94 lines
2.5 KiB
TypeScript
94 lines
2.5 KiB
TypeScript
export type HistoryHandler = {
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undo: (action: HistoryAction) => void;
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redo: (action: HistoryAction) => void;
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}
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interface HistoryEvent
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{
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source: string;
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event: string;
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actions: HistoryAction[];
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}
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interface HistoryAction
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{
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element: any;
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from?: any;
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to?: any;
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}
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export class History
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{
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private handlers: Record<string, { handlers: Record<string, HistoryHandler>, any?: (action: HistoryAction) => any }>;
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private history: HistoryEvent[];
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private position: number;
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constructor()
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{
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this.handlers = {};
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this.history = [];
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this.position = -1;
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}
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get last()
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{
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return this.history.length > 0 && this.position > -1 ? this.history[this.position] : undefined;
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}
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get undoable()
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{
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return this.history && this.position !== -1;
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}
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get redoable()
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{
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return this.history && this.position < this.history.length - 1;
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}
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undo()
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{
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const last = this.last;
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if(!last)
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return;
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last.actions.forEach(e => {
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this.handlers[last.source] && this.handlers[last.source].handlers[last.event]?.undo(e)
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this.handlers[last.source] && this.handlers[last.source].any && this.handlers[last.source].any!(e);
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});
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this.position--;
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}
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redo()
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{
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if(!this.history || this.history.length - 1 <= this.position)
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return;
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this.position++;
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const last = this.last;
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if(!last)
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{
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this.position--;
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return;
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}
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last.actions.forEach(e => {
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this.handlers[last.source] && this.handlers[last.source].handlers[last.event]?.redo(e)
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this.handlers[last.source] && this.handlers[last.source].any && this.handlers[last.source].any!(e);
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});
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}
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add(source: string, event: string, actions: HistoryAction[], apply: boolean = false)
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{
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this.position++;
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this.history.splice(this.position, history.length - this.position, { source, event, actions });
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if(apply)
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actions.forEach(e => {
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this.handlers[source] && this.handlers[source].handlers[event]?.redo(e);
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this.handlers[source] && this.handlers[source].any && this.handlers[source].any(e);
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});
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}
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register(source: string, handlers: Record<string, HistoryHandler>, any?: (action: HistoryAction) => any)
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{
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this.handlers[source] = { handlers, any };
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}
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unregister(source: string)
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{
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delete this.handlers[source];
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}
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} |