diff options
Diffstat (limited to 'src/corelib/doc/snippets/qloggingcategory/main.cpp')
-rw-r--r-- | src/corelib/doc/snippets/qloggingcategory/main.cpp | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/corelib/doc/snippets/qloggingcategory/main.cpp b/src/corelib/doc/snippets/qloggingcategory/main.cpp new file mode 100644 index 0000000000..d6d9ae0ff3 --- /dev/null +++ b/src/corelib/doc/snippets/qloggingcategory/main.cpp @@ -0,0 +1,113 @@ +/**************************************************************************** +** +** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names +** of its contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QCoreApplication> +#include <QLoggingCategory> + +//![1] +// in a header +Q_DECLARE_LOGGING_CATEGORY(QT_DRIVER_USB) + +// in one source file +Q_LOGGING_CATEGORY(QT_DRIVER_USB, "qt.driver.usb") +//![1] + + +// Completely made up example, inspired by en.wikipedia.org/wiki/USB :) +struct UsbEntry { + int id; + int classtype; +}; + +QDebug operator<<(QDebug &dbg, const UsbEntry &entry) +{ + dbg.nospace() << "" << entry.id << " (" << entry.classtype << ")"; + return dbg.space(); +} + +QList<UsbEntry> usbEntries() { + QList<UsbEntry> entries; + return entries; +} + +void main(int argc, char *argv[]) +{ + QCoreApplication a(argc, argv); + +//![2] + // don't run the expensive code if the string won't print + if (QT_DRIVER_USB().isEnabled<QtDebugMsg>()) { + QStringList items; + foreach (const UsbEntry &entry, usbEntries()) + items << QString("%1 (%2)").arg(entry.id, entry.classtype); + qCDebug(QT_DRIVER_USB) << "devices: " << items; + } +//![2] + +//![3] + // usbEntries() will only be called if QT_DRIVER_USB category is enabled + qCDebug(QT_DRIVER_USB) << "devices: " << usbEntries(); +//![3] + + { +//![10] + QLoggingCategory category("qt.driver.usb"); + qCDebug(category) << "a debug message"; +//![10] + } + + { +//![11] + QLoggingCategory category("qt.driver.usb"); + qCWarning(category) << "a warning message"; +//![11] + } + + { +//![12] + QLoggingCategory category("qt.driver.usb"); + qCCritical(category) << "a critical message"; +//![12] + } +} + +//![20] +void myCategoryFilter(QLoggingCategory *); +//![20] |