diff options
Diffstat (limited to 'src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp')
-rw-r--r-- | src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp | 585 |
1 files changed, 585 insertions, 0 deletions
diff --git a/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp b/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp new file mode 100644 index 0000000000..16f6783a52 --- /dev/null +++ b/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp @@ -0,0 +1,585 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation 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 Nokia Corporation 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." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +//! [0] +label->setAlignment(Qt::AlignLeft | Qt::AlignTop); +//! [0] + + +//! [1] +class MyClass +{ +public: + enum Option { + NoOptions = 0x0, + ShowTabs = 0x1, + ShowAll = 0x2, + SqueezeBlank = 0x4 + }; + Q_DECLARE_FLAGS(Options, Option) + ... +}; + +Q_DECLARE_OPERATORS_FOR_FLAGS(MyClass::Options) +//! [1] + +//! [meta-object flags] +Q_FLAGS(Options) +//! [meta-object flags] + +//! [2] +typedef QFlags<Enum> Flags; +//! [2] + + +//! [3] +int myValue = 10; +int minValue = 2; +int maxValue = 6; + +int boundedValue = qBound(minValue, myValue, maxValue); +// boundedValue == 6 +//! [3] + + +//! [4] +if (!driver()->isOpen() || driver()->isOpenError()) { + qWarning("QSqlQuery::exec: database not open"); + return false; +} +//! [4] + + +//! [5] +qint64 value = Q_INT64_C(932838457459459); +//! [5] + + +//! [6] +quint64 value = Q_UINT64_C(932838457459459); +//! [6] + + +//! [7] +void myMsgHandler(QtMsgType, const char *); +//! [7] + + +//! [8] +qint64 value = Q_INT64_C(932838457459459); +//! [8] + + +//! [9] +quint64 value = Q_UINT64_C(932838457459459); +//! [9] + + +//! [10] +int absoluteValue; +int myValue = -4; + +absoluteValue = qAbs(myValue); +// absoluteValue == 4 +//! [10] + + +//! [11] +qreal valueA = 2.3; +qreal valueB = 2.7; + +int roundedValueA = qRound(valueA); +// roundedValueA = 2 +int roundedValueB = qRound(valueB); +// roundedValueB = 3 +//! [11] + + +//! [12] +qreal valueA = 42949672960.3; +qreal valueB = 42949672960.7; + +int roundedValueA = qRound(valueA); +// roundedValueA = 42949672960 +int roundedValueB = qRound(valueB); +// roundedValueB = 42949672961 +//! [12] + + +//! [13] +int myValue = 6; +int yourValue = 4; + +int minValue = qMin(myValue, yourValue); +// minValue == yourValue +//! [13] + + +//! [14] +int myValue = 6; +int yourValue = 4; + +int maxValue = qMax(myValue, yourValue); +// maxValue == myValue +//! [14] + + +//! [15] +int myValue = 10; +int minValue = 2; +int maxValue = 6; + +int boundedValue = qBound(minValue, myValue, maxValue); +// boundedValue == 6 +//! [15] + + +//! [16] +#if QT_VERSION >= 0x040100 + QIcon icon = style()->standardIcon(QStyle::SP_TrashIcon); +#else + QPixmap pixmap = style()->standardPixmap(QStyle::SP_TrashIcon); + QIcon icon(pixmap); +#endif +//! [16] + + +//! [17] +// File: div.cpp + +#include <QtGlobal> + +int divide(int a, int b) +{ + Q_ASSERT(b != 0); + return a / b; +} +//! [17] + + +//! [18] +ASSERT: "b == 0" in file div.cpp, line 7 +//! [18] + + +//! [19] +// File: div.cpp + +#include <QtGlobal> + +int divide(int a, int b) +{ + Q_ASSERT_X(b != 0, "divide", "division by zero"); + return a / b; +} +//! [19] + + +//! [20] +ASSERT failure in divide: "division by zero", file div.cpp, line 7 +//! [20] + + +//! [21] +int *a; + +Q_CHECK_PTR(a = new int[80]); // WRONG! + +a = new (nothrow) int[80]; // Right +Q_CHECK_PTR(a); +//! [21] + + +//! [22] +template<typename TInputType> +const TInputType &myMin(const TInputType &value1, const TInputType &value2) +{ + qDebug() << Q_FUNC_INFO << "was called with value1:" << value1 << "value2:" << value2; + + if(value1 < value2) + return value1; + else + return value2; +} +//! [22] + + +//! [23] +#include <qapplication.h> +#include <stdio.h> +#include <stdlib.h> + +void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const char *msg) +{ + switch (type) { + case QtDebugMsg: + fprintf(stderr, "Debug: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function); + break; + case QtWarningMsg: + fprintf(stderr, "Warning: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function); + break; + case QtCriticalMsg: + fprintf(stderr, "Critical: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function); + break; + case QtFatalMsg: + fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function); + abort(); + } +} + +int main(int argc, char **argv) +{ + qInstallMessageHandler(myMessageOutput); + QApplication app(argc, argv); + ... + return app.exec(); +} +//! [23] + + +//! [24] +qDebug("Items in list: %d", myList.size()); +//! [24] + + +//! [25] +qDebug() << "Brush:" << myQBrush << "Other value:" << i; +//! [25] + + +//! [26] +void f(int c) +{ + if (c > 200) + qWarning("f: bad argument, c == %d", c); +} +//! [26] + + +//! [27] +qWarning() << "Brush:" << myQBrush << "Other value:" +<< i; +//! [27] + + +//! [28] +void load(const QString &fileName) +{ + QFile file(fileName); + if (!file.exists()) + qCritical("File '%s' does not exist!", qPrintable(fileName)); +} +//! [28] + + +//! [29] +qCritical() << "Brush:" << myQBrush << "Other +value:" << i; +//! [29] + + +//! [30] +int divide(int a, int b) +{ + if (b == 0) // program error + qFatal("divide: cannot divide by zero"); + return a / b; +} +//! [30] + + +//! [31] +forever { + ... +} +//! [31] + + +//! [32] +CONFIG += no_keywords +//! [32] + + +//! [33] +CONFIG += no_keywords +//! [33] + + +//! [34] +QString FriendlyConversation::greeting(int type) +{ +static const char *greeting_strings[] = { + QT_TR_NOOP("Hello"), + QT_TR_NOOP("Goodbye") +}; +return tr(greeting_strings[type]); +} +//! [34] + + +//! [35] +static const char *greeting_strings[] = { + QT_TRANSLATE_NOOP("FriendlyConversation", "Hello"), + QT_TRANSLATE_NOOP("FriendlyConversation", "Goodbye") +}; + +QString FriendlyConversation::greeting(int type) +{ + return tr(greeting_strings[type]); +} + +QString global_greeting(int type) +{ + return qApp->translate("FriendlyConversation", + greeting_strings[type]); +} +//! [35] + + +//! [36] + +static { const char *source; const char *comment; } greeting_strings[] = +{ + QT_TRANSLATE_NOOP3("FriendlyConversation", "Hello", + "A really friendly hello"), + QT_TRANSLATE_NOOP3("FriendlyConversation", "Goodbye", + "A really friendly goodbye") +}; + +QString FriendlyConversation::greeting(int type) +{ + return tr(greeting_strings[type].source, + greeting_strings[type].comment); +} + +QString global_greeting(int type) +{ + return qApp->translate("FriendlyConversation", + greeting_strings[type].source, + greeting_strings[type].comment); +} +//! [36] + + +//! [qttrid] + //% "%n fooish bar(s) found.\n" + //% "Do you want to continue?" + QString text = qtTrId("qtn_foo_bar", n); +//! [qttrid] + + +//! [qttrid_noop] +static const char * const ids[] = { + //% "This is the first text." + QT_TRID_NOOP("qtn_1st_text"), + //% "This is the second text." + QT_TRID_NOOP("qtn_2nd_text"), + 0 +}; + +void TheClass::addLabels() +{ + for (int i = 0; ids[i]; ++i) + new QLabel(qtTrId(ids[i]), this); +} +//! [qttrid_noop] + + +//! [37] +qWarning("%s: %s", qPrintable(key), qPrintable(value)); +//! [37] + + +//! [38] +struct Point2D +{ + int x; + int y; +}; + +Q_DECLARE_TYPEINFO(Point2D, Q_PRIMITIVE_TYPE); +//! [38] + + +//! [39] +class Point2D +{ +public: + Point2D() { data = new int[2]; } + Point2D(const Point2D &other) { ... } + ~Point2D() { delete[] data; } + + Point2D &operator=(const Point2D &other) { ... } + + int x() const { return data[0]; } + int y() const { return data[1]; } + +private: + int *data; +}; + +Q_DECLARE_TYPEINFO(Point2D, Q_MOVABLE_TYPE); +//! [39] + + +//! [40] +#if Q_BYTE_ORDER == Q_BIG_ENDIAN +... +#endif + +or + +#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN +... +#endif + +//! [40] + + +//! [41] + +#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN +... +#endif + +//! [41] + + +//! [42] +#if Q_BYTE_ORDER == Q_BIG_ENDIAN +... +#endif + +//! [42] + +//! [begin namespace macro] +namespace QT_NAMESPACE { +//! [begin namespace macro] + +//! [end namespace macro] +} +//! [end namespace macro] + +//! [43] +class MyClass : public QObject +{ + + private: + Q_DISABLE_COPY(MyClass) +}; + +//! [43] + +//! [44] +class MyClass : public QObject +{ + + private: + MyClass(const MyClass &); + MyClass &operator=(const MyClass &); +}; +//! [44] + +//! [45] + QWidget w = QWidget(); +//! [45] + +//! [46] + // Instead of comparing with 0.0 + qFuzzyCompare(0.0,1.0e-200); // This will return false + // Compare adding 1 to both values will fix the problem + qFuzzyCompare(1 + 0.0, 1 + 1.0e-200); // This will return true +//! [46] + +//! [47] +CApaApplication *myApplicationFactory(); +//! [47] + + +//! [49] +void myMessageHandler(QtMsgType, const QMessageLogContext &, const char *); +//! [49] + +//! [qlikely] + // the condition inside the "if" will be successful most of the times + for (int i = 1; i <= 365; i++) { + if (Q_LIKELY(isWorkingDay(i))) { + ... + } + ... + } +//! [qlikely] + +//! [qunlikely] +bool readConfiguration(const QFile &file) +{ + // We expect to be asked to read an existing file + if (Q_UNLIKELY(!file.exists())) { + qWarning() << "File not found"; + return false; + } + + ... + return true; +} +//! [qunlikely] + +//! [qunreachable-enum] + enum Shapes { + Rectangle, + Triangle, + Circle, + NumShapes + }; +//! [qunreachable-enum] + +//! [qunreachable-switch] + switch (shape) { + case Rectangle: + return rectangle(); + case Triangle: + return triangle(); + case Circle: + return circle(); + case NumShapes: + Q_UNREACHABLE(); + break; + } +//! [qunreachable-switch] |