Move image viewer example to manual test

Change-Id: I4b64033f1a075681ce5b918fdf2e018ad05a7869
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit b8f588bea74aae0a890e1af18b936b0bfbf8c237)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

examples/widgets/doc/src/imageviewer.qdoc

@@ -1,320 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
-
-/*!
-    \example widgets/imageviewer
-    \title Image Viewer Example
-    \ingroup examples-widgets
-    \brief The example shows how to combine QLabel and QScrollArea to
-    display an image.
-
-    QLabel is typically used for displaying text,
-    but it can also display an image. QScrollArea provides a
-    scrolling view around another widget. If the child widget exceeds
-    the size of the frame, QScrollArea automatically provides scroll
-    bars.
-
-    The example demonstrates how QLabel's ability to scale its
-    contents (QLabel::scaledContents), and QScrollArea's ability to
-    automatically resize its contents (QScrollArea::widgetResizable),
-    can be used to implement zooming and scaling features. In
-    addition the example shows how to use QPainter to print an image.
-
-    \borderedimage imageviewer-example.png
-    \caption Screenshot of the Image Viewer example
-
-    With the Image Viewer application, the users can view an image of
-    their choice. The \uicontrol File menu gives the user the possibility
-    to:
-
-    \list
-    \li \uicontrol{Open...} - Open an image file
-    \li \uicontrol{Print...} - Print an image
-    \li \uicontrol{Exit} - Exit the application
-    \endlist
-
-    Once an image is loaded, the \uicontrol View menu allows the users to:
-
-    \list
-    \li \uicontrol{Zoom In} - Scale the image up by 25%
-    \li \uicontrol{Zoom Out} - Scale the image down by 25%
-    \li \uicontrol{Normal Size} - Show the image at its original size
-    \li \uicontrol{Fit to Window} - Stretch the image to occupy the entire window
-    \endlist
-
-    In addition the \uicontrol Help menu provides the users with information
-    about the Image Viewer example in particular, and about Qt in
-    general.
-
-    \section1 ImageViewer Class Definition
-
-    \snippet widgets/imageviewer/imageviewer.h 0
-
-    The \c ImageViewer class inherits from QMainWindow. We reimplement
-    the constructor, and create several private slots to facilitate
-    the menu entries. In addition we create four private functions.
-
-    We use \c createActions() and \c createMenus() when constructing
-    the \c ImageViewer widget. We use the \c updateActions() function
-    to update the menu entries when a new image is loaded, or when
-    the \uicontrol {Fit to Window} option is toggled. The zoom slots use \c
-    scaleImage() to perform the zooming. In turn, \c
-    scaleImage() uses \c adjustScrollBar() to preserve the focal point after
-    scaling an image.
-
-    \section1 ImageViewer Class Implementation
-
-    \snippet widgets/imageviewer/imageviewer.cpp 0
-
-    In the constructor we first create the label and the scroll area.
-
-    We set \c {imageLabel}'s size policy to \l
-    {QSizePolicy::Ignored}{ignored}, making the users able to scale
-    the image to whatever size they want when the \uicontrol {Fit to Window}
-    option is turned on. Otherwise, the default size polizy (\l
-    {QSizePolicy::Preferred}{preferred}) will make scroll bars appear
-    when the scroll area becomes smaller than the label's minimum size
-    hint.
-
-    We ensure that the label will scale its contents to fill all
-    available space, to enable the image to scale properly when
-    zooming. If we omitted to set the \c {imageLabel}'s \l
-    {QLabel::scaledContents}{scaledContents} property, zooming in
-    would enlarge the QLabel, but leave the pixmap at
-    its original size, exposing the QLabel's background.
-
-    We make \c imageLabel the scroll area's child widget, and we make
-    \c scrollArea the central widget of the QMainWindow. At the end
-    we create the associated actions and menus, and customize the \c
-    {ImageViewer}'s appearance.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 1
-
-    In the \c open() slot, we show a file dialog to the user. We compile
-    a list of mime types for use as a filter by querying QImageReader
-    for the available mime type names.
-
-    We show the file dialog until a valid file name is entered or
-    the user cancels.
-
-    The function \c loadFile() is used to load the image.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 2
-
-    In the \c loadFile() function, we instantiate a QImageReader
-    and enable automatic transformations by calling
-    QImageReader::setAutoTransform(). For files in JPEG format,
-    this ensures that portrait mode images of digital cameras are shown
-    correctly by applying the appropriate orientation read from the
-    EXIF meta data stored in the image file.
-
-    We then load the image using QImageReader::read(). If this returns
-    a null image, indicating that the file is not an image file,
-    we use a QMessageBox to alert the user.
-
-    The QMessageBox class provides a modal dialog with a short
-    message, an icon, and some buttons. As with QFileDialog the
-    easiest way to create a QMessageBox is to use its static
-    convenience functions. QMessageBox provides a range of different
-    messages arranged along two axes: severity (question,
-    information, warning and critical) and complexity (the number of
-    necessary response buttons). In this particular example an
-    information message with an \uicontrol OK button (the default) is
-    sufficient, since the message is part of a normal operation.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 4
-
-    If the format is supported, we display the image in \c imageLabel
-    by setting the label's \l {QLabel::pixmap}{pixmap}. Then we enable
-    the \uicontrol Print and \uicontrol {Fit to Window} menu entries and update
-    the rest of the view menu entries. The \uicontrol Open and \uicontrol Exit
-    entries are enabled by default.
-
-    If the \uicontrol {Fit to Window} option is turned off, the
-    QScrollArea::widgetResizable property is \c false and it is
-    our responsibility (not QScrollArea's) to give the QLabel a
-    reasonable size based on its contents. We call
-    \{QWidget::adjustSize()}{adjustSize()} to achieve this, which is
-    essentially the same as
-
-    \code
-    imageLabel->resize(imageLabel->pixmap()->size());
-    \endcode
-
-    In the \c print() slot, we first make sure that an image has been
-    loaded into the application:
-
-    \snippet widgets/imageviewer/imageviewer.cpp 5
-    \snippet widgets/imageviewer/imageviewer.cpp 6
-
-    If the application is built in debug mode, the \c Q_ASSERT() macro
-    will expand to
-
-    \code
-    if (imageLabel->pixmap().isNull())
-        qFatal("ASSERT: "imageLabel->pixmap().isNull()" in file ...");
-    \endcode
-
-    In release mode, the macro simply disappear. The mode can be set
-    in the application's \c .pro file. One way to do so is to add an
-    option to \uicontrol qmake when building the application:
-
-    \code
-    qmake "CONFIG += debug" foo.pro
-    \endcode
-
-    or
-
-    \code
-    qmake "CONFIG += release" foo.pro
-    \endcode
-
-    Another approach is to add this line directly to the \c .pro
-    file.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 7
-    \snippet widgets/imageviewer/imageviewer.cpp 8
-
-    Then we present a print dialog allowing the user to choose a
-    printer and to set a few options. We construct a painter with a
-    QPrinter as the paint device. We set the painter's window
-    and viewport in such a way that the image is as large as possible
-    on the paper, but without altering its
-    \l{Qt::KeepAspectRatio}{aspect ratio}.
-
-    In the end we draw the pixmap at position (0, 0).
-
-    \snippet widgets/imageviewer/imageviewer.cpp 9
-    \snippet widgets/imageviewer/imageviewer.cpp 10
-
-    We implement the zooming slots using the private \c scaleImage()
-    function. We set the scaling factors to 1.25 and 0.8,
-    respectively. These factor values ensure that a \uicontrol {Zoom In}
-    action and a \uicontrol {Zoom Out} action will cancel each other (since
-    1.25 * 0.8 == 1), and in that way the normal image size can be
-    restored using the zooming features.
-
-    The screenshots below show an image in its normal size, and the
-    same image after zooming in:
-
-    \table
-    \row
-    \li \inlineimage imageviewer-original_size.png
-    \li \inlineimage imageviewer-zoom_in_1.png
-    \li \inlineimage imageviewer-zoom_in_2.png
-    \endtable
-
-    \snippet widgets/imageviewer/imageviewer.cpp 11
-    \snippet widgets/imageviewer/imageviewer.cpp 12
-
-    When zooming, we use the QLabel's ability to scale its contents.
-    Such scaling doesn't change the actual size hint of the contents.
-    And since the \l {QLabel::adjustSize()}{adjustSize()} function
-    use those size hint, the only thing we need to do to restore the
-    normal size of the currently displayed image is to call \c
-    adjustSize() and reset the scale factor to 1.0.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 13
-    \snippet widgets/imageviewer/imageviewer.cpp 14
-
-    The \c fitToWindow() slot is called each time the user toggled
-    the \uicontrol {Fit to Window} option. If the slot is called to turn on
-    the option, we tell the scroll area to resize its child widget
-    with the QScrollArea::setWidgetResizable() function. Then we
-    disable the \uicontrol {Zoom In}, \uicontrol {Zoom Out} and \uicontrol {Normal
-    Size} menu entries using the private \c updateActions() function.
-
-    If the \l {QScrollArea::widgetResizable} property is set to \c
-    false (the default), the scroll area honors the size of its child
-    widget. If this property is set to \c true, the scroll area will
-    automatically resize the widget in order to avoid scroll bars
-    where they can be avoided, or to take advantage of extra space.
-    But the scroll area will honor the minimum size hint of its child
-    widget independent of the widget resizable property. So in this
-    example we set \c {imageLabel}'s size policy to \l
-    {QSizePolicy::Ignored}{ignored} in the constructor, to avoid that
-    scroll bars appear when the scroll area becomes smaller than the
-    label's minimum size hint.
-
-    The screenshots below shows an image in its normal size, and the
-    same image with the \uicontrol {Fit to window} option turned on.
-    Enlarging the window will stretch the image further, as shown in
-    the third screenshot.
-
-    \table
-    \row
-    \li \inlineimage imageviewer-original_size.png
-    \li \inlineimage imageviewer-fit_to_window_1.png
-    \li \inlineimage imageviewer-fit_to_window_2.png
-    \endtable
-
-    If the slot is called to turn off the option, the
-    {QScrollArea::setWidgetResizable} property is set to \c false. We
-    also restore the image pixmap to its normal size by adjusting the
-    label's size to its content. And in the end we update the view
-    menu entries.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 15
-    \snippet widgets/imageviewer/imageviewer.cpp 16
-
-    We implement the \c about() slot to create a message box
-    describing what the example is designed to show.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 17
-    \snippet widgets/imageviewer/imageviewer.cpp 18
-
-    In the private \c createAction() function, we create the
-    actions providing the application features and populate
-    a menu with them.
-
-    We assign a short-cut key to each action and connect them to the
-    appropriate slots. We only enable the \c openAct and \c exitAct at
-    the time of creation, the others are updated once an image has
-    been loaded into the application. In addition we make the \c
-    fitToWindowAct \l {QAction::checkable}{checkable}.
-
-    The QMenu class provides a menu widget for use in menu bars,
-    context menus, and other popup menus. The QMenuBar class provides
-    a horizontal menu bar that consists of a list of pull-down menu
-    items. So we put the menus in the \c {ImageViewer}'s
-    menu bar which we retrieve with the QMainWindow::menuBar()
-    function.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 21
-    \snippet widgets/imageviewer/imageviewer.cpp 22
-
-    The private \c updateActions() function enables or disables the
-    \uicontrol {Zoom In}, \uicontrol {Zoom Out} and \uicontrol {Normal Size} menu
-    entries depending on whether the \uicontrol {Fit to Window} option is
-    turned on or off.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 23
-    \snippet widgets/imageviewer/imageviewer.cpp 24
-
-    In \c scaleImage(), we use the \c factor parameter to calculate
-    the new scaling factor for the displayed image, and resize \c
-    imageLabel. Since we set the
-    \l{QLabel::scaledContents}{scaledContents} property to \c true in
-    the constructor, the call to QWidget::resize() will scale the
-    image displayed in the label. We also adjust the scroll bars to
-    preserve the focal point of the image.
-
-    At the end, if the scale factor is less than 33.3% or greater
-    than 300%, we disable the respective menu entry to prevent the
-    image pixmap from becoming too large, consuming too much
-    resources in the window system.
-
-    \snippet widgets/imageviewer/imageviewer.cpp 25
-    \snippet widgets/imageviewer/imageviewer.cpp 26
-
-    Whenever we zoom in or out, we need to adjust the scroll bars in
-    consequence. It would have been tempting to simply call
-
-    \code
-    scrollBar->setValue(int(factor * scrollBar->value()));
-    \endcode
-
-    but this would make the top-left corner the focal point, not the
-    center. Therefore we need to take into account the scroll bar
-    handle's size (the \l{QScrollBar::pageStep}{page step}).
-*/

examples/widgets/widgets/CMakeLists.txt

@@ -5,7 +5,6 @@ qt_internal_add_example(analogclock)
 qt_internal_add_example(calculator)
 qt_internal_add_example(calendarwidget)
 qt_internal_add_example(groupbox)
-qt_internal_add_example(imageviewer)
 qt_internal_add_example(lineedits)
 if(QT_FEATURE_movie)
     qt_internal_add_example(movie)

examples/widgets/widgets/widgets.pro

@@ -3,7 +3,6 @@ SUBDIRS       = analogclock \
                 calculator \
                 calendarwidget \
                 groupbox \
-                imageviewer \
                 lineedits \
                 movie \
                 scribble \

src/widgets/widgets/qscrollarea.cpp

@@ -91,11 +91,7 @@ QT_BEGIN_NAMESPACE
     cause the size of the scroll area to be updated whenever the
     contents of the layout changes.
 
-    For a complete example using the QScrollArea class, see the \l
-    {widgets/imageviewer}{Image Viewer} example. The example shows how
-    to combine QLabel and QScrollArea to display an image.
-
-    \sa QAbstractScrollArea, QScrollBar, {Image Viewer Example}
+    \sa QAbstractScrollArea, QScrollBar
 */