Specifying Dynamic Properties
Each preset component has a set of preset properties that you can specify values for. You can add custom properties that would not otherwise exist for a particular component type. You bind the properties to dynamic expressions to define global properties for a component that can be read by other components. For example, you can specify global properties for the root component that you can use in the child components.
For example, to specify spacing between UI elements, you could define a margin for a component that does not have a margin property, and then use bindings to refer to the value of the margin property from other components.
Similarly, you can add custom properties for your own components that are based on preset components.
You can add properties for components in Connection View > Properties.
To add properties for a component:
- Select View > Views > Connection View > Properties.
- Select the (Add) button to add a dynamic property for the currently selected component. The component ID is displayed in the Item column.
- Double-click the value in the Property Type column to specify the type of the property.
- Double-click the value in the Property Value column to specify the value of the property.
Right-click a property and select Open Binding Editor in the context menu to bind the value of the property to that of another one or to data accessible in the application in Binding Editor. For more information, see Setting Bindings.
For an example of using custom properties in an application, see Creating a Mobile Application.
The following table describes the supported property types:
|alias||Property alias that holds a reference to another property|
|color||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: Qt.rgba(), Qt.hsva(), Qt.hsla(), Qt.darker(), Qt.lighter(), and Qt.tint().|
|int||Whole integer number, such as 0, 10, or -20|
|real||Number with a decimal point|
|string||Free form text string|
|url||Resource locator, such as a file name. It can be either absolute, (|
|variant||Generic property type. For example, variant properties can store numbers, strings, objects, arrays, and functions.|
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