@fluentui/react
Version:
Reusable React components for building web experiences.
91 lines • 4 kB
JavaScript
define(["require", "exports", "tslib", "../Dropdown.types"], function (require, exports, tslib_1, Dropdown_types_1) {
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.DropdownSizePosCache = void 0;
/**
* A utility class to cache size and position in cache.
*
* Dropdown options has non-selectable display types. It is therefore not cheap to determine
* the total number of actual selectable options as well as the position an option is in the
* list of options - O(n) cost for each lookup.
*
* Given that we potentially have to make this determination on every single render pass, this
* cache should provide a little bit of relief.
*/
var DropdownSizePosCache = /** @class */ (function () {
function DropdownSizePosCache() {
this._size = 0;
}
/**
* Invalidates the cache and recalculate the size of selectable options.
*/
DropdownSizePosCache.prototype.updateOptions = function (options) {
var displayOnlyOptionsCache = [];
var notSelectableOptionsCache = [];
var size = 0;
for (var i = 0; i < options.length; i++) {
var _a = options[i], itemType = _a.itemType, hidden = _a.hidden;
if (itemType === Dropdown_types_1.DropdownMenuItemType.Divider || itemType === Dropdown_types_1.DropdownMenuItemType.Header) {
displayOnlyOptionsCache.push(i);
notSelectableOptionsCache.push(i);
}
else if (hidden) {
notSelectableOptionsCache.push(i);
}
else {
size++;
}
}
this._size = size;
this._displayOnlyOptionsCache = displayOnlyOptionsCache;
this._notSelectableOptionsCache = notSelectableOptionsCache;
this._cachedOptions = tslib_1.__spreadArray([], options, true);
};
Object.defineProperty(DropdownSizePosCache.prototype, "optionSetSize", {
/**
* The size of all the selectable options.
*/
get: function () {
return this._size;
},
enumerable: false,
configurable: true
});
Object.defineProperty(DropdownSizePosCache.prototype, "cachedOptions", {
/**
* The chached options array.
*/
get: function () {
return this._cachedOptions;
},
enumerable: false,
configurable: true
});
/**
* Returns the position of this option element relative to the full set of selectable option elements.
* Note: the first selectable element is position 1 in the set.
* @param index The raw index of the option element.
*/
DropdownSizePosCache.prototype.positionInSet = function (index) {
if (index === undefined) {
return undefined;
}
// we could possibly memoize this too but this should be good enough, most of the time (the expectation is that
// when you have a lot of options, the selectable options will heavily dominate over the non-selectable options.
var offset = 0;
while (index > this._notSelectableOptionsCache[offset]) {
offset++;
}
if (this._displayOnlyOptionsCache[offset] === index) {
throw new Error("Unexpected: Option at index ".concat(index, " is not a selectable element."));
}
if (this._notSelectableOptionsCache[offset] === index) {
return undefined;
}
return index - offset + 1;
};
return DropdownSizePosCache;
}());
exports.DropdownSizePosCache = DropdownSizePosCache;
});
//# sourceMappingURL=DropdownSizePosCache.js.map