Quickly sets both horizontalGap and verticalGap to the same value. The gap getter always returns the value of horizontalGap, but the value of verticalGap may be different.

The default value is 0.

See also

The alignment of the items horizontally, on the x-axis.

Note: The HorizontalAlign.JUSTIFY constant is not supported.

The default value is feathers.layout.HorizontalAlign.CENTER.

See also

The horizontal space, in pixels, between columns.

The default value is 0.

Quickly sets all padding properties to the same value. The padding getter always returns the value of paddingTop, but the other padding values may be different.

The default value is 0.

See also

The space, in pixels, that appears on the bottom, below the items.

The default value is 0.

The minimum space, in pixels, to the left of the items.

The default value is 0.

The minimum space, in pixels, to the right of the items.

The default value is 0.

The space, in pixels, that appears on top, above the items.

The default value is 0.

Requests that the layout uses a specific number of columns, if possible. Set to 0 to calculate the maximum of columns that will fit in the available space.

If the view port's explicit or maximum width is not large enough to fit the requested number of columns, it will use fewer. If the view port doesn't have an explicit width and the maximum width is equal to Number.POSITIVE_INFINITY, the width will be calculated automatically to fit the exact number of requested columns.

The default value is 0.

The vertical space, in pixels, between items in a column.

The default value is 0.

Constructor.

Using the current index and a key press, calculates the new index. This might be use to change a list's selectedIndex when a key is pressed.

Parameters

Calculates the scroll position nearest to the current scroll position that will display the full bounds of the item within the view port. If the item is already fully displayed in the view port, the current scroll position will be returned unchanged.

While the item will be displayed in the view port without being clipped in any way, it may not be placed in the most prominent position possible. To give the item a more prominent location, use getScrollPositionForIndex() instead.

This function should always be called after the layout() function. The width and height arguments are the final bounds of the view port, which may be calculated in the layout() function.

Parameters

Using the item dimensions, calculates a scroll position that will ensure that the item at a given index will be visible within the specified bounds.

Typically, this function is used to show the item in the most prominent way, such as centering. To scroll a minimum distance required to display the full bounds of the item in the view port, use getNearestScrollPositionForIndex() instead.

This function should always be called after the layout() function. The width and height arguments are the final bounds of the view port, which may be calculated in the layout() function.

Parameters

Used internally by a component, such as List, to determines which indices are visible with the specified view port bounds and scroll position. Indices that aren't returned are typically not displayed and can be replaced virtually. Uses the typical items dimensions, or cached dimensions, if available.

This function is meant to be called by the List or other component that uses the virtual layout. If you're simply creating a layout for a List or another component, do not call this function. It is meant for developers creating custom components only.

Parameters

Positions (and possibly resizes) the supplied items within the optional bounds argument. If no bounds are specified, the layout algorithm will assume that the bounds start a 0,0 and have unbounded dimensions. Returns the actual bounds of the content, which may be different than the specified bounds.

Note: The items are not absolutely restricted to appear only within the bounds. The bounds can affect positioning, but the algorithm may very well ignore them completely.

If a layout implementation needs to access accurate width and height values from items that are of type IFeathersControl, it must call validate() manually. For performance reasons, the container that is the parent of the items will not call validate() before passing the items to a layout implementation. Meeting this requirement may be as simple as looping through the items at the beginning of layout() and validating all items that are Feathers UI controls:

const itemCount:int = items.length;
for(var i:int = 0; i < itemCount; i++)
{
    var item:IFeathersControl = items[i] as IFeathersControl;
    if(item)
    {
        item.validate();
    }
}

Parameters

Used internally by a component, such as List, to measure the view port based on the typical item dimensions or cached dimensions, if available.

This function is meant to be called by the List or other component that uses the virtual layout. If you're simply creating a layout for a List or another component, do not call this function. It is meant for developers creating custom components only.

Parameters

Dispatched when a property of the layout changes, indicating that a redraw is probably needed.

The properties of the event object have the following values: