From 99eaae4323ff1fda2d8cc0184d824b6d9c3f23ad Mon Sep 17 00:00:00 2001 From: Volker Hilsheimer Date: Tue, 19 Dec 2023 11:16:23 +0100 Subject: Turn SpinBox Delegate example into snippets The essence of the example was already fully quoted in the model/view documentation. Move the code into a snippet source, and update the screenshot. Fixes: QTBUG-119976 Pick-to: 6.7 6.6 Change-Id: Id2f10bb26a650419969bbfa9b76cb74babd3319e Reviewed-by: Richard Moe Gustavsen Reviewed-by: Andreas Eliasson --- examples/widgets/doc/src/spinboxdelegate.qdoc | 118 -------------------------- 1 file changed, 118 deletions(-) delete mode 100644 examples/widgets/doc/src/spinboxdelegate.qdoc (limited to 'examples/widgets/doc/src/spinboxdelegate.qdoc') diff --git a/examples/widgets/doc/src/spinboxdelegate.qdoc b/examples/widgets/doc/src/spinboxdelegate.qdoc deleted file mode 100644 index bd3b68aa97..0000000000 --- a/examples/widgets/doc/src/spinboxdelegate.qdoc +++ /dev/null @@ -1,118 +0,0 @@ -// Copyright (C) 2016 The Qt Company Ltd. -// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only - -/*! - \example itemviews/spinboxdelegate - \title Spin Box Delegate Example - \examplecategory {User Interface Components} - \ingroup examples-itemviews - \brief The Spin Box Delegate example shows how to create an editor for a custom delegate in - the model/view framework by reusing a standard Qt editor widget. - - The model/view framework provides a standard delegate that is used by default - with the standard view classes. For most purposes, the selection of editor - widgets available through this delegate is sufficient for editing text, boolean - values, and other simple data types. However, for specific data types, it is - sometimes necessary to use a custom delegate to either display the data in a - specific way, or allow the user to edit it with a custom control. - - \image spinboxdelegate-example.png - - This concepts behind this example are covered in the - \l{Model/View Programming#Delegate Classes}{Delegate Classes} chapter - of the \l{Model/View Programming} overview. - - \section1 SpinBoxDelegate Class Definition - - The definition of the delegate is as follows: - - \snippet itemviews/spinboxdelegate/delegate.h 0 - - The delegate class declares only those functions that are needed to - create an editor widget, display it at the correct location in a view, - and communicate with a model. Custom delegates can also provide their - own painting code by reimplementing the \c paintEvent() function. - Furthermore it is also possible to reuse (and avoid deleting) the editor - widget by reimplementing the \a destroyEditor() function. A reused widget - could be a mutable member created in the constructor and deleted in - the destructor. - - \section1 SpinBoxDelegate Class Implementation - - Delegates are often stateless. The constructor only needs to - call the base class's constructor with the parent QObject as its - argument: - - \snippet itemviews/spinboxdelegate/delegate.cpp 0 - - Since the delegate is a subclass of QStyledItemDelegate, the data it retrieves - from the model is displayed in a default style, and we do not need to - provide a custom \c paintEvent(). - - The \c createEditor() function returns an editor widget, in this case a - spin box that restricts values from the model to integers from 0 to 100 - inclusive. - - \snippet itemviews/spinboxdelegate/delegate.cpp 1 - - We install an event filter on the spin box to ensure that it behaves in - a way that is consistent with other delegates. The implementation for - the event filter is provided by the base class. - - The \c setEditorData() function reads data from the model, converts it - to an integer value, and writes it to the editor widget. - - \snippet itemviews/spinboxdelegate/delegate.cpp 2 - - Since the view treats delegates as ordinary QWidget instances, we have - to use a static cast before we can set the value in the spin box. - - The \c setModelData() function reads the contents of the spin box, and - writes it to the model. - - \snippet itemviews/spinboxdelegate/delegate.cpp 3 - - We call \l{QSpinBox::interpretText()}{interpretText()} to make sure that - we obtain the most up-to-date value in the spin box. - - The \c updateEditorGeometry() function updates the editor widget's - geometry using the information supplied in the style option. This is the - minimum that the delegate must do in this case. - - \snippet itemviews/spinboxdelegate/delegate.cpp 4 - - More complex editor widgets may divide the rectangle available in - \c{option.rect} between different child widgets if required. - - \section1 The Main Function - - This example is written in a slightly different way to many of the - other examples supplied with Qt. To demonstrate the use of a custom - editor widget in a standard view, it is necessary to set up a model - containing some arbitrary data and a view to display it. - - We set up the application in the normal way, construct a standard item - model to hold some data, set up a table view to use the data in the - model, and construct a custom delegate to use for editing: - - \snippet itemviews/spinboxdelegate/main.cpp 0 - - The table view is informed about the delegate, and will use it to - display each of the items. Since the delegate is a subclass of - QStyledItemDelegate, each cell in the table will be rendered using standard - painting operations. - - We insert some arbitrary data into the model for demonstration purposes: - - \snippet itemviews/spinboxdelegate/main.cpp 1 - \snippet itemviews/spinboxdelegate/main.cpp 2 - - Finally, the table view is displayed with a window title, and we start - the application's event loop: - - \snippet itemviews/spinboxdelegate/main.cpp 3 - - Each of the cells in the table can now be edited in the usual way, but - the spin box ensures that the data returned to the model is always - constrained by the values allowed by the spin box delegate. -*/ -- cgit v1.2.3