os/graphics/graphicsdeviceinterface/gdi/sgdi/FontArabic.cpp
changeset 0 bde4ae8d615e
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/graphics/graphicsdeviceinterface/gdi/sgdi/FontArabic.cpp	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,449 @@
     1.4 +// Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.5 +// All rights reserved.
     1.6 +// This component and the accompanying materials are made available
     1.7 +// under the terms of "Eclipse Public License v1.0"
     1.8 +// which accompanies this distribution, and is available
     1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.10 +//
    1.11 +// Initial Contributors:
    1.12 +// Nokia Corporation - initial contribution.
    1.13 +//
    1.14 +// Contributors:
    1.15 +//
    1.16 +// Description:
    1.17 +//
    1.18 +
    1.19 +/**
    1.20 + @file
    1.21 + @internalComponent
    1.22 +*/
    1.23 +
    1.24 +
    1.25 +#include <gdi.h>
    1.26 +#include "FontArabic.h"
    1.27 +#include "GDIPANIC.h"
    1.28 +
    1.29 +
    1.30 +//
    1.31 +// Arabic Presentation Forms.
    1.32 +//
    1.33 +
    1.34 +
    1.35 +/**
    1.36 + The contextual forms of each character in the range 0621 - 064A, in
    1.37 + the order final, initial, medial; followed by the forms of
    1.38 + the lam-alef ligatures (lam with 0622, 0623, 0625 and 0627);
    1.39 + followed by the forms of the characters in the range 0671 - 06D3
    1.40 +*/
    1.41 +LOCAL_D const TUint16 TheArabicShapeTable[] =
    1.42 +	{
    1.43 +	// Contextual forms for standard Arabic letters
    1.44 +	0x621, 0x621, 0x621,			// 621
    1.45 +	0xfe82, 0x622, 0x622,			// 622
    1.46 +	0xfe84, 0x623, 0x623,			// 623
    1.47 +	0xfe86, 0x624, 0x624,			// 624
    1.48 +	0xfe88, 0x625, 0x625,			// 625
    1.49 +	0xfe8a, 0xfe8b, 0xfe8c,			// 626
    1.50 +	0xfe8e, 0x627,	0x627,			// 627
    1.51 +	0xfe90, 0xfe91, 0xfe92,			// 628
    1.52 +	0xfe94, 0x629, 0x629,			// 629
    1.53 +	0xfe96, 0xfe97, 0xfe98,			// 62a
    1.54 +	0xfe9a, 0xfe9b, 0xfe9c,			// 62b
    1.55 +	0xfe9e, 0xfe9f, 0xfea0,			// 62c
    1.56 +	0xfea2, 0xfea3, 0xfea4,			// 62d
    1.57 +	0xfea6, 0xfea7, 0xfea8,			// 62e
    1.58 +	0xfeaa, 0x62f, 0x62f,			// 62f
    1.59 +	0xfeac, 0x630, 0x630,			// 630
    1.60 +	0xfeae, 0x631, 0x631,			// 631
    1.61 +	0xfeb0, 0x632, 0x632,			// 632
    1.62 +	0xfeb2, 0xfeb3, 0xfeb4,			// 633
    1.63 +	0xfeb6, 0xfeb7, 0xfeb8,			// 634
    1.64 +	0xfeba, 0xfebb, 0xfebc,			// 635
    1.65 +	0xfebe, 0xfebf, 0xfec0,			// 636
    1.66 +	0xfec2, 0xfec3, 0xfec4,			// 637
    1.67 +	0xfec6, 0xfec7, 0xfec8,			// 638
    1.68 +	0xfeca, 0xfecb, 0xfecc,			// 639
    1.69 +	0xfece, 0xfecf, 0xfed0,			// 63a
    1.70 +	0x63b, 0x63b, 0x63b,			// placeholder
    1.71 +	0x63c, 0x63c, 0x63c,			// placeholder
    1.72 +	0x63d, 0x63d, 0x63d,			// placeholder
    1.73 +	0x63e, 0x63e, 0x63e,			// placeholder
    1.74 +	0x63f, 0x63f, 0x63f,			// placeholder
    1.75 +	0x640, 0x640, 0x640,			// 640
    1.76 +	0xfed2, 0xfed3, 0xfed4,			// 641
    1.77 +	0xfed6, 0xfed7, 0xfed8,			// 642
    1.78 +	0xfeda, 0xfedb, 0xfedc,			// 643
    1.79 +	0xfede, 0xfedf, 0xfee0,			// 644
    1.80 +	0xfee2, 0xfee3, 0xfee4,			// 645
    1.81 +	0xfee6, 0xfee7, 0xfee8,			// 646
    1.82 +	0xfeea, 0xfeeb, 0xfeec,			// 647
    1.83 +	0xfeee, 0x648, 0x648,			// 648
    1.84 +	0xfef0, 0xfbe8, 0xfbe9,			// 649
    1.85 +	0xfef2, 0xfef3, 0xfef4,			// 64A
    1.86 +
    1.87 +	// Contextual forms for lam-alef ligatures
    1.88 +	0xfef6, 0xfef5, 0xfef5,			// 644 + 622
    1.89 +	0xfef8, 0xfef7, 0xfef7,			// 644 + 623
    1.90 +	0xfefa, 0xfef9, 0xfef9,			// 644 + 625
    1.91 +	0xfefc, 0xfefb, 0xfefb,			// 644 + 627
    1.92 +
    1.93 +	// Contextual forms for extended Arabic letters for Persian, Urdu, Sindhi, etc.
    1.94 +	0xfb51, 0x0671, 0x0671,			// 671
    1.95 +	0x0672, 0x0672, 0x0672,			// placeholder
    1.96 +	0x0673, 0x0673, 0x0673,			// placeholder
    1.97 +	0x0674, 0x0674, 0x0674,			// placeholder
    1.98 +	0x0675, 0x0675, 0x0675,			// placeholder
    1.99 +	0x0676, 0x0676, 0x0676,			// placeholder
   1.100 +	0x0677, 0x0677, 0x0677,			// placeholder
   1.101 +	0x0678, 0x0678, 0x0678,			// placeholder
   1.102 +	0xfb67, 0xfb68, 0xfb69,			// 679
   1.103 +	0xfb5f, 0xfb60, 0xfb61,			// 67a
   1.104 +	0xfb53, 0xfb54, 0xfb55,			// 67b
   1.105 +	0x067c, 0x067c, 0x067c,			// placeholder
   1.106 +	0x067d, 0x067d, 0x067d,			// placeholder
   1.107 +	0xfb57, 0xfb58, 0xfb59,			// 67e
   1.108 +	0xfb63, 0xfb64, 0xfb65,			// 67f
   1.109 +
   1.110 +	0xfb5b, 0xfb5c, 0xfb5d,			// 680
   1.111 +	0x0681, 0x0681, 0x0681,			// placeholder
   1.112 +	0x0682, 0x0682, 0x0682,			// placeholder
   1.113 +	0xfb77, 0xfb78, 0xfb79,			// 683
   1.114 +	0xfb73, 0xfb74, 0xfb75,			// 684
   1.115 +	0x0685, 0x0685, 0x0685,			// placeholder
   1.116 +	0xfb7b, 0xfb7c, 0xfb7d,			// 686
   1.117 +	0xfb7f, 0xfb80, 0xfb81,			// 687
   1.118 +	0xfb89, 0x0688, 0x0688,			// 688
   1.119 +	0x0689, 0x0689, 0x0689,			// placeholder
   1.120 +	0x068a, 0x068a, 0x068a,			// placeholder
   1.121 +	0x068b, 0x068b, 0x068b,			// placeholder
   1.122 +	0xfb85, 0x068c, 0x068c,			// 68c
   1.123 +	0xfb83, 0x068d, 0x068d,			// 68d
   1.124 +	0xfb87, 0x068e, 0x068e,			// 68e
   1.125 +	0x068f, 0x068f, 0x068f,			// placeholder
   1.126 +
   1.127 +	0x0690, 0x0690, 0x0690,			// placeholder
   1.128 +	0xfb8d, 0x0691, 0x0691,			// 691
   1.129 +	0x0692, 0x0692, 0x0692,			// placeholder
   1.130 +	0x0693, 0x0693, 0x0693,			// placeholder
   1.131 +	0x0694, 0x0694, 0x0694,			// placeholder
   1.132 +	0x0695, 0x0695, 0x0695,			// placeholder
   1.133 +	0x0696, 0x0696, 0x0696,			// placeholder
   1.134 +	0x0697, 0x0697, 0x0697,			// placeholder
   1.135 +	0xfb8b, 0x0698, 0x0698,			// 698
   1.136 +	0x0699, 0x0699, 0x0699,			// placeholder
   1.137 +	0x069a, 0x069a, 0x069a,			// placeholder
   1.138 +	0x069b, 0x069b, 0x069b,			// placeholder
   1.139 +	0x069c, 0x069c, 0x069c,			// placeholder
   1.140 +	0x069d, 0x069d, 0x069d,			// placeholder
   1.141 +	0x069e, 0x069e, 0x069e,			// placeholder
   1.142 +	0x069f, 0x069f, 0x069f,			// placeholder
   1.143 +
   1.144 +	0x06a0, 0x06a0, 0x06a0,			// placeholder
   1.145 +	0x06a1, 0x06a1, 0x06a1,			// placeholder
   1.146 +	0x06a2, 0x06a2, 0x06a2,			// placeholder
   1.147 +	0x06a3, 0x06a3, 0x06a3,			// placeholder
   1.148 +	0xfb6b, 0xfb6c, 0xfb6d,			// 6a4
   1.149 +	0x06a5, 0x06a5, 0x06a5,			// placeholder
   1.150 +	0xfb6f, 0xfb70, 0xfb71,			// 6a6
   1.151 +	0x06a7, 0x06a7, 0x06a7,			// placeholder
   1.152 +	0x06a8, 0x06a8, 0x06a8,			// placeholder
   1.153 +	0xfb8f, 0xfb90, 0xfb91,			// 6a9
   1.154 +	0x06aa, 0x06aa, 0x06aa,			// 6aa
   1.155 +	0x06ab, 0x06ab, 0x06ab,			// 6ab
   1.156 +	0x06ac, 0x06ac, 0x06ac,			// 6ac
   1.157 +	0xfbd4, 0xfbd5, 0xfbd6,			// 6ad
   1.158 +	0x06ae, 0x06ae, 0x06ae,			// 6ae
   1.159 +	0xfb93, 0xfb94, 0xfb95,			// 6af
   1.160 +
   1.161 +	0x06b0, 0x06b0, 0x06b0,			// placeholder
   1.162 +	0xfb9b, 0xfb9c, 0xfb9d,			// 6b1
   1.163 +	0x06b2, 0x06b2, 0x06b2,			// 6b2
   1.164 +	0xfb97, 0xfb98, 0xfb99,			// 6b3
   1.165 +	0x06b4, 0x06b4, 0x06b4,			// placeholder
   1.166 +	0x06b5, 0x06b5, 0x06b5,			// placeholder
   1.167 +	0x06b6, 0x06b6, 0x06b6,			// placeholder
   1.168 +	0x06b7, 0x06b7, 0x06b7,			// placeholder
   1.169 +	0x06b8, 0x06b8, 0x06b8,			// placeholder
   1.170 +	0x06b9, 0x06b9, 0x06b9,			// placeholder
   1.171 +	0xfb9f, 0x06ba, 0x06ba,			// 6ba
   1.172 +	0xfba1, 0xfba2, 0xfba3,			// 6bb
   1.173 +	0x06bc, 0x06bc, 0x06bc,			// placeholder
   1.174 +	0x06bd, 0x06bd, 0x06bd,			// placeholder
   1.175 +	0xfbab, 0xfbac, 0xfbad,			// 6be
   1.176 +	0x06bf, 0x06bf, 0x06bf,			// placeholder
   1.177 +
   1.178 +	0xfba5, 0x06c0, 0x06c0,			// 6c0
   1.179 +	0xfba7, 0xfba8, 0xfba9,			// 6c1
   1.180 +	0x06c2, 0x06c2, 0x06c2,			// placeholder
   1.181 +	0x06c3, 0x06c3, 0x06c3,			// placeholder
   1.182 +	0x06c4, 0x06c4, 0x06c4,			// placeholder
   1.183 +	0xfbe1, 0x06c5, 0x06c5,			// 6c5
   1.184 +	0xfbda, 0x06c6, 0x06c6,			// 6c6
   1.185 +	0xfbd8, 0x06c7, 0x06c7,			// 6c7
   1.186 +	0xfbdc, 0x06c8, 0x06c8,			// 6c8
   1.187 +	0xfbe3, 0x06c9, 0x06c9,			// 6c9
   1.188 +	0x06ca, 0x06ca, 0x06ca,			// placeholder
   1.189 +	0xfbdf, 0x06cb, 0x06cb,			// 6cb
   1.190 +	0xfbfd, 0xfbfe, 0xfbff,			// 6cc
   1.191 +	0x06cd, 0x06cd, 0x06cd,			// placeholder
   1.192 +	0x06ce, 0x06ce, 0x06ce,			// placeholder
   1.193 +	0x06cf, 0x06cf, 0x06cf,			// placeholder
   1.194 +
   1.195 +	0xfbe5, 0xfbe6, 0xfbe7,			// 6d0
   1.196 +	0x06d1, 0x06d1, 0x06d1,			// placeholder
   1.197 +	0xfbaf, 0x06d2, 0x06d2,			// 6d2
   1.198 +	0xfbb1, 0x06d3, 0x06d3			// 6d3
   1.199 +	};
   1.200 +
   1.201 +
   1.202 +static const int KFinal = 0;
   1.203 +static const int KInitial = 1;
   1.204 +static const int KMedial = 2;
   1.205 +static const int KStandardShapeTableOffset = 0x621;
   1.206 +static const int KLamAlefShapeTableStart = 0x64B - 0x621;
   1.207 +static const int KExtendedShapeTableOffset = 0x671 - (0x64f - 0x621);
   1.208 +
   1.209 +
   1.210 +static inline TInt ArabicShapeTableIndex(TInt aCode)
   1.211 +	{
   1.212 +	if (aCode >= 0x621 && aCode <= 0x64a)
   1.213 +		return (aCode - KStandardShapeTableOffset) * 3;
   1.214 +	if (aCode >= 0x671 && aCode <= 0x6d3)
   1.215 +		return (aCode - KExtendedShapeTableOffset) * 3;
   1.216 +	return KErrNotFound;
   1.217 +	}
   1.218 +
   1.219 +
   1.220 +static inline TBool IsArabicPoint(TInt aCode)
   1.221 +	{
   1.222 +	return (aCode >= 0x64B && aCode <= 0x655) || aCode == 0x670;
   1.223 +	}
   1.224 +
   1.225 +TInt ConsumeCharsAndDeterminePresentationForm(const TUtf32Iterator& aText,
   1.226 +	TUint aFlags, TInt& aLigaturePortionsRemaining)
   1.227 +/**
   1.228 + Get the Arabic or other presentation form, consuming as many characters 
   1.229 + as necessary. This function can cope with text that has already been 
   1.230 + reversed.
   1.231 +@internalComponent
   1.232 +*/
   1.233 +	{
   1.234 +	TUint c = aText.Get();
   1.235 +	TInt index = ArabicShapeTableIndex(c);
   1.236 +	if (index != -1)
   1.237 +		{
   1.238 +		if (aLigaturePortionsRemaining != 0)
   1.239 +			{
   1.240 +			--aLigaturePortionsRemaining;
   1.241 +			GDI_ASSERT_DEBUG(!aText.AtEnd(), EGdiPanic_Invariant);
   1.242 +			return 0xFFFF;
   1.243 +			}
   1.244 +
   1.245 +		int position = -1;
   1.246 +
   1.247 +		// Find previous and next character, skipping Arabic points.
   1.248 +		TUtf32Iterator tmpText(aText);		
   1.249 +		tmpText.Prev();
   1.250 +        TUint prev = 0xFFFF;
   1.251 +        while (!tmpText.BeforeStart() && (prev == 0xFFFF || IsArabicPoint(prev)))
   1.252 +            prev = tmpText.GetThenPrev();		
   1.253 +
   1.254 +		tmpText = aText;
   1.255 +		tmpText.Next();
   1.256 +        TUint next = 0xFFFF;
   1.257 +        while (!tmpText.AtEnd() && (next == 0xFFFF || IsArabicPoint(next)))
   1.258 +            next = tmpText.GetThenNext();		
   1.259 +		
   1.260 +		TInt possible_lam = (aFlags & CFont::TPositionParam::EFLogicalOrder)?
   1.261 +			c : next;
   1.262 +		TInt possible_alef = (aFlags & CFont::TPositionParam::EFLogicalOrder)?
   1.263 +			next : c;
   1.264 +
   1.265 +		// Perform lam-alef ligation if necessary.
   1.266 +		if (possible_lam == 0x644 &&
   1.267 +			(possible_alef == 0x622 || possible_alef == 0x623 || possible_alef == 0x625 || possible_alef == 0x627))
   1.268 +			{
   1.269 +			switch(possible_alef)
   1.270 +				{
   1.271 +				case 0x622:
   1.272 +					{
   1.273 +					c = 0xfef5;
   1.274 +					index = KLamAlefShapeTableStart;
   1.275 +					break;
   1.276 +					}
   1.277 +				case 0x623:
   1.278 +					{
   1.279 +					c = 0xfef7;
   1.280 +					index = KLamAlefShapeTableStart + 1;
   1.281 +					break;
   1.282 +					}
   1.283 +				case 0x625:
   1.284 +					{
   1.285 +					c = 0xfef9;
   1.286 +					index = KLamAlefShapeTableStart + 2;
   1.287 +					break;
   1.288 +					}
   1.289 +				default:
   1.290 +					{
   1.291 +					c = 0xfefb;
   1.292 +					index = KLamAlefShapeTableStart + 3;
   1.293 +					}
   1.294 +				}
   1.295 +			index *= 3;
   1.296 +			aLigaturePortionsRemaining = 2;
   1.297 +
   1.298 +			next = 0xFFFF;
   1.299 +			while (!tmpText.AtEnd() && (next == 0xFFFF || IsArabicPoint(next)))
   1.300 +				{
   1.301 +				next = tmpText.Get();
   1.302 +				tmpText.Next();
   1.303 +				}
   1.304 +			}
   1.305 +
   1.306 +		TInt left = (aFlags & CFont::TPositionParam::EFLogicalOrder)? prev : next;
   1.307 +		TInt right = (aFlags & CFont::TPositionParam::EFLogicalOrder)? next : prev;
   1.308 +
   1.309 +		TBool prefix = FALSE;
   1.310 +		if (left == 0x640 || left == 0x200D) // kashida or Zero-Width Joiner
   1.311 +			prefix = TRUE;
   1.312 +		else
   1.313 +			{
   1.314 +			TInt left_index = ArabicShapeTableIndex(left);
   1.315 +			if (left_index != -1)
   1.316 +				{
   1.317 +				if (static_cast<TInt>(TheArabicShapeTable[left_index + KInitial]) != left ||
   1.318 +					static_cast<TInt>(TheArabicShapeTable[left_index + KMedial]) != left)
   1.319 +					prefix = TRUE;
   1.320 +				}
   1.321 +			}
   1.322 +		TBool suffix = FALSE;
   1.323 +		if (right == 0x640 || right == 0x200D) // kashida or Zero-Width Joiner
   1.324 +			suffix = TRUE;
   1.325 +		else 
   1.326 +			{
   1.327 +			TInt right_index = ArabicShapeTableIndex(right);
   1.328 +			if (right_index != -1)
   1.329 +				{
   1.330 +				if (static_cast<TInt>(TheArabicShapeTable[right_index + KFinal]) != right ||
   1.331 +					static_cast<TInt>(TheArabicShapeTable[right_index + KMedial]) != right)
   1.332 +					suffix = TRUE;
   1.333 +				}
   1.334 +			}
   1.335 +		TBool medial = static_cast<TUint>(TheArabicShapeTable[index + KMedial]) != c;
   1.336 +		if (medial)
   1.337 +			{
   1.338 +			if (prefix && suffix)
   1.339 +				position = KMedial;
   1.340 +			else if (prefix)
   1.341 +				position = KFinal;
   1.342 +			else if (suffix)
   1.343 +				position = KInitial;
   1.344 +			}
   1.345 +		else
   1.346 +			{
   1.347 +			if (prefix)
   1.348 +				position = KFinal;
   1.349 +			else if (suffix)
   1.350 +				position = KInitial;
   1.351 +			}
   1.352 +		if (position >= 0)
   1.353 +			c = TheArabicShapeTable[index + position];
   1.354 +		}
   1.355 +
   1.356 +	return c;
   1.357 +	}
   1.358 +
   1.359 +
   1.360 +// 
   1.361 +//
   1.362 +// GlyphSelector_Arabic Class definition
   1.363 +//
   1.364 +//
   1.365 +
   1.366 +TBool GlyphSelector_Arabic::Process(TGlyphSelectionState& aGss, RShapeInfo&) 
   1.367 +	{
   1.368 +	// Select glyph - use presentation form if applicable.
   1.369 +	TInt ligaturePortions = aGss.iLigaturePortionsRemaining;
   1.370 +	TUint flags = aGss.iParam.iFlags;
   1.371 +	TUint code = ConsumeCharsAndDeterminePresentationForm(aGss.iText,
   1.372 +		flags, ligaturePortions);
   1.373 +
   1.374 +	aGss.iText.Next();
   1.375 +	aGss.iClusterState = !aGss.iText.AtEnd() &&
   1.376 +		(aGss.iText.Get().GetCategory() & 0xF0) == TChar::EMarkGroup?
   1.377 +		TGlyphSelectionState::EGClusterNotComplete
   1.378 +		: TGlyphSelectionState::EGClusterComplete;
   1.379 +
   1.380 +	// If we are beginning a new portion of a ligature, we must set the state.
   1.381 +	if (ligaturePortions != aGss.iLigaturePortionsRemaining)
   1.382 +		{
   1.383 +		if (ligaturePortions != 1)
   1.384 +			aGss.iClusterState = TGlyphSelectionState::EGClusterNotComplete;
   1.385 +		aGss.iLigaturePortionFirstMark = aGss.iParam.iOutputGlyphs;
   1.386 +		if (ligaturePortions < aGss.iLigaturePortionsRemaining)
   1.387 +			{
   1.388 +			aGss.iLigaturePortionsRemaining = ligaturePortions;
   1.389 +			// We have just swallowed a non-initial part of the ligature, which
   1.390 +			// must not be drawn.
   1.391 +			GDI_ASSERT_DEBUG(code == 0xFFFF, EGdiPanic_Invariant);
   1.392 +			return ETrue;
   1.393 +			}
   1.394 +		aGss.iLigaturePortionsRemaining = ligaturePortions;
   1.395 +		}
   1.396 +
   1.397 +	// In this method we always output the glyph code calculate previously.
   1.398 +	if (!aGss.AppendGlyphToCluster(code))
   1.399 +		return EFalse;
   1.400 +
   1.401 +	if (!aGss.IsCombiningClass())
   1.402 +		{
   1.403 +		aGss.iPen = TGlyphSelectionState::EPenAdvance_Yes;
   1.404 +		return ETrue;
   1.405 +		}
   1.406 +
   1.407 +	// Adjust glyph's bounds further to position this character.
   1.408 +	aGss.iPen = TGlyphSelectionState::EPenAdvance_No;
   1.409 +	TRect baseBounds = aGss.iParam.iOutput[0].iBounds;
   1.410 +	TInt firstMark = 1;
   1.411 +	if (aGss.iLigaturePortionsRemaining != 0)
   1.412 +		{
   1.413 +		TInt centre = (baseBounds.iBr.iX + baseBounds.iTl.iX) >> 1;
   1.414 +		TBool firstHalf = aGss.iLigaturePortionsRemaining == 2;
   1.415 +		TBool rightHandSide = flags & CFont::TPositionParam::EFLogicalOrder?
   1.416 +			firstHalf : !firstHalf;
   1.417 +		if (rightHandSide)
   1.418 +			baseBounds.iTl.iX = centre;
   1.419 +		else
   1.420 +			baseBounds.iBr.iX = centre;
   1.421 +		if (firstHalf)
   1.422 +			aGss.iClusterState = TGlyphSelectionState::EGClusterNotComplete;
   1.423 +		firstMark = aGss.iLigaturePortionFirstMark;
   1.424 +		}
   1.425 +	aGss.CombineLastGlyphToBase(baseBounds, firstMark);
   1.426 +
   1.427 +	return ETrue;
   1.428 +	}
   1.429 +
   1.430 +
   1.431 +TBool GlyphSelector_Arabic::CharactersJoin(TInt aLeftCharacter, TInt aRightCharacter)
   1.432 +	{
   1.433 +	// All the characters join to the right, so we don't need to look them up.
   1.434 +	// as long as they are there at all, it is OK.
   1.435 +	TBool leftIsFixedJoiner = aLeftCharacter == 0x640 || aLeftCharacter == 0x200D;
   1.436 +	if (!leftIsFixedJoiner)
   1.437 +		{
   1.438 +		TInt leftIndex = ArabicShapeTableIndex(aLeftCharacter);
   1.439 +		if (leftIndex == -1)
   1.440 +			return EFalse;
   1.441 +		if (static_cast<TInt>(TheArabicShapeTable[leftIndex + KFinal])
   1.442 +			== aLeftCharacter)
   1.443 +			return EFalse;
   1.444 +		}
   1.445 +	if (aRightCharacter == 0x640 || aRightCharacter == 0x200D)
   1.446 +		return !leftIsFixedJoiner;
   1.447 +	TInt rightIndex = ArabicShapeTableIndex(aRightCharacter);
   1.448 +	return rightIndex != -1
   1.449 +		&& static_cast<TInt>(TheArabicShapeTable[rightIndex + KInitial])
   1.450 +			!= aRightCharacter;
   1.451 +	}
   1.452 +