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| author | Frederik Gladhorn <frederik.gladhorn@digia.com> | 2014-03-24 16:10:15 +0100 |
|---|---|---|
| committer | Frederik Gladhorn <frederik.gladhorn@digia.com> | 2014-03-24 16:10:15 +0100 |
| commit | 3b5c0bc0780f1749fed7c07bd8b691400a0282b7 (patch) | |
| tree | 1022f5553ad5a0aca9b5f3b49ca38a01c2329d20 /src/corelib/tools/qcommandlineparser.cpp | |
| parent | c79918733a194ebbe5a2fe1617c884659f3e4b9f (diff) | |
| parent | 21f1738a94fc8544ece04b3b1ee03a11986fe59b (diff) | |
Merge remote-tracking branch 'origin/stable' into dev
Conflicts:
src/gui/image/qjpeghandler.cpp
Change-Id: I9db3acea7d5c82f5da679c8eaeb29431136665f0
Diffstat (limited to 'src/corelib/tools/qcommandlineparser.cpp')
| -rw-r--r-- | src/corelib/tools/qcommandlineparser.cpp | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src/corelib/tools/qcommandlineparser.cpp b/src/corelib/tools/qcommandlineparser.cpp index 0f5d9a6827..168701d13c 100644 --- a/src/corelib/tools/qcommandlineparser.cpp +++ b/src/corelib/tools/qcommandlineparser.cpp @@ -187,6 +187,78 @@ QStringList QCommandLineParserPrivate::aliases(const QString &optionName) const QCoreApplication::arguments() before QCommandLineParser defines the \c{profile} option and parses the command line. + \section2 How to Use QCommandLineParser in Complex Applications + + In practice, additional error checking needs to be performed on the positional + arguments and option values. For example, ranges of numbers should be checked. + + It is then advisable to introduce a function to do the command line parsing + which takes a struct or class receiving the option values returning an + enumeration representing the result. The dnslookup example of the QtNetwork + module illustrates this: + + \snippet dnslookup.h 0 + + \snippet dnslookup.cpp 0 + + In the main function, help should be printed to the standard output if the help option + was passed and the application should return the exit code 0. + + If an error was detected, the error message should be printed to the standard + error output and the application should return an exit code other than 0. + + \snippet dnslookup.cpp 1 + + A special case to consider here are GUI applications on Windows and mobile + platforms. These applications may not use the standard output or error channels + since the output is either discarded or not accessible. + + For such GUI applications, it is recommended to display help texts and error messages + using a QMessageBox. To preserve the formatting of the help text, rich text + with \c <pre> elements should be used: + + \code + + switch (parseCommandLine(parser, &query, &errorMessage)) { + case CommandLineOk: + break; + case CommandLineError: +#ifdef Q_OS_WIN + QMessageBox::warning(0, QGuiApplication::applicationDisplayName(), + "<html><head/><body><h2>" + errorMessage + "</h2><pre>" + + parser.helpText() + "</pre></body></html>"); +#else + fputs(qPrintable(errorMessage), stderr); + fputs("\n\n", stderr); + fputs(qPrintable(parser.helpText()), stderr); +#endif + return 1; + case CommandLineVersionRequested: +#ifdef Q_OS_WIN + QMessageBox::information(0, QGuiApplication::applicationDisplayName(), + QGuiApplication::applicationDisplayName() + ' ' + + QCoreApplication::applicationVersion()); +#else + printf("%s %s\n", QGuiApplication::applicationDisplayName(), + qPrintable(QCoreApplication::applicationVersion())); +#endif + return 0; + case CommandLineHelpRequested: +#ifdef Q_OS_WIN + QMessageBox::warning(0, QGuiApplication::applicationDisplayName(), + "<html><head/><body><pre>" + + parser.helpText() + "</pre></body></html>"); + return 0; +#else + parser.showHelp(); + Q_UNREACHABLE(); +#endif + } + \endcode + + However, this does not apply to the dnslookup example, because it is a + console application. + \sa QCommandLineOption, QCoreApplication */ |