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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Connects multiple Data Sources with multiple View Models.
* Aggregator owns Data Sources.
* Aggregator weakly refers to View Models.
*/
export class Aggregator {
#sources = [];
#attachedViewModels = [];
attachViewModel(viewModel) {
// Weak reference the View Model so we do not keep it in memory forever
this.#attachedViewModels.push(new WeakRef(viewModel));
}
detachViewModel(viewModel) {
for (let i = this.#attachedViewModels.length - 1; i >= 0; i--) {
const knownViewModel = this.#attachedViewModels[i].deref();
if (viewModel == knownViewModel || !knownViewModel) {
this.#attachedViewModels.splice(i, 1);
}
}
}
/**
* Run action on each of the alive attached view models.
* Remove dead consumers.
*
* @param {Function} action to perform on each alive consumer
*/
forEachViewModel(action) {
for (let i = this.#attachedViewModels.length - 1; i >= 0; i--) {
const viewModel = this.#attachedViewModels[i].deref();
if (viewModel) {
action(viewModel);
} else {
this.#attachedViewModels.splice(i, 1);
}
}
}
*enumerateLines(searchText) {
for (let source of this.#sources) {
yield* source.enumerateLines(searchText);
}
}
/**
*
* @param {Function} createSourceFn (aggregatorApi) used to create Data Source.
* aggregatorApi is the way for Data Source to push data
* to the Aggregator.
*/
addSource(createSourceFn) {
const api = this.#apiForDataSource();
const source = createSourceFn(api);
this.#sources.push(source);
}
callFunction(dataSource, functionName, ...params) {
const source = this.#sources.find(
source => source.constructor.name === dataSource
);
if (source && source[functionName]) {
return source[functionName](params);
}
return null;
}
/**
* Exposes interface for a datasource to communicate with Aggregator.
*/
#apiForDataSource() {
const aggregator = this;
return {
refreshSingleLineOnScreen(line) {
aggregator.forEachViewModel(vm => vm.refreshSingleLineOnScreen(line));
},
refreshAllLinesOnScreen() {
aggregator.forEachViewModel(vm => vm.refreshAllLinesOnScreen());
},
setLayout(layout) {
aggregator.forEachViewModel(vm => vm.setLayout(layout));
},
setNotification(notification) {
aggregator.forEachViewModel(vm => vm.setNotification(notification));
},
};
}
}