Revision control
++ // Copyright (C) 2022 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
++ /*!
++ \title Qt Quick Examples - Item Variable Refresh Rate
++ \example itemvariablerefreshrate
++ \image qml-itemvariablerefreshrate-example.png {Rotated Qt logo with
++ FPS counter and frame rate control slider}
++ \brief A Qt Quick example shows how to setup variable refresh rate for
++ specific parts of the UI.
++ \ingroup qtquickexamples
++ \examplecategory {Graphics}
++
++ This example demonstrates using the live property of a \l{Item Layers} to get a
++ variable and independent refresh rate for Quick items. This can provide a significant
++ boost to performance if specific parts of a UI does not need to be re-rendered
++ every frame, but still require internal updates. Drawing parts that are static
++ most of the time or animations that does not have to run smoothly at all times
++ is a waste of resources. This property gives the user control over when the item
++ is drawn.
++
++ \note Using \l{Item Layers} may involve a performance penalty, depending on the size
++ of the layered item subtree, due to using separate render targets (textures),
++ which are then blended together in the main render pass.
++ Application designers should always evaluate the impact to ensure that the benefits
++ of using layers outweigh the potential disadvantages.
++
++ The example uses \l FrameAnimation to control how often the item is rendered.
++ Useful when you only want to e.g. every second frame.
++ Using something like a timer or other mechanics to toggle the flag is also valid.
++ \snippet itemvariablerefreshrate/itemvariablerefreshrate.qml frameAnimation
++ In the above snippet, the fps property is only there for visual demonstration purposes.
++
++ The item requires layer.enabled to be true, and then the item will
++ be rendered depending on the state of layer.live as shown in the below snippet.
++ \snippet itemvariablerefreshrate/itemvariablerefreshrate.qml item
++ Using modulo operator and a slider to set the value, we can dynamically change
++ how often the Qt logo is rendered.
++ */