Method _handleRangeSelection

packages/main/src/TableSelection.ts:358–390

* Handles the range selection * @param targetRow row that is currently focused * @param change indicates direction * @private

(targetRow: TableRow, change: number)

	 * @private
	 */
	_handleRangeSelection(targetRow: TableRow, change: number) {
		if (!this._rangeSelection) {
			return;
		}

		const isUp = change > 0;
		this._rangeSelection.isUp ??= isUp;

		const shouldReverseSelection = isUp !== this._rangeSelection.isUp && !this._rangeSelection.isMouse;
		let selectionChanged = shouldReverseSelection && this.isSelected(targetRow);

		if (shouldReverseSelection) {
			this._reverseRangeSelection();
		} else {
			const rowIndex = this._table!.rows.indexOf(targetRow);
			const [startIndex, endIndex] = [rowIndex, rowIndex - change].sort((a, b) => a - b);

			selectionChanged = this._table?.rows.slice(startIndex, endIndex + 1).reduce((changed, row) => {
				const isRowNotInSelection = !this._rangeSelection?.rows.includes(row);
				const isRowSelectionDifferent = this.isSelected(row) !== this._rangeSelection!.selected;

				if (isRowNotInSelection) {
					this._rangeSelection?.rows.push(row);
				}

				this._selectRow(row, this._rangeSelection!.selected);

				return changed || isRowSelectionDifferent;
			}, selectionChanged) || false;
		}

		selectionChanged && this.fireDecoratorEvent("change");
	}

	_stopRangeSelection() {
		this._rangeSelection = null;