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/****************************************************************************
**
** Copyright (C) 2020 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Creator documentation.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** 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.
**
****************************************************************************/
/*!
\previouspage quick-signals.html
\page quick-dynamic-properties.html
\nextpage quick-property-bindings.html
\title Specifying Dynamic Properties
Each predefined QML type has a set of predefined properties that you can
specify values for. You can add custom properties that would not otherwise
exist for a particular type. You bind the properties to dynamic expressions
to define global properties for an object that can be read by other objects.
For example, you can specify global properties for the root object that you
can use in the child objects.
For example, to specify spacing between UI elements, you could define a
margin for an object of a QML type that does not have a margin property,
and then use bindings to refer to the value of the margin property from
other objects.
Similarly, you can add custom properties for your own QML types that are
based on the predefined types.
You can add properties for objects in the \uicontrol Connections view,
\uicontrol Properties tab.
\image qmldesigner-dynamicprops.png "Custom properties in Connection View Custom Properties tab"
To add properties for an object:
\list 1
\li Select \uicontrol View > \uicontrol Views >
\uicontrol {Connections View} > \uicontrol {Properties}.
\li Select the \inlineimage plus.png
(\uicontrol Add) button to add a dynamic property for the currently
selected item. The item ID is displayed in the \uicontrol Item
column.
\li Double-click the value in the \uicontrol Property column to give a
name to the property.
\li Double-click the value in the \uicontrol {Property Type} column to
specify the \l{Supported Property Types}{type of the property}.
\li Double-click the value in the \uicontrol {Property Value} column
to specify the value of the property.
\endlist
The properties you add for a QML type are displayed in the
\uicontrol Properties view when you select a component of
that type in \uicontrol Navigator or \uicontrol {Form Editor}.
\image qtquick-custom-properties.png "Custom properties in Properties view"
For more information about setting property values in the
\uicontrol Properties view, see \l{Specifying Item Properties}.
For an example of using custom properties in an application, see
\l{Creating a Mobile Application}.
\section1 Supported Property Types
The following table describes the supported property types:
\table
\header
\li Type
\li Description
\row
\li alias
\li \l{Property Aliases}{Property alias} that holds a reference to
another property
\row
\li bool
\li Binary \c true or \c false value
\row
\li color
\li Color value that can be specified by using an SVG color name, such
as "red", "green", or "lightsteelblue", or a hexadecimal triplet or
quad in the form "#RRGGBB" and "#AARRGGBB", respectively. For
example, the color red corresponds to a triplet of "#FF0000" and
a slightly transparent blue to a quad of "#800000FF".
In addition, you can use the following Qt functions: \l{Qt::rgba()}
{Qt.rgba()}, \l{Qt::hsva()}{Qt.hsva()}, \l{Qt::hsla()}{Qt.hsla()},
\l{Qt::darker()}{Qt.darker()}, \l{Qt::lighter()}{Qt.lighter()}, and
\l{Qt::tint()}{Qt.tint()}.
\row
\li int
\li Whole integer number, such as 0, 10, or -20
\row
\li real
\li Number with a decimal point
\row
\li string
\li Free form text string
\row
\li url
\li Resource locator, such as a file name. It can be either absolute,
(\c http://qt-project.org), or relative (\c pics/logo.png). A
relative URL is resolved relative to the URL of the parent
component.
\row
\li variant
\li Generic property type. For example, variant properties can store
numbers, strings, objects, arrays, and functions.
\endtable
*/
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