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    12 <concept xml:lang="en" id="GUID-6A5FAD55-DE84-569D-B5EB-1474DD2AF392"><title>Introduction to text handling</title><prolog><metadata><keywords/></metadata></prolog><conbody><p> Text handling facilities begin with descriptors. These provide a basic API for constructing strings, passing them to functions, manipulating them, and extracting data. Additionally, they work with both 8-bit and 16-bit character sets.</p> <p>For graphics applications, the support for text begins with the font classes provided by the GDI, and the <xref href="GUID-DAD09DCF-3123-38B4-99E9-91FB24B92138.dita#GUID-DAD09DCF-3123-38B4-99E9-91FB24B92138/GUID-8B1AAB31-0CC2-369B-A0A3-77053AB5974D"><apiname>CGraphicsContext::DrawText()</apiname></xref> function. These provide facilities to select a font, and to draw a single descriptor to any kind of graphics device.</p> <p>These basic facilities are provided, in various forms, by most operating systems. For most real applications, there are several key requirements which go beyond this:</p> <ul><li id="GUID-BDC839B5-640C-59C1-929B-6E0D0F81C8ED"><p>text of unbounded length — i.e., any length from 0 to infinity</p> </li> <li id="GUID-2689B6C0-4939-5D42-85A2-9095E8E0D528"><p>paragraphs, pictures and other document-type objects in the text</p> </li> <li id="GUID-2564165D-ECB3-56EE-B47C-123CA6FB413D"><p>formats for characters and/or paragraphs, including fonts, style, indents, borders, colour etc.</p> </li> <li id="GUID-90BEBD77-0A32-5ED4-8CBD-FDC411843D37"><p>layout on a graphics device — screen, printer etc. — including all the details of line wrapping, justification and honouring the details of the text's format</p> </li> <li id="GUID-9351AB87-D1C0-57E3-984E-D5D4CDDDDD1A"><p>storage and retrieval of text, in files, clipboards etc.</p> </li> <li id="GUID-32DF351F-4BD3-5A49-87D8-EEE0C0DEA744"><p>manipulation and editing of such text</p> </li> <li id="GUID-59C5DCD3-0C99-53A5-B025-EAC46917F5D3"><p>efficiency in terms of speed, memory utilisation, and ease of programming</p> </li> </ul> </conbody></concept>