Jewel VGroup
Reference
Available since version 0.9.7.
| Class | Extends |
|---|---|
| org.apache.royale.jewel.VGroup | org.apache.royale.jewel.supportClasses.group.AlignmentItemsGroupWithGap |
Note: This component is currently only available for JavaScript.
Overview
The Jewel VGroup class is a Group that lays out elements verticaly and provides some properties to allow more flexibility, like gap to define some spacing between items, and itemsHorizontalAlign and itemsVerticalAlign, to distribute elements in different ways along the horizontal and vertical axis.
Example of use
In MXML declare a VGroup like this:
<j:VGroup width="100%" height="300" gap="3" itemsVerticalAlign="itemsBottom">
<j:Card width="50%" height="100">
<j:Label text="vert bottom"/>
</j:Card>
<j:Card width="50%" height="100">
<j:Label text="vert bottom"/>
</j:Card>
</j:VGroup>
In ActionScript we can do the same in the following way.
var vg:VGroup = new VGroup();
// add a label to the VGroup
var label:Label = new Label();
label.text = "Some text";
vg.addElement(label);
// add the VGroup to the parent
parent.addElement(vg);
where parent is the container where the VGroup will be added.
Relevant Properties and Methods
Check the Reference of org.apache.royale.jewel.VGroup for a more detailed list of properties and methods.
Properties
| PROPERTY | Type | Description |
|---|---|---|
| currentState | String | The name of the current state. |
| itemsExpand | Boolean | Make items resize to the fill all container space. |
| itemsHorizontalAlign | String | Distribute all items horizontaly. Possible values are: itemsLeft, itemsCenter, itemsRight, itemsSpaceBetween, itemsSpaceAround |
| itemsVerticalAlign | String | Distribute all items verticaly. Possible values are: itemsSameHeight, itemsCenter, itemsTop, itemsBottom |
| gap | Number | Assigns variable gap in steps predefined in Jewel CSS. |
| numElements | int | The number of element children that can be laid out. |
| mxmlContent | Array | The array of childs for this group. Is the DefaultProperty. |
| states | Array | The array of view states. These should be instances of org.apache.royale.states.State |
| variableRowHeight | Boolean | Specifies whether layout elements are allocated their preferred height. |
Methods
| Method | Parameters | Description |
|---|---|---|
| addElement | c(IChild), dispatchEvent(Boolean=true) | Add a component to the parent. |
| addElementAt | c(IChild), index(int), dispatchEvent(Boolean=true) | Add a component to the parent at the specified index. |
| getElementIndex | c(IChild) | Gets the index of this subcomponent. |
| getElementAt | index(int) | Get a component from the parent at specified index. |
| removeElement | c(IChild), dispatchEvent(Boolean=true) | Remove a component from the parent. |
Relevant Events
The most important event is initComplete, which indicates that initialization of the group is complete.
It is needed when some action coded in a callback function needs to be triggered when the group is ready to use after initialization.
You can attach callback listeners to the initComplete event in MXML as follows:
<j:VGroup initComplete="initCompleteHandler(event)"/>
the initComplete event will use the initCompleteHandler callback function you provide in ActionScript:
<fx:Script>
<![CDATA[
private function initCompleteHandler(event:Event):void {
trace("VGroup is ready!");
}
]]>
</fx:Script>
When the group is initialized the message “VGroup is ready!” appears in the console log.
In ActionScript we can add an event handler this way:
var vg:VGroup = new VGroup();
vg.addEventListener('initComplete', initCompleteHandler);
parent.addElement(vg);
Relevant Beads
| Bead Type | Implementation | Description |
|---|---|---|
| GroupView | org.apache.royale.core.IBeadView | This is the default view bead. |
| VerticalLayout | org.apache.royale.core.IBeadLayout | This is the default layout bead. |
Optional Beads
| Bead Type | Implementation | Description |
|---|---|---|
| ContainerDataBinding | org.apache.royale.binding.DataBindingBase | Provide binding capabilities to the group. |
More examples
- Using Jewel TileHorizontalLayout
- Using View States to show or hide content
- Customization through the Royale API
Related controls
Other useful Jewel containers components are: