// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only

/*!
    \example richtext/orderform
    \title Order Form Example
    \examplecategory {User Interface Components}
    \ingroup examples-richtext
    \brief The Order Form example shows how to generate rich text
    documents by combining a simple template with data input by the
    user in a dialog.

    \brief The Order Form example shows how to generate rich text documents by
    combining a simple template with data input by the user in a dialog. Data
    is extracted from a \c DetailsDialog object and displayed on a QTextEdit
    with a QTextCursor, using various formats. Each form generated is added
    to a QTabWidget for easy access.

    \image orderform-example.png
           {Application showing a completed order form for a customer}

    \section1 DetailsDialog Definition

    The \c DetailsDialog class is a subclass of QDialog, implementing a slot
    \c verify() to allow contents of the \c DetailsDialog to be verified later.
    This is further explained in \c DetailsDialog Implementation.

    \snippet richtext/orderform/detailsdialog.h 0

    The constructor of \c DetailsDialog accepts parameters \a title and
    \a parent. The class defines four \e{getter} functions: \c orderItems(),
    \c senderName(), \c senderAddress(), and \c sendOffers() to allow data
    to be accessed externally.

    The class definition includes input widgets for the required
    fields, \c nameEdit and \c addressEdit. Also, a QCheckBox and a
    QDialogButtonBox are defined; the former to provide the user with the
    option to receive information on products and offers, and the latter
    to ensure that buttons used are arranged according to the user's native
    platform. In addition, a QTableWidget, \c itemsTable, is used to hold
    order details.

    The screenshot below shows the \c DetailsDialog we intend to create.

    \image orderform-example-detailsdialog.png
           {Dialog for entering customer order information}

    \section1 DetailsDialog Implementation

    The constructor of \c DetailsDialog instantiates the earlier defined fields
    and their respective labels. The label for \c offersCheckBox is set and the
    \c setupItemsTable() function is invoked to setup and populate
    \c itemsTable. The QDialogButtonBox object, \c buttonBox, is instantiated
    with \uicontrol OK and \uicontrol Cancel buttons. This \c buttonBox's \c accepted() and
    \c rejected() signals are connected to the \c verify() and \c reject()
    slots in \c DetailsDialog.

    \snippet richtext/orderform/detailsdialog.cpp 0

    A QGridLayout is used to place all the objects on the \c DetailsDialog.

    \snippet richtext/orderform/detailsdialog.cpp 1

    The \c setupItemsTable() function instantiates the QTableWidget object,
    \c itemsTable, and sets the number of rows based on the QStringList
    object, \c items, which holds the type of items ordered. The number of
    columns is set to 2, providing a "name" and "quantity" layout. A \c for
    loop is used to populate the \c itemsTable and the \c name item's flag
    is set to Qt::ItemIsEnabled or Qt::ItemIsSelectable. For demonstration
    purposes, the \c quantity item is set to a 1 and all items in the
    \c itemsTable have this value for quantity; but this can be modified by
    editing the contents of the cells at run time.

    \snippet richtext/orderform/detailsdialog.cpp 2

    The \c orderItems() function extracts data from the \c itemsTable and
    returns it in the form of a QList<QPair<QString,int>> where each QPair
    corresponds to an item and the quantity ordered.

    \snippet richtext/orderform/detailsdialog.cpp 3

    The \c senderName() function is used to return the value of the QLineEdit
    used to store the name field for the order form.

    \snippet richtext/orderform/detailsdialog.cpp 4

    The \c senderAddress() function is used to return the value of the
    QTextEdit containing the address for the order form.

    \snippet richtext/orderform/detailsdialog.cpp 5

    The \c sendOffers() function is used to return a \c true or \c false
    value that is used to determine if the customer in the order form
    wishes to receive more information on the company's offers and promotions.

    \snippet richtext/orderform/detailsdialog.cpp 6

    The \c verify() function is an additionally implemented slot used to
    verify the details entered by the user into the \c DetailsDialog. If
    the details entered are incomplete, a QMessageBox is displayed
    providing the user the option to discard the \c DetailsDialog. Otherwise,
    the details are accepted and the \c accept() function is invoked.

    \snippet richtext/orderform/detailsdialog.cpp 7

    \section1 MainWindow Definition

    The \c MainWindow class is a subclass of QMainWindow, implementing two
    slots - \c openDialog() and \c printFile(). It also contains a private
    instance of QTabWidget, \c letters.

    \snippet richtext/orderform/mainwindow.h 0

    \section1 MainWindow Implementation

    The \c MainWindow constructor sets up the \c fileMenu and the required
    actions, \c newAction and \c printAction. These actions' \c triggered()
    signals are connected to the additionally implemented openDialog() slot
    and the default close() slot. The QTabWidget, \c letters, is
    instantiated and set as the window's central widget.

    \snippet richtext/orderform/mainwindow.cpp 0

    The \c createLetter() function creates a new QTabWidget with a QTextEdit,
    \c editor, as the parent. This function accepts four parameters that
    correspond to we obtained through \c DetailsDialog, in order to "fill"
    the \c editor.

    \snippet richtext/orderform/mainwindow.cpp 1

    We then obtain the cursor for the \c editor using QTextEdit::textCursor().
    The \c cursor is then moved to the start of the document using
    QTextCursor::Start.

    \snippet richtext/orderform/mainwindow.cpp 2

    Recall the structure of a \l{Rich Text Document Structure}
    {Rich Text Document}, where sequences of frames and
    tables are always separated by text blocks, some of which may contain no
    information.

    In the case of the Order Form Example, the document structure for this portion
    is described by the table below:

    \table
        \row
            \li {1, 8} frame with \e{referenceFrameFormat}
        \row
            \li block \li \c{A company}
        \row
            \li block
        \row
            \li block \li \c{321 City Street}
        \row
            \li block
        \row
            \li block \li \c{Industry Park}
        \row
            \li block
        \row
            \li block \li \c{Another country}
    \endtable

    This is accomplished with the following code:

    \snippet richtext/orderform/mainwindow.cpp 3

    Note that \c topFrame is the \c {editor}'s top-level frame and is not shown
    in the document structure.

    We then set the \c{cursor}'s position back to its last position in
    \c topFrame and fill in the customer's name (provided by the constructor)
    and address - using a range-based for loop to traverse the QString, \c address.

    \snippet richtext/orderform/mainwindow.cpp 4

    The \c cursor is now back in \c topFrame and the document structure for
    the above portion of code is:

    \table
        \row
            \li block \li \c{Donald}
        \row
            \li block \li \c{47338 Park Avenue}
        \row
            \li block \li \c{Big City}
    \endtable

    For spacing purposes, we invoke \l{QTextCursor::insertBlock()}
    {insertBlock()} twice. The \l{QDate::currentDate()}{currentDate()} is
    obtained and displayed. We use \l{QTextFrameFormat::setWidth()}
    {setWidth()} to increase the width of \c bodyFrameFormat and we insert
    a new frame with that width.

    \snippet richtext/orderform/mainwindow.cpp 5

    The following code inserts standard text into the order form.

    \snippet richtext/orderform/mainwindow.cpp 6
    \snippet richtext/orderform/mainwindow.cpp 7

    This part of the document structure now contains the date, a frame with
    \c bodyFrameFormat, as well as the standard text.

    \table
        \row
            \li block
        \row
            \li block
        \row
            \li block \li \c{Date: 25 May 2007}
        \row
            \li block
        \row
            \li {1, 4} frame with \e{bodyFrameFormat}
        \row
            \li block \li \c{I would like to place an order for the following items:}
        \row
            \li block
        \row
            \li block
    \endtable

    A QTextTableFormat object, \c orderTableFormat, is used to hold the type
    of item and the quantity ordered.

    \snippet richtext/orderform/mainwindow.cpp 8

    We use \l{QTextTable::cellAt()}{cellAt()} to set the headers for the
    \c orderTable.

    \snippet richtext/orderform/mainwindow.cpp 9

    Then, we iterate through the QList of QPair objects to populate
    \c orderTable.

    \snippet richtext/orderform/mainwindow.cpp 10

    The resulting document structure for this section is:

    \table
        \row
            \li {1, 11} \c{orderTable} with \e{orderTableFormat}
        \row
            \li block \li \c{Product}
        \row
            \li block \li \c{Quantity}
        \row
            \li block \li \c{T-shirt}
        \row
            \li block \li \c{4}
        \row
            \li block \li \c{Badge}
        \row
            \li block \li \c{3}
        \row
            \li block \li \c{Reference book}
        \row
            \li block \li \c{2}
        \row
            \li block \li \c{Coffee cup}
        \row
            \li block \li \c{5}
    \endtable

    The \c cursor is then moved back to \c{topFrame}'s
    \l{QTextFrame::lastPosition()}{lastPosition()} and more standard text
    is inserted.

    \snippet richtext/orderform/mainwindow.cpp 11
    \snippet richtext/orderform/mainwindow.cpp 12

    Another QTextTable is inserted, to display the customer's
    preference regarding offers.

    \snippet richtext/orderform/mainwindow.cpp 13

    The document structure for this portion is:

    \table
        \row
            \li block
        \row
            \li block\li \c{Please update my...}
        \row
            \li {1, 5} block
        \row
            \li {1, 4} \c{offersTable}
        \row
            \li block \li \c{I want to receive...}
        \row
            \li block \li \c{I do not want to receive...}
        \row
            \li block \li \c{X}
    \endtable

    The \c cursor is moved to insert "Sincerely" along with the customer's
    name. More blocks are inserted for spacing purposes. The \c printAction
    is enabled to indicate that an order form can now be printed.

    \snippet richtext/orderform/mainwindow.cpp 14

    The bottom portion of the document structure is:

    \table
        \row
            \li block
        \row
            \li {1, 5} block\li \c{Sincerely,}
        \row
            \li block
        \row
            \li block
        \row
            \li block
        \row
            \li block \li \c{Donald}
    \endtable

    The \c createSample() function is used for illustration purposes, to create
    a sample order form.

    \snippet richtext/orderform/mainwindow.cpp 15

    The \c openDialog() function opens a \c DetailsDialog object. If the
    details in \c dialog are accepted, the \c createLetter() function is
    invoked using the parameters extracted from \c dialog.

    \snippet richtext/orderform/mainwindow.cpp 16

    In order to print out the order form, a \c printFile() function is
    included, as shown below:

    \snippet richtext/orderform/mainwindow.cpp 17

    This function also allows the user to print a selected area with
    QTextCursor::hasSelection(), instead of printing the entire document.

    \section1 \c main() Function

    The \c main() function instantiates \c MainWindow and sets its size to
    640x480 pixels before invoking the \c show() function and
    \c createSample() function.

    \snippet richtext/orderform/main.cpp 0

*/
