зеркало из https://github.com/mozilla/gecko-dev.git
540 строки
22 KiB
C++
540 строки
22 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is mozilla.org code.
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*
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* The Initial Developer of the Original Code is
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* IBM Corporation.
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* Portions created by the Initial Developer are Copyright (C) 2000
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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* IBM Corporation
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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#ifdef IBMBIDI
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#ifndef nsBidiPresUtils_h___
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#define nsBidiPresUtils_h___
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#include "nsTArray.h"
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#include "nsIFrame.h"
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#include "nsBidi.h"
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#include "nsBidiUtils.h"
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#include "nsCOMPtr.h"
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#include "nsDataHashtable.h"
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#include "nsBlockFrame.h"
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#include "nsTHashtable.h"
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#ifdef DrawText
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#undef DrawText
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#endif
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/**
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* A structure representing some continuation state for each frame on the line,
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* used to determine the first and the last continuation frame for each
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* continuation chain on the line.
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*/
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struct nsFrameContinuationState : public nsVoidPtrHashKey
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{
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nsFrameContinuationState(const void *aFrame) : nsVoidPtrHashKey(aFrame) {}
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/**
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* The first visual frame in the continuation chain containing this frame, or
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* nsnull if this frame is the first visual frame in the chain.
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*/
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nsIFrame* mFirstVisualFrame;
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/**
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* The number of frames in the continuation chain containing this frame, if
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* this frame is the first visual frame of the chain, or 0 otherwise.
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*/
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PRUint32 mFrameCount;
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/**
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* TRUE if this frame is the first visual frame of its continuation chain on
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* this line and the chain has some frames on the previous lines.
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*/
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PRPackedBool mHasContOnPrevLines;
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/**
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* TRUE if this frame is the first visual frame of its continuation chain on
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* this line and the chain has some frames left for next lines.
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*/
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PRPackedBool mHasContOnNextLines;
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};
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/*
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* Following type is used to pass needed hashtable to reordering methods
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*/
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typedef nsTHashtable<nsFrameContinuationState> nsContinuationStates;
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/**
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* A structure representing a logical position which should be resolved
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* into its visual position during BiDi processing.
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*/
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struct nsBidiPositionResolve
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{
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// [in] Logical index within string.
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PRInt32 logicalIndex;
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// [out] Visual index within string.
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// If the logical position was not found, set to kNotFound.
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PRInt32 visualIndex;
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// [out] Visual position of the character, from the left (on the X axis), in twips.
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// Eessentially, this is the X position (relative to the rendering context) where the text was drawn + the font metric of the visual string to the left of the given logical position.
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// If the logical position was not found, set to kNotFound.
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PRInt32 visualLeftTwips;
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// [out] Visual width of the character, in twips.
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// If the logical position was not found, set to kNotFound.
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PRInt32 visualWidth;
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};
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class nsBidiPresUtils {
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public:
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nsBidiPresUtils();
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~nsBidiPresUtils();
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PRBool IsSuccessful(void) const;
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/**
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* Interface for the processor used by ProcessText. Used by process text to
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* collect information about the width of subruns and to notify where each
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* subrun should be rendered.
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*/
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class BidiProcessor {
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public:
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virtual ~BidiProcessor() { }
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/**
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* Sets the current text with the given length and the given direction.
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*
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* @remark The reason that the function gives a string instead of an index
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* is that ProcessText copies and modifies the string passed to it, so
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* passing an index would be impossible.
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*
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* @param aText The string of text.
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* @param aLength The length of the string of text.
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* @param aDirection The direction of the text. The string will never have
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* mixed direction.
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*/
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virtual void SetText(const PRUnichar* aText,
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PRInt32 aLength,
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nsBidiDirection aDirection) = 0;
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/**
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* Returns the measured width of the text given in SetText. If SetText was
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* not called with valid parameters, the result of this call is undefined.
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* This call is guaranteed to only be called once between SetText calls.
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* Will be invoked before DrawText.
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*/
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virtual nscoord GetWidth() = 0;
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/**
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* Draws the text given in SetText to a rendering context. If SetText was
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* not called with valid parameters, the result of this call is undefined.
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* This call is guaranteed to only be called once between SetText calls.
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*
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* @param aXOffset The offset of the left side of the substring to be drawn
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* from the beginning of the overall string passed to ProcessText.
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* @param aWidth The width returned by GetWidth.
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*/
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virtual void DrawText(nscoord aXOffset,
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nscoord aWidth) = 0;
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};
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/**
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* Make Bidi engine calculate the embedding levels of the frames that are
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* descendants of a given block frame.
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*
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* @param aBlockFrame The block frame
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*
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* @lina 06/18/2000
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*/
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nsresult Resolve(nsBlockFrame* aBlockFrame);
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void ResolveParagraph(nsBlockFrame* aBlockFrame);
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void ResolveParagraphWithinBlock(nsBlockFrame* aBlockFrame);
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/**
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* Reorder this line using Bidi engine.
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* Update frame array, following the new visual sequence.
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*
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* @lina 05/02/2000
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*/
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void ReorderFrames(nsIFrame* aFirstFrameOnLine,
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PRInt32 aNumFramesOnLine);
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/**
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* Format Unicode text, taking into account bidi capabilities
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* of the platform. The formatting includes: reordering, Arabic shaping,
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* symmetric and numeric swapping, removing control characters.
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*
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* @lina 06/18/2000
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*/
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nsresult FormatUnicodeText(nsPresContext* aPresContext,
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PRUnichar* aText,
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PRInt32& aTextLength,
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nsCharType aCharType,
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PRBool aIsOddLevel);
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/**
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* Reorder plain text using the Unicode Bidi algorithm and send it to
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* a rendering context for rendering.
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*
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* @param[in] aText the string to be rendered (in logical order)
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* @param aLength the number of characters in the string
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* @param aBaseDirection the base direction of the string
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* NSBIDI_LTR - left-to-right string
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* NSBIDI_RTL - right-to-left string
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* @param aPresContext the presentation context
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* @param aRenderingContext the rendering context to render to
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* @param aTextRunConstructionContext the rendering context to be used to construct the textrun (affects font hinting)
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* @param aX the x-coordinate to render the string
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* @param aY the y-coordinate to render the string
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* @param[in,out] aPosResolve array of logical positions to resolve into visual positions; can be nsnull if this functionality is not required
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* @param aPosResolveCount number of items in the aPosResolve array
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*/
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nsresult RenderText(const PRUnichar* aText,
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PRInt32 aLength,
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nsBidiDirection aBaseDirection,
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nsPresContext* aPresContext,
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nsRenderingContext& aRenderingContext,
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nsRenderingContext& aTextRunConstructionContext,
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nscoord aX,
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nscoord aY,
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nsBidiPositionResolve* aPosResolve = nsnull,
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PRInt32 aPosResolveCount = 0)
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{
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return ProcessTextForRenderingContext(aText, aLength, aBaseDirection, aPresContext, aRenderingContext,
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aTextRunConstructionContext, MODE_DRAW, aX, aY, aPosResolve, aPosResolveCount, nsnull);
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}
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nscoord MeasureTextWidth(const PRUnichar* aText,
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PRInt32 aLength,
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nsBidiDirection aBaseDirection,
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nsPresContext* aPresContext,
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nsRenderingContext& aRenderingContext)
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{
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nscoord length;
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nsresult rv = ProcessTextForRenderingContext(aText, aLength, aBaseDirection, aPresContext,
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aRenderingContext, aRenderingContext,
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MODE_MEASURE, 0, 0, nsnull, 0, &length);
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return NS_SUCCEEDED(rv) ? length : 0;
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}
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/**
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* Check if a line is reordered, i.e., if the child frames are not
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* all laid out left-to-right.
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* @param aFirstFrameOnLine : first frame of the line to be tested
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* @param aNumFramesOnLine : number of frames on this line
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* @param[out] aLeftMost : leftmost frame on this line
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* @param[out] aRightMost : rightmost frame on this line
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*/
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PRBool CheckLineOrder(nsIFrame* aFirstFrameOnLine,
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PRInt32 aNumFramesOnLine,
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nsIFrame** aLeftmost,
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nsIFrame** aRightmost);
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/**
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* Get the frame to the right of the given frame, on the same line.
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* @param aFrame : We're looking for the frame to the right of this frame.
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* If null, return the leftmost frame on the line.
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* @param aFirstFrameOnLine : first frame of the line to be tested
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* @param aNumFramesOnLine : number of frames on this line
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*/
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nsIFrame* GetFrameToRightOf(const nsIFrame* aFrame,
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nsIFrame* aFirstFrameOnLine,
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PRInt32 aNumFramesOnLine);
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/**
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* Get the frame to the left of the given frame, on the same line.
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* @param aFrame : We're looking for the frame to the left of this frame.
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* If null, return the rightmost frame on the line.
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* @param aFirstFrameOnLine : first frame of the line to be tested
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* @param aNumFramesOnLine : number of frames on this line
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*/
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nsIFrame* GetFrameToLeftOf(const nsIFrame* aFrame,
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nsIFrame* aFirstFrameOnLine,
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PRInt32 aNumFramesOnLine);
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/**
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* Get the bidi embedding level of the given (inline) frame.
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*/
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static nsBidiLevel GetFrameEmbeddingLevel(nsIFrame* aFrame);
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/**
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* Get the bidi base level of the given (inline) frame.
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*/
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static nsBidiLevel GetFrameBaseLevel(nsIFrame* aFrame);
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enum Mode { MODE_DRAW, MODE_MEASURE };
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/**
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* Reorder plain text using the Unicode Bidi algorithm and send it to
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* a processor for rendering or measuring
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*
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* @param[in] aText the string to be processed (in logical order)
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* @param aLength the number of characters in the string
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* @param aBaseDirection the base direction of the string
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* NSBIDI_LTR - left-to-right string
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* NSBIDI_RTL - right-to-left string
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* @param aPresContext the presentation context
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* @param aprocessor the bidi processor
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* @param aMode the operation to process
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* MODE_DRAW - invokes DrawText on the processor for each substring
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* MODE_MEASURE - does not invoke DrawText on the processor
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* Note that the string is always measured, regardless of mode
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* @param[in,out] aPosResolve array of logical positions to resolve into
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* visual positions; can be nsnull if this functionality is not required
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* @param aPosResolveCount number of items in the aPosResolve array
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* @param[out] aWidth Pointer to where the width will be stored (may be null)
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*/
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nsresult ProcessText(const PRUnichar* aText,
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PRInt32 aLength,
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nsBidiDirection aBaseDirection,
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nsPresContext* aPresContext,
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BidiProcessor& aprocessor,
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Mode aMode,
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nsBidiPositionResolve* aPosResolve,
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PRInt32 aPosResolveCount,
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nscoord* aWidth);
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/**
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* Make a copy of a string, converting from logical to visual order
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*
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* @param aSource the source string
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* @param aDest the destination string
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* @param aBaseDirection the base direction of the string
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* (NSBIDI_LTR or NSBIDI_RTL to force the base direction;
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* NSBIDI_DEFAULT_LTR or NSBIDI_DEFAULT_RTL to let the bidi engine
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* determine the direction from rules P2 and P3 of the bidi algorithm.
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* @see nsBidi::GetPara
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* @param aOverride if TRUE, the text has a bidi override, according to
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* the direction in aDir
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*/
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void CopyLogicalToVisual(const nsAString& aSource,
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nsAString& aDest,
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nsBidiLevel aBaseDirection,
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PRBool aOverride);
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/**
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* Guess at how much memory is being used by this nsBidiPresUtils instance,
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* including memory used by nsBidi.
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*/
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PRUint32 EstimateMemoryUsed();
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void Traverse(nsCycleCollectionTraversalCallback &cb) const;
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void Unlink();
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private:
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nsresult ProcessTextForRenderingContext(const PRUnichar* aText,
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PRInt32 aLength,
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nsBidiDirection aBaseDirection,
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nsPresContext* aPresContext,
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nsRenderingContext& aRenderingContext,
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nsRenderingContext& aTextRunConstructionContext,
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Mode aMode,
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nscoord aX, // DRAW only
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nscoord aY, // DRAW only
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nsBidiPositionResolve* aPosResolve, /* may be null */
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PRInt32 aPosResolveCount,
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nscoord* aWidth /* may be null */);
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void AdvanceAndAppendFrame(nsIFrame** aFrame,
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nsBlockInFlowLineIterator* aLineIter,
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nsIFrame** aNextSibling);
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/**
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* Traverse the child frames of the block element and:
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* Set up an array of the frames in logical order
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* Create a string containing the text content of all the frames
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* If we encounter content that requires us to split the element into more
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* than one paragraph for bidi resolution, resolve the paragraph up to that
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* point.
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*/
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void TraverseFrames(nsBlockFrame* aBlockFrame,
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nsBlockInFlowLineIterator* aLineIter,
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nsIFrame* aCurrentFrame);
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/**
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* Initialize the logically-ordered array of frames
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* using the top-level frames of a single line
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*/
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void InitLogicalArrayFromLine(nsIFrame* aFirstFrameOnLine,
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PRInt32 aNumFramesOnLine);
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/**
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* Reorder the frame array from logical to visual order
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*
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* @param aReordered TRUE on return if the visual order is different from
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* the logical order
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* @param aHasRTLFrames TRUE on return if at least one of the frames is RTL
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* (and therefore might have reordered descendents)
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*/
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nsresult Reorder(PRBool& aReordered, PRBool& aHasRTLFrames);
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/*
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* Position aFrame and it's descendants to their visual places. Also if aFrame
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* is not leaf, resize it to embrace it's children.
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*
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* @param aFrame The frame which itself and its children are going
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* to be repositioned
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* @param aIsOddLevel TRUE means the embedding level of this frame is odd
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* @param[in,out] aLeft IN value is the starting position of aFrame(without
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* considering its left margin)
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* OUT value will be the ending position of aFrame(after
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* adding its right margin)
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* @param aContinuationStates A map from nsIFrame* to nsFrameContinuationState
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*/
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void RepositionFrame(nsIFrame* aFrame,
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PRBool aIsOddLevel,
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nscoord& aLeft,
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nsContinuationStates* aContinuationStates) const;
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/*
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* Initialize the continuation state(nsFrameContinuationState) to
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* (nsnull, 0) for aFrame and its descendants.
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*
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* @param aFrame The frame which itself and its descendants will
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* be initialized
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* @param aContinuationStates A map from nsIFrame* to nsFrameContinuationState
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*/
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void InitContinuationStates(nsIFrame* aFrame,
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nsContinuationStates* aContinuationStates) const;
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/*
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* Determine if aFrame is leftmost or rightmost, and set aIsLeftMost and
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* aIsRightMost values. Also set continuation states of aContinuationStates.
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*
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* A frame is leftmost if it's the first appearance of its continuation chain
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* on the line and the chain is on its first line if it's LTR or the chain is
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* on its last line if it's RTL.
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* A frame is rightmost if it's the last appearance of its continuation chain
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* on the line and the chain is on its first line if it's RTL or the chain is
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* on its last line if it's LTR.
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*
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* @param aContinuationStates A map from nsIFrame* to nsFrameContinuationState
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* @param[out] aIsLeftMost TRUE means aFrame is leftmost frame or continuation
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* @param[out] aIsRightMost TRUE means aFrame is rightmost frame or continuation
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*/
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void IsLeftOrRightMost(nsIFrame* aFrame,
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nsContinuationStates* aContinuationStates,
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PRBool& aIsLeftMost /* out */,
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PRBool& aIsRightMost /* out */) const;
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/**
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* Adjust frame positions following their visual order
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*
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* @param aFirstChild the first kid
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*
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* @lina 04/11/2000
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*/
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void RepositionInlineFrames(nsIFrame* aFirstChild) const;
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/**
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* Helper method for Resolve()
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* Truncate a text frame to the end of a single-directional run and possibly
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* create a continuation frame for the remainder of its content.
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*
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* @param aFrame the original frame
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* @param aNewFrame [OUT] the new frame that was created
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* @param aFrameIndex [IN/OUT] index of aFrame in mLogicalFrames
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* @param aStart [IN] the start of the content mapped by aFrame (and
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* any fluid continuations)
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* @param aEnd [IN] the offset of the end of the single-directional
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* text run.
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* @see Resolve()
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* @see RemoveBidiContinuation()
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*/
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inline
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void EnsureBidiContinuation(nsIFrame* aFrame,
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nsIFrame** aNewFrame,
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PRInt32& aFrameIndex,
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PRInt32 aStart,
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PRInt32 aEnd);
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/**
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* Helper method for Resolve()
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* Convert one or more bidi continuation frames created in a previous reflow by
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* EnsureBidiContinuation() into fluid continuations.
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* @param aFrame the frame whose continuations are to be removed
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|
* @param aFirstIndex index of aFrame in mLogicalFrames
|
|
* @param aLastIndex index of the last frame to be removed
|
|
* @param aOffset [OUT] count of directional frames removed. Since
|
|
* directional frames have control characters
|
|
* corresponding to them in mBuffer, the pointers to
|
|
* mBuffer in Resolve() will need to be updated after
|
|
* deleting the frames.
|
|
*
|
|
* @see Resolve()
|
|
* @see EnsureBidiContinuation()
|
|
*/
|
|
void RemoveBidiContinuation(nsIFrame* aFrame,
|
|
PRInt32 aFirstIndex,
|
|
PRInt32 aLastIndex,
|
|
PRInt32& aOffset) const;
|
|
void CalculateCharType(PRInt32& aOffset,
|
|
PRInt32 aCharTypeLimit,
|
|
PRInt32& aRunLimit,
|
|
PRInt32& aRunLength,
|
|
PRInt32& aRunCount,
|
|
PRUint8& aCharType,
|
|
PRUint8& aPrevCharType) const;
|
|
|
|
void StripBidiControlCharacters(PRUnichar* aText,
|
|
PRInt32& aTextLength) const;
|
|
|
|
static PRBool WriteLogicalToVisual(const PRUnichar* aSrc,
|
|
PRUint32 aSrcLength,
|
|
PRUnichar* aDest,
|
|
nsBidiLevel aBaseDirection,
|
|
nsBidi* aBidiEngine);
|
|
|
|
static void WriteReverse(const PRUnichar* aSrc,
|
|
PRUint32 aSrcLength,
|
|
PRUnichar* aDest);
|
|
|
|
nsString mBuffer;
|
|
nsTArray<PRUnichar> mEmbeddingStack;
|
|
nsTArray<nsIFrame*> mLogicalFrames;
|
|
nsTArray<nsLineBox*> mLinePerFrame;
|
|
nsTArray<nsIFrame*> mVisualFrames;
|
|
nsDataHashtable<nsISupportsHashKey, PRInt32> mContentToFrameIndex;
|
|
PRInt32 mArraySize;
|
|
PRInt32* mIndexMap;
|
|
PRUint8* mLevels;
|
|
nsresult mSuccess;
|
|
PRPackedBool mIsVisual;
|
|
nsBidiLevel mParaLevel;
|
|
nsIFrame* mPrevFrame;
|
|
nsIContent* mPrevContent;
|
|
|
|
nsBidi* mBidiEngine;
|
|
};
|
|
|
|
#endif /* nsBidiPresUtils_h___ */
|
|
|
|
#endif // IBMBIDI
|