1 // minmax.js: make IE5+/Win support CSS min/max-width/height
2 // version 1.0, 08-Aug-2003
3 // written by Andrew Clover <and@doxdesk.com>, use freely
5 /*@cc_on
6 @if (@_win32 && @_jscript_version>4)
8 var minmax_elements;
10 minmax_props= new Array(
11 new Array('min-width', 'minWidth'),
12 new Array('max-width', 'maxWidth'),
13 new Array('min-height','minHeight'),
14 new Array('max-height','maxHeight')
15 );
17 // Binding. Called on all new elements. If <body>, initialise; check all
18 // elements for minmax properties
20 function minmax_bind(el) {
21 var i, em, ms;
22 var st= el.style, cs= el.currentStyle;
24 if (minmax_elements==window.undefined) {
25 // initialise when body element has turned up, but only on IE
26 if (!document.body || !document.body.currentStyle) return;
27 minmax_elements= new Array();
28 window.attachEvent('onresize', minmax_delayout);
29 // make font size listener
30 em= document.createElement('div');
31 em.setAttribute('id', 'minmax_em');
32 em.style.position= 'absolute'; em.style.visibility= 'hidden';
33 em.style.fontSize= 'xx-large'; em.style.height= '5em';
34 em.style.top='-5em'; em.style.left= '0';
35 if (em.style.setExpression) {
36 em.style.setExpression('width', 'minmax_checkFont()');
37 document.body.insertBefore(em, document.body.firstChild);
38 }
39 }
41 // transform hyphenated properties the browser has not caught to camelCase
42 for (i= minmax_props.length; i-->0;)
43 if (cs[minmax_props[i][0]])
44 st[minmax_props[i][1]]= cs[minmax_props[i][0]];
45 // add element with properties to list, store optimal size values
46 for (i= minmax_props.length; i-->0;) {
47 ms= cs[minmax_props[i][1]];
48 if (ms && ms!='auto' && ms!='none' && ms!='0' && ms!='') {
49 st.minmaxWidth= cs.width; st.minmaxHeight= cs.height;
50 minmax_elements[minmax_elements.length]= el;
51 // will need a layout later
52 minmax_delayout();
53 break;
54 } }
55 }
57 // check for font size changes
59 var minmax_fontsize= 0;
60 function minmax_checkFont() {
61 var fs= document.getElementById('minmax_em').offsetHeight;
62 if (minmax_fontsize!=fs && minmax_fontsize!=0)
63 minmax_delayout();
64 minmax_fontsize= fs;
65 return '5em';
66 }
68 // Layout. Called after window and font size-change. Go through elements we
69 // picked out earlier and set their size to the minimum, maximum and optimum,
70 // choosing whichever is appropriate
72 // Request re-layout at next available moment
73 var minmax_delaying= false;
74 function minmax_delayout() {
75 if (minmax_delaying) return;
76 minmax_delaying= true;
77 window.setTimeout(minmax_layout, 0);
78 }
80 function minmax_stopdelaying() {
81 minmax_delaying= false;
82 }
84 function minmax_layout() {
85 window.setTimeout(minmax_stopdelaying, 100);
86 var i, el, st, cs, optimal, inrange;
87 for (i= minmax_elements.length; i-->0;) {
88 el= minmax_elements[i]; st= el.style; cs= el.currentStyle;
90 // horizontal size bounding
91 st.width= st.minmaxWidth; optimal= el.offsetWidth;
92 inrange= true;
93 if (inrange && cs.minWidth && cs.minWidth!='0' && cs.minWidth!='auto' && cs.minWidth!='') {
94 st.width= cs.minWidth;
95 inrange= (el.offsetWidth<optimal);
96 }
97 if (inrange && cs.maxWidth && cs.maxWidth!='none' && cs.maxWidth!='auto' && cs.maxWidth!='') {
98 st.width= cs.maxWidth;
99 inrange= (el.offsetWidth>optimal);
100 }
101 if (inrange) st.width= st.minmaxWidth;
103 // vertical size bounding
104 st.height= st.minmaxHeight; optimal= el.offsetHeight;
105 inrange= true;
106 if (inrange && cs.minHeight && cs.minHeight!='0' && cs.minHeight!='auto' && cs.minHeight!='') {
107 st.height= cs.minHeight;
108 inrange= (el.offsetHeight<optimal);
109 }
110 if (inrange && cs.maxHeight && cs.maxHeight!='none' && cs.maxHeight!='auto' && cs.maxHeight!='') {
111 st.height= cs.maxHeight;
112 inrange= (el.offsetHeight>optimal);
113 }
114 if (inrange) st.height= st.minmaxHeight;
115 }
116 }
118 // Scanning. Check document every so often until it has finished loading. Do
119 // nothing until <body> arrives, then call main init. Pass any new elements
120 // found on each scan to be bound
122 var minmax_SCANDELAY= 500;
124 function minmax_scan() {
125 var el;
126 for (var i= 0; i<document.all.length; i++) {
127 el= document.all[i];
128 if (!el.minmax_bound) {
129 el.minmax_bound= true;
130 minmax_bind(el);
131 } }
132 }
134 var minmax_scanner;
135 function minmax_stop() {
136 window.clearInterval(minmax_scanner);
137 minmax_scan();
138 }
140 minmax_scan();
141 minmax_scanner= window.setInterval(minmax_scan, minmax_SCANDELAY);
142 window.attachEvent('onload', minmax_stop);
144 @end @*/