2 * extensions/leaders.js
4 * Part of the jsMath package for mathematics on the web.
6 * This file implements the \overbrace, \underbrace, \overrightarrow
7 * and \overleftarrow macros. It will be loaded automatically when needed,
10 * jsMath.Extension.Require('leaders');
12 * ---------------------------------------------------------------------
14 * Copyright 2005-2006 by Davide P. Cervone
16 * Licensed under the Apache License, Version 2.0 (the "License");
17 * you may not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
20 * http://www.apache.org/licenses/LICENSE-2.0
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an "AS IS" BASIS,
24 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
29 /********************************************************************/
31 jsMath.Add(jsMath.Box,{
34 * Create a horizontally stretchable "delimiter" (like over- and
38 Leaders: function (W,leader) {
39 var h; var d; var w; var html; var font;
40 if (leader.lmid) {// braces
41 font = jsMath.TeX.fam[leader.left[0]];
42 var left = this.GetCharCode(leader.left);
43 var right = this.GetCharCode(leader.right);
44 var lmid = this.GetCharCode(leader.lmid);
45 var rmid = this.GetCharCode(leader.rmid);
46 w = (W - left.w - right.w - lmid.w - rmid.w)/2 - .1; h = .4; d = .3;
48 html = this.AddClass(left.tclass,left.c,left.font)
49 + jsMath.HTML.Rule(w,left.h)
50 + this.AddClass(lmid.tclass,lmid.c+rmid.c,lmid.font)
51 + jsMath.HTML.Rule(w,right.h)
52 + this.AddClass(right.tclass,right.c,right.font);
54 font = jsMath.TeX.fam[leader.rep[0]];
55 var left = this.GetCharCode(leader.left? leader.left: leader.rep);
56 var rep = this.GetCharCode(leader.rep);
57 var right = this.GetCharCode(leader.right? leader.right: leader.rep);
58 var n = Math.ceil((W - left.w - right.w + .4)/(rep.w - .3));
59 w = (W - left.w - right.w + .4 - n*(rep.w - .3));
60 if (leader.left) {h = left.h; d = left.d} else {h = right.h; d = right.d}
61 if (d == null) {d = 0}; if (h == null) {h = 0}
62 var html = this.AddClass(left.tclass,left.c,left.font); var m = Math.floor(n/2);
63 var ext = jsMath.HTML.Place(rep.c,-.3,0);
64 var ehtml = ''; for (var i = 0; i < m; i++) {ehtml += ext};
65 html += this.AddClass(rep.tclass,ehtml,rep.font) + jsMath.HTML.Spacer(w);
66 ehtml = ''; for (var i = m; i < n; i++) {ehtml += ext};
67 html += this.AddClass(rep.tclass,ehtml,rep.font);
68 if (jsMath.Browser.msieFontBug) {html += '<span style="display: none">x</span>'}
69 html += jsMath.HTML.Place(this.AddClass(right.tclass,right.c,right.font),-.4,0);
71 w = jsMath.EmBoxFor(html).w;
73 w = jsMath.HTML.Spacer((W-w)/2);
76 var box = new jsMath.Box('html',html,W,h,d);
77 box.bh = jsMath.TeX[font].h; box.bd = jsMath.TeX[font].d;
83 jsMath.Package(jsMath.Parser,{
86 overbrace: ['HandleLeaders','downbrace',1],
87 underbrace: ['HandleLeaders','upbrace',1,1,-.05],
88 overrightarrow: ['HandleLeaders','rightarrow'],
89 underrightarrow: ['HandleLeaders','rightarrow',null,1,-.2],
90 overleftarrow: ['HandleLeaders','leftarrow'],
91 underleftarrow: ['HandleLeaders','leftarrow',null,1,-.2],
92 overleftrightarrow: ['HandleLeaders','leftrightarrow'],
93 underleftrightarrow: ['HandleLeaders','leftrightarrow',null,1,-.2]
97 * The horizontally stretchable delimiters
100 downbrace: {left: [3,0x7A], lmid: [3,0x7D], rmid: [3,0x7C], right: [3,0x7B]},
101 upbrace: {left: [3,0x7C], lmid: [3,0x7B], rmid: [3,0x7A], right: [3,0x7D]},
102 leftarrow: {left: [2,0x20], rep: [2,0x00]},
103 rightarrow: {rep: [2,0x00], right: [2,0x21]},
104 leftrightarrow: {left: [2,0x20], rep: [2, 0x00], right: [2,0x21]}
108 * Implements \overbrace, \underbrace, etc.
110 HandleLeaders: function (name,data) {
111 var box = this.ProcessArg(this.cmd+name); if (this.error) return;
112 box = jsMath.Box.Set(box,'D',this.mlist.data.size).Remeasured();
113 var leader = jsMath.Box.Leaders(box.w,this.leaders[data[0]]);
114 if (data[2]) {leader.y = -leader.h-box.d+(data[3]||0)}
115 else {leader.y = box.h + Math.max(0,leader.d)+(data[3]||0)}
116 box.x = -(leader.w + box.w)/2;
117 var space = jsMath.Box.Space((leader.w-box.w)/2);
118 box = jsMath.mItem.Atom(data[1]? 'op': 'ord',
119 jsMath.Box.SetList([leader,box,space],'T',this.mlist.data.size));
120 box.limits = (data[1]? 1: 0);