_keyDownHandler: function hub_keyDownHandler()

in src/Clients/Web/winjs/js/winjs.js [63262:63316]

• 47 lines of code
• 34 McCabe index (conditional complexity)

                _keyDownHandler: function hub_keyDownHandler(ev) {
                    var leftKey = this._rtl ? Key.rightArrow : Key.leftArrow;
                    var rightKey = this._rtl ? Key.leftArrow : Key.rightArrow;

                        if (ev.keyCode === Key.upArrow || ev.keyCode === Key.downArrow || ev.keyCode === Key.leftArrow || ev.keyCode === Key.rightArrow || ev.keyCode === Key.pageUp || ev.keyCode === Key.pageDown) {
                        var headerTabStopElement = this._findHeaderTabStop(ev.target);
                        if (headerTabStopElement && !this._isHeaderInteractive(ev.target)) {
                            var currentSection = this.sections.indexOf(headerTabStopElement.parentElement.parentElement.winControl);
                            var targetSectionIndex;
                            var useEnsureVisible = false;
                            // Page up/down go to the next/previous header and line it up with the app header. Up/Right/Down/Left
                            // move focus to the next/previous header and move it on screen (app header distance from either edge).
                            if (ev.keyCode === Key.pageDown ||
                                (this.orientation === _UI.Orientation.horizontal && ev.keyCode === rightKey) ||
                                (this.orientation === _UI.Orientation.vertical && ev.keyCode === Key.downArrow)) {
                                // Do not include hidden headers.
                                for (var i = currentSection + 1; i < this.sections.length; i++) {
                                    if (this._tryFocus(i)) {
                                        targetSectionIndex = i;
                                        break;
                                    }
                                }
                            } else if (ev.keyCode === Key.pageUp ||
                                (this.orientation === _UI.Orientation.horizontal && ev.keyCode === leftKey) ||
                                (this.orientation === _UI.Orientation.vertical && ev.keyCode === Key.upArrow)) {
                                // Do not include hidden headers.
                                for (var i = currentSection - 1; i >= 0; i--) {
                                    if (this._tryFocus(i)) {
                                        targetSectionIndex = i;
                                        break;
                                    }
                                }
                            }
                            if (ev.keyCode === Key.upArrow || ev.keyCode === Key.downArrow || ev.keyCode === Key.leftArrow || ev.keyCode === Key.rightArrow) {
                                useEnsureVisible = true;
                            }

                            if (+targetSectionIndex === targetSectionIndex) {
                                if (useEnsureVisible) {
                                    this._ensureVisible(targetSectionIndex, true);
                                } else {
                                    this._scrollToSection(targetSectionIndex, true);
                                }
                            }

                            ev.preventDefault();
                        }
                    } else if (ev.keyCode === Key.home || ev.keyCode === Key.end) {
                        // Home/End scroll to start/end and leave focus where it is.
                        this._measure();
                        var maxScrollPos = Math.max(0, this._scrollLength - this._viewportSize);
                        this._scrollTo(ev.keyCode === Key.home ? 0 : maxScrollPos, true);
                        ev.preventDefault();
                    }
                },