2019-07-19 20:38:08 -07:00

120 lines
4.0 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {ViewRef} from '../../linker/view_ref';
import {TNode} from './node';
import {RComment, RElement} from './renderer';
import {HOST, LView, NEXT, PARENT, T_HOST} from './view';
/**
* Special location which allows easy identification of type. If we have an array which was
* retrieved from the `LView` and that array has `true` at `TYPE` location, we know it is
* `LContainer`.
*/
export const TYPE = 1;
/**
* Below are constants for LContainer indices to help us look up LContainer members
* without having to remember the specific indices.
* Uglify will inline these when minifying so there shouldn't be a cost.
*/
export const ACTIVE_INDEX = 2;
// PARENT and NEXT are indices 3 and 4
// As we already have these constants in LView, we don't need to re-create them.
export const MOVED_VIEWS = 5;
// T_HOST is index 6
// We already have this constants in LView, we don't need to re-create it.
export const NATIVE = 7;
export const VIEW_REFS = 8;
/**
* Size of LContainer's header. Represents the index after which all views in the
* container will be inserted. We need to keep a record of current views so we know
* which views are already in the DOM (and don't need to be re-added) and so we can
* remove views from the DOM when they are no longer required.
*/
export const CONTAINER_HEADER_OFFSET = 9;
/**
* The state associated with a container.
*
* This is an array so that its structure is closer to LView. This helps
* when traversing the view tree (which is a mix of containers and component
* views), so we can jump to viewOrContainer[NEXT] in the same way regardless
* of type.
*/
export interface LContainer extends Array<any> {
/**
* The host element of this LContainer.
*
* The host could be an LView if this container is on a component node.
* In that case, the component LView is its HOST.
*/
readonly[HOST]: RElement|RComment|LView;
/**
* This is a type field which allows us to differentiate `LContainer` from `StylingContext` in an
* efficient way. The value is always set to `true`
*/
[TYPE]: true;
/**
* The next active index in the views array to read or write to. This helps us
* keep track of where we are in the views array.
* In the case the LContainer is created for a ViewContainerRef,
* it is set to null to identify this scenario, as indices are "absolute" in that case,
* i.e. provided directly by the user of the ViewContainerRef API.
*/
[ACTIVE_INDEX]: number;
/**
* Access to the parent view is necessary so we can propagate back
* up from inside a container to parent[NEXT].
*/
[PARENT]: LView;
/**
* This allows us to jump from a container to a sibling container or component
* view with the same parent, so we can remove listeners efficiently.
*/
[NEXT]: LView|LContainer|null;
/**
* A collection of views created based on the underlying `<ng-template>` element but inserted into
* a different `LContainer`. We need to track views created from a given declaration point since
* queries collect matches from the embedded view declaration point and _not_ the insertion point.
*/
[MOVED_VIEWS]: LView[]|null;
/**
* Pointer to the `TNode` which represents the host of the container.
*/
[T_HOST]: TNode;
/** The comment element that serves as an anchor for this LContainer. */
readonly[NATIVE]:
RComment; // TODO(misko): remove as this value can be gotten by unwrapping `[HOST]`
/**
* Array of `ViewRef`s used by any `ViewContainerRef`s that point to this container.
*
* This is lazily initialized by `ViewContainerRef` when the first view is inserted.
*/
[VIEW_REFS]: ViewRef[]|null;
}
// Note: This hack is necessary so we don't erroneously get a circular dependency
// failure based on types.
export const unusedValueExportToPlacateAjd = 1;