scribble-mathjax/unpacked/extensions/a11y/auto-collapse.js
2017-04-24 15:46:28 -04:00

499 lines
17 KiB
JavaScript

/*************************************************************
*
* [Contrib]/a11y/auto-collapse.js
*
* Implements the ability to have long expressions collapse
* automatically on screen size changes.
*
* ---------------------------------------------------------------------
*
* Copyright (c) 2016-2017 The MathJax Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
(function (HUB) {
var SETTINGS = HUB.config.menuSettings;
var COOKIE = {}; // replaced when menu is available
//
// Set up the a11y path,if it isn't already in place
//
var PATH = MathJax.Ajax.config.path;
if (!PATH.a11y) PATH.a11y = HUB.config.root + "/extensions/a11y";
var Collapse = MathJax.Extension["auto-collapse"] = {
version: "1.2.2",
config: HUB.CombineConfig("auto-collapse",{
disabled: false
}),
dependents: [], // the extensions that depend on this one
/*****************************************************************/
Enable: function (update,menu) {
SETTINGS.autocollapse = true;
if (menu) COOKIE.autocollapse = true
this.config.disabled = false;
MathJax.Extension.collapsible.Enable(false,menu);
if (update) {
HUB.Queue(
["Reprocess",HUB],
["CollapseWideMath",this]
);
}
},
Disable: function (update,menu) {
SETTINGS.autocollapse = false;
if (menu) COOKIE.autocollapse = false;
this.config.disabled = true;
for (var i = this.dependents.length-1; i >= 0; i--) {
var dependent = this.dependents[i];
if (dependent.Disable) dependent.Disable(false,menu);
}
if (update) HUB.Queue(["Rerender",HUB]);
},
//
// Register a dependent
//
Dependent: function (extension) {
this.dependents.push(extension);
},
Startup: function () {
//
// Inform collapsible extension that we are a dependent
//
var Collapsible = MathJax.Extension.collapsible;
if (Collapsible) Collapsible.Dependent(this);
//
// Add the filter into the post-input hooks (priority 150, so other
// hooks run first, in particular, the enrichment and complexity hooks).
//
HUB.postInputHooks.Add(["Filter",Collapse],150);
//
// Add the auto-collapsing
//
HUB.Queue(function () {return Collapse.CollapseWideMath()});
//
// Add a resize handler to check for math that needs
// to be collapsed or expanded.
//
if (window.addEventListener) window.addEventListener("resize",Collapse.resizeHandler,false);
else if (window.attachEvent) window.attachEvent("onresize",Collapse.resizeHandler);
else window.onresize = Collapse.resizeHandler;
},
//
// If the math is block-level (or in an element "by itself"), then
// add the SRE actions for this element.
//
Filter: function (jax,id,script) {
if (!jax.enriched || this.config.disabled) return;
if (jax.root.Get("display") === "block" ||
script.parentNode.childNodes.length <= 3) {
jax.root.SRE = {action: this.Actions(jax.root)};
}
},
//
// Produce an array of collapsible actions
// sorted by depth and complexity
//
Actions: function (node) {
var actions = [];
this.getActions(node,0,actions);
return this.sortActions(actions);
},
getActions: function (node,depth,actions) {
if (node.isToken || !node.data) return;
depth++;
for (var i = 0, m = node.data.length; i < m; i++) {
if (node.data[i]) {
var child = node.data[i];
if (child.collapsible) {
if (!actions[depth]) actions[depth] = [];
actions[depth].push(child);
this.getActions(child.data[1],depth,actions);
} else {
this.getActions(child,depth,actions);
}
}
}
},
sortActions: function (actions) {
var ACTIONS = [];
for (var i = 0, m = actions.length; i < m; i++) {
if (actions[i]) ACTIONS = ACTIONS.concat(actions[i].sort(this.sortActionsBy));
}
return ACTIONS;
},
sortActionsBy: function (a,b) {
a = a.data[1].complexity; b = b.data[1].complexity;
return (a < b ? -1 : a > b ? 1 : 0);
},
/*****************************************************************/
/*
* These routines implement the automatic collapsing of equations
* based on container widths.
*/
//
// Find math that is too wide and collapse it.
//
CollapseWideMath: function (element) {
if (this.config.disabled) return;
this.GetContainerWidths(element);
var jax = HUB.getAllJax(element);
var state = {collapse: [], jax: jax, m: jax.length, i: 0, changed:false};
return this.collapseState(state);
},
collapseState: function (state) {
var collapse = state.collapse;
while (state.i < state.m) {
var jax = state.jax[state.i];
var SRE = jax.root.SRE; state.changed = false;
if (SRE && SRE.action.length) {
if (SRE.cwidth < SRE.m || SRE.cwidth > SRE.M) {
var restart = this.getActionWidths(jax,state); if (restart) return restart;
this.collapseActions(SRE,state);
if (state.changed) collapse.push(jax.SourceElement());
}
}
state.i++;
}
if (collapse.length === 0) return;
if (collapse.length === 1) collapse = collapse[0];
return HUB.Rerender(collapse);
},
//
// Find the actions that need to be collapsed to acheive
// the correct width, and retain the sizes that would cause
// the equation to be expanded or collapsed further.
//
collapseActions: function (SRE,state) {
var w = SRE.width, m = w, M = 1000000;
for (var j = SRE.action.length-1; j >= 0; j--) {
var action = SRE.action[j], selection = action.selection;
if (w > SRE.cwidth) {
action.selection = 1;
m = action.SREwidth; M = w;
} else {
action.selection = 2;
}
w = action.SREwidth;
if (SRE.DOMupdate) {
document.getElementById(action.id).setAttribute("selection",action.selection);
} else if (action.selection !== selection) {
state.changed = true;
}
}
SRE.m = m; SRE.M = M;
},
//
// Get the widths of the different collapsings,
// trapping any restarts, and restarting the process
// when the event has occurred.
//
getActionWidths: function (jax,state) {
if (!jax.root.SRE.actionWidths) {
MathJax.OutputJax[jax.outputJax].getMetrics(jax);
try {this.computeActionWidths(jax)} catch (err) {
if (!err.restart) throw err;
return MathJax.Callback.After(["collapseState",this,state],err.restart);
}
state.changed = true;
}
return null;
},
//
// Compute the action widths by collapsing each maction,
// and recording the width of the complete equation.
//
computeActionWidths: function (jax) {
var SRE = jax.root.SRE, actions = SRE.action, j, state = {};
SRE.width = jax.sreGetRootWidth(state);
for (j = actions.length-1; j >= 0; j--) actions[j].selection = 2;
for (j = actions.length-1; j >= 0; j--) {
var action = actions[j];
if (action.SREwidth == null) {
action.selection = 1;
action.SREwidth = jax.sreGetActionWidth(state,action);
}
}
SRE.actionWidths = true;
},
//
// Get the widths of the containers of tall the math elements
// that can be collapsed (so we can tell which ones NEED to be
// collapsed). Do this in a way that only causes two reflows.
//
GetContainerWidths: function (element) {
var JAX = HUB.getAllJax(element);
var i, m, script, span = MathJax.HTML.Element("span",{style:{display:"block"}});
var math = [], jax, root;
for (i = 0, m = JAX.length; i < m; i++) {
jax = JAX[i], root = jax.root, SRE = root.SRE;
if (SRE && SRE.action.length) {
if (SRE.width == null) {
jax.sreGetMetrics();
SRE.m = SRE.width; SRE.M = 1000000;
}
script = jax.SourceElement();
script.previousSibling.style.display = "none";
script.parentNode.insertBefore(span.cloneNode(false),script);
math.push([jax,script]);
}
}
for (i = 0, m = math.length; i < m; i++) {
jax = math[i][0], script = math[i][1];
if (script.previousSibling.offsetWidth)
jax.root.SRE.cwidth = script.previousSibling.offsetWidth * jax.root.SRE.em;
}
for (i = 0, m = math.length; i < m; i++) {
jax = math[i][0], script = math[i][1];
script.parentNode.removeChild(script.previousSibling);
script.previousSibling.style.display = "";
}
},
/*****************************************************************/
//
// A resize handler that can be tied to the window resize event
// to collapse math automatically on resize.
//
timer: null,
running: false,
retry: false,
saved_delay: 0,
resizeHandler: function (event) {
if (Collapse.config.disabled) return;
if (Collapse.running) {Collapse.retry = true; return}
if (Collapse.timer) clearTimeout(Collapse.timer);
Collapse.timer = setTimeout(Collapse.resizeAction, 100);
},
resizeAction: function () {
Collapse.timer = null;
Collapse.running = true;
HUB.Queue(
function () {
//
// Prevent flicker between input and output phases.
//
Collapse.saved_delay = HUB.processSectionDelay;
HUB.processSectionDelay = 0;
},
["CollapseWideMath",Collapse],
["resizeCheck",Collapse]
);
},
resizeCheck: function () {
Collapse.running = false;
HUB.processSectionDelay = Collapse.saved_delay;
if (Collapse.retry) {
Collapse.retry = false;
setTimeout(Collapse.resizeHandler,0);
}
}
};
HUB.Register.StartupHook("End Extensions", function () {
if (SETTINGS.autocollapse == null) {
SETTINGS.autocollapse = !Collapse.config.disabled;
} else {
Collapse.config.disabled = !SETTINGS.autocollapse;
}
HUB.Register.StartupHook("MathMenu Ready", function () {
COOKIE = MathJax.Menu.cookie;
var Switch = function(menu) {
Collapse[SETTINGS.autocollapse ? "Enable" : "Disable"](true,true);
MathJax.Menu.saveCookie();
};
var ITEM = MathJax.Menu.ITEM,
MENU = MathJax.Menu.menu;
var menu = ITEM.CHECKBOX(
['AutoCollapse','Auto Collapse'], 'autocollapse', {action: Switch}
);
var submenu = (MENU.FindId('Accessibility')||{}).submenu, index;
if (submenu) {
index = submenu.IndexOfId('AutoCollapse');
if (index !== null) {
submenu.items[index] = menu;
} else {
index = submenu.IndexOfId('CollapsibleMath');
submenu.items.splice(index+1,0,menu);
}
} else {
index = MENU.IndexOfId('CollapsibleMath');
MENU.items.splice(index+1,0,menu);
}
var init = function () {Collapse[SETTINGS.autocollapse ? "Enable" : "Disable"]()};
if (MathJax.Extension.collapse) init();
else MathJax.Hub.Register.StartupHook("Auto Collapse Ready", init);
},25); // after Assistive-Explore
},25);
})(MathJax.Hub);
/*****************************************************************/
/*
* Add methods to the ElementJax and OutputJax to get the
* widths of the collapsed elements.
*/
//
// Add SRE methods to ElementJax.
//
MathJax.ElementJax.Augment({
sreGetMetrics: function () {
MathJax.OutputJax[this.outputJax].sreGetMetrics(this,this.root.SRE);
},
sreGetRootWidth: function (state) {
return MathJax.OutputJax[this.outputJax].sreGetRootWidth(this,state);
},
sreGetActionWidth: function (state,action) {
return MathJax.OutputJax[this.outputJax].sreGetActionWidth(this,state,action);
}
});
//
// Add default methods to base OutputJax class.
//
MathJax.OutputJax.Augment({
getMetrics: function () {}, // make sure it is defined
sreGetMetrics: function (jax,SRE) {SRE.cwidth = 1000000; SRE.width = 0; SRE.em = 12},
sreGetRootWidth: function (jax,state) {return 0},
sreGetActionWidth: function (jax,state,action) {return 0}
});
//
// Specific implementations for HTML-CSS output.
//
MathJax.Hub.Register.StartupHook("HTML-CSS Jax Ready",function () {
MathJax.OutputJax["HTML-CSS"].Augment({
sreGetMetrics: function (jax,SRE) {
SRE.width = jax.root.data[0].HTMLspanElement().parentNode.bbox.w;
SRE.em = 1 / jax.HTMLCSS.em / jax.HTMLCSS.scale;
},
sreGetRootWidth: function (jax,state) {
var html = jax.root.data[0].HTMLspanElement();
state.box = html.parentNode;
return state.box.bbox.w;
},
sreGetActionWidth: function (jax,state,action) {
return jax.root.data[0].toHTML(state.box).bbox.w;
}
});
});
//
// Specific implementations for SVG output.
//
MathJax.Hub.Register.StartupHook("SVG Jax Ready",function () {
MathJax.OutputJax.SVG.Augment({
getMetrics: function (jax) {
this.em = MathJax.ElementJax.mml.mbase.prototype.em = jax.SVG.em; this.ex = jax.SVG.ex;
this.linebreakWidth = jax.SVG.lineWidth; this.cwidth = jax.SVG.cwidth;
},
sreGetMetrics: function (jax,SRE) {
SRE.width = jax.root.SVGdata.w/1000;
SRE.em = 1/jax.SVG.em;
},
sreGetRootWidth: function (jax,state) {
state.span = document.getElementById(jax.inputID+"-Frame");
return jax.root.SVGdata.w/1000;
},
sreGetActionWidth: function (jax,state,action) {
this.mathDiv = state.span;
state.span.appendChild(this.textSVG);
try {var svg = jax.root.data[0].toSVG()} catch(err) {var error = err}
state.span.removeChild(this.textSVG);
if (error) throw error; // can happen when a restart is needed
return jax.root.data[0].SVGdata.w/1000;
}
});
});
//
// Specific implementations for CommonHTML output.
//
MathJax.Hub.Register.StartupHook("CommonHTML Jax Ready",function () {
MathJax.OutputJax.CommonHTML.Augment({
sreGetMetrics: function (jax,SRE) {
SRE.width = jax.root.CHTML.w;
SRE.em = 1 / jax.CHTML.em / jax.CHTML.scale;
},
sreGetRootWidth: function (jax,state) {
state.span = document.getElementById(jax.inputID+"-Frame").firstChild;
state.tmp = document.createElement("span");
state.tmp.className = state.span.className;
return jax.root.CHTML.w / jax.CHTML.scale;
},
sreGetActionWidth: function (jax,state,action) {
state.span.parentNode.replaceChild(state.tmp,state.span);
MathJax.OutputJax.CommonHTML.CHTMLnode = state.tmp;
try {jax.root.data[0].toCommonHTML(state.tmp)} catch (err) {var error = err}
state.tmp.parentNode.replaceChild(state.span,state.tmp);
if (error) throw error; // can happen when a restart is needed
return jax.root.data[0].CHTML.w / jax.CHTML.scale;
}
});
});
//
// Specific implementations for NativeMML output.
//
MathJax.Hub.Register.StartupHook("NativeMML Jax Ready",function () {
MathJax.OutputJax.NativeMML.Augment({
sreGetMetrics: function (jax,SRE) {
var span = document.getElementById(jax.inputID+"-Frame");
SRE.width = span.offsetWidth;
SRE.em = 1; SRE.DOMupdate = true;
},
sreGetRootWidth: function (jax,state) {
state.span = document.getElementById(jax.inputID+"-Frame").firstChild;
return state.span.offsetWidth;
},
sreGetActionWidth: function (jax,state,action) {
var maction = document.getElementById(action.id);
maction.setAttribute("selection",1);
var w = state.span.offsetWidth;
return w;
}
});
});
/*****************************************************************/
//
// Load the collapsible extension and
// signal the start up when that has loaded.
//
MathJax.Ajax.Require("[a11y]/collapsible.js");
MathJax.Hub.Register.StartupHook("Collapsible Ready", function () {
MathJax.Extension["auto-collapse"].Startup(); // Initialize the collapsing process
MathJax.Hub.Startup.signal.Post("Auto Collapse Ready");
MathJax.Ajax.loadComplete("[a11y]/auto-collapse.js");
});