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