ListView

Accessibility objects are used by assistive technologies for people with disabilities or special needs (for example, visual impairment).

Label {
    id: nameLabel
    text: "Your name:"
}
TextArea {
    accessibility {
        labelledBy: nameLabel
    }
}
Button {
    text: "Submit"
    accessibility {
        description: "Submit your name to the lottery"
    }
}

Label *label = Label::create().text("Your name:");
TextArea *textArea = TextArea::create();
Button *button = Button::create().text("Submit");

textArea->accessibility()->addLabel(label);
button->accessibility()->setDescription("Submit your name to the lottery");

This property defines how the control and its subtree will be exposed to assistive technologies. The default value is Default which means that the framework automates accessibility mode based on accessible information and context. Typically accessibility information is assumed to be available, unless any parent is configured with accessibilityMode = Collapsed.

When accessibility information is available, the accessibility property will be used to define the accessibility properties.

This node will be used as the implicit target for the animations in this list.

This QDeclarativeListProperty can contain any QObject. When a QObject is added to property, the UIObject takes ownership of the attached object.

This feature is typically used from QML to specify business logic object or any other shared objects for the subnodes of this UIObject. In C++ the same functionality can be achived by setting a parent of a QObject to be attached to the QObject which is going to own it.

QML usage example (MyObject is a custom class registered for QML using the qmlRegisterType() function):

Container {
    Label { text: "Title: " + myObject.title } 
    Label { text: "Subject: " + myObject.subject }
    attachedObjects: [
        MyObject { id: myObject
            title: "Hello World"
            subject: "Nice Day"
        }
    ]
}

Margins are positive values that specify the space around a control.

How the margin is actually used depends on how the control is laid out within it's parent container. When the control is laid out in a StackLayout, the margin is considered between the siblings in the layout direction. In that case the distance between two children in the layout direction will be the largest margin of the two adjacent margins in the layout direction.

If true the bottom Margin has been set on a control, if false the bottomMargin is not set. By default, bottomMargin is false, meaning that the control will use control-specific default

The default bottom padding is 0.

Negative padding values are supported in the ListView control, for all other controls negative padding is undefined.

This property is used when all Control's built-in shortcuts should be enabled or disabled. Cotrol's built-in shortcuts are shortcuts like Navigation shortcuts in ScrollView and ListView.

These action sets are displayed in the Context Menu for this control. When the context menu is opened, the first ActionSet object in the list is displayed initially, and the user can cycle through them in the order that they are added to the control.

Setting this handler allows you to listen on events from the Context menu. For example the ContextMenuHandler::showing() signal is emitted when the Context menu is about to show, allowing you to update the content of your context actions just-in-time.

When a control is disabled, it does not respond to user input. The disabled control continues to receive events, but does not process them. Changing the enabled state may also affect the appearance of the control.

If true the control is enabled, if false it's disabled.

The default focusAutoShow value is Default.

If true the control is focused, if false it's not focused.

The default focusPolicy value is None. A disabled Control can not have focus.

Normally, a control loses focus whenever a user touches outside of the control or on another control, or when scrolling a ListView (may differ from device to device). However, it may be convenient at times to retain focus. This property makes it possible to specify the conditions under which the control should lose focus and when it shouldn't. The property only affects focus changes initiated by user interaction, not when programmatically changing focus (i.e. by calling requestFocus() on a control).

Here's an example of how to set the focus retention policy in QML:

TextArea {
    focusRetentionPolicyFlags: FocusRetentionPolicy.LoseToNonFocusable |
            FocusRetentionPolicy.LoseOnScroll
    text: "Loses Focus"        
}

The default alignment is HorizontalAlignment::Left.

This property affects implicit animations on the following properties for a control.

The default is true meaning that implicit animations are enabled.

For VisualNode properties, you can customize implicit animations by using ImplicitAnimationController. These properties include translation, rotation, scaling, pivoting, and opacity.

The order in which key listeners are added does not change their behavior

The layoutProperties property specifies how the parent container should position and size the control. The layoutProperties object must match the Layout type of the container. For example, if the parent container uses a stack layout, the layoutProperties should be a StackLayoutProperties object.

By default, a control's layoutProperties is 0. If the layoutProperties for a control is not explicitly set, the parent container uses the default layout properties for the type of layout that it's using.

Margins are positive values that specify the space around a control.

How the margin is actually used depends on how the control is laid out within its parent container. When the control is laid out in a StackLayout, the margin is considered between the siblings in the layout direction. In that case the distance between two children in the layout direction will be the largest margin of the two adjacent margins in the layout direction.

The default value depends on the actual control. For the Container class the value is 0.0.

If true the left margin has been set on a control, if false the leftMargin is not set. By default, leftMargin is false, meaning that the control will use control-specific default

The default left padding is 0.

Negative padding values are supported in the ListView control, for all other controls negative padding is undefined.

The max height is a positive value used by the layout system to position the control.

The default maxHeight is infinitely large (no limit). The control can determine the effective maxHeight of a control by combining the maxHeight with the size of contents of the control.

The max width is a positive value used by the layout system to position the control.

The default maxWidth is infinitely large (no limit). The control can determine the effective maxWidth of a control by combining the maxWidth with the size of contents of the control.

The min height is a positive value used by the layout system to position the control.

The default minHeight for a control is 0.0. The control can determine the effective minHeight of a control by combining the minHeight with the size of contents of the control.

The min width is a positive value used by the layout system to position the control.

The default minWidth for a control is 0.0. The control can determine the effective minWidth of a control by combining the minWidth with the size of contents of the control.

As the objectName property is overridden from the QObject class, this signal will not be emitted if setObjectName() function is called directly on QObject.

The default value of this property is QString::null.

A value between 0.0 (transparent) and 1.0 (opaque). This is the local opacity of the visual node, i.e. not taking the ancestor opacities into account. The default opacity is 1.0 (opaque).

If overlap touch policy is OverlapTouchPolicy::Deny, overlapped nodes will be excluded from touch propagation at an early stage during the processing of touch input. This means a scene with many layers of visual nodes with overlap touch policy set to OverlapTouchPolicy::Allow, may affect touch performance negatively.

The parent of an object is specified using QObject::setParent(QObject*). The purpose of the property is to expose the object's parent to QML.

This property is read-only to prevent modifications from QML, where typically the parent is declaratively set. In C++ code, the parent can be explicitly set using QObject::setParent(QObject*), or implicitly set by adding it to a visual container.

The default value of this property is 0.

The pivot is used as the anchoring point when rotating and scaling the visual node. It is defined by the components pivotX, pivotY and pivotZ and is relative to the center of the visual node. The default position of the pivot point is (0.0, 0.0, 0.0), which means it is at the center of the visual node.

The pivot is used as the anchoring point when rotating and scaling the visual node. It is defined by the components pivotX, pivotY and pivotZ and is relative to the center of the visual node. The default position of the pivot point is (0.0, 0.0, 0.0), which means it is at the center of the visual node.

The preferred height is a positive value used by the Layout of the parent Container to position the control. If the preferred height for a control is not set, the parent container ignores this value and uses the control-specific default height. See the API reference for a specific control for more details about its default height. You can check whether the preferredHeight of a control is set by calling isPreferredHeightSet().

However, just because the preferred height has been set on a control, does not mean it is being used. The preferred height is ignored by the parent container if it is smaller than the minimum size allowed for that control.

If true the preferred height has been set on a control, if false the preferred height is not set. By default, preferredHeightSet is false, meaning that the parent container ignores the preferred height and uses the control-specific default instead.

The preferred width is a positive value used by the Layout of the parent Container to position the control. If the preferred width for a control is not set (or was set but has since been reset), the parent container ignores this value and uses the control-specific default width. See the API reference for a specific control for more details about its default width. You can check whether the preferredWidth of a control is set by calling isPreferredWidthSet().

However, just because the preferred width has been set on a control, does not mean it is being used. The preferred width is ignored by the parent container if it is smaller than the minimum size allowed for that control.

If true the preferred width has been set on a control, if false the preferred width is not set. By default, preferredWidthSet is false, meaning that the parent container ignores the preferred width and uses the control-specific default instead.

Margins are positive values that specify the space around a control.

How the margin is actually used depends on how the control is laid out within it's parent container. When the control is laid out in a StackLayout, the margin is considered between the siblings in the layout direction. In that case the distance between two children in the layout direction will be the largest margin of the two adjacent margins in the layout direction.

The default value depends on the actual control. For the Container class the value is 0.0.

If true the right margin has been set on a control, if false the rightMargin is not set. By default, rightMargin is false, meaning that the control will use control-specific default

The default right padding is 0.

Negative padding values are supported in the ListView control, for all other controls negative padding is undefined.

The visual node is rotated around the z-axis, centered around a pivot point defined by the components pivotX, pivotY and pivotZ. The default rotation is 0.0 degrees.

The visual node is scaled along the x-axis, centered around a pivot point defined by the components pivotX, pivotY and pivotZ. The default scale factor is 1.0 (not scaled).

The visual node is scaled along the y-axis, centered around a pivot point defined by the components pivotX, pivotY and pivotZ. The default scale factor is 1.0 (not scaled).

The order in which they are added will determine which shortcut will be triggered in case of an overlap. Note that predefined shortcuts have precedence over shortcuts defined via QString in case of a collision

Margins are positive values that specify the space around a control.

How the margin is actually used depends on how the control is laid out within it's parent container. When the control is laid out in a StackLayout, the margin is considered between the siblings in the layout direction. In that case the distance between two children in the layout direction will be the largest margin of the two adjacent margins in the layout direction.

The default value depends on the actual control. For the Container class the value is 0.0.

If true the top Margin has been set on a control, if false the topMargin is not set. By default, topMargin is false, meaning that the control will use control-specific default

The default top padding is 0.

Negative padding values are supported in the ListView control, for all other controls negative padding is undefined.

This property controls how the visual node and its subtree partakes in touch event propagation. There are three possible modes, as defined by TouchPropagationMode::Type:

The default propagation mode is TouchPropagationMode::Full.

The translationX and translationY correspond to pixels as long as the translationZ is 0.0.

The translation is mostly useful for animations as it doesn't affect the actual laid out position of the visual node. This translation is added after the node has been laid out so it doesn't affect layout in any way.

The translationX and translationY correspond to pixels as long as the translationZ is 0.0.

The translation is mostly useful for animations as it doesn't affect the actual laid out position of the visual node. This translation is added after the node has been laid out so it doesn't affect layout in any way.

The default alignment is VerticalAlignment::Top.

If the visible property is set to false, the visual node is neither laid out nor rendered. The default visible value is true.

Important: Setting the visible value to false is not the same as setting opacity to 0.0f (transparent). While a transparent node is still laid out taking up room in the scene, a node that is not visible, will neither be rendered nor laid out inside the scene. It will behave as if it was removed from the scene without actually been unlinked from the scene graph. No touch events will be sent to the node if the visible value is false. This a convenient way of removing nodes to optimize the performance of the scene without is actually unlinking them. It is highly recommended to use this property to hide visual nodes whenever possible.