86 lines
2.7 KiB
JavaScript
86 lines
2.7 KiB
JavaScript
//@flow
|
|
/*
|
|
Copyright 2017 Aviral Dasgupta
|
|
|
|
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.
|
|
*/
|
|
|
|
import {Value} from 'slate';
|
|
|
|
import _clamp from 'lodash/clamp';
|
|
|
|
type MessageFormat = 'rich' | 'markdown';
|
|
|
|
class HistoryItem {
|
|
// We store history items in their native format to ensure history is accurate
|
|
// and then convert them if our RTE has subsequently changed format.
|
|
value: Value;
|
|
format: MessageFormat = 'rich';
|
|
|
|
constructor(value: ?Value, format: ?MessageFormat) {
|
|
this.value = value;
|
|
this.format = format;
|
|
}
|
|
|
|
static fromJSON(obj: Object): HistoryItem {
|
|
return new HistoryItem(
|
|
Value.fromJSON(obj.value),
|
|
obj.format,
|
|
);
|
|
}
|
|
|
|
toJSON(): Object {
|
|
return {
|
|
value: this.value.toJSON(),
|
|
format: this.format,
|
|
};
|
|
}
|
|
}
|
|
|
|
export default class ComposerHistoryManager {
|
|
history: Array<HistoryItem> = [];
|
|
prefix: string;
|
|
lastIndex: number = 0; // used for indexing the storage
|
|
currentIndex: number = 0; // used for indexing the loaded validated history Array
|
|
|
|
constructor(roomId: string, prefix: string = 'mx_composer_history_') {
|
|
this.prefix = prefix + roomId;
|
|
|
|
// TODO: Performance issues?
|
|
let item;
|
|
for (; item = sessionStorage.getItem(`${this.prefix}[${this.currentIndex}]`); this.currentIndex++) {
|
|
try {
|
|
this.history.push(
|
|
HistoryItem.fromJSON(JSON.parse(item)),
|
|
);
|
|
} catch (e) {
|
|
console.warn("Throwing away unserialisable history", e);
|
|
}
|
|
}
|
|
this.lastIndex = this.currentIndex;
|
|
// reset currentIndex to account for any unserialisable history
|
|
this.currentIndex = this.history.length;
|
|
}
|
|
|
|
save(value: Value, format: MessageFormat) {
|
|
const item = new HistoryItem(value, format);
|
|
this.history.push(item);
|
|
this.currentIndex = this.history.length;
|
|
sessionStorage.setItem(`${this.prefix}[${this.lastIndex++}]`, JSON.stringify(item.toJSON()));
|
|
}
|
|
|
|
getItem(offset: number): ?HistoryItem {
|
|
this.currentIndex = _clamp(this.currentIndex + offset, 0, this.history.length - 1);
|
|
return this.history[this.currentIndex];
|
|
}
|
|
}
|