scottohara/loot

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src/og-components/og-table-navigable/directives/og-table-navigable.ts

Summary

Maintainability
F
3 days
Test Coverage
A
100%
import type {
    OgTableActionCallback,
    OgTableMovementKeys,
    OgTableNavigableScope,
} from "~/og-components/og-table-navigable/types";
import type OgTableNavigableService from "~/og-components/og-table-navigable/services/og-table-navigable";
import angular from "angular";

export default class OgTableNavigableDirective {
    public constructor(
        $window: angular.IWindowService,
        ogTableNavigableService: OgTableNavigableService,
    ) {
        const directive: angular.IDirective = {
            restrict: "A",
            scope: {
                handlers: "=ogTableNavigable",
            },
            link(scope: OgTableNavigableScope, iElement: JQuery<Element>): void {
                // Helper function to return all TR elements in the table body
                scope.getRows = (): JQuery<Element> =>
                    $window
                        .$(iElement)
                        .children("tbody")
                        .children("tr") as JQuery<Element>;

                // Helper function to return the TR element for the specified index
                scope.getRowAtIndex = (index: number): JQuery<Element> =>
                    scope.getRows().eq(index);

                // Focus a row in the table
                scope.focusRow = (row: JQuery<Element>): void => {
                    const rowIndex: number = angular
                        .element(row)
                        .scope<angular.IRepeatScope>().$index;

                    // Highlight the row
                    scope.highlightRow(row);

                    // Ensure the focussed row is in the current viewport
                    scope.scrollToRow(row);

                    // Store the focussed row index
                    scope.focussedRow = rowIndex;

                    // Invoke the focus action for the focussed row
                    scope.handlers.focusAction(rowIndex);
                };

                // Highlight the focussed row in the table
                scope.highlightRow = (row: JQuery<Element>): void => {
                    const focusClass = "warning";

                    // Clear highlighting on any previously focussed row
                    scope.getRows().removeClass(focusClass);

                    // Highlight the focussed row
                    row.addClass(focusClass);
                };

                // Checks if a row is off screen, and if so scrolls it into view
                scope.scrollToRow = (row: JQuery<Element>): void => {
                    // Get the top/bottom of the focussed row, and the top/bottom of the viewport
                    const rowOffset: JQueryCoordinates | undefined = row.offset(),
                        viewTop = Number($window.$(document).scrollTop()),
                        rowTop: number = rowOffset?.top ?? viewTop,
                        rowBottom: number = rowTop + Number(row.height()),
                        viewBottom: number = viewTop + Number($window.$(window).height()),
                        scrollNeeded: boolean = rowTop < viewTop || rowBottom > viewBottom;

                    // If we have somewhere to scroll, do it now
                    if (scrollNeeded) {
                        row[0].scrollIntoView({ behavior: "smooth" });
                    }
                };

                // Helper function to make sure we're not outside the bounds of the table
                function checkTargetIndex(
                    targetIndex: number,
                    totalRows: number,
                ): number {
                    let checkedTargetIndex: number = targetIndex;

                    if (checkedTargetIndex < 0) {
                        checkedTargetIndex = 0;
                    } else if (checkedTargetIndex >= totalRows) {
                        checkedTargetIndex = totalRows - 1;
                    }

                    return checkedTargetIndex;
                }

                // Jump to X rows before or after the currently focussed row
                scope.jumpToRow = (offset: number): void => {
                    // If there is no current row focussed, do nothing
                    if (null === scope.focussedRow) {
                        return;
                    }

                    // Determine the row index to focus
                    const totalRows: number = scope.getRows().length,
                        targetIndex: number = checkTargetIndex(
                            scope.focussedRow + offset,
                            totalRows,
                        ),
                        targetRow: JQuery<Element> = scope.getRowAtIndex(targetIndex);

                    if (targetRow.length) {
                        scope.focusRow(targetRow);
                    }
                };

                // Helper function to determine the parent TR element (that is a direct descendent of the element for this directive) where an event occurred
                function closestRow(target: EventTarget): JQuery<Element> {
                    return $window
                        .$(target)
                        .closest("[og-table-navigable] > tbody > tr") as JQuery<Element>;
                }

                // Declare a click handler to focus a row by clicking it
                scope.clickHandler = (event: JQuery.ClickEvent): void => {
                    if (ogTableNavigableService.enabled) {
                        // The event target could be any element in the table (including nested tables), so we need the closest row
                        const clickedRow: JQuery<Element> = closestRow(
                            event.target as EventTarget,
                        );

                        if (clickedRow.length) {
                            // Focus the clicked row
                            scope.focusRow(clickedRow);
                        }
                    }
                };

                // Declare a double-click handler to perform an action on a row
                scope.doubleClickHandler = (event: JQuery.DoubleClickEvent): void => {
                    if (ogTableNavigableService.enabled) {
                        // If the event target was a button, do nothing
                        if ("button" === event.target.localName) {
                            return;
                        }

                        // The event target could be any element in the table (including nested tables), so we need the closest row
                        const clickedRow: JQuery<Element> = closestRow(
                            event.target as EventTarget,
                        );

                        if (clickedRow.length) {
                            // Invoke the select action for the clicked row
                            scope.handlers.selectAction(
                                angular.element(clickedRow).scope<angular.IRepeatScope>()
                                    .$index,
                            );
                        }
                    }
                };

                // Expose a function on the handlers object for external controllers to focus on a row
                scope.handlers.focusRow = (index: number): void => {
                    // Focus the target row (if not already focussed)
                    const targetRow: JQuery<Element> = scope.getRowAtIndex(index);

                    if (targetRow.length) {
                        if (scope.focussedRow === index) {
                            // Row is already focussed, just ensure it's highlighted
                            scope.highlightRow(targetRow);
                        } else {
                            scope.focusRow(targetRow);
                        }
                    }
                };

                const MOVEMENT_KEYS: Record<string, OgTableMovementKeys> = {
                        PageUp: -10,
                        PageDown: 10,
                        ArrowUp: -1,
                        ArrowDown: 1,
                        J: 1,
                        j: 1,
                        K: -1,
                        k: -1,
                    },
                    ACTION_KEYS: Record<string, OgTableActionCallback | undefined> = {
                        Backspace: scope.handlers.deleteAction,
                        Enter: scope.handlers.selectAction,
                        Escape: scope.handlers.cancelAction,
                        Insert: scope.handlers.insertAction,
                        Delete: scope.handlers.deleteAction,
                    },
                    CTRL_ACTION_KEYS: Record<string, OgTableActionCallback> = {
                        E: scope.handlers.editAction,
                        N: scope.handlers.insertAction,
                    };

                // Declare key handler to focus a row with the arrow keys
                scope.keyHandler = (event: JQuery.KeyDownEvent): void => {
                    if (ogTableNavigableService.enabled) {
                        // Check if the key pressed was a movement key
                        if (
                            undefined !==
                            Object.getOwnPropertyDescriptor(MOVEMENT_KEYS, event.key)
                        ) {
                            // Jump the specified number of rows for the key
                            scope.jumpToRow(MOVEMENT_KEYS[event.key]);
                            event.preventDefault();
                        }

                        // Check if the key pressed was an action key
                        if (
                            undefined !==
                            Object.getOwnPropertyDescriptor(ACTION_KEYS, event.key)
                        ) {
                            const callback = ACTION_KEYS[event.key];

                            // If an action is defined, invoke it for the focussed row
                            callback?.(Number(scope.focussedRow));
                            event.preventDefault();
                        }

                        // Check if the key pressed was a CTRL action key
                        if (
                            event.ctrlKey &&
                            Object.getOwnPropertyDescriptor(
                                CTRL_ACTION_KEYS,
                                event.key.toUpperCase(),
                            )
                        ) {
                            // If an action is defined, invoke it for the focussed row
                            if (
                                undefined !==
                                (CTRL_ACTION_KEYS[event.key.toUpperCase()] as
                                    | OgTableActionCallback
                                    | undefined)
                            ) {
                                CTRL_ACTION_KEYS[event.key.toUpperCase()](
                                    Number(scope.focussedRow),
                                );
                            }
                            event.preventDefault();
                        }
                    }
                };

                // Attach the event handlers (the handlers are wrapped in functions to aid with unit testing)
                function clickHandler(event: JQuery.ClickEvent): void {
                    scope.clickHandler(event);
                }

                function doubleClickHandler(event: JQuery.DoubleClickEvent): void {
                    scope.doubleClickHandler(event);
                }

                function keyHandler(event: JQuery.KeyDownEvent): void {
                    scope.keyHandler(event);
                }

                iElement.on("click", clickHandler);
                iElement.on("dblclick", doubleClickHandler);
                $window.$(document).on("keydown", keyHandler);

                // When the element is destroyed, remove all event handlers
                iElement.on("$destroy", (): void => {
                    iElement.off("click", clickHandler);
                    iElement.off("dblclick", doubleClickHandler);
                    $window.$(document).off("keydown", keyHandler);
                });
            },
        };

        return directive;
    }

    public static factory(
        $window: angular.IWindowService,
        ogTableNavigableService: OgTableNavigableService,
    ): OgTableNavigableDirective {
        return new OgTableNavigableDirective($window, ogTableNavigableService);
    }
}

OgTableNavigableDirective.factory.$inject = [
    "$window",
    "ogTableNavigableService",
];