private handleMouseDownEvent()

in packages/roosterjs-editor-plugins/lib/plugins/TableCellSelection/TableCellSelection.ts [280:341]
56 lines of code
12 McCabe index (conditional complexity)

    private handleMouseDownEvent(event: PluginMouseDownEvent) {
        const { which, shiftKey } = event.rawEvent;

        if (which == RIGHT_CLICK && this.tableSelection) {
            //If the user is right clicking To open context menu
            const td = this.editor.getElementAtCursor(TABLE_CELL_SELECTOR);
            if (td?.classList.contains(TABLE_CELL_SELECTED)) {
                this.firstTarget = null;
                this.lastTarget = null;

                this.editor.queryElements('td.' + TABLE_CELL_SELECTED, node => {
                    this.firstTarget = this.firstTarget || node;
                    this.lastTarget = node;
                });
                const selection = this.editor.getDocument().defaultView.getSelection();
                selection.setBaseAndExtent(this.firstTarget, 0, this.lastTarget, 0);
                highlight(this.vTable);
                return;
            }
        }
        this.editor.getDocument().addEventListener('mouseup', this.onMouseUp, true /*setCapture*/);
        if (which == LEFT_CLICK && !shiftKey) {
            this.clearState();
            this.editor
                .getDocument()
                .addEventListener('mousemove', this.onMouseMove, true /*setCapture*/);
            this.startedSelection = true;
        }

        if (which == LEFT_CLICK && shiftKey) {
            this.editor.runAsync(editor => {
                const sel = editor.getDocument().defaultView.getSelection();
                const first = getCellAtCursor(editor, sel.anchorNode);
                const last = getCellAtCursor(editor, sel.focusNode);
                const firstTable = getTableAtCursor(editor, first);
                const targetTable = getTableAtCursor(editor, first);
                if (
                    firstTable! == targetTable! &&
                    safeInstanceOf(first, 'HTMLTableCellElement') &&
                    safeInstanceOf(last, 'HTMLTableCellElement')
                ) {
                    this.vTable = new VTable(first);
                    const firstCord = getCellCoordinates(this.vTable, first);
                    const lastCord = getCellCoordinates(this.vTable, last);

                    this.vTable.selection = {
                        firstCell: firstCord,
                        lastCell: lastCord,
                    };

                    this.firstTarget = first;
                    this.lastTarget = last;
                    highlight(this.vTable);
                    this.tableRange = this.vTable.selection;
                    this.tableSelection = true;
                    this.firstTable = firstTable as HTMLTableElement;
                    this.targetTable = targetTable;
                    updateSelection(editor, first, 0);
                }
            });
        }
    }