_keyDownHandler: function _KeyboardBehavior_keyDownHandler()

in Canvas/CanvasSimple/lib/winjs-4.0.1/js/base.js [11872:11950]

• 71 lines of code
• 30 McCabe index (conditional complexity)

                _keyDownHandler: function _KeyboardBehavior_keyDownHandler(ev) {
                    if (!ev.altKey) {
                        if (_ElementUtilities._matchesSelector(ev.target, ".win-interactive, .win-interactive *")) {
                            return;
                        }
                        var newIndex = this.currentIndex;
                        var maxIndex = this._element.children.length - 1;

                        var rtl = _Global.getComputedStyle(this._element).direction === "rtl";
                        var leftStr = rtl ? Key.rightArrow : Key.leftArrow;
                        var rightStr = rtl ? Key.leftArrow : Key.rightArrow;

                        var targetIndex = this.getAdjacent && this.getAdjacent(newIndex, ev.keyCode);
                        if (+targetIndex === targetIndex) {
                            newIndex = targetIndex;
                        } else {
                            var modFixedSize = newIndex % this.fixedSize;

                            if (ev.keyCode === leftStr) {
                                if (this.fixedDirection === _KeyboardBehavior.FixedDirection.width) {
                                    if (modFixedSize !== 0) {
                                        newIndex--;
                                    }
                                } else {
                                    if (newIndex >= this.fixedSize) {
                                        newIndex -= this.fixedSize;
                                    }
                                }
                            } else if (ev.keyCode === rightStr) {
                                if (this.fixedDirection === _KeyboardBehavior.FixedDirection.width) {
                                    if (modFixedSize !== this.fixedSize - 1) {
                                        newIndex++;
                                    }
                                } else {
                                    if (newIndex + this.fixedSize - modFixedSize <= maxIndex) {
                                        newIndex += this.fixedSize;
                                    }
                                }
                            } else if (ev.keyCode === Key.upArrow) {
                                if (this.fixedDirection === _KeyboardBehavior.FixedDirection.height) {
                                    if (modFixedSize !== 0) {
                                        newIndex--;
                                    }
                                } else {
                                    if (newIndex >= this.fixedSize) {
                                        newIndex -= this.fixedSize;
                                    }
                                }
                            } else if (ev.keyCode === Key.downArrow) {
                                if (this.fixedDirection === _KeyboardBehavior.FixedDirection.height) {
                                    if (modFixedSize !== this.fixedSize - 1) {
                                        newIndex++;
                                    }
                                } else {
                                    if (newIndex + this.fixedSize - modFixedSize <= maxIndex) {
                                        newIndex += this.fixedSize;
                                    }
                                }
                            } else if (ev.keyCode === Key.home) {
                                newIndex = 0;
                            } else if (ev.keyCode === Key.end) {
                                newIndex = this._element.children.length - 1;
                            }
                        }

                        newIndex = Math.max(0, Math.min(this._element.children.length - 1, newIndex));

                        if (newIndex !== this.currentIndex) {
                            this._focus(newIndex, ev.keyCode);

                            // Allow KeyboardBehavior to be nested
                            if (ev.keyCode === leftStr || ev.keyCode === rightStr || ev.keyCode === Key.upArrow || ev.keyCode === Key.downArrow) {
                                ev.stopPropagation();
                            }

                            ev.preventDefault();
                        }
                    }
                },