53 lines
1.8 KiB
TypeScript
53 lines
1.8 KiB
TypeScript
/*
|
|
Copyright 2017 New Vector Ltd
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
export interface ScrollState {
|
|
focussedEvent: string;
|
|
pixelOffset: number;
|
|
}
|
|
|
|
/**
|
|
* Stores where the user has scrolled to in each room
|
|
*/
|
|
export class RoomScrollStateStore {
|
|
// A map from room id to scroll state.
|
|
//
|
|
// If there is no special scroll state (ie, we are following the live
|
|
// timeline), the scroll state is null. Otherwise, it is an object with
|
|
// the following properties:
|
|
//
|
|
// focussedEvent: the ID of the 'focussed' event. Typically this is
|
|
// the last event fully visible in the viewport, though if we
|
|
// have done an explicit scroll to an explicit event, it will be
|
|
// that event.
|
|
//
|
|
// pixelOffset: the number of pixels the window is scrolled down
|
|
// from the focussedEvent.
|
|
private scrollStateMap = new Map<string, ScrollState>();
|
|
|
|
public getScrollState(roomId: string): ScrollState {
|
|
return this.scrollStateMap.get(roomId);
|
|
}
|
|
|
|
setScrollState(roomId: string, scrollState: ScrollState): void {
|
|
this.scrollStateMap.set(roomId, scrollState);
|
|
}
|
|
}
|
|
|
|
if (window.mxRoomScrollStateStore === undefined) {
|
|
window.mxRoomScrollStateStore = new RoomScrollStateStore();
|
|
}
|
|
export default window.mxRoomScrollStateStore;
|