egroupware/etemplate/js/et2_dataview_view_grid.js
2011-09-05 14:35:28 +00:00

264 lines
7.0 KiB
JavaScript

/**
* eGroupWare eTemplate2 - Class which contains the "grid" base class
*
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @package etemplate
* @subpackage dataview
* @link http://www.egroupware.org
* @author Andreas Stöckel
* @copyright Stylite 2011
* @version $Id$
*/
"use strict";
/*egw:uses
jquery.jquery;
et2_core_common;
et2_dataview_interfaces;
et2_dataview_view_partitionTree;
*/
/**
* Determines how many pixels the view range of the gridview is extended.
*/
var ET2_GRID_VIEW_EXT = 25;
/**
* Determines the timeout after which the scroll-event is processed.
*/
var ET2_GRID_SCROLL_TIMEOUT = 100;
var partitionTree = null;
var et2_dataview_grid = Class.extend(et2_dataview_IViewRange, {
/**
* Creates the grid.
*
* @param _parent is the parent grid class - if null, this means that this
* is the outer grid which manages the scrollarea. If not null, all other
* parameters are ignored and copied from the given grid instance.
* @param _outerId is the id of the grid container it uses for the css
* classes.
* @param _columnIds is the id of the individual columns used for the css
* classes.
* @param _avgHeight is the starting average height of the column rows.
*/
init: function(_parent, _outerId, _columnIds, _dataProvider, _rowProvider,
_avgHeight) {
// If the parent is given, copy all other parameters from it
if (_parent != null)
{
this._outerId = _parent._outerId;
this._columnIds = _parent._columnIds;
this._dataProvider = _parent._dataProvider;
this._avgHeight = _parent._partitionTree.getAverageHeight();
this._rowProvider = _parent._rowProvider;
}
else
{
// Otherwise copy the given parameters
this._outerId = _outerId;
this._columnIds = _columnIds;
this._dataProvider = _dataProvider;
this._rowProvider = _rowProvider;
this._avgHeight = _avgHeight;
this._scrollHeight = 0;
this._scrollTimeout = null;
}
// The "treeChanged" variable is called whenever the viewrange has been
// set - changing the viewrange is the function which causes new elements
// to be generated and thus the partition tree to degenerate
this._treeChanged = false;
// Count of elements which are buffered at top and bottom of the viewrange
// before they get replaced with placeholders
this._holdCount = 50;
// The current range holds the currently visible nodes
this._currentRange = et2_range(0, 0);
// Build the grid outer nodes
this._createNodes();
// Create the partition tree object which is used to organize the tree
// items.
partitionTree = this._partitionTree = new et2_dataview_partitionTree(this._dataProvider,
this._rowProvider, this._avgHeight, this.innerTbody);
// Setup the "rebuild" timer - it rebuilds the complete partition tree
// if any change has been done to it. Rebuilding the partition tree is
// necessary as the tree structure happens to degenerate.
var self = this;
this._rebuildTimer = window.setInterval(function() {
self._checkTreeRebuild();
}, 10 * 1000);
},
destroy: function() {
// Stop the scroll timeout
if (this._scrollTimeout)
{
window.clearTimeout(this._scrollTimeout);
}
// Stop the rebuild timer
window.clearInterval(this._rebuildTimer);
// Free the partition tree
this._partitionTree.free();
},
/**
* The setViewRange function updates the range in which columns are shown.
*/
setViewRange: function(_range) {
this._treeChanged = true;
// Copy the given range
this._currentRange = et2_bounds(_range.top, _range.bottom);
// Display all elements in the given range
var nodes = this._partitionTree.getRangeNodes(_range);
for (var i = 0; i < nodes.length; i++)
{
if (nodes[i].implements(et2_dataview_IViewRange))
{
nodes[i].setViewRange(_range);
}
}
// Deactivated the code below for testing purposes
// Calculate the range of the actually shown elements
var displayTop = _range.top;
var displayBottom = _range.bottom;
if (nodes.length > 0)
{
displayTop = nodes[0].getPosTop();
displayBottom = nodes[nodes.length - 1].getPosBottom();
}
// Hide everything except for _holdCount elements at the top and bottom
// of the viewrange
var ah = this._partitionTree.getAverageHeight();
var reduceHeight = ah * this._holdCount;
if (displayTop > reduceHeight)
{
this._partitionTree.reduceRange(et2_bounds(0, displayTop - reduceHeight));
}
if (displayBottom + reduceHeight < this._partitionTree.getHeight())
{
this._partitionTree.reduceRange(et2_bounds(displayBottom + reduceHeight,
this._partitionTree.getHeight()));
}
},
/**
* Updates the scrollheight
*/
setScrollHeight: function(_height) {
this._height = _height;
// Update the height of the outer container
if (this.scrollarea)
{
this.scrollarea.height(_height);
}
// Update the viewing range
this.setViewRange(et2_range(this._currentRange.top, this._height));
},
/**
* Returns the JQuery outer DOM-Node
*/
getJNode: function() {
return this.outerCell;
},
/* ---- PRIVATE FUNCTIONS ---- */
/**
* Checks whether the partition tree has to be rebuilt and if yes, does
* that.
*/
_checkTreeRebuild: function() {
if (this._treeChanged)
{
var depth = this._partitionTree.getDepth();
var count = this._partitionTree.getManagedCount();
// Check whether the depth of the tree is very unproportional
// regarding to the count of elements managed in it
if (count < Math.pow(ET2_PARTITION_TREE_WIDTH, depth - 1))
{
et2_debug("info", "Rebuilding dataview partition tree");
this._partitionTree.rebuild();
et2_debug("info", "Done.");
}
// Reset the "treeChanged" function.
this._treeChanged = false;
}
},
/**
* Creates the grid DOM-Nodes
*/
_createNodes: function() {
this.outerCell = $j(document.createElement("td"))
.addClass("frame")
.attr("colspan", this._columnIds.length + (this._parent ? 0 : 1));
// Create the scrollarea div if this is the outer grid
this.scrollarea = null;
if (this._parent == null)
{
this.scrollarea = $j(document.createElement("div"))
.addClass("egwGridView_scrollarea")
.scroll(this, function(e) {
// Clear any older scroll timeout
if (e.data._scrollTimeout)
{
window.clearTimeout(e.data._scrollTimeout);
}
// Set a new timeout which calls the setViewArea
// function
e.data._scrollTimeout = window.setTimeout(function() {
if (typeof ET2_GRID_PAUSE != "undefined")
return;
e.data.setViewRange(et2_range(
e.data.scrollarea.scrollTop() - ET2_GRID_VIEW_EXT,
e.data._height + ET2_GRID_VIEW_EXT * 2
));
}, ET2_GRID_SCROLL_TIMEOUT);
})
.height(this._scrollHeight)
.appendTo(this.outerCell);
}
// Create the inner table
var table = $j(document.createElement("table"))
.addClass("egwGridView_grid")
.appendTo(this.scrollarea ? this.scrollarea : this.outerCell);
this.innerTbody = $j(document.createElement("tbody"))
.appendTo(table);
}
});