|
1 // Copyright (c) 2002-2010 Nokia Corporation and/or its subsidiary(-ies). |
|
2 // All rights reserved. |
|
3 // This component and the accompanying materials are made available |
|
4 // under the terms of "Eclipse Public License v1.0" |
|
5 // which accompanies this distribution, and is available |
|
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
7 // |
|
8 // Initial Contributors: |
|
9 // Nokia Corporation - initial contribution. |
|
10 // |
|
11 // Contributors: |
|
12 // |
|
13 // Description: |
|
14 // |
|
15 |
|
16 #include "BidiCompact.h" |
|
17 #include "BidiCopy.h" |
|
18 #include <textbase.h> |
|
19 |
|
20 static const TInt KZeroWidthJoiner = 0x200D; |
|
21 // This gets round the compiler warning about converting |
|
22 // EFRightToLeft to unsigned long. |
|
23 inline TUint FRightToLeft() { return static_cast<TUint>(TRunInfoCompact::EFRightToLeft); } |
|
24 |
|
25 /** |
|
26 Constructs a run description without considering optimisations based |
|
27 on the text itself. |
|
28 @param aStart Index of the start of the run. |
|
29 @param aLength Length of the run. |
|
30 @param aReverse ETrue if the run is right-to-left. |
|
31 @internalTechnology |
|
32 */ |
|
33 TRunInfoCompact::TRunInfoCompact(TInt aStart, TInt aLength, |
|
34 TBool aReverse) |
|
35 : iStart(aStart), iLengthAndType(aLength) |
|
36 { |
|
37 if (aReverse) |
|
38 iLengthAndType |= FRightToLeft(); |
|
39 } |
|
40 |
|
41 /** |
|
42 Constructs a run description. |
|
43 |
|
44 @param aStart Index of the start of the run. |
|
45 @param aLength Length of the run. |
|
46 @param aReverse ETrue if the run is right-to-left. |
|
47 @param aText The text that this run refers to (starting at index 0, not |
|
48 the start of the run). This is required only to determine if optimisations |
|
49 to the re-ordering are possible. |
|
50 @internalTechnology |
|
51 */ |
|
52 TRunInfoCompact::TRunInfoCompact(TInt aStart, TInt aLength, |
|
53 TBool aReverse, const TText* aText) |
|
54 : iStart(aStart), iLengthAndType(aLength) |
|
55 { |
|
56 ASSERT(0 <= aLength); |
|
57 ASSERT(aLength < 0x10000000); |
|
58 ASSERT(0 <= aStart); |
|
59 if (!aReverse) |
|
60 return; |
|
61 iLengthAndType |= FRightToLeft(); |
|
62 TUint32 flags = EFNoPairsNoCombiners | EFNoMirroredCharacters; |
|
63 aText += aStart; |
|
64 |
|
65 for (const TText* end = aText + aLength; aText < end && flags; ++aText) |
|
66 { |
|
67 TInt code = *aText; |
|
68 if ((code & 0xF800) == 0xD800) |
|
69 { |
|
70 flags &= ~EFNoPairsNoCombiners; |
|
71 if ((code & 0xFC00) == 0xDC00 |
|
72 && aText + 1 < end |
|
73 && (aText[1] & 0xFC00) == 0xD800) |
|
74 { |
|
75 code = (aText[1] << 10) + (code & 0x3FF) |
|
76 + (0x10000 - 0xD800*0x400); |
|
77 ++aText; |
|
78 } |
|
79 } |
|
80 TChar c = code; |
|
81 if (c.GetCombiningClass() != 0) |
|
82 flags &= ~EFNoPairsNoCombiners; |
|
83 if (BidiCopy::Mirror(code) != code) |
|
84 flags &= ~EFNoMirroredCharacters; |
|
85 } |
|
86 iLengthAndType |= flags; |
|
87 } |
|
88 |
|
89 /** |
|
90 Attempts to extend a run. |
|
91 |
|
92 @param aToBeAdded The run to be merged. |
|
93 @return ETrue if extension succeeded, EFalse if not. |
|
94 @internalTechnology |
|
95 */ |
|
96 TBool TRunInfoCompact::AddRun(const TRunInfoCompact& aToBeAdded) |
|
97 { |
|
98 TInt length = Length(); |
|
99 if (length == 0) |
|
100 { |
|
101 *this = aToBeAdded; |
|
102 return ETrue; |
|
103 } |
|
104 |
|
105 // Are both runs in the same direction? |
|
106 if ((iLengthAndType ^ aToBeAdded.iLengthAndType) & FRightToLeft()) |
|
107 return EFalse; |
|
108 |
|
109 TBool rightToLeft = TypeFlags() & EFRightToLeft; |
|
110 TInt end = rightToLeft? |
|
111 Start() - Length() : Start() + Length(); |
|
112 |
|
113 if (end != aToBeAdded.Start()) |
|
114 return EFalse; |
|
115 |
|
116 length += aToBeAdded.Length(); |
|
117 |
|
118 iLengthAndType = length | (TypeFlags() & aToBeAdded.TypeFlags()); |
|
119 |
|
120 if (rightToLeft) |
|
121 iStart -= aToBeAdded.Length(); |
|
122 |
|
123 return ETrue; |
|
124 } |
|
125 |
|
126 /** |
|
127 Reorders text described by this run according to aContext. Allow 6 extra |
|
128 bytes for a truncation. |
|
129 @param aDestination Where to write this run of visually-ordered text to. |
|
130 @param aContext The source of the text to be ordered. |
|
131 @return The first byte not written to: in other words, what aDestination |
|
132 should be updated to. |
|
133 @internalTechnology |
|
134 */ |
|
135 TText* TRunInfoCompact::Reorder(TText* aDestination, |
|
136 const TRunInfoCompact::TReorderingContext& aContext) const |
|
137 { |
|
138 TInt start = Start(); |
|
139 if (aContext.iEnd < start) |
|
140 // does not overlap |
|
141 return aDestination; |
|
142 TInt end = Start() + Length(); |
|
143 if (end <= aContext.iStart) |
|
144 // does not overlap |
|
145 return aDestination; |
|
146 TBool startJoins = EFalse; |
|
147 if (start <= aContext.iStart) |
|
148 { |
|
149 start = aContext.iStart; |
|
150 startJoins = aContext.iJoinsAtStart; |
|
151 } |
|
152 TBool truncated = EFalse; |
|
153 TBool endJoins = EFalse; |
|
154 if (aContext.iEnd <= end) |
|
155 { |
|
156 if (aContext.iEnd < end |
|
157 && aContext.iTruncation != 0xFFFF) |
|
158 truncated = ETrue; |
|
159 end = aContext.iEnd; |
|
160 endJoins = aContext.iJoinsAtEnd; |
|
161 } |
|
162 TInt length = end - start; |
|
163 if (length == 0 && !truncated) |
|
164 return aDestination; |
|
165 ASSERT(0 <= length); |
|
166 const TText* source = aContext.iSource + start; |
|
167 if (TypeFlags() & FRightToLeft()) |
|
168 { |
|
169 // Right-to-left |
|
170 if (truncated) |
|
171 aDestination = BidiCopy::OutputTChar(aDestination, aContext.iTruncation); |
|
172 if (endJoins) |
|
173 *(aDestination++) = KZeroWidthJoiner; |
|
174 if (TypeFlags() & EFNoPairsNoCombiners) |
|
175 { |
|
176 // Simple |
|
177 aDestination = TypeFlags() & EFNoMirroredCharacters? |
|
178 BidiCopy::CopyBackwards(aDestination, source, length) |
|
179 : BidiCopy::CopyBackwardsWithMirroring(aDestination, source, length); |
|
180 } |
|
181 else |
|
182 // Respect groups |
|
183 aDestination = BidiCopy::CopyGroupsBackwards(aDestination, source, length); |
|
184 if (startJoins) |
|
185 *aDestination++ = KZeroWidthJoiner; |
|
186 return aDestination; |
|
187 } |
|
188 // Left-to-right |
|
189 if (startJoins) |
|
190 *aDestination++ = KZeroWidthJoiner; |
|
191 Mem::Copy(aDestination, source, length * sizeof(TText)); |
|
192 aDestination += length; |
|
193 if (endJoins) |
|
194 *aDestination++ = KZeroWidthJoiner; |
|
195 if (truncated) |
|
196 aDestination = BidiCopy::OutputTChar(aDestination, aContext.iTruncation); |
|
197 return aDestination; |
|
198 } |
|
199 |
|
200 /** |
|
201 Converts an array of aArraySize TBidirectionalState::TRunInfos into a |
|
202 compact form. |
|
203 |
|
204 @param aBuffer Memory to output to, or null just to find out how large the output |
|
205 array will need to be. |
|
206 @param aText The text that aRunArray refers to. |
|
207 @param aRunArray The array to be converted. |
|
208 @param aArraySize The length of aRunArray. |
|
209 @return The length of the output array. |
|
210 @internalTechnology |
|
211 */ |
|
212 TInt TRunInfoCompact::Convert(TRunInfoCompact* aBuffer, const TDesC& aText, |
|
213 const TBidirectionalState::TRunInfo* aRunArray, TInt aArraySize) |
|
214 { |
|
215 const TText* text = aText.Ptr(); |
|
216 TInt outputSize = 0; |
|
217 |
|
218 TRunInfoCompact currentRun; |
|
219 while (aArraySize) |
|
220 { |
|
221 TRunInfoCompact newRun(aRunArray->iStart, aRunArray->iLength, |
|
222 aRunArray->iDirection, text); |
|
223 --aArraySize; |
|
224 if (!currentRun.AddRun(newRun)) |
|
225 { |
|
226 if (aBuffer) |
|
227 *aBuffer++ = currentRun; |
|
228 ++outputSize; |
|
229 currentRun = newRun; |
|
230 } |
|
231 ++aRunArray; //point to next run |
|
232 } |
|
233 if (0 < currentRun.Length()) |
|
234 { |
|
235 if (aBuffer) |
|
236 *aBuffer++ = currentRun; |
|
237 ++outputSize; |
|
238 } |
|
239 |
|
240 return outputSize; |
|
241 } |
|
242 |
|
243 /** |
|
244 Utility tells whether a character will form a join with the previous |
|
245 base character. |
|
246 |
|
247 @param aText The text. |
|
248 @param aIndex The index into aText of the character to test. |
|
249 @return ETrue if there is a join before the character. |
|
250 */ |
|
251 TBool TRunInfoCompact::JoinBefore(const TText* aText, TInt aIndex) |
|
252 { |
|
253 TInt charUnderTest = aText[aIndex]; |
|
254 if (!CFont::CharactersJoin(charUnderTest, KZeroWidthJoiner)) |
|
255 // Character does not join with anything, so we |
|
256 // will not do any more work. |
|
257 return EFalse; |
|
258 while (aIndex != 0) |
|
259 { |
|
260 --aIndex; |
|
261 TInt c = aText[aIndex]; |
|
262 // If it is an Arabic point, we will skip it. |
|
263 if (0x64B <= c && c < 0x671 |
|
264 && !(0x656 <= c && c < 0x670)) |
|
265 continue; |
|
266 return CFont::CharactersJoin(charUnderTest, c); |
|
267 } |
|
268 return EFalse; |
|
269 } |