class ListView
package feathers.controls
extends BaseScrollContainer › FeathersControl › MeasureSprite › ValidatingSprite
implements IFocusContainer, IDataSelector<Dynamic>, IIndexSelector
Displays a one-dimensional list of items. Supports scrolling, custom item renderers, and custom layouts.
Layouts may be, and are highly encouraged to be, virtual, meaning that the list view is capable of creating a limited number of item renderers to display a subset of the data provider that is currently visible, instead of creating a renderer for every single item. This allows for optimized performance with very large data providers.
The following example creates a list view, gives it a data provider, tells the item renderer how to interpret the data, and listens for when the selection changes:
var listView = new ListView();
listView.dataProvider = new ArrayCollection([
{ text: "Milk" },
{ text: "Eggs" },
{ text: "Bread" },
{ text: "Chicken" },
]);
listView.itemToText = (item:Dynamic) -> {
return item.text;
};
listView.addEventListener(Event.CHANGE, (event:Event) -> {
var listView = cast(event.currentTarget, ListView);
trace("ListView changed: " + listView.selectedIndex + " " + listView.selectedItem.text);
});
this.addChild(listView);Events:
openfl.events.Event.CHANGE | Dispatched when either
|
|---|---|
feathers.events.ListViewEvent.ITEM_TRIGGER | Dispatched when the user taps or clicks an item renderer in the list view. The pointer must remain within the bounds of the item renderer on release, and the list view cannot scroll before release, or the gesture will be ignored. |
1.0.0
.See also:
Static variables
staticfinalread onlyCHILD_VARIANT_ITEM_RENDERER:String = "listView_itemRenderer"
The variant used to style the list view's item renderers in a theme.
To override this default variant, set the
ListView.customItemRendererVariant property.
1.0.0
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staticfinalread onlyVARIANT_BORDER:String = "border"
A variant used to style the list view with a border. This variant is used by default on desktop.
The following example uses this variant:
var listView = new ListView();
listView.variant = ListView.VARIANT_BORDER;1.0.0
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staticfinalread onlyVARIANT_BORDERLESS:String = "borderless"
A variant used to style the list view without a border. The variant is used by default on mobile.
The following example uses this variant:
var listView = new ListView();
listView.variant = ListView.VARIANT_BORDERLESS;1.0.0
.See also:
staticfinalread onlyVARIANT_POP_UP:String = "popUp"
A variant used to style the list view as a pop-up.
The following example uses this variant:
var listView = new ListView();
listView.variant = ListView.VARIANT_POP_UP;1.0.0
.See also:
Constructor
new(?dataProvider:IFlatCollection<Dynamic>, ?changeListener:Event ‑> Void)
Creates a new ListView object.
1.0.0
.Variables
allowMultipleSelection:Bool
Determines if multiple items may be selected at the same time. Has no
effect if selectable is false.
In the following example, multiple selection is enabled:
listView.allowMultipleSelection = true;1.0.0
.See also:
customItemRendererVariant:String
A custom variant to set on all item renderers, instead of
ListView.CHILD_VARIANT_ITEM_RENDERER.
The customItemRendererVariant will be not be used if the result of
itemRendererRecycler.create() already has a variant set.
1.0.0
.See also:
dataProvider:IFlatCollection<Dynamic>
The collection of data displayed by the list view.
Items in the collection must be class instances or anonymous structures. Do not add primitive values (such as strings, booleans, or numeric values) directly to the collection.
Additionally, all items in the collection must be unique object instances. Do not add the same instance to the collection more than once because a runtime exception will be thrown.
The following example passes in a data provider and tells the item renderer how to interpret the data:
listView.dataProvider = new ArrayCollection([
{ text: "Milk" },
{ text: "Eggs" },
{ text: "Bread" },
{ text: "Chicken" },
]);
listView.itemToText = (item:Dynamic) -> {
return item.text;
};1.0.0
.See also:
forceItemStateUpdate:Bool
Forces the itemRendererRecycler.update() method to be called with the
ListViewItemState when the list view validates, even if the item's
state has not changed since the previous validation.
Before Feathers UI 1.2, update() was called more frequently, and this
property is provided to enable backwards compatibility, temporarily, to
assist in migration from earlier versions of Feathers UI.
In general, when this property needs to be enabled, its often because of
a missed call to dataProvider.updateAt() (preferred) or
dataProvider.updateAll() (less common).
The forceItemStateUpdate property may be removed in a future major
version, so it is best to avoid relying on it as a long-term solution.
1.2.0
.itemRendererRecycler:AbstractDisplayObjectRecycler<Dynamic, ListViewItemState, DisplayObject>
Manages item renderers used by the list view.
In the following example, the list view uses a custom item renderer class:
listView.itemRendererRecycler = DisplayObjectRecycler.withClass(CustomItemRenderer);1.0.0
.layout:ILayout
The layout algorithm used to position and size the list view's items.
By default, if no layout is provided by the time that the list view initializes, a default layout that displays items vertically will be created.
The following example tells the list view to use a horizontal layout:
var layout = new HorizontalListLayout();
layout.gap = 20.0;
layout.padding = 20.0;
listView.layout = layout;1.0.0
.pointerSelectionEnabled:Bool = true
Indicates if selection is changed with MouseEvent.CLICK or
TouchEvent.TOUCH_TAP when the item renderer does not implement the
IToggle interface. If set to false, all item renderers must control
their own selection manually (not only ones that implement IToggle).
The following example disables pointer selection:
listView.pointerSelectionEnabled = false;1.0.0
.selectable:Bool
Determines if items in the list view may be selected. By default only a single item may be selected at any given time. In other words, if item A is already selected, and the user selects item B, item A will be deselected automatically.
The following example disables selection of items in the list view:
listView.selectable = false;See also:
selectedIndices:Array<Int>
Contains all of the indices that are currently selected. The most recently selected index will appear at the beginning of the array. In other words, the indices are in the reverse order that they were selected by the user.
When the selectedIndices array contains multiple items, the
selectedIndex property will return the first item from
selectedIndices.
1.0.0
.See also:
selectedItems:Array<Dynamic>
Contains all of the items that are currently selected. The most recently selected item will appear at the beginning of the array. In other words, the items are in the reverse order that they were selected by the user.
When the selectedItems array contains multiple items, the
selectedItem property will return the first item from selectedItems.
1.0.0
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virtualLayout:Bool
Indicates if the list view's layout is allowed to virtualize items or not.
The following example disables virtual layouts:
listView.virtualLayout = false;1.0.0
.itemRendererRecyclerIDFunction:(state:ListViewItemState) ‑> String
When a list view requires multiple item renderer types, this function is
used to determine which type of item renderer is required for a specific
item. Returns the ID of the item renderer recycler to use for the item,
or null if the default itemRendererRecycler should be used.
The following example provides an itemRendererRecyclerIDFunction:
var regularItemRecycler = DisplayObjectRecycler.withClass(ItemRenderer);
var firstItemRecycler = DisplayObjectRecycler.withClass(MyCustomItemRenderer);
listView.setItemRendererRecycler("regular-item", regularItemRecycler);
listView.setItemRendererRecycler("first-item", firstItemRecycler);
listView.itemRendererRecyclerIDFunction = function(state:ListViewItemState):String {
if(state.index == 0) {
return "first-item";
}
return "regular-item";
};1.0.0
.See also:
`ListView.itemRendererRecycler
Methods
getItemRendererRecycler(id:String):DisplayObjectRecycler<Dynamic, ListViewItemState, DisplayObject>
Returns the item renderer recycler associated with a specific ID.
Returns null if no recycler is associated with the ID.
1.0.0
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indexToItemRenderer(index:Int):DisplayObject
Returns the current item renderer used to render the item at the
specified index in the data provider. May return null if an item
doesn't currently have an item renderer.
Note: Most list views use "virtual" layouts, which means that only the currently-visible subset of items will have an item renderer. As the list view scrolls, the items with item renderers will change, and item renderers may even be re-used to display different items.
1.0.0
.itemRendererToItem(itemRenderer:DisplayObject):Dynamic
Returns the current item from the data provider that is rendered by a specific item renderer.
1.0.0
.dynamicitemToEnabled(data:Dynamic):Bool
Determines if an item should be enabled or disabled. By default, all
items are enabled, unless the ListView is disabled. This method
may be replaced to provide a custom value for enabled.
For example, consider the following item:
{ text: "Example Item", disable: true }If the ListView should disable an item if the disable field is
true, a custom implementation of itemToEnabled() might look like
this:
listView.itemToEnabled = (item:Dynamic) -> {
return !item.disable;
};1.2.0
.itemToItemRenderer(item:Dynamic):DisplayObject
Returns the current item renderer used to render a specific item from
the data provider. May return null if an item doesn't currently have
an item renderer.
Note: Most list views use "virtual" layouts, which means that only the currently-visible subset of items will have an item renderer. As the list view scrolls, the items with item renderers will change, and item renderers may even be re-used to display different items.
1.0.0
.dynamicitemToText(data:Dynamic):String
Converts an item to text to display within list view. By default, the
toString() method is called to convert an item to text. This method
may be replaced to provide custom text.
For example, consider the following item:
{ text: "Example Item" }If the ListView should display the text "Example Item", a custom
implementation of itemToText() might look like this:
listView.itemToText = (item:Dynamic) -> {
return item.text;
};1.0.0
.scrollToIndex(index:Int, ?animationDuration:Float):Void
Scrolls the list view so that the specified item renderer is completely visible. If the item renderer is already completely visible, does not update the scroll position.
A custom animation duration may be specified. To update the scroll
position without animation, pass a value of 0.0 for the duration.
1.0.0
.setItemRendererRecycler(id:String, recycler:AbstractDisplayObjectRecycler<Dynamic, ListViewItemState, DisplayObject>):Void
Associates an item renderer recycler with an ID to allow multiple types
of item renderers may be displayed in the list view. A custom
itemRendererRecyclerIDFunction may be specified to return the ID of
the recycler to use for a specific item in the data provider.
To clear a recycler, pass in null for the value.
1.0.0
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