nsIMathMLFrame.h
/* -*- 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 MathML Project.
*
* The Initial Developer of the Original Code is
* The University Of Queensland.
* Portions created by the Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Roger B. Sidje <rbs@maths.uq.edu.au>
* Frederic Wang <fred.wang@free.fr>
*
* 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 ***** */
//#define SHOW_BOUNDING_BOX 1
#ifndef nsIMathMLFrame_h___
#define nsIMathMLFrame_h___
#include "nsIFrame.h"
struct nsPresentationData;
struct nsEmbellishData;
struct nsHTMLReflowMetrics;
class nsRenderingContext;
// For MathML, this 'type' will be used to determine the spacing between frames
// Subclasses can return a 'type' that will give them a particular spacing
enum eMathMLFrameType {
eMathMLFrameType_UNKNOWN = -1,
eMathMLFrameType_Ordinary,
eMathMLFrameType_OperatorOrdinary,
eMathMLFrameType_OperatorInvisible,
eMathMLFrameType_OperatorUserDefined,
eMathMLFrameType_Inner,
eMathMLFrameType_ItalicIdentifier,
eMathMLFrameType_UprightIdentifier,
eMathMLFrameType_COUNT
};
// Abstract base class that provides additional methods for MathML frames
class nsIMathMLFrame
{
public:
NS_DECL_QUERYFRAME_TARGET(nsIMathMLFrame)
// helper to check whether the frame is "space-like", as defined by the spec.
virtual PRBool IsSpaceLike() = 0;
/* SUPPORT FOR PRECISE POSITIONING */
/*====================================================================*/
/* Metrics that _exactly_ enclose the text of the frame.
* The frame *must* have *already* being reflowed, before you can call
* the GetBoundingMetrics() method.
* Note that for a frame with nested children, the bounding metrics
* will exactly enclose its children. For example, the bounding metrics
* of msub is the smallest rectangle that exactly encloses both the
* base and the subscript.
*/
NS_IMETHOD
GetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) = 0;
NS_IMETHOD
SetBoundingMetrics(const nsBoundingMetrics& aBoundingMetrics) = 0;
NS_IMETHOD
SetReference(const nsPoint& aReference) = 0;
virtual eMathMLFrameType GetMathMLFrameType() = 0;
/* SUPPORT FOR STRETCHY ELEMENTS */
/*====================================================================*/
/* Stretch :
* Called to ask a stretchy MathML frame to stretch itself depending
* on its context.
*
* An embellished frame is treated in a special way. When it receives a
* Stretch() command, it passes the command to its embellished child and
* the stretched size is bubbled up from the inner-most <mo> frame. In other
* words, the stretch command descend through the embellished hierarchy.
*
* @param aStretchDirection [in] the direction where to attempt to
* stretch.
* @param aContainerSize [in] struct that suggests the maximumn size for
* the stretched frame. Only member data of the struct that are
* relevant to the direction are used (the rest is ignored).
* @param aDesiredStretchSize [in/out] On input the current size
* of the frame, on output the size after stretching.
*/
NS_IMETHOD
Stretch(nsRenderingContext& aRenderingContext,
nsStretchDirection aStretchDirection,
nsBoundingMetrics& aContainerSize,
nsHTMLReflowMetrics& aDesiredStretchSize) = 0;
/* Get the mEmbellishData member variable. */
NS_IMETHOD
GetEmbellishData(nsEmbellishData& aEmbellishData) = 0;
/* SUPPORT FOR SCRIPTING ELEMENTS */
/*====================================================================*/
/* Get the mPresentationData member variable. */
NS_IMETHOD
GetPresentationData(nsPresentationData& aPresentationData) = 0;
/* InheritAutomaticData() / TransmitAutomaticData() :
* There are precise rules governing each MathML frame and its children.
* Properties such as the scriptlevel or the embellished nature of a frame
* depend on those rules. Also, certain properties that we use to emulate
* TeX rendering rules are frame-dependent too. These two methods are meant
* to be implemented by frame classes that need to assert specific properties
* within their subtrees.
*
* InheritAutomaticData() is called in a top-down manner [like nsIFrame::Init],
* as we descend the frame tree, whereas TransmitAutomaticData() is called in a
* bottom-up manner, as we ascend the tree [like nsIFrame::SetInitialChildList].
* However, unlike Init() and SetInitialChildList() which are called only once
* during the life-time of a frame (when initially constructing the frame tree),
* these two methods are called to build automatic data after the <math>...</math>
* subtree has been constructed fully, and are called again as we walk a child's
* subtree to handle dynamic changes that happen in the content model.
*
* As a rule of thumb:
*
* 1. Use InheritAutomaticData() to set properties related to your ancestors:
* - set properties that are intrinsic to yourself
* - set properties that depend on the state that you expect your ancestors
* to have already reached in their own InheritAutomaticData().
* - set properties that your descendants assume that you would have set in
* your InheritAutomaticData() -- this way, they can safely query them and
* the process will feed upon itself.
*
* 2. Use TransmitAutomaticData() to set properties related to your descendants:
* - set properties that depend on the state that you expect your descendants
* to have reached upon processing their own TransmitAutomaticData().
* - transmit properties that your descendants expect that you will transmit to
* them in your TransmitAutomaticData() -- this way, they remain up-to-date.
* - set properties that your ancestors expect that you would set in your
* TransmitAutomaticData() -- this way, they can safely query them and the
* process will feed upon itself.
*/
NS_IMETHOD
InheritAutomaticData(nsIFrame* aParent) = 0;
NS_IMETHOD
TransmitAutomaticData() = 0;
/* UpdatePresentationData :
* Updates the frame's displaystyle and compression flags. The displaystyle
* flag of an environment gets updated according to the MathML specification.
* A frame becomes "compressed" (or "cramped") according to TeX rendering
* rules (TeXBook, Ch.17, p.140-141).
*
* Note that <mstyle> is the only tag which allows to set
* <mstyle displaystyle="true|false">
* Therefore <mstyle> has its own peculiar version of this method.
*
* @param aFlagsValues [in]
* The new values (e.g., display, compress) that are going to be
* updated.
*
* @param aWhichFlags [in]
* The flags that are relevant to this call. Since not all calls
* are meant to update all flags at once, aWhichFlags is used
* to distinguish flags that need to retain their existing values
* from flags that need to be turned on (or turned off). If a bit
* is set in aWhichFlags, then the corresponding value (which
* can be 0 or 1) is taken from aFlagsValues and applied to the
* frame. Therefore, by setting their bits in aWhichFlags, and
* setting their desired values in aFlagsValues, it is possible to
* update some flags in the frame, leaving the other flags unchanged.
*/
NS_IMETHOD
UpdatePresentationData(PRUint32 aFlagsValues,
PRUint32 aWhichFlags) = 0;
/* UpdatePresentationDataFromChildAt :
* Sets displaystyle and compression flags on the whole tree. For child frames
* at aFirstIndex up to aLastIndex, this method sets their displaystyle and
* compression flags. The update is propagated down the subtrees of each of
* these child frames.
*
* Note that <mstyle> is the only tag which allows
* <mstyle displaystyle="true|false">
* Therefore <mstyle> has its own peculiar version of this method.
*
* @param aFirstIndex [in]
* Index of the first child from where the update is propagated.
*
* @param aLastIndex [in]
* Index of the last child where to stop the update.
* A value of -1 means up to last existing child.
*
* @param aFlagsValues [in]
* The new values (e.g., display, compress) that are going to be
* assigned in the whole sub-trees.
*
* @param aWhichFlags [in]
* The flags that are relevant to this call. See UpdatePresentationData()
* for more details about this parameter.
*/
NS_IMETHOD
UpdatePresentationDataFromChildAt(PRInt32 aFirstIndex,
PRInt32 aLastIndex,
PRUint32 aFlagsValues,
PRUint32 aWhichFlags) = 0;
};
// struct used by a container frame to keep track of its embellishments.
// By convention, the data that we keep here is bubbled from the embellished
// hierarchy, and it remains unchanged unless we have to recover from a change
// that occurs in the embellished hierarchy. The struct remains in its nil
// state in those frames that are not part of the embellished hierarchy.
struct nsEmbellishData {
// bits used to mark certain properties of our embellishments
PRUint32 flags;
// pointer on the <mo> frame at the core of the embellished hierarchy
nsIFrame* coreFrame;
// stretchy direction that the nsMathMLChar owned by the core <mo> supports
nsStretchDirection direction;
// spacing that may come from <mo> depending on its 'form'. Since
// the 'form' may also depend on the position of the outermost
// embellished ancestor, the set up of these values may require
// looking up the position of our ancestors.
nscoord leftSpace;
nscoord rightSpace;
nsEmbellishData() {
flags = 0;
coreFrame = nsnull;
direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
leftSpace = 0;
rightSpace = 0;
}
};
// struct used by a container frame to modulate its presentation.
// By convention, the data that we keep in this struct can change depending
// on any of our ancestors and/or descendants. If a data can be resolved
// solely from the embellished hierarchy, and it remains immutable once
// resolved, we put it in |nsEmbellishData|. If it can be affected by other
// things, it comes here. This struct is updated as we receive information
// transmitted by our ancestors and is kept in sync with changes in our
// descendants that affects us.
struct nsPresentationData {
// bits for: displaystyle, compressed, etc
PRUint32 flags;
// handy pointer on our base child (the 'nucleus' in TeX), but it may be
// null here (e.g., tags like <mrow>, <mfrac>, <mtable>, etc, won't
// pick a particular child in their child list to be the base)
nsIFrame* baseFrame;
// up-pointer on the mstyle frame, if any, that defines the scope
nsIFrame* mstyle;
nsPresentationData() {
flags = 0;
baseFrame = nsnull;
mstyle = nsnull;
}
};
// ==========================================================================
// Bits used for the presentation flags -- these bits are set
// in their relevant situation as they become available
// This bit is set if the frame is in the *context* of displaystyle=true.
// Note: This doesn't mean that the frame has displaystyle=true as attribute,
// the displaystyle attribute is only allowed on <mstyle> and <mtable>.
// The bit merely tells the context of the frame. In the context of
// displaystyle="false", it is intended to slightly alter how the
// rendering is done in inline mode.
#define NS_MATHML_DISPLAYSTYLE 0x00000001U
// This bit is used to emulate TeX rendering.
// Internal use only, cannot be set by the user with an attribute.
#define NS_MATHML_COMPRESSED 0x00000002U
// This bit is set if the frame will fire a vertical stretch
// command on all its (non-empty) children.
// Tags like <mrow> (or an inferred mrow), mpadded, etc, will fire a
// vertical stretch command on all their non-empty children
#define NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY 0x00000004U
// This bit is set if the frame will fire a horizontal stretch
// command on all its (non-empty) children.
// Tags like munder, mover, munderover, will fire a
// horizontal stretch command on all their non-empty children
#define NS_MATHML_STRETCH_ALL_CHILDREN_HORIZONTALLY 0x00000008U
// This bit is set if the frame has the explicit attribute
// displaystyle="true" or "false". It is only relevant to <mstyle> and <mtable>
// because they are the only tags where the attribute is allowed by the spec.
#define NS_MATHML_EXPLICIT_DISPLAYSTYLE 0x00000020U
// This bit is set if the frame is "space-like", as defined by the spec.
#define NS_MATHML_SPACE_LIKE 0x00000040U
// This bit is set when the frame cannot be formatted due to an
// error (e.g., invalid markup such as a <msup> without an overscript).
// When set, a visual feedback will be provided to the user.
#define NS_MATHML_ERROR 0x80000000U
// a bit used for debug
#define NS_MATHML_STRETCH_DONE 0x20000000U
// This bit is used for visual debug. When set, the bounding box
// of your frame is painted. This visual debug enable to ensure that
// you have properly filled your mReference and mBoundingMetrics in
// Place().
#define NS_MATHML_SHOW_BOUNDING_METRICS 0x10000000U
// Macros that retrieve those bits
#define NS_MATHML_IS_DISPLAYSTYLE(_flags) \
(NS_MATHML_DISPLAYSTYLE == ((_flags) & NS_MATHML_DISPLAYSTYLE))
#define NS_MATHML_IS_COMPRESSED(_flags) \
(NS_MATHML_COMPRESSED == ((_flags) & NS_MATHML_COMPRESSED))
#define NS_MATHML_WILL_STRETCH_ALL_CHILDREN_VERTICALLY(_flags) \
(NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY == ((_flags) & NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY))
#define NS_MATHML_WILL_STRETCH_ALL_CHILDREN_HORIZONTALLY(_flags) \
(NS_MATHML_STRETCH_ALL_CHILDREN_HORIZONTALLY == ((_flags) & NS_MATHML_STRETCH_ALL_CHILDREN_HORIZONTALLY))
#define NS_MATHML_HAS_EXPLICIT_DISPLAYSTYLE(_flags) \
(NS_MATHML_EXPLICIT_DISPLAYSTYLE == ((_flags) & NS_MATHML_EXPLICIT_DISPLAYSTYLE))
#define NS_MATHML_IS_SPACE_LIKE(_flags) \
(NS_MATHML_SPACE_LIKE == ((_flags) & NS_MATHML_SPACE_LIKE))
#define NS_MATHML_HAS_ERROR(_flags) \
(NS_MATHML_ERROR == ((_flags) & NS_MATHML_ERROR))
#define NS_MATHML_STRETCH_WAS_DONE(_flags) \
(NS_MATHML_STRETCH_DONE == ((_flags) & NS_MATHML_STRETCH_DONE))
#define NS_MATHML_PAINT_BOUNDING_METRICS(_flags) \
(NS_MATHML_SHOW_BOUNDING_METRICS == ((_flags) & NS_MATHML_SHOW_BOUNDING_METRICS))
// ==========================================================================
// Bits used for the embellish flags -- these bits are set
// in their relevant situation as they become available
// This bit is set if the frame is an embellished operator.
#define NS_MATHML_EMBELLISH_OPERATOR 0x00000001
// This bit is set if the frame is an <mo> frame or an embellihsed
// operator for which the core <mo> has movablelimits="true"
#define NS_MATHML_EMBELLISH_MOVABLELIMITS 0x00000002
// This bit is set if the frame is an <mo> frame or an embellihsed
// operator for which the core <mo> has accent="true"
#define NS_MATHML_EMBELLISH_ACCENT 0x00000004
// This bit is set if the frame is an <mover> or <munderover> with
// an accent frame
#define NS_MATHML_EMBELLISH_ACCENTOVER 0x00000008
// This bit is set if the frame is an <munder> or <munderover> with
// an accentunder frame
#define NS_MATHML_EMBELLISH_ACCENTUNDER 0x00000010
// Macros that retrieve those bits
#define NS_MATHML_IS_EMBELLISH_OPERATOR(_flags) \
(NS_MATHML_EMBELLISH_OPERATOR == ((_flags) & NS_MATHML_EMBELLISH_OPERATOR))
#define NS_MATHML_EMBELLISH_IS_MOVABLELIMITS(_flags) \
(NS_MATHML_EMBELLISH_MOVABLELIMITS == ((_flags) & NS_MATHML_EMBELLISH_MOVABLELIMITS))
#define NS_MATHML_EMBELLISH_IS_ACCENT(_flags) \
(NS_MATHML_EMBELLISH_ACCENT == ((_flags) & NS_MATHML_EMBELLISH_ACCENT))
#define NS_MATHML_EMBELLISH_IS_ACCENTOVER(_flags) \
(NS_MATHML_EMBELLISH_ACCENTOVER == ((_flags) & NS_MATHML_EMBELLISH_ACCENTOVER))
#define NS_MATHML_EMBELLISH_IS_ACCENTUNDER(_flags) \
(NS_MATHML_EMBELLISH_ACCENTUNDER == ((_flags) & NS_MATHML_EMBELLISH_ACCENTUNDER))
#endif /* nsIMathMLFrame_h___ */
