layout/base/nsFrameManager.h

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   6  *
   7  * The contents of this file are subject to the Mozilla Public License Version
   8  * 1.1 (the "License"); you may not use this file except in compliance with
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  17  * The Original Code is mozilla.org code.
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  19  * The Initial Developer of the Original Code is
  20  * Netscape Communications Corporation.
  21  * Portions created by the Initial Developer are Copyright (C) 1998
  22  * the Initial Developer. All Rights Reserved.
  23  *
  24  * Contributor(s):
  25  *   Pierre Phaneuf <pp@ludusdesign.com>
  26  *
  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either of the GNU General Public License Version 2 or later (the "GPL"),
  29  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  30  * in which case the provisions of the GPL or the LGPL are applicable instead
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  39  * ***** END LICENSE BLOCK *****
  40  *
  41  * This Original Code has been modified by IBM Corporation. Modifications made
  42  * by IBM described herein are Copyright (c) International Business Machines
  43  * Corporation, 2000. Modifications to Mozilla code or documentation identified
  44  * per MPL Section 3.3
  45  *
  46  * Date             Modified by     Description of modification
  47  * 04/20/2000       IBM Corp.      OS/2 VisualAge build.
  48  */
  49
  50 /* storage of the frame tree and information about it */
  51
  52 #ifndef _nsFrameManager_h_
  53 #define _nsFrameManager_h_
  54
  55 #include "nsIFrame.h"
  56 #include "nsIStatefulFrame.h"
  57 #include "nsChangeHint.h"
  58 #include "nsFrameManagerBase.h"
  59
  60 namespace mozilla {
  61 namespace css {
  62 class RestyleTracker;
  63 } // namespace css
  64 } // namespace mozilla
  65
  66 /**
  67  * Frame manager interface. The frame manager serves two purposes:
  68  * <li>provides a service for mapping from content to frame and from
  69  * out-of-flow frame to placeholder frame.
  70  * <li>handles structural modifications to the frame model. If the frame model
  71  * lock can be acquired, then the changes are processed immediately; otherwise,
  72  * they're queued and processed later.
  73  *
  74  * Do not add virtual methods to this class, or bryner will punish you.
  75  */
  76
  77 class nsFrameManager : public nsFrameManagerBase
  78 {
  79   typedef mozilla::css::RestyleTracker RestyleTracker;
  80
  81 public:
  82   nsFrameManager() NS_HIDDEN;
  83   ~nsFrameManager() NS_HIDDEN;
  84
  85   void* operator new(size_t aSize, nsIPresShell* aHost) {
  86     NS_ASSERTION(aSize == sizeof(nsFrameManager), "Unexpected subclass");
  87     NS_ASSERTION(aSize == sizeof(nsFrameManagerBase),
  88                  "Superclass/subclass mismatch");
  89     return aHost->FrameManager();
  90   }
  91
  92   // Initialization
  93   NS_HIDDEN_(nsresult) Init(nsIPresShell* aPresShell, nsStyleSet* aStyleSet);
  94
  95   /*
  96    * After Destroy is called, it is an error to call any FrameManager methods.
  97    * Destroy should be called when the frame tree managed by the frame
  98    * manager is no longer being displayed.
  99    */
 100   NS_HIDDEN_(void) Destroy();
 101
 102   // Placeholder frame functions
 103   NS_HIDDEN_(nsPlaceholderFrame*) GetPlaceholderFrameFor(nsIFrame* aFrame);
 104   NS_HIDDEN_(nsresult)
 105     RegisterPlaceholderFrame(nsPlaceholderFrame* aPlaceholderFrame);
 106
 107   NS_HIDDEN_(void)
 108     UnregisterPlaceholderFrame(nsPlaceholderFrame* aPlaceholderFrame);
 109
 110   NS_HIDDEN_(void)      ClearPlaceholderFrameMap();
 111
 112   // Mapping undisplayed content
 113   NS_HIDDEN_(nsStyleContext*) GetUndisplayedContent(nsIContent* aContent);
 114   NS_HIDDEN_(void) SetUndisplayedContent(nsIContent* aContent,
 115                                          nsStyleContext* aStyleContext);
 116   NS_HIDDEN_(void) ChangeUndisplayedContent(nsIContent* aContent,
 117                                             nsStyleContext* aStyleContext);
 118   NS_HIDDEN_(void) ClearUndisplayedContentIn(nsIContent* aContent,
 119                                              nsIContent* aParentContent);
 120   NS_HIDDEN_(void) ClearAllUndisplayedContentIn(nsIContent* aParentContent);
 121
 122   // Functions for manipulating the frame model
 123   NS_HIDDEN_(nsresult) AppendFrames(nsIFrame*       aParentFrame,
 124                                     nsIAtom*        aListName,
 125                                     nsFrameList&    aFrameList)
 126   {
 127     return aParentFrame->AppendFrames(aListName, aFrameList);
 128   }
 129
 130   NS_HIDDEN_(nsresult) InsertFrames(nsIFrame*       aParentFrame,
 131                                     nsIAtom*        aListName,
 132                                     nsIFrame*       aPrevFrame,
 133                                     nsFrameList&    aFrameList);
 134
 135   NS_HIDDEN_(nsresult) RemoveFrame(nsIAtom*        aListName,
 136                                    nsIFrame*       aOldFrame);
 137
 138   /*
 139    * Notification that a frame is about to be destroyed. This allows any
 140    * outstanding references to the frame to be cleaned up.
 141    */
 142   NS_HIDDEN_(void)     NotifyDestroyingFrame(nsIFrame* aFrame);
 143
 144   /*
 145    * Reparent the style contexts of this frame subtree.  The parent frame of
 146    * aFrame must be changed to the new parent before this function is called;
 147    * the new parent style context will be automatically computed based on the
 148    * new position in the frame tree.
 149    *
 150    * @param aFrame the root of the subtree to reparent.  Must not be null.
 151    */
 152   NS_HIDDEN_(nsresult) ReparentStyleContext(nsIFrame* aFrame);
 153
 154   /*
 155    * Re-resolve the style contexts for a frame tree, building
 156    * aChangeList based on the resulting style changes, plus aMinChange
 157    * applied to aFrame.
 158    */
 159   NS_HIDDEN_(void)
 160     ComputeStyleChangeFor(nsIFrame* aFrame,
 161                           nsStyleChangeList* aChangeList,
 162                           nsChangeHint aMinChange,
 163                           RestyleTracker& aRestyleTracker,
 164                           PRBool aRestyleDescendants);
 165
 166   /*
 167    * Capture/restore frame state for the frame subtree rooted at aFrame.
 168    * aState is the document state storage object onto which each frame
 169    * stores its state.
 170    */
 171
 172   NS_HIDDEN_(void) CaptureFrameState(nsIFrame*              aFrame,
 173                                      nsILayoutHistoryState* aState);
 174
 175   NS_HIDDEN_(void) RestoreFrameState(nsIFrame*              aFrame,
 176                                      nsILayoutHistoryState* aState);
 177
 178   /*
 179    * Add/restore state for one frame
 180    * (special, global type, like scroll position)
 181    */
 182   NS_HIDDEN_(void) CaptureFrameStateFor(nsIFrame*              aFrame,
 183                                         nsILayoutHistoryState* aState,
 184                                         nsIStatefulFrame::SpecialStateID aID =
 185                                                       nsIStatefulFrame::eNoID);
 186
 187   NS_HIDDEN_(void) RestoreFrameStateFor(nsIFrame*              aFrame,
 188                                         nsILayoutHistoryState* aState,
 189                                         nsIStatefulFrame::SpecialStateID aID =
 190                                                       nsIStatefulFrame::eNoID);
 191
 192 #ifdef NS_DEBUG
 193   /**
 194    * DEBUG ONLY method to verify integrity of style tree versus frame tree
 195    */
 196   NS_HIDDEN_(void) DebugVerifyStyleTree(nsIFrame* aFrame);
 197 #endif
 198
 199   NS_HIDDEN_(nsIPresShell*) GetPresShell() const { return mPresShell; }
 200   NS_HIDDEN_(nsPresContext*) GetPresContext() const {
 201     return mPresShell->GetPresContext();
 202   }
 203
 204 private:
 205   enum DesiredA11yNotifications {
 206     eSkipNotifications,
 207     eSendAllNotifications,
 208     eNotifyIfShown
 209   };
 210
 211   enum A11yNotificationType {
 212     eDontNotify,
 213     eNotifyShown,
 214     eNotifyHidden
 215   };
 216
 217   // Use eRestyle_Self for the aRestyleHint argument to mean
 218   // "reresolve our style context but not kids", use eRestyle_Subtree
 219   // to mean "reresolve our style context and kids", and use
 220   // nsRestyleHint(0) to mean recompute a new style context for our
 221   // current parent and existing rulenode, and the same for kids.
 222   NS_HIDDEN_(nsChangeHint)
 223     ReResolveStyleContext(nsPresContext    *aPresContext,
 224                           nsIFrame          *aFrame,
 225                           nsIContent        *aParentContent,
 226                           nsStyleChangeList *aChangeList,
 227                           nsChangeHint       aMinChange,
 228                           nsRestyleHint      aRestyleHint,
 229                           RestyleTracker&    aRestyleTracker,
 230                           DesiredA11yNotifications aDesiredA11yNotifications,
 231                           nsTArray<nsIContent*>& aVisibleKidsOfHiddenElement);
 232 };
 233
 234 #endif