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diff --git a/examples/datavisualization/qmlbars/doc/src/qmlbars.qdoc b/examples/datavisualization/qmlbars/doc/src/qmlbars.qdoc index 60815d48..2b0a1c4b 100644 --- a/examples/datavisualization/qmlbars/doc/src/qmlbars.qdoc +++ b/examples/datavisualization/qmlbars/doc/src/qmlbars.qdoc @@ -1,136 +1,110 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Free Documentation License Usage -** Alternatively, this file may be used under the terms of the GNU Free -** Documentation License version 1.3 as published by the Free Software -** Foundation and appearing in the file included in the packaging of -** this file. Please review the following information to ensure -** the GNU Free Documentation License version 1.3 requirements -** will be met: https://www.gnu.org/licenses/fdl-1.3.html. -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only /*! \example qmlbars - \title Qt Quick 2 Bars Example - \ingroup qtdatavisualization_examples + \meta tags {DataVisualization, Barsr3D, Multiple Series} + \title Simple Bar Graph + \ingroup qtdatavisualization_qmlexamples \brief Using Bars3D in a QML application. - The Qt Quick 2 bars example shows how to make a simple 3D bar graph using Bars3D and Qt - Quick 2. + \e {Simple Bar Graph} shows how to make a simple 3D bar graph using Bars3D and QML. \image qmlbars-example.png - The interesting thing about this example is switching series and displaying more than one series - at once. We'll concentrate on those and skip explaining the basic Bars3D functionality - for - more detailed QML example documentation, see \l{Qt Quick 2 Scatter Example}. + The following sections describe how to switch series and display more than one series + at a time. For more information about basic QML application functionality, see + \l{Simple Scatter Graph}. \include examples-run.qdocinc \section1 Data - The example data is monthly income and expenses of a fictional company over several years. + The example data set is the monthly income and expenses of a fictional company over several years. The data is defined in a list model in \c Data.qml like this: \snippet qmlbars/qml/qmlbars/Data.qml 0 \dots Each data item has three roles: timestamp, income, and expenses. The timestamp value is in - format: \c{<four digit year>-<two digit month>}. Years and months are natural to map to rows and - columns of a bar chart, but we can only show either income or expenses as the value. + format: \c{<four digit year>-<two digit month>}. Usually, you would map years and months to rows + and columns of a bar chart, but you can only show either income or expenses as the value. - Now we need to add the data to the Bars3D graph. We will create two Bar3DSeries inside it, - starting with a series for the income: + Now, add the data to the Bars3D graph. Create two Bar3DSeries inside it, starting with a series + for the income: \snippet qmlbars/qml/qmlbars/main.qml 3 \dots The data is attached to the \c itemModel property of the ItemModelBarDataProxy inside the - series. For \c valueRole we simply specify the \c income field, as it contains the value we - want, but getting the years and months is a bit more complicated, since they are both found - in the same field. To extract those values, we specify the \c timestamp field for both + series. For \c{valueRole}, specify the \c income field, as it contains the value you + want. Getting the years and months is a bit more complicated, since they are both found + in the same field. To extract those values, specify the \c timestamp field for both \c rowRole and \c columnRole, and additionally specify a search pattern and a replace rule for those roles to extract the correct portion of the field contents for each role. The search pattern is a normal JavaScript regular expression and the replace rule specifies what the field content that matches the regular expression is replaced with. - In this case we want to replace the entire field content with just the year or the month, + In this case, replace the entire field content with just the year or the month, which is the first captured substring for both rows and columns. - For more information how the replace using regular expressions works, see + For more information about the replace functionality with regular expression, see QString::replace(const QRegExp &rx, const QString &after) function documentation. The \c multiMatchBehavior property specifies what to do in case multiple item model items match - the same row/column combination. In this case we want to add their values together. - This property has no effect when we are showing values for each month, as there are no - duplicate months in our item model, but it becomes relevant later when we want to show + the same row/column combination. In this case, add their values together. + This property has no effect when showing values for each month, as there are no + duplicate months in our item model, but it becomes relevant later when you want to show the yearly totals. - Then we add another series for the expenses: + Then, add another series for the expenses: \snippet qmlbars/qml/qmlbars/main.qml 4 \dots - The model contains expenses as negative values, but we want to show them as positive bars, so - that we can easily compare them to income bars. We use \c valueRolePattern to remove the minus + The model contains expenses as negative values, but you want to show them as positive bars, so + that they can be easily compared to income bars. Use the \c valueRolePattern to remove the minus sign to achieve this. No replacement string needs to be specified as the default replacement is an empty string. - We use the \c visible property of the series to hide the second series for now. + Use the \c visible property of the series to hide the second series for now. \section1 Custom Axis Labels - One interesting tidbit about axes is that we redefine the category labels for column axis in - \c Axes.qml. This is done because the data contains numbers for months, which we don't want - to use for our column labels: + \c Axes.qml redefines the category labels for the column axis because the data contains numbers + for months, which would clutter the labels: \snippet qmlbars/qml/qmlbars/Axes.qml 0 - We also set automatic axis label rotation to make axis labels more readable at low camera - angles. + To make axis labels more readable at low camera angles, set automatic axis label rotation. \section1 Switching Series - In the \c main.qml, we set up the graph and various UI elements. There are three interesting - code blocks we want to highlight here. The first one shows how to change the - visualized data between income, expenses, and both, by simply changing visibility of the two - series: + In \c main.qml, set up the graph and various UI elements. There are three interesting + code blocks to highlight here. The first one shows how to change the visualized data between + income, expenses, and both, by simply changing the visibility of the two series: \snippet qmlbars/qml/qmlbars/main.qml 0 The axis label format and item selection label formats are tweaked to get the negative sign showing properly for expenses, which were actually resolved as positive values. - The second interesting block is where we change the visualized data by adjusting the proxy - propertes: + The second interesting block is where the visualized data is changed by adjusting the proxy + properties: \snippet qmlbars/qml/qmlbars/main.qml 1 - To show yearly totals, we need to combine the twelve months of each year into a single bar. - We achieve this by specifying a \c columnRolePattern that matches all model items. That way - the data proxy will only have a single column. The cumulative \c multiMatchBehavior we + To show the yearly totals, combine the twelve months of each year into a single bar. + This is achieved by specifying a \c columnRolePattern that matches all model items. That way, + the data proxy will only have a single column. The cumulative \c multiMatchBehavior specified earlier for the proxy becomes relevant now, causing the values of all twelve months of each year to be added up into a single bar. - To show just a subset of years, we set \c autoRowCategories to false on the - ItemModelBarDataProxy item and define the row categories explicitly. This way, only the items - in specified row categories are visualized. + To show just a subset of years, set \c autoRowCategories to false on the ItemModelBarDataProxy + item and define the row categories explicitly. This way, only the items in the specified row + categories are visualized. - The third interesting block shows how to get the row and column index of an item if you know the - row and column values by using ItemModelBarDataProxy methods \c rowCategoryIndex() and \c columnCategoryIndex(): + The third interesting block shows how to get the row and column index of an item if you know + the row and column values by using ItemModelBarDataProxy methods \c rowCategoryIndex() + and \c columnCategoryIndex(): \snippet qmlbars/qml/qmlbars/main.qml 2 */ |