KDE 4.4 API Reference qca
QCA::Console Class Reference
[QCA user API]
QCA Console system More...
#include <QtCrypto>
Public Types | |
| enum | ChannelMode { Read, ReadWrite } |
| enum | TerminalMode { Default, Interactive } |
| enum | Type { Tty, Stdio } |
Public Member Functions | |
| Console (Type type, ChannelMode cmode, TerminalMode tmode, QObject *parent=0) | |
| ~Console () | |
| QByteArray | bytesLeftToRead () |
| QByteArray | bytesLeftToWrite () |
| ChannelMode | channelMode () const |
| void | release () |
| TerminalMode | terminalMode () const |
| Type | type () const |
Static Public Member Functions | |
| static bool | isStdinRedirected () |
| static bool | isStdoutRedirected () |
| static Console * | stdioInstance () |
| static Console * | ttyInstance () |
Detailed Description
QCA Console system
QCA provides an API for asynchronous, event-based access to the console and stdin/stdout, as these facilities are otherwise not portable. The primary use of this system within QCA is for passphrase prompting in command-line applications, using the tty console type.
How it works: Create a Console object for the type of console desired, and then use ConsoleReference to act on the console. Only one ConsoleReference may operate on a Console at a time.
A Console object takes over either the physical console (Console::Tty type) or stdin/stdout (Console::Stdio type). Only one of each type may be created at a time.
Whenever code is written that needs a tty or stdio object, the code should first call one of the static methods (ttyInstance() or stdioInstance()) to see if a console object for the desired type exists already. If the object exists, use it. If it does not exist, the rule is that the relevant code should create the object, use the object, and then destroy the object when the operation is completed.
By following the above rule, you can write code that utilizes a console without the application having to create some master console object for you. Of course, if the application has created a console then it will be used.
The reason why there is a master console object is that it is not guaranteed that all I/O will survive creation and destruction of a console object. If you are using the Stdio Type, then you probably want a long-lived console object. It is possible to capture unprocessed I/O by calling bytesLeftToRead or bytesLeftToWrite. However, it is not expected that general console-needing code will call these functions when utilizing a temporary console. Thus, an application developer would need to create his own console object, invoke the console-needing code, and then do his own extraction of the unprocessed I/O if necessary. Another reason to extract unprocessed I/O is if you need to switch from Console back to standard functions (e.g. fgets() ).
Definition at line 552 of file qca_support.h.
Member Enumeration Documentation
The type of I/O to use with the console object.
- Enumerator:
Read Read only (equivalent to stdin).
ReadWrite Read/write (equivalent to stdin and stdout).
Definition at line 567 of file qca_support.h.
The nature of the console operation.
Definition at line 576 of file qca_support.h.
| enum QCA::Console::Type |
The type of console object.
Definition at line 559 of file qca_support.h.
Constructor & Destructor Documentation
| QCA::Console::Console | ( | Type | type, | |
| ChannelMode | cmode, | |||
| TerminalMode | tmode, | |||
| QObject * | parent = 0 | |||
| ) |
Standard constructor.
Note that library code should not create a new Console object without checking whether there is already a Console object of the required Type. See the main documentation for Console for the rationale for this.
- Parameters:
-
type the Type of Console object to create cmode the ChannelMode (I/O type) to use tmode the TerminalMode to use parent the parent object for this object
- See also:
- ttyInstance() and stdioInstance for static methods that allow you to test whether there is already a Console object of the required Type, and if there is, obtain a reference to that object.
Definition at line 427 of file console.cpp.
| QCA::Console::~Console | ( | ) |
Definition at line 500 of file console.cpp.
Member Function Documentation
| QByteArray QCA::Console::bytesLeftToRead | ( | ) |
Obtain remaining data from the Console, awaiting a read operation.
Definition at line 567 of file console.cpp.
| QByteArray QCA::Console::bytesLeftToWrite | ( | ) |
Obtain remaining data from the Console, awaiting a write operation.
Definition at line 572 of file console.cpp.
| Console::ChannelMode QCA::Console::channelMode | ( | ) | const |
The ChannelMode of this Console object.
Definition at line 516 of file console.cpp.
| bool QCA::Console::isStdinRedirected | ( | ) | [static] |
Test whether standard input is redirected.
- See also:
- type() and channelMode()
Definition at line 526 of file console.cpp.
| bool QCA::Console::isStdoutRedirected | ( | ) | [static] |
Test whether standard output is redirected.
- See also:
- type() and channelMode()
Definition at line 539 of file console.cpp.
| void QCA::Console::release | ( | ) |
Release the Console.
This allows access to buffers containing any remaining data
Definition at line 562 of file console.cpp.
| Console * QCA::Console::stdioInstance | ( | ) | [static] |
The current stdio-type console object.
Definition at line 557 of file console.cpp.
| Console::TerminalMode QCA::Console::terminalMode | ( | ) | const |
The TerminalMode of this Console object.
Definition at line 521 of file console.cpp.
| Console * QCA::Console::ttyInstance | ( | ) | [static] |
The current terminal-type console object.
Definition at line 552 of file console.cpp.
| Console::Type QCA::Console::type | ( | ) | const |
The Type of this Console object.
Definition at line 511 of file console.cpp.
The documentation for this class was generated from the following files:
