45 // Defines for various style related constants
  46
  47 enum nsChangeHint {
  48   // change was visual only (e.g., COLOR=)
  49   nsChangeHint_RepaintFrame = 0x01,
  50
  51   // For reflow, we want flags to give us arbitrary FrameNeedsReflow behavior.
  52   // just do a FrameNeedsReflow
  53   nsChangeHint_NeedReflow = 0x02,
  54
  55   // Invalidate intrinsic widths on the frame's ancestors.  Must not be set
  56   // without setting nsChangeHint_NeedReflow.
  57   nsChangeHint_ClearAncestorIntrinsics = 0x04,
  58
  59   // Invalidate intrinsic widths on the frame's descendants.  Must not be set
  60   // without also setting nsChangeHint_ClearAncestorIntrinsics.
  61   nsChangeHint_ClearDescendantIntrinsics = 0x08,
  62
  63   // Force unconditional reflow of all descendants.  Must not be set without
  64   // setting nsChangeHint_NeedReflow, but is independent of both the
  65   // Clear*Intrinsics flags.
  66   nsChangeHint_NeedDirtyReflow = 0x10,
  67
  68   // change requires view to be updated, if there is one (e.g., clip:)
  69   nsChangeHint_SyncFrameView = 0x20,
  70
  71   // The currently shown mouse cursor needs to be updated
  72   nsChangeHint_UpdateCursor = 0x40,
  73
  74   /**
  75    * SVG filter/mask/clip effects need to be recomputed because the URI
  76    * in the filter/mask/clip-path property has changed. This wipes
  77    * out cached nsSVGPropertyBase and subclasses which hold a reference to
  78    * the element referenced by the URI, and a mutation observer for
  79    * the DOM subtree rooted at that element. Also, for filters they store a
  80    * bounding-box for the filter result so that if the filter changes we can
  81    * invalidate the old covered area.
  82    */
  83   nsChangeHint_UpdateEffects = 0x80,
  84
  85   /**
  86    * Visual change only, but the change can be handled entirely by
  87    * updating the layer(s) for the frame.
  88    */
  89   nsChangeHint_UpdateOpacityLayer = 0x100,
  90   nsChangeHint_UpdateTransformLayer = 0x200,
  91
  92   // change requires frame change (e.g., display:).
  93   // This subsumes all the above.
  94   nsChangeHint_ReconstructFrame = 0x400
  95 };
  96
  97 // Redefine these operators to return nothing. This will catch any use
  98 // of these operators on hints. We should not be using these operators
  99 // on nsChangeHints
 100 inline void operator<(nsChangeHint s1, nsChangeHint s2) {}
 101 inline void operator>(nsChangeHint s1, nsChangeHint s2) {}
 102 inline void operator!=(nsChangeHint s1, nsChangeHint s2) {}
 103 inline void operator==(nsChangeHint s1, nsChangeHint s2) {}
 104 inline void operator<=(nsChangeHint s1, nsChangeHint s2) {}
 105 inline void operator>=(nsChangeHint s1, nsChangeHint s2) {}
 106
 107 // Operators on nsChangeHints
 108
 109 // Merge two hints, taking the union
 110 inline nsChangeHint NS_CombineHint(nsChangeHint aH1, nsChangeHint aH2) {
 111   return (nsChangeHint)(aH1 | aH2);
 112 }
 113
 114 // Merge two hints, taking the union
 115 inline nsChangeHint NS_SubtractHint(nsChangeHint aH1, nsChangeHint aH2) {
 116   return (nsChangeHint)(aH1 & ~aH2);
 117 }
 118
 119 // Merge the "src" hint into the "dst" hint
 120 // Returns true iff the destination changed
 121 inline PRBool NS_UpdateHint(nsChangeHint& aDest, nsChangeHint aSrc) {
 122   nsChangeHint r = (nsChangeHint)(aDest | aSrc);
 123   PRBool changed = (int)r != (int)aDest;
 124   aDest = r;
 125   return changed;
 126 }
 127
 128 // Returns true iff the second hint contains all the hints of the first hint
 129 inline PRBool NS_IsHintSubset(nsChangeHint aSubset, nsChangeHint aSuperSet) {
 130   return (aSubset & aSuperSet) == aSubset;
 131 }
 132
 133 // Redefine the old NS_STYLE_HINT constants in terms of the new hint structure
 134 #define NS_STYLE_HINT_NONE \
 135   nsChangeHint(0)
 136 #define NS_STYLE_HINT_VISUAL \
 137   nsChangeHint(nsChangeHint_RepaintFrame | nsChangeHint_SyncFrameView)
 138 #define nsChangeHint_ReflowFrame                        \
 139   nsChangeHint(nsChangeHint_NeedReflow |                \
 140                nsChangeHint_ClearAncestorIntrinsics |   \
 141                nsChangeHint_ClearDescendantIntrinsics | \
 142                nsChangeHint_NeedDirtyReflow)
 143 #define NS_STYLE_HINT_REFLOW \
 144   nsChangeHint(NS_STYLE_HINT_VISUAL | nsChangeHint_ReflowFrame)
 145 #define NS_STYLE_HINT_FRAMECHANGE \
 146   nsChangeHint(NS_STYLE_HINT_REFLOW | nsChangeHint_ReconstructFrame)
 147
 148 /**
 149  * |nsRestyleHint| is a bitfield for the result of
 150  * |HasStateDependentStyle| and |HasAttributeDependentStyle|.  When no
 151  * restyling is necessary, use |nsRestyleHint(0)|.
 152  */
 153 enum nsRestyleHint {
 154   eRestyle_Self = 0x1,
 155   eRestyle_Subtree = 0x2, /* self and descendants */
 156   eRestyle_LaterSiblings = 0x4 /* implies "and descendants" */
 157 };
 158
 159
 160 #endif /* nsChangeHint_h___ */