Symbian3/SDK/Source/GUID-F46D5A5B-EC44-53B0-9A11-886735B28610.dita
author Dominic Pinkman <Dominic.Pinkman@Nokia.com>
Wed, 31 Mar 2010 11:11:55 +0100
changeset 7 51a74ef9ed63
parent 0 89d6a7a84779
child 13 48780e181b38
permissions -rw-r--r--
Week 12 contribution of API Specs and fix SDK submission
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
0
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     1
<?xml version="1.0" encoding="utf-8"?>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     2
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     3
<!-- This component and the accompanying materials are made available under the terms of the License 
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     4
"Eclipse Public License v1.0" which accompanies this distribution, 
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     5
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     6
<!-- Initial Contributors:
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     7
    Nokia Corporation - initial contribution.
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     8
Contributors: 
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     9
-->
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    10
<!DOCTYPE concept
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    11
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    12
<concept id="GUID-F46D5A5B-EC44-53B0-9A11-886735B28610" xml:lang="en"><title>How to
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    13
use the modifiable pointer descriptor — TPtr</title><shortdesc>Modifiable pointer descriptors are useful for referencing strings
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    14
or data which can be accessed and changed.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    15
<ul>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    16
<li id="GUID-80F50BD5-A919-5EB3-B28E-4BDF7A2A0121"><p>For text data, it is
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    17
usual to construct a <codeph>TPtr</codeph> type and allow the appropriate
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    18
variant, either a <codeph>TPtr</codeph> or a <codeph>TPtrC</codeph> to be
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    19
selected at build time.</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    20
<li id="GUID-965CB6DC-DE3E-5744-A6D8-10C9A0567011"><p>For binary data, an
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    21
explicit <codeph>TPtr8</codeph> is used.</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    22
<li id="GUID-40B8DB60-33DB-56D3-BDE7-263B1B48840E"><p>It is rare to use an
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    23
explicit <codeph>TPtr16</codeph>.</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    24
</ul>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    25
<section id="GUID-AEBBFA2C-D87D-48F8-ADBF-0A042F371EC1"><title>Constructing a TPtr</title> <p>A modifiable pointer descriptor
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    26
can be constructed in a number of ways:</p> <ul>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    27
<li id="GUID-C3767C93-A5BA-5B09-A90D-FAD74E9CDC3F"><p>another modifiable pointer
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    28
descriptor.</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    29
<li id="GUID-9704F005-0931-5DA0-B4C7-7F263270300C"><p>from a non-modifiable
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    30
buffer descriptor using the <codeph>Des()</codeph> function</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    31
<li id="GUID-2F09FD0B-7FE7-5D4E-B353-233B2609F9FC"><p>from an explicit pointer
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    32
into memory and specifying a maximum length.</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    33
<li id="GUID-F9C4E446-B390-56AD-8771-A0C393ADA246"><p>from an explicit pointer
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    34
into memory and specifying the length of the data and a maximum length.</p> </li>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    35
</ul> <p>The following code fragment constructs a <codeph>TPtr</codeph> to
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    36
represent the data already represented by another <codeph>TPtr</codeph>:</p> <codeblock id="GUID-B9296BAB-8B81-52C4-9730-2290C357656A" xml:space="preserve">TPtr ptr1;
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    37
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    38
TPtr ptr2(ptr1);
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    39
...</codeblock> <p>The following code fragment constructs a <codeph>TPtr</codeph> for
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    40
a non-modifiable buffer descriptor, a <codeph>TBufC&lt;TInt&gt;</codeph>, using
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    41
the <codeph>Des()</codeph> function. Data that would normally be unmodifiable
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    42
through the <codeph>TBufC&lt;TInt&gt;</codeph> can be changed through the <codeph>TPtr</codeph>.</p> <p>The
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    43
source are literals which are converted to descriptor type.</p> <codeblock id="GUID-86F2890B-6AD2-5637-90B6-469554026C12" xml:space="preserve">_LIT(KText,"Hello World!");
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    44
_LIT(KExtraText," &amp; Hi");
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    45
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    46
TBufC&lt;16&gt; buf1(KText);
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    47
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    48
TPtr ptr = buf1.Des();
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    49
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    50
ptr.Delete((ptr.Length()-1),1);
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    51
ptr.Append(KExtraText);</codeblock> <p>Define a <codeph>TText</codeph> area
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    52
initialised to contain the string "Have a nice day":</p> <p>The following
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    53
code fragments show the construction of a <codeph>TPtr</codeph> using a pointer
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    54
and specifying a length and a maximum length. This technique is not commonly
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    55
used. Literals are a much better way of defining string constants.</p> <codeblock id="GUID-998F1C38-942B-53F5-BBC5-E33781AF1253" xml:space="preserve">TText str[16] =  {'H', 'a', 'v', 'e', ' ', 'a',
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    56
    ' ', 'n', 'i', 'c', 'e',
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    57
    ' ', 'd', 'a', 'y', '\0'};</codeblock> <codeblock id="GUID-EF4302BB-F536-5B20-B109-1505688B8B60" xml:space="preserve">TPtr ptr(&amp;str[0],15,16);</codeblock> <p>The
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    58
descriptor <codeph>ptr</codeph> represents the data in <codeph>str</codeph> and
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    59
is constructed to have a current length of 15 (the length of the text, excluding
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    60
the zero terminator) and a maximum length of 16 (the actual length of <codeph>str</codeph>).
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    61
Once the descriptor has been constructed, it has no further use for the zero
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    62
terminator.</p> <codeblock id="GUID-23A4799F-7B57-5B2B-B549-2BD168D208EC" xml:space="preserve">TPtr ptr(&amp;str[0],15,16);</codeblock> </section>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    63
<section id="GUID-AA957AF0-8791-446C-B6E3-DD5EDB642E9E"><title>Replacing data through the TPtr</title> <p>Data can be completely
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    64
replaced using the assignment operator or the <xref href="GUID-CD3C9BD5-1386-3CF5-A8F6-9BE1AE40689F.dita"><apiname>Copy()</apiname></xref> function.:</p> <codeblock id="GUID-DBF0A411-CA03-5EAD-AFCD-1617C52C195F" xml:space="preserve">_LIT(KText,"Hi there");
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    65
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    66
ptr = KText;
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    67
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    68
ptr.Copy(KText);</codeblock> <p>Note the use of the <codeph>_LIT</codeph> macro
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    69
to define the source string. A literal is converted into a descriptor type.</p> <p>The
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    70
length of <codeph>ptr</codeph> is now 8 but the maximum length remains unchanged.
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    71
The size depends on the build variant. In a non-Unicode build, this is 8 but
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    72
in a Unicode build, this becomes 16 (two bytes for every character).</p> </section>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    73
<section id="GUID-4A13D438-C058-4370-970E-1139708758E3"><title>Changing the length of data</title> <p>The length of the data
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    74
represented can be changed. </p> <codeblock id="GUID-0AE02AC5-2E85-5950-894A-FF7B6C8C5856" xml:space="preserve">_LIT(KText,"Hi there");
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    75
...
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    76
ptr = KText;
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    77
ptr.SetLength(2);
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    78
ptr.Zero();
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    79
</codeblock> <p>For example, after <codeph>ptr.SetLength(2)</codeph>, the
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    80
descriptor represents the string "Hi". The length can even be set to zero
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    81
so that after <codeph>ptr.Zero()</codeph>, the descriptor represents no data.
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    82
Nevertheless, the maximum length remains unchanged.</p> </section>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    83
</conbody><related-links>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    84
<link>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    85
<desc><xref href="GUID-7CB11EAD-260E-551A-85F1-FEAC975FE722.dita">Literal Descriptors</xref></desc>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    86
</link>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    87
</related-links></concept>