/*!
* Ext JS Library 3.3.0
* Copyright(c) 2006-2010 Ext JS, Inc.
* licensing@extjs.com
* http://www.extjs.com/license
*/
Ext.ns('Ext.ux.grid');
/**
* @class Ext.ux.grid.BufferView
* @extends Ext.grid.GridView
* A custom GridView which renders rows on an as-needed basis.
*/
Ext.ux.grid.BufferView = Ext.extend(Ext.grid.GridView, {
/**
* @cfg {Number} rowHeight
* The height of a row in the grid.
*/
rowHeight: 19,
/**
* @cfg {Number} borderHeight
* The combined height of border-top and border-bottom of a row.
*/
borderHeight: 2,
/**
* @cfg {Boolean/Number} scrollDelay
* The number of milliseconds before rendering rows out of the visible
* viewing area. Defaults to 100. Rows will render immediately with a config
* of false.
*/
scrollDelay: 100,
/**
* @cfg {Number} cacheSize
* The number of rows to look forward and backwards from the currently viewable
* area. The cache applies only to rows that have been rendered already.
*/
cacheSize: 20,
/**
* @cfg {Number} cleanDelay
* The number of milliseconds to buffer cleaning of extra rows not in the
* cache.
*/
cleanDelay: 500,
initTemplates : function(){
Ext.ux.grid.BufferView.superclass.initTemplates.call(this);
var ts = this.templates;
// empty div to act as a place holder for a row
ts.rowHolder = new Ext.Template(
''
);
ts.rowHolder.disableFormats = true;
ts.rowHolder.compile();
ts.rowBody = new Ext.Template(
'',
'{cells}
',
(this.enableRowBody ? '{body} |
' : ''),
'
'
);
ts.rowBody.disableFormats = true;
ts.rowBody.compile();
},
getStyleRowHeight : function(){
return Ext.isBorderBox ? (this.rowHeight + this.borderHeight) : this.rowHeight;
},
getCalculatedRowHeight : function(){
return this.rowHeight + this.borderHeight;
},
getVisibleRowCount : function(){
var rh = this.getCalculatedRowHeight(),
visibleHeight = this.scroller.dom.clientHeight;
return (visibleHeight < 1) ? 0 : Math.ceil(visibleHeight / rh);
},
getVisibleRows: function(){
var count = this.getVisibleRowCount(),
sc = this.scroller.dom.scrollTop,
start = (sc === 0 ? 0 : Math.floor(sc/this.getCalculatedRowHeight())-1);
return {
first: Math.max(start, 0),
last: Math.min(start + count + 2, this.ds.getCount()-1)
};
},
doRender : function(cs, rs, ds, startRow, colCount, stripe, onlyBody){
var ts = this.templates,
ct = ts.cell,
rt = ts.row,
rb = ts.rowBody,
last = colCount-1,
rh = this.getStyleRowHeight(),
vr = this.getVisibleRows(),
tstyle = 'width:'+this.getTotalWidth()+';height:'+rh+'px;',
// buffers
buf = [],
cb,
c,
p = {},
rp = {tstyle: tstyle},
r;
for (var j = 0, len = rs.length; j < len; j++) {
r = rs[j]; cb = [];
var rowIndex = (j+startRow),
visible = rowIndex >= vr.first && rowIndex <= vr.last;
if (visible) {
for (var i = 0; i < colCount; i++) {
c = cs[i];
p.id = c.id;
p.css = i === 0 ? 'x-grid3-cell-first ' : (i == last ? 'x-grid3-cell-last ' : '');
p.attr = p.cellAttr = "";
p.value = c.renderer(r.data[c.name], p, r, rowIndex, i, ds);
p.style = c.style;
if (p.value === undefined || p.value === "") {
p.value = " ";
}
if (r.dirty && typeof r.modified[c.name] !== 'undefined') {
p.css += ' x-grid3-dirty-cell';
}
cb[cb.length] = ct.apply(p);
}
}
var alt = [];
if(stripe && ((rowIndex+1) % 2 === 0)){
alt[0] = "x-grid3-row-alt";
}
if(r.dirty){
alt[1] = " x-grid3-dirty-row";
}
rp.cols = colCount;
if(this.getRowClass){
alt[2] = this.getRowClass(r, rowIndex, rp, ds);
}
rp.alt = alt.join(" ");
rp.cells = cb.join("");
buf[buf.length] = !visible ? ts.rowHolder.apply(rp) : (onlyBody ? rb.apply(rp) : rt.apply(rp));
}
return buf.join("");
},
isRowRendered: function(index){
var row = this.getRow(index);
return row && row.childNodes.length > 0;
},
syncScroll: function(){
Ext.ux.grid.BufferView.superclass.syncScroll.apply(this, arguments);
this.update();
},
// a (optionally) buffered method to update contents of gridview
update: function(){
if (this.scrollDelay) {
if (!this.renderTask) {
this.renderTask = new Ext.util.DelayedTask(this.doUpdate, this);
}
this.renderTask.delay(this.scrollDelay);
}else{
this.doUpdate();
}
},
onRemove : function(ds, record, index, isUpdate){
Ext.ux.grid.BufferView.superclass.onRemove.apply(this, arguments);
if(isUpdate !== true){
this.update();
}
},
doUpdate: function(){
if (this.getVisibleRowCount() > 0) {
var g = this.grid,
cm = g.colModel,
ds = g.store,
cs = this.getColumnData(),
vr = this.getVisibleRows(),
row;
for (var i = vr.first; i <= vr.last; i++) {
// if row is NOT rendered and is visible, render it
if(!this.isRowRendered(i) && (row = this.getRow(i))){
var html = this.doRender(cs, [ds.getAt(i)], ds, i, cm.getColumnCount(), g.stripeRows, true);
row.innerHTML = html;
}
}
this.clean();
}
},
// a buffered method to clean rows
clean : function(){
if(!this.cleanTask){
this.cleanTask = new Ext.util.DelayedTask(this.doClean, this);
}
this.cleanTask.delay(this.cleanDelay);
},
doClean: function(){
if (this.getVisibleRowCount() > 0) {
var vr = this.getVisibleRows();
vr.first -= this.cacheSize;
vr.last += this.cacheSize;
var i = 0, rows = this.getRows();
// if first is less than 0, all rows have been rendered
// so lets clean the end...
if(vr.first <= 0){
i = vr.last + 1;
}
for(var len = this.ds.getCount(); i < len; i++){
// if current row is outside of first and last and
// has content, update the innerHTML to nothing
if ((i < vr.first || i > vr.last) && rows[i].innerHTML) {
rows[i].innerHTML = '';
}
}
}
},
removeTask: function(name){
var task = this[name];
if(task && task.cancel){
task.cancel();
this[name] = null;
}
},
destroy : function(){
this.removeTask('cleanTask');
this.removeTask('renderTask');
Ext.ux.grid.BufferView.superclass.destroy.call(this);
},
layout: function(){
Ext.ux.grid.BufferView.superclass.layout.call(this);
this.update();
}
});