gecko-dev/layout/mathml/nsMathMLChar.h

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/* -*- 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>
* Shyjan Mahamud <mahamud@cs.cmu.edu>
* Karl Tomlinson <karlt+@karlt.net>, Mozilla Corporation
*
* 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 nsMathMLChar_h___
#define nsMathMLChar_h___
#include "nsMathMLOperators.h"
#include "nsMathMLFrame.h"
class nsGlyphTable;
// Hints for Stretch() to indicate criteria for stretching
enum {
// Don't stretch
NS_STRETCH_NONE = 0x00,
// Variable size stretches
NS_STRETCH_VARIABLE_MASK = 0x0F,
NS_STRETCH_NORMAL = 0x01, // try to stretch to requested size
NS_STRETCH_NEARER = 0x02, // stretch very close to requested size
NS_STRETCH_SMALLER = 0x04, // don't stretch more than requested size
NS_STRETCH_LARGER = 0x08, // don't stretch less than requested size
// A largeop in displaystyle
NS_STRETCH_LARGEOP = 0x10,
// Intended for internal use:
// Find the widest metrics that might be returned from a vertical stretch
NS_STRETCH_MAXWIDTH = 0x20
};
// A single glyph in our internal representation is characterized by a 'code@font'
// pair. The 'code' is interpreted as a Unicode point or as the direct glyph index
// (depending on the type of nsGlyphTable where this comes from). The 'font' is a
// numeric identifier given to the font to which the glyph belongs.
struct nsGlyphCode {
PRUnichar code;
PRInt32 font;
PRBool Exists() const
{
return (code != 0);
}
PRBool operator==(const nsGlyphCode& other) const
{
return other.code == code && other.font == font;
}
PRBool operator!=(const nsGlyphCode& other) const
{
return ! operator==(other);
}
};
// Class used to handle stretchy symbols (accent, delimiter and boundary symbols).
// There are composite characters that need to be built recursively from other
// characters. Since these are rare we use a light-weight mechanism to handle
// them. Specifically, as need arises we append a singly-linked list of child
// chars with their mParent pointing to the first element in the list, except in
// the originating first element itself where it points to null. mSibling points
// to the next element in the list. Since the originating first element is the
// parent of the others, we call it the "root" char of the list. Testing !mParent
// tells whether you are that "root" during the recursion. The parent delegates
// most of the tasks to the children.
class nsMathMLChar
{
public:
// constructor and destructor
nsMathMLChar(nsMathMLChar* aParent = nsnull) {
MOZ_COUNT_CTOR(nsMathMLChar);
mStyleContext = nsnull;
mSibling = nsnull;
mParent = aParent;
}
~nsMathMLChar() { // not a virtual destructor: this class is not intended to be subclassed
MOZ_COUNT_DTOR(nsMathMLChar);
// there is only one style context owned by the "root" char
// and it may be used by child chars as well
if (!mParent && mStyleContext) { // only the "root" need to release it
mStyleContext->Release();
}
if (mSibling) {
delete mSibling;
}
}
nsresult
Display(nsDisplayListBuilder* aBuilder,
nsIFrame* aForFrame,
const nsDisplayListSet& aLists,
const nsRect* aSelectedRect = nsnull);
void PaintForeground(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsPoint aPt,
PRBool aIsSelected);
// This is the method called to ask the char to stretch itself.
// @param aContainerSize - IN - suggested size for the stretched char
// @param aDesiredStretchSize - OUT - the size that the char wants
nsresult
Stretch(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsStretchDirection aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
PRUint32 aStretchHint = NS_STRETCH_NORMAL);
void
SetData(nsPresContext* aPresContext,
nsString& aData);
void
GetData(nsString& aData) {
aData = mData;
}
PRInt32
Length() {
return mData.Length();
}
nsStretchDirection
GetStretchDirection() {
return mDirection;
}
// Sometimes we only want to pass the data to another routine,
// this function helps to avoid copying
const PRUnichar*
get() {
return mData.get();
}
void
GetRect(nsRect& aRect) {
aRect = mRect;
}
void
SetRect(const nsRect& aRect) {
mRect = aRect;
// shift the orgins of child chars if any
if (!mParent && mSibling) { // only a "root" having child chars can enter here
for (nsMathMLChar* child = mSibling; child; child = child->mSibling) {
nsRect rect;
child->GetRect(rect);
rect.MoveBy(mRect.x, mRect.y);
child->SetRect(rect);
}
}
}
// Get the maximum width that the character might have after a vertical
// Stretch().
//
// @param aStretchHint can be the value that will be passed to Stretch().
// It is used to determine whether the operator is stretchy or a largeop.
// @param aMaxSize is the value of the "maxsize" attribute.
// @param aMaxSizeIsAbsolute indicates whether the aMaxSize is an absolute
// value in app units (PR_TRUE) or a multiplier of the base size (PR_FALSE).
nscoord
GetMaxWidth(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
PRUint32 aStretchHint = NS_STRETCH_NORMAL,
float aMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY,
// Perhaps just nsOperatorFlags aFlags.
// But need DisplayStyle for largeOp,
// or remove the largeop bit from flags.
PRBool aMaxSizeIsAbsolute = PR_FALSE);
// Metrics that _exactly_ enclose the char. The char *must* have *already*
// being stretched before you can call the GetBoundingMetrics() method.
// IMPORTANT: since chars have their own style contexts, and may be rendered
// with glyphs that are not in the parent font, just calling the default
// aRenderingContext.GetBoundingMetrics(aChar) can give incorrect results.
void
GetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) {
aBoundingMetrics = mBoundingMetrics;
}
void
SetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) {
mBoundingMetrics = aBoundingMetrics;
}
// Hooks to access the extra leaf style contexts given to the MathMLChars.
// They provide an interface to make them accessible to the Style System via
// the Get/Set AdditionalStyleContext() APIs. Owners of MathMLChars
// should honor these APIs.
nsStyleContext* GetStyleContext() const;
void SetStyleContext(nsStyleContext* aStyleContext);
protected:
friend class nsGlyphTable;
nsString mData;
// support for handling composite stretchy chars like TeX over/under braces
nsMathMLChar* mSibling;
nsMathMLChar* mParent;
private:
nsRect mRect;
PRInt32 mOperator;
nsStretchDirection mDirection;
nsBoundingMetrics mBoundingMetrics;
nsStyleContext* mStyleContext;
nsGlyphTable* mGlyphTable;
nsGlyphCode mGlyph;
// mFamily is non-empty when the family for the current size is different
// from the family in the nsStyleContext.
nsString mFamily;
class StretchEnumContext;
friend class StretchEnumContext;
// helper methods
nsresult
StretchInternal(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsStretchDirection& aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
PRUint32 aStretchHint,
float aMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY,
PRBool aMaxSizeIsAbsolute = PR_FALSE);
nsresult
ComposeChildren(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsGlyphTable* aGlyphTable,
nscoord aTargetSize,
nsBoundingMetrics& aCompositeSize,
PRUint32 aStretchHint);
nsresult
PaintVertically(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsFont& aFont,
nsStyleContext* aStyleContext,
nsGlyphTable* aGlyphTable,
nsRect& aRect);
nsresult
PaintHorizontally(nsPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsFont& aFont,
nsStyleContext* aStyleContext,
nsGlyphTable* aGlyphTable,
nsRect& aRect);
};
#endif /* nsMathMLChar_h___ */