Documentation; preparation for beta release.

doc/js/page_effects.js

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+function visibleInParent(element) {
+    var position = $(element).position().top
+    return position > -50 && position < ($(element).offsetParent().height() - 50)
+}
+
+function hasFragment(link, fragment) {
+    return $(link).attr("href").indexOf("#" + fragment) != -1
+}
+
+function findLinkByFragment(elements, fragment) {
+    return $(elements).filter(function(i, e) { return hasFragment(e, fragment)}).first()
+}
+
+function scrollToCurrentVarLink(elements) {
+    var elements = $(elements);
+    var parent   = elements.offsetParent();
+
+    if (elements.length == 0) return;
+
+    var top    = elements.first().position().top;
+    var bottom = elements.last().position().top + elements.last().height();
+
+    if (top >= 0 && bottom <= parent.height()) return;
+
+    if (top < 0) {
+        parent.scrollTop(parent.scrollTop() + top);
+    }
+    else if (bottom > parent.height()) {
+        parent.scrollTop(parent.scrollTop() + bottom - parent.height());
+    }
+}
+
+function setCurrentVarLink() {
+    $('.secondary a').parent().removeClass('current')
+    $('.anchor').
+        filter(function(index) { return visibleInParent(this) }).
+        each(function(index, element) {
+            findLinkByFragment(".secondary a", element.id).
+                parent().
+                addClass('current')
+        });
+    scrollToCurrentVarLink('.secondary .current');
+}
+
+var hasStorage = (function() { try { return localStorage.getItem } catch(e) {} }())
+
+function scrollPositionId(element) {
+    var directory = window.location.href.replace(/[^\/]+\.html$/, '')
+    return 'scroll::' + $(element).attr('id') + '::' + directory
+}
+
+function storeScrollPosition(element) {
+    if (!hasStorage) return;
+    localStorage.setItem(scrollPositionId(element) + "::x", $(element).scrollLeft())
+    localStorage.setItem(scrollPositionId(element) + "::y", $(element).scrollTop())
+}
+
+function recallScrollPosition(element) {
+    if (!hasStorage) return;
+    $(element).scrollLeft(localStorage.getItem(scrollPositionId(element) + "::x"))
+    $(element).scrollTop(localStorage.getItem(scrollPositionId(element) + "::y"))
+}
+
+function persistScrollPosition(element) {
+    recallScrollPosition(element)
+    $(element).scroll(function() { storeScrollPosition(element) })
+}
+
+function sidebarContentWidth(element) {
+    var widths = $(element).find('.inner').map(function() { return $(this).innerWidth() })
+    return Math.max.apply(Math, widths)
+}
+
+function calculateSize(width, snap, margin, minimum) {
+    if (width == 0) {
+        return 0
+    }
+    else {
+        return Math.max(minimum, (Math.ceil(width / snap) * snap) + (margin * 2))
+    }
+}
+
+function resizeSidebars() {
+    var primaryWidth   = sidebarContentWidth('.primary')
+    var secondaryWidth = 0
+
+    if ($('.secondary').length != 0) {
+        secondaryWidth = sidebarContentWidth('.secondary')
+    }
+
+    // snap to grid
+    primaryWidth   = calculateSize(primaryWidth, 32, 13, 160)
+    secondaryWidth = calculateSize(secondaryWidth, 32, 13, 160)
+
+    $('.primary').css('width', primaryWidth)
+    $('.secondary').css('width', secondaryWidth).css('left', primaryWidth + 1)
+
+    if (secondaryWidth > 0) {
+        $('#content').css('left', primaryWidth + secondaryWidth + 2)
+    }
+    else {
+        $('#content').css('left', primaryWidth + 1)
+    }
+}
+
+$(window).ready(resizeSidebars)
+$(window).ready(setCurrentVarLink)
+$(window).ready(function() { persistScrollPosition('.primary')})
+$(window).ready(function() {
+    $('#content').scroll(setCurrentVarLink)
+    $(window).resize(setCurrentVarLink)
+})