# PolymerList
The PolymerList
component is the base layout component for almost all list-based components in the Core Engine.
Internally, an iron-list is used to represent the list's data. Through various parameters and layout actors, the iron-list is enabled to communicate with other Core Engine layout components to provide further functionalities. This includes the selection and marking concept, the zooming of tiles, and the navigation within the list via keyboard.
The advantage of using an iron-list as the displaying component is the possibility to reuse of ItemRenderers. The iron-list does not create a separate ItemRenderer for each data set, but only as many as are required.
For example, if a list is scrolled, the data in the ItemRenderers is only updated instead of creating new ItemRenderers. That in turn leads to a better performance.
Find more information about iron-lists here (external link) (opens new window).
# Properties
HTMLElement
Components
Element tag:
polymer-list
# Parameter
Name | Type | Description |
---|---|---|
itemRenderer | string | The class name of the ListItemRenderer component to be used as the ItemRenderer. Must be either the ListItemRenderer component or a component based on it. |
grid | boolean | Defines whether the PolymerList should be displayed as a tile view. All other settings regarding the tile view are made via the zoomActor (see below). |
listActor | ListActor | The data held in the ListActor is represented by the PolymerList. |
selectionActor | SelectionActor | The SelectionActor manages selected or marked objects. It is used by the PolymerList to make list entries selectable or markable (more details). |
factory | ListItemRendererFactory | Used as a factory for the ItemRenderers to be created. Please note: Overwrites parameter ItemRenderer . |
zoomActor | ZoomActor | Only if grid = true If a ZoomActor is passed to the PolymerList, it is able to adjust the tile size depending on the information in the ZoomActor (more details). |
# Selecting and Marking
In order for object selections and markings to be visible to system users, an ItemRenderer is required that supports this. The ListItemRenderer component is such an ItemRenderer.
All components used that are based on the ListItemRenderer should be checked individually to see if they override the functionality.
# Tile Zooming
By default, each tile is 200 px x 200 px. With each zoom in or out the size changes by 10 px in both dimensions.
However, the default size of a tile can be overridden by the ItemRenderer used.