- Author:
- David Nickerson <nickerso@users.sourceforge.net>
- Date:
- 2009-07-16 02:00:03+12:00
- Desc:
- the starting point for the HH tutorial example
- Permanent Source URI:
- https://models.fieldml.org/workspace/a1/rawfile/f6a8f90307388eb4b040ee3566b84d88b59247f7/dojo-presentation/js/dojo/dojox/grid/_Scroller.js
dojo.provide("dojox.grid._Scroller");
(function(){
var indexInParent = function(inNode){
var i=0, n, p=inNode.parentNode;
while((n = p.childNodes[i++])){
if(n == inNode){
return i - 1;
}
}
return -1;
};
var cleanNode = function(inNode){
if(!inNode){
return;
}
var filter = function(inW){
return inW.domNode && dojo.isDescendant(inW.domNode, inNode, true);
}
var ws = dijit.registry.filter(filter);
for(var i=0, w; (w=ws[i]); i++){
w.destroy();
}
delete ws;
};
var getTagName = function(inNodeOrId){
var node = dojo.byId(inNodeOrId);
return (node && node.tagName ? node.tagName.toLowerCase() : '');
};
var nodeKids = function(inNode, inTag){
var result = [];
var i=0, n;
while((n = inNode.childNodes[i++])){
if(getTagName(n) == inTag){
result.push(n);
}
}
return result;
};
var divkids = function(inNode){
return nodeKids(inNode, 'div');
};
dojo.declare("dojox.grid._Scroller", null, {
constructor: function(inContentNodes){
this.setContentNodes(inContentNodes);
this.pageHeights = [];
this.pageNodes = [];
this.stack = [];
},
// specified
rowCount: 0, // total number of rows to manage
defaultRowHeight: 10, // default height of a row
keepRows: 100, // maximum number of rows that should exist at one time
contentNode: null, // node to contain pages
scrollboxNode: null, // node that controls scrolling
// calculated
defaultPageHeight: 0, // default height of a page
keepPages: 10, // maximum number of pages that should exists at one time
pageCount: 0,
windowHeight: 0,
firstVisibleRow: 0,
lastVisibleRow: 0,
// private
page: 0,
pageTop: 0,
// init
init: function(inRowCount, inKeepRows, inRowsPerPage){
switch(arguments.length){
case 3: this.rowsPerPage = inRowsPerPage;
case 2: this.keepRows = inKeepRows;
case 1: this.rowCount = inRowCount;
}
this.defaultPageHeight = this.defaultRowHeight * this.rowsPerPage;
//this.defaultPageHeight = this.defaultRowHeight * Math.min(this.rowsPerPage, this.rowCount);
this.pageCount = this._getPageCount(this.rowCount, this.rowsPerPage);
this.setKeepInfo(this.keepRows);
this.invalidate();
if(this.scrollboxNode){
this.scrollboxNode.scrollTop = 0;
this.scroll(0);
this.scrollboxNode.onscroll = dojo.hitch(this, 'onscroll');
}
},
_getPageCount: function(rowCount, rowsPerPage){
return rowCount ? (Math.ceil(rowCount / rowsPerPage) || 1) : 0;
},
destroy: function(){
this.invalidateNodes();
delete this.contentNodes;
delete this.contentNode;
delete this.scrollboxNode;
},
setKeepInfo: function(inKeepRows){
this.keepRows = inKeepRows;
this.keepPages = !this.keepRows ? this.keepRows : Math.max(Math.ceil(this.keepRows / this.rowsPerPage), 2);
},
// nodes
setContentNodes: function(inNodes){
this.contentNodes = inNodes;
this.colCount = (this.contentNodes ? this.contentNodes.length : 0);
this.pageNodes = [];
for(var i=0; i<this.colCount; i++){
this.pageNodes[i] = [];
}
},
getDefaultNodes: function(){
return this.pageNodes[0] || [];
},
// updating
invalidate: function(){
this.invalidateNodes();
this.pageHeights = [];
this.height = (this.pageCount ? (this.pageCount - 1)* this.defaultPageHeight + this.calcLastPageHeight() : 0);
this.resize();
},
updateRowCount: function(inRowCount){
this.invalidateNodes();
this.rowCount = inRowCount;
// update page count, adjust document height
var oldPageCount = this.pageCount;
this.pageCount = this._getPageCount(this.rowCount, this.rowsPerPage);
if(this.pageCount < oldPageCount){
for(var i=oldPageCount-1; i>=this.pageCount; i--){
this.height -= this.getPageHeight(i);
delete this.pageHeights[i]
}
}else if(this.pageCount > oldPageCount){
this.height += this.defaultPageHeight * (this.pageCount - oldPageCount - 1) + this.calcLastPageHeight();
}
this.resize();
},
// implementation for page manager
pageExists: function(inPageIndex){
return Boolean(this.getDefaultPageNode(inPageIndex));
},
measurePage: function(inPageIndex){
return this.getDefaultPageNode(inPageIndex).offsetHeight;
},
positionPage: function(inPageIndex, inPos){
for(var i=0; i<this.colCount; i++){
this.pageNodes[i][inPageIndex].style.top = inPos + 'px';
}
},
repositionPages: function(inPageIndex){
var nodes = this.getDefaultNodes();
var last = 0;
for(var i=0; i<this.stack.length; i++){
last = Math.max(this.stack[i], last);
}
//
var n = nodes[inPageIndex];
var y = (n ? this.getPageNodePosition(n) + this.getPageHeight(inPageIndex) : 0);
//console.log('detected height change, repositioning from #%d (%d) @ %d ', inPageIndex + 1, last, y, this.pageHeights[0]);
//
for(var p=inPageIndex+1; p<=last; p++){
n = nodes[p];
if(n){
//console.log('#%d @ %d', inPageIndex, y, this.getPageNodePosition(n));
if(this.getPageNodePosition(n) == y){
return;
}
//console.log('placing page %d at %d', p, y);
this.positionPage(p, y);
}
y += this.getPageHeight(p);
}
},
installPage: function(inPageIndex){
for(var i=0; i<this.colCount; i++){
this.contentNodes[i].appendChild(this.pageNodes[i][inPageIndex]);
}
},
preparePage: function(inPageIndex, inPos, inReuseNode){
var p = (inReuseNode ? this.popPage() : null);
for(var i=0; i<this.colCount; i++){
var nodes = this.pageNodes[i];
var new_p = (p === null ? this.createPageNode() : this.invalidatePageNode(p, nodes));
new_p.pageIndex = inPageIndex;
new_p.id = (this._pageIdPrefix || "") + 'page-' + inPageIndex;
nodes[inPageIndex] = new_p;
}
},
// rendering implementation
renderPage: function(inPageIndex){
var nodes = [];
for(var i=0; i<this.colCount; i++){
nodes[i] = this.pageNodes[i][inPageIndex];
}
//this.renderRows(inPageIndex*this.rowsPerPage, this.rowsPerPage, nodes);
for(var i=0, j=inPageIndex*this.rowsPerPage; (i<this.rowsPerPage)&&(j<this.rowCount); i++, j++){
this.renderRow(j, nodes);
}
},
removePage: function(inPageIndex){
for(var i=0, j=inPageIndex*this.rowsPerPage; i<this.rowsPerPage; i++, j++){
this.removeRow(j);
}
},
destroyPage: function(inPageIndex){
for(var i=0; i<this.colCount; i++){
dojo._destroyElement(this.invalidatePageNode(inPageIndex, this.pageNodes[i]));
}
},
pacify: function(inShouldPacify){
},
// pacification
pacifying: false,
pacifyTicks: 200,
setPacifying: function(inPacifying){
if(this.pacifying != inPacifying){
this.pacifying = inPacifying;
this.pacify(this.pacifying);
}
},
startPacify: function(){
this.startPacifyTicks = new Date().getTime();
},
doPacify: function(){
var result = (new Date().getTime() - this.startPacifyTicks) > this.pacifyTicks;
this.setPacifying(true);
this.startPacify();
return result;
},
endPacify: function(){
this.setPacifying(false);
},
// default sizing implementation
resize: function(){
if(this.scrollboxNode){
this.windowHeight = this.scrollboxNode.clientHeight;
}
for(var i=0; i<this.colCount; i++){
dojox.grid.util.setStyleHeightPx(this.contentNodes[i], this.height);
}
},
calcLastPageHeight: function(){
if(!this.pageCount){
return 0;
}
var lastPage = this.pageCount - 1;
var lastPageHeight = ((this.rowCount % this.rowsPerPage)||(this.rowsPerPage)) * this.defaultRowHeight;
this.pageHeights[lastPage] = lastPageHeight;
return lastPageHeight;
},
updateContentHeight: function(inDh){
this.height += inDh;
this.resize();
},
updatePageHeight: function(inPageIndex){
if(this.pageExists(inPageIndex)){
var oh = this.getPageHeight(inPageIndex);
var h = (this.measurePage(inPageIndex))||(oh);
this.pageHeights[inPageIndex] = h;
if((h)&&(oh != h)){
this.updateContentHeight(h - oh)
this.repositionPages(inPageIndex);
}
}
},
rowHeightChanged: function(inRowIndex){
this.updatePageHeight(Math.floor(inRowIndex / this.rowsPerPage));
},
// scroller core
invalidateNodes: function(){
while(this.stack.length){
this.destroyPage(this.popPage());
}
},
createPageNode: function(){
var p = document.createElement('div');
p.style.position = 'absolute';
//p.style.width = '100%';
p.style[dojo._isBodyLtr() ? "left" : "right"] = '0';
return p;
},
getPageHeight: function(inPageIndex){
var ph = this.pageHeights[inPageIndex];
return (ph !== undefined ? ph : this.defaultPageHeight);
},
// FIXME: this is not a stack, it's a FIFO list
pushPage: function(inPageIndex){
return this.stack.push(inPageIndex);
},
popPage: function(){
return this.stack.shift();
},
findPage: function(inTop){
var i = 0, h = 0;
for(var ph = 0; i<this.pageCount; i++, h += ph){
ph = this.getPageHeight(i);
if(h + ph >= inTop){
break;
}
}
this.page = i;
this.pageTop = h;
},
buildPage: function(inPageIndex, inReuseNode, inPos){
this.preparePage(inPageIndex, inReuseNode);
this.positionPage(inPageIndex, inPos);
// order of operations is key below
this.installPage(inPageIndex);
this.renderPage(inPageIndex);
// order of operations is key above
this.pushPage(inPageIndex);
},
needPage: function(inPageIndex, inPos){
var h = this.getPageHeight(inPageIndex), oh = h;
if(!this.pageExists(inPageIndex)){
this.buildPage(inPageIndex, this.keepPages&&(this.stack.length >= this.keepPages), inPos);
h = this.measurePage(inPageIndex) || h;
this.pageHeights[inPageIndex] = h;
if(h && (oh != h)){
this.updateContentHeight(h - oh)
}
}else{
this.positionPage(inPageIndex, inPos);
}
return h;
},
onscroll: function(){
this.scroll(this.scrollboxNode.scrollTop);
},
scroll: function(inTop){
if(this.colCount){
this.startPacify();
this.findPage(inTop);
var h = this.height;
var b = this.getScrollBottom(inTop);
for(var p=this.page, y=this.pageTop; (p<this.pageCount)&&((b<0)||(y<b)); p++){
y += this.needPage(p, y);
}
this.firstVisibleRow = this.getFirstVisibleRow(this.page, this.pageTop, inTop);
this.lastVisibleRow = this.getLastVisibleRow(p - 1, y, b);
// indicates some page size has been updated
if(h != this.height){
this.repositionPages(p-1);
}
this.endPacify();
}
},
getScrollBottom: function(inTop){
return (this.windowHeight >= 0 ? inTop + this.windowHeight : -1);
},
// events
processNodeEvent: function(e, inNode){
var t = e.target;
while(t && (t != inNode) && t.parentNode && (t.parentNode.parentNode != inNode)){
t = t.parentNode;
}
if(!t || !t.parentNode || (t.parentNode.parentNode != inNode)){
return false;
}
var page = t.parentNode;
e.topRowIndex = page.pageIndex * this.rowsPerPage;
e.rowIndex = e.topRowIndex + indexInParent(t);
e.rowTarget = t;
return true;
},
processEvent: function(e){
return this.processNodeEvent(e, this.contentNode);
},
// virtual rendering interface
renderRow: function(inRowIndex, inPageNode){
},
removeRow: function(inRowIndex){
},
// page node operations
getDefaultPageNode: function(inPageIndex){
return this.getDefaultNodes()[inPageIndex];
},
positionPageNode: function(inNode, inPos){
},
getPageNodePosition: function(inNode){
return inNode.offsetTop;
},
invalidatePageNode: function(inPageIndex, inNodes){
var p = inNodes[inPageIndex];
if(p){
delete inNodes[inPageIndex];
this.removePage(inPageIndex, p);
cleanNode(p);
p.innerHTML = '';
}
return p;
},
// scroll control
getPageRow: function(inPage){
return inPage * this.rowsPerPage;
},
getLastPageRow: function(inPage){
return Math.min(this.rowCount, this.getPageRow(inPage + 1)) - 1;
},
getFirstVisibleRow: function(inPage, inPageTop, inScrollTop){
if(!this.pageExists(inPage)){
return 0;
}
var row = this.getPageRow(inPage);
var nodes = this.getDefaultNodes();
var rows = divkids(nodes[inPage]);
for(var i=0,l=rows.length; i<l && inPageTop<inScrollTop; i++, row++){
inPageTop += rows[i].offsetHeight;
}
return (row ? row - 1 : row);
},
getLastVisibleRow: function(inPage, inBottom, inScrollBottom){
if(!this.pageExists(inPage)){
return 0;
}
var nodes = this.getDefaultNodes();
var row = this.getLastPageRow(inPage);
var rows = divkids(nodes[inPage]);
for(var i=rows.length-1; i>=0 && inBottom>inScrollBottom; i--, row--){
inBottom -= rows[i].offsetHeight;
}
return row + 1;
},
findTopRow: function(inScrollTop){
var nodes = this.getDefaultNodes();
var rows = divkids(nodes[this.page]);
for(var i=0,l=rows.length,t=this.pageTop,h; i<l; i++){
h = rows[i].offsetHeight;
t += h;
if(t >= inScrollTop){
this.offset = h - (t - inScrollTop);
return i + this.page * this.rowsPerPage;
}
}
return -1;
},
findScrollTop: function(inRow){
var rowPage = Math.floor(inRow / this.rowsPerPage);
var t = 0;
for(var i=0; i<rowPage; i++){
t += this.getPageHeight(i);
}
this.pageTop = t;
this.needPage(rowPage, this.pageTop);
var nodes = this.getDefaultNodes();
var rows = divkids(nodes[rowPage]);
var r = inRow - this.rowsPerPage * rowPage;
for(var i=0,l=rows.length; i<l && i<r; i++){
t += rows[i].offsetHeight;
}
return t;
},
dummy: 0
});
})();
