Remove wiggly example

It demonstrates timerEvent() and some QFontMetrics
There are other examples that demonstrates this

Pick-to: 6.5
Change-Id: I4ad6f30c8ef93c995f980545ed88ab13b9aa9c7d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

doc/global/manifest-meta.qdocconf

@@ -178,7 +178,6 @@ manifestmeta.ios.names              =  "QtCore/Contiguous Cache Example" \
                                        "QtWidgets/Sliders Example" \
                                        "QtWidgets/Validators Example" \
                                        "QtWidgets/Window Flags Example" \
-                                       "QtWidgets/Wiggly Example" \
                                        "QtQuick/Qt Quick Examples - Animation" \
                                        "QtQuick/Qt Quick Examples - Canvas" \
                                        "QtQuick/Qt Quick Examples - Drag and Drop" \

examples/widgets/doc/src/wiggly.qdoc

@@ -1,147 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
-
-/*!
-    \example widgets/wiggly
-    \title Wiggly Example
-    \ingroup examples-widgets
-    \brief The Wiggly example shows how to animate a widget using
-    QBasicTimer and \l{QObject::timerEvent()}{timerEvent()}. In
-    addition, the example demonstrates how to use QFontMetrics to
-    determine the size of text on screen.
-
-    \borderedimage wiggly-example.png
-    \caption Screenshot of the Wiggly example
-
-    QBasicTimer is a low-level class for timers. Unlike QTimer,
-    QBasicTimer doesn't inherit from QObject; instead of emitting a
-    \l{QTimer::timeout()}{timeout()} signal when a certain amount of
-    time has passed, it sends a QTimerEvent to a QObject of our
-    choice. This makes QBasicTimer a more lightweight alternative to
-    QTimer. Qt's built-in widgets use it internally, and it is
-    provided in Qt's API for highly-optimized applications (such as
-    embedded applications).
-
-    The example consists of two classes:
-
-    \list
-    \li \c WigglyWidget is the custom widget displaying the text
-        in a wiggly line.
-
-    \li \c Dialog is the dialog widget allowing the user to enter a
-        text. It combines a \c WigglyWidget and a \c QLineEdit.
-    \endlist
-
-    We will first take a quick look at the \c Dialog class, then we
-    will review the \c WigglyWidget class.
-
-    \section1 Dialog Class Definition
-
-    \snippet widgets/wiggly/dialog.h 0
-
-    The \c Dialog class provides a dialog widget that allows the user
-    to enter a text. The text is then rendered by \c WigglyWidget.
-
-    \section1 Dialog Class Implementation
-
-    \snippet widgets/wiggly/dialog.cpp 0
-
-    In the constructor we create a wiggly widget along with a
-    \l{QLineEdit}{line edit}, and we put the two widgets in a
-    vertical layout. We connect the line edit's \l
-    {QLineEdit::textChanged()}{textChanged()} signal to the wiggly
-    widget's \c setText() slot to obtain the real time interaction
-    with the wiggly widget. The widget's default text is "Hello
-    world!", with an emoji thrown in for fun.
-
-    \section1 WigglyWidget Class Definition
-
-    \snippet widgets/wiggly/wigglywidget.h 0
-
-    The \c WigglyWidget class provides the wiggly line displaying the
-    text. We subclass QWidget and reimplement the standard \l
-    {QWidget::paintEvent()}{paintEvent()} and \l
-    {QObject::timerEvent()}{timerEvent()} functions to draw and update
-    the widget. In addition we implement a public \c setText() slot
-    that sets the widget's text.
-
-    The \c timer variable, of type QBasicTimer, is used to update the
-    widget at regular intervals, making the widget move. The \c text
-    variable is used to store the currently displayed text, and \c
-    step to calculate position and color for each character on the
-    wiggly line.
-
-    \section1 WigglyWidget Class Implementation
-
-    \snippet widgets/wiggly/wigglywidget.cpp 0
-
-    In the constructor, we make the widget's background slightly
-    lighter than the usual background using the QPalette::Midlight
-    color role. The background role defines the brush from the
-    widget's palette that Qt uses to paint the background. Then we
-    enlarge the widget's font with 20 points.
-
-    Finally we start the timer; the call to QBasicTimer::start()
-    makes sure that \e this particular wiggly widget will receive the
-    timer events generated when the timer times out (every 60
-    milliseconds).
-
-    \snippet widgets/wiggly/wigglywidget.cpp 1
-    \snippet widgets/wiggly/wigglywidget.cpp 2
-
-    The \c paintEvent() function is called whenever a QPaintEvent is
-    sent to the widget. Paint events are sent to widgets that need to
-    update themselves, for instance when part of a widget is exposed
-    because a covering widget was moved. For the wiggly widget, a
-    paint event will also be generated every 60 milliseconds from
-    the \c timerEvent() slot.
-
-    The \c sineTable represents y-values of the sine curve,
-    multiplied by 100. It is used to make the wiggly widget move
-    along the sine curve.
-
-    The QFontMetrics object provides information about the widget's
-    font. The \c x variable is the horizontal position where we start
-    drawing the text. The \c y variable is the vertical position of
-    the text's base line. Both variables are computed so that the
-    text is horizontally and vertically centered. To compute the base
-    line, we take into account the font's ascent (the height of the
-    font above the base line) and font's descent (the height of the
-    font below the base line). If the descent equals the ascent, they
-    cancel out each other and the base line is at \c height() / 2.
-
-    \snippet widgets/wiggly/wigglywidget.cpp 3
-    \snippet widgets/wiggly/wigglywidget.cpp 4
-
-    Each time the \c paintEvent() function is called, we create a
-    QPainter object \c painter to draw the contents of the widget.
-    Since we are going to paint the character symbols individually, we
-    extract the unique unicode code point for each character from \c
-    text, and convert it to a string \c symbol. For each \c symbol, we
-    determine the color and the position on the wiggly line based on
-    \c step and its \c offset from the start of the text. In addition,
-    \c x is incremented by the symbol's width.
-
-    For simplicity, we assume that QFontMetrics::horizontalAdvance(\c text)
-    returns the sum of the individual character advances
-    (QFontMetrics::horizontalAdvance(\c symbol)). In practice, this is not
-    always the case because QFontMetrics::horizontalAdvance(\c text) also takes
-    into account the kerning between certain letters (e.g., 'A' and
-    'V'). The result is that the text isn't perfectly centered. You
-    can verify this by typing "AVAVAVAVAVAV" in the line edit.
-
-    \snippet widgets/wiggly/wigglywidget.cpp 5
-    \snippet widgets/wiggly/wigglywidget.cpp 6
-
-    The \c timerEvent() function receives all the timer events that
-    are generated for this widget. If a timer event is sent from the
-    widget's QBasicTimer, we increment \c step to make the text move,
-    and call QWidget::update() to refresh the display. Any other
-    timer event is passed on to the base class's implementation of
-    the \l{QWidget::timerEvent()}{timerEvent()} function.
-
-    The QWidget::update() slot does not cause an immediate repaint;
-    instead the slot schedules a paint event for processing when Qt
-    returns to the main event loop. The paint events are then handled
-    by \c{WigglyWidget}'s \c paintEvent() function.
-*/

examples/widgets/widgets/CMakeLists.txt

@@ -26,5 +26,4 @@ qt_internal_add_example(tablet)
 qt_internal_add_example(tetrix)
 qt_internal_add_example(tooltips)
 qt_internal_add_example(validators)
-qt_internal_add_example(wiggly)
 qt_internal_add_example(windowflags)

examples/widgets/widgets/widgets.pro

@@ -21,5 +21,4 @@ SUBDIRS       = analogclock \
                 tetrix \
                 tooltips \
                 validators \
-                wiggly \
                 windowflags

examples/widgets/widgets/wiggly/CMakeLists.txt

@@ -1,38 +0,0 @@
-# Copyright (C) 2022 The Qt Company Ltd.
-# SPDX-License-Identifier: BSD-3-Clause
-
-cmake_minimum_required(VERSION 3.16)
-project(wiggly LANGUAGES CXX)
-
-if(NOT DEFINED INSTALL_EXAMPLESDIR)
-    set(INSTALL_EXAMPLESDIR "examples")
-endif()
-
-set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/widgets/wiggly")
-
-find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
-
-qt_standard_project_setup()
-
-qt_add_executable(wiggly
-    dialog.cpp dialog.h
-    main.cpp
-    wigglywidget.cpp wigglywidget.h
-)
-
-set_target_properties(wiggly PROPERTIES
-    WIN32_EXECUTABLE TRUE
-    MACOSX_BUNDLE TRUE
-)
-
-target_link_libraries(wiggly PRIVATE
-    Qt6::Core
-    Qt6::Gui
-    Qt6::Widgets
-)
-
-install(TARGETS wiggly
-    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
-    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
-    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
-)

examples/widgets/widgets/wiggly/dialog.cpp

@@ -1,27 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#include "dialog.h"
-#include "wigglywidget.h"
-
-#include <QLineEdit>
-#include <QVBoxLayout>
-
-//! [0]
-Dialog::Dialog(QWidget *parent)
-    : QDialog(parent)
-{
-    WigglyWidget *wigglyWidget = new WigglyWidget;
-    QLineEdit *lineEdit = new QLineEdit;
-
-    QVBoxLayout *layout = new QVBoxLayout(this);
-    layout->addWidget(wigglyWidget);
-    layout->addWidget(lineEdit);
-
-    connect(lineEdit, &QLineEdit::textChanged, wigglyWidget, &WigglyWidget::setText);
-    lineEdit->setText(u8"🖖 " + tr("Hello world!"));
-
-    setWindowTitle(tr("Wiggly"));
-    resize(360, 145);
-}
-//! [0]

examples/widgets/widgets/wiggly/dialog.h

@@ -1,19 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#ifndef DIALOG_H
-#define DIALOG_H
-
-#include <QDialog>
-
-//! [0]
-class Dialog : public QDialog
-{
-    Q_OBJECT
-
-public:
-    explicit Dialog(QWidget *parent = nullptr);
-};
-//! [0]
-
-#endif

examples/widgets/widgets/wiggly/main.cpp

@@ -1,16 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#include "dialog.h"
-
-#include <QApplication>
-
-int main(int argc, char *argv[])
-{
-    QApplication app(argc, argv);
-
-    Dialog dialog;
-    dialog.show();
-
-    return app.exec();
-}

examples/widgets/widgets/wiggly/wiggly.pro

@@ -1,11 +0,0 @@
-QT += widgets
-
-HEADERS       = wigglywidget.h \
-                dialog.h
-SOURCES       = wigglywidget.cpp \
-                dialog.cpp \
-                main.cpp
-
-# install
-target.path = $$[QT_INSTALL_EXAMPLES]/widgets/widgets/wiggly
-INSTALLS += target

examples/widgets/widgets/wiggly/wigglywidget.cpp

@@ -1,65 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#include "wigglywidget.h"
-
-#include <QFontMetrics>
-#include <QPainter>
-#include <QTimerEvent>
-
-//! [0]
-WigglyWidget::WigglyWidget(QWidget *parent)
-    : QWidget(parent), step(0)
-{
-    setBackgroundRole(QPalette::Midlight);
-    setAutoFillBackground(true);
-
-    QFont newFont = font();
-    newFont.setPointSize(newFont.pointSize() + 20);
-    setFont(newFont);
-
-    timer.start(60, this);
-}
-//! [0]
-
-//! [1]
-void WigglyWidget::paintEvent(QPaintEvent * /* event */)
-//! [1] //! [2]
-{
-    static constexpr int sineTable[16] = {
-        0, 38, 71, 92, 100, 92, 71, 38, 0, -38, -71, -92, -100, -92, -71, -38
-    };
-
-    QFontMetrics metrics(font());
-    int x = (width() - metrics.horizontalAdvance(text)) / 2;
-    int y = (height() + metrics.ascent() - metrics.descent()) / 2;
-    QColor color;
-//! [2]
-
-//! [3]
-    QPainter painter(this);
-//! [3] //! [4]
-    int offset = 0;
-    for (char32_t codePoint : text.toUcs4()) {
-        int index = (step + offset++) % 16;
-        color.setHsv((15 - index) * 16, 255, 191);
-        painter.setPen(color);
-        QString symbol = QString::fromUcs4(&codePoint, 1);
-        painter.drawText(x, y - ((sineTable[index] * metrics.height()) / 400), symbol);
-        x += metrics.horizontalAdvance(symbol);
-    }
-}
-//! [4]
-
-//! [5]
-void WigglyWidget::timerEvent(QTimerEvent *event)
-//! [5] //! [6]
-{
-    if (event->timerId() == timer.timerId()) {
-        ++step;
-        update();
-    } else {
-        QWidget::timerEvent(event);
-    }
-//! [6]
-}

examples/widgets/widgets/wiggly/wigglywidget.h

@@ -1,32 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-#ifndef WIGGLYWIDGET_H
-#define WIGGLYWIDGET_H
-
-#include <QBasicTimer>
-#include <QWidget>
-
-//! [0]
-class WigglyWidget : public QWidget
-{
-    Q_OBJECT
-
-public:
-    WigglyWidget(QWidget *parent = nullptr);
-
-public slots:
-    void setText(const QString &newText) { text = newText; }
-
-protected:
-    void paintEvent(QPaintEvent *event) override;
-    void timerEvent(QTimerEvent *event) override;
-
-private:
-    QBasicTimer timer;
-    QString text;
-    int step;
-};
-//! [0]
-
-#endif

src/corelib/kernel/qbasictimer.cpp

@@ -36,7 +36,7 @@ QT_BEGIN_NAMESPACE
     The \l{widgets/wiggly}{Wiggly} example uses QBasicTimer to repaint
     a widget at regular intervals.
 
-    \sa QTimer, QTimerEvent, QObject::timerEvent(), Timers, {Wiggly Example}
+    \sa QTimer, QTimerEvent, QObject::timerEvent(), Timers, {Affine Transformations}
 */
 
 

src/corelib/kernel/qtimer.cpp

@@ -105,7 +105,7 @@ QT_BEGIN_NAMESPACE
     used; Qt tries to work around these limitations.
 
     \sa QBasicTimer, QTimerEvent, QObject::timerEvent(), Timers,
-        {Analog Clock Example}, {Wiggly Example}
+        {Analog Clock Example}, {Tetrix Example}
 */
 
 /*!