_measure: function NavBarContainer_measure()

in src/Clients/Web/winjs/js/winjs.js [75375:75478]

• 86 lines of code
• 14 McCabe index (conditional complexity)

                _measure: function NavBarContainer_measure() {
                    if (!this._measured) {
                        this._resizeImpl();
                        this._writeProfilerMark("measure,StartTM");

                        var sizes = this._sizes;

                        sizes.rtl = _Global.getComputedStyle(this._element).direction === "rtl";

                        var itemCount = this._surfaceEl.children.length;
                        if (itemCount > 0) {
                            if (!this._sizes.itemMeasured) {
                                this._writeProfilerMark("measureItem,StartTM");

                                var elementToMeasure = this._surfaceEl.firstElementChild;
                                // Clear inline margins set by NavBarContainer before measuring.
                                elementToMeasure.style.margin = "";
                                elementToMeasure.style.width = "";
                                var elementComputedStyle = _Global.getComputedStyle(elementToMeasure);
                                sizes.itemOffsetWidth = parseFloat(_Global.getComputedStyle(elementToMeasure).width);
                                if (elementToMeasure.offsetWidth === 0) {
                                    sizes.itemOffsetWidth = 0;
                                }
                                sizes.itemMarginLeft = parseFloat(elementComputedStyle.marginLeft);
                                sizes.itemMarginRight = parseFloat(elementComputedStyle.marginRight);
                                sizes.itemWidth = sizes.itemOffsetWidth + sizes.itemMarginLeft + sizes.itemMarginRight;
                                sizes.itemOffsetHeight = parseFloat(_Global.getComputedStyle(elementToMeasure).height);
                                if (elementToMeasure.offsetHeight === 0) {
                                    sizes.itemOffsetHeight = 0;
                                }
                                sizes.itemMarginTop = parseFloat(elementComputedStyle.marginTop);
                                sizes.itemMarginBottom = parseFloat(elementComputedStyle.marginBottom);
                                sizes.itemHeight = sizes.itemOffsetHeight + sizes.itemMarginTop + sizes.itemMarginBottom;
                                if (sizes.itemOffsetWidth > 0 && sizes.itemOffsetHeight > 0) {
                                    sizes.itemMeasured = true;
                                }
                                this._writeProfilerMark("measureItem,StopTM");
                            }

                            sizes.viewportOffsetWidth = parseFloat(_Global.getComputedStyle(this._viewportEl).width);
                            if (this._viewportEl.offsetWidth === 0) {
                                sizes.viewportOffsetWidth = 0;
                            }
                            sizes.viewportOffsetHeight = parseFloat(_Global.getComputedStyle(this._viewportEl).height);
                            if (this._viewportEl.offsetHeight === 0) {
                                sizes.viewportOffsetHeight = 0;
                            }

                            if (sizes.viewportOffsetWidth === 0 || sizes.itemOffsetHeight === 0) {
                                this._measured = false;
                            } else {
                                this._measured = true;
                            }

                            if (this.layout === _UI.Orientation.horizontal) {
                                this._scrollPosition = _ElementUtilities.getScrollPosition(this._viewportEl).scrollLeft;

                                sizes.leadingEdge = this._leftArrowEl.offsetWidth + parseInt(_Global.getComputedStyle(this._leftArrowEl).marginLeft) + parseInt(_Global.getComputedStyle(this._leftArrowEl).marginRight);
                                var usableSpace = sizes.viewportOffsetWidth - sizes.leadingEdge * 2;
                                sizes.maxColumns = sizes.itemWidth ? Math.max(1, Math.floor(usableSpace / sizes.itemWidth)) : 1;
                                sizes.rowsPerPage = Math.min(this.maxRows, Math.ceil(itemCount / sizes.maxColumns));
                                sizes.columnsPerPage = Math.min(sizes.maxColumns, itemCount);
                                sizes.pages = Math.ceil(itemCount / (sizes.columnsPerPage * sizes.rowsPerPage));
                                sizes.trailingEdge = sizes.leadingEdge;
                                sizes.extraSpace = usableSpace - (sizes.columnsPerPage * sizes.itemWidth);

                                this._scrollLength = sizes.viewportOffsetWidth * sizes.pages;

                                this._keyboardBehavior.fixedSize = sizes.rowsPerPage;
                                this._keyboardBehavior.fixedDirection = _KeyboardBehavior._KeyboardBehavior.FixedDirection.height;

                                this._surfaceEl.style.height = (sizes.itemHeight * sizes.rowsPerPage) + "px";
                                this._surfaceEl.style.width = this._scrollLength + "px";
                            } else {
                                this._scrollPosition = this._viewportEl.scrollTop;

                                sizes.leadingEdge = 0;
                                sizes.rowsPerPage = itemCount;
                                sizes.columnsPerPage = 1;
                                sizes.pages = 1;
                                sizes.trailingEdge = 0;

                                // Reminder there is margin collapsing so just use scrollHeight instead of itemHeight * itemCount
                                this._scrollLength = this._viewportEl.scrollHeight;

                                this._keyboardBehavior.fixedSize = sizes.columnsPerPage;
                                this._keyboardBehavior.fixedDirection = _KeyboardBehavior._KeyboardBehavior.FixedDirection.width;

                                this._surfaceEl.style.height = "";
                                this._surfaceEl.style.width = "";
                            }

                            this._updateGridStyles();
                        } else {
                            sizes.pages = 1;
                            this._hasPreviousContent = false;
                            this._hasNextContent = false;
                            this._surfaceEl.style.height = "";
                            this._surfaceEl.style.width = "";
                        }

                        this._writeProfilerMark("measure,StopTM");
                    }
                },