/* SpryPagedView.js - Revision: Spry Preview Release 1.4.X */

// (version 0.1)
//
// Copyright (c) 2006. Adobe Systems Incorporated.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//   * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//   * Neither the name of Adobe Systems Incorporated nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

var Spry; if (!Spry) Spry = {}; if (!Spry.Data) Spry.Data = {};

Spry.Data.PagedView = function(ds, options)
{
	Spry.Data.DataSet.call(this);

	this.ds = ds;

	// The max number of rows in a given page.

	this.pageSize = 10;

	// The unfiltered row index of the first item on the
	// current page.

	this.pageOffset = 0;

	// Does the user want the last page of data to always
	// be a full page? Default allows the last page to be
	// less than a page full.

	this.forceFullPages = false;

	// Does the user want to use zero-based page indexes?
	// Default is one-based.

	this.useZeroBasedIndexes = false;

	Spry.Utils.setOptions(this, options);

	// Set the adjustmentValue *after* options are set.
	// adjustmentValue is used in calculations to make sure
	// we calculate correct values in either zero-based or
	// one-based page index mode.

	this.adjustmentValue = 1;
	if (!this.useZeroBasedIndexes)
		this.adjustmentValue = 0;

	// Init the pageStop after the options are set.
	this.pageStop = this.pageOffset + this.pageSize;

	// Set up a dependency on the data set that was
	// passed into our constructor.

	this.ds.addObserver(this);

	// Extract and pre-process any data in the data set
	// if it exists.

	this.preProcessData();

	// Set up an initial filter if necessary on this data set so that
	// any data that is loaded is paged immediately.

	if (this.pageSize > 0)
		this.filter(this.getFilterFunc());
}

Spry.Data.PagedView.prototype = new Spry.Data.DataSet();
Spry.Data.PagedView.prototype.constructor = Spry.Data.PagedView;

Spry.Data.PagedView.prototype.setCurrentRow = function(rowID)
{
	// Pass on any setCurrentRow calls to the data set we
	// depend on.

	if (this.ds)
		this.ds.setCurrentRow(rowID);
};

Spry.Data.PagedView.prototype.setCurrentRowNumber = function(rowNumber)
{
	// Pass on any setCurrentRowNumber calls to the data set we
	// depend on.

	if (this.ds)
		this.ds.setCurrentRowNumber(rowNumber);
};

Spry.Data.PagedView.prototype.loadData = function()
{
	// Pass on any loadData requests to the data set we
	// depend on. This data set will automatically be notified
	// when the data set we depend on is done loading and will
	// update our data at that point.

	if (!this.ds || this.ds.getLoadDataRequestIsPending())
		return;

	if (!this.ds.getDataWasLoaded())
	{
		this.ds.loadData();
		return;
	}

	Spry.Data.DataSet.prototype.loadData.call(this);
};

Spry.Data.PagedView.prototype.onDataChanged = function(notifier, data)
{
	// The data in the data set we depend on has changed.
	// We need to extract and pre-process its data.

	this.pageOffset = 0;
	this.pageStop = this.pageOffset + this.pageSize;

	this.preProcessData();
};

Spry.Data.PagedView.prototype.onCurrentRowChanged = function(notifier, data)
{
	// this.preProcessData();
	var self = this;
	setTimeout(function() { self.notifyObservers("onCurrentRowChanged", data); }, 0);
};

Spry.Data.PagedView.prototype.updatePagerColumns = function()
{
	var rows = this.getData(true);
	if (!rows || rows.length < 1)
		return;

	var numRows = rows.length;
	var pageSize = (this.pageSize > 0) ? this.pageSize : numRows;
	var firstItem = 1;
	var lastItem = firstItem + pageSize - 1;
	lastItem = (lastItem < firstItem) ? firstItem : (lastItem > numRows ? numRows : lastItem);

	var pageNum = 1;
	var pageCount = parseInt((numRows + pageSize - 1) / pageSize);

	for (var i = 0; i < numRows; i++)
	{
		itemIndex = i + 1;
		if (itemIndex > lastItem)
		{
			firstItem = itemIndex;
			lastItem = firstItem + this.pageSize - 1;
			lastItem = (lastItem > numRows) ? numRows : lastItem;
			++pageNum;
		}
		var row = rows[i];
		if (row)
		{
			row.ds_PageNumber = pageNum;
			row.ds_PageItemRowNumber = i;
			row.ds_PageItemNumber = itemIndex;
			row.ds_PageFirstItemNumber = firstItem;
			row.ds_PageLastItemNumber = lastItem;
			row.ds_PageCount = pageCount;
		}
	}
};

Spry.Data.PagedView.prototype.preProcessData = function()
{
	if (!this.ds || !this.ds.getDataWasLoaded())
		return;

	this.notifyObservers("onPreLoad");

	this.unfilteredData = null;
	this.data = [];
	this.dataHash = {};
	var rows = this.ds.getData();

	if (rows)
	{
		// Make a copy of the rows in the data set we are
		// going to page. We need to do this because we are going to
		// add custom columns to the rows that the Pager manages.

		var numRows = rows.length;

		for (var i = 0; i < numRows; i++)
		{
			var row = rows[i];
			var newRow = new Object();
			Spry.Utils.setOptions(newRow, row);
			this.data.push(newRow);
			this.dataHash[newRow.ds_RowID] = newRow;
		}

		if (numRows > 0)
			this.curRowID = rows[0].ds_RowID;
		this.updatePagerColumns();
	}

	this.notifyObservers("onPostLoad");

	this.loadData();
};

Spry.Data.PagedView.prototype.getFilterFunc = function()
{
	var self = this;
	return function(ds, row, rowNumber) {
		if (rowNumber < self.pageOffset || rowNumber >= self.pageStop)
			return null;
		return row;
	};
};

Spry.Data.PagedView.prototype.filterDataSet = function(offset)
{
	if (this.pageSize < 1)
		return;

	var numRows = this.getData(true).length;
	
	if (this.forceFullPages && offset > (numRows - pageSize))
		offset = numRows - pageSize;

	if (offset < 0)
		offset = 0;

	this.pageOffset = offset;
	this.pageStop = offset + this.pageSize;

	// We need to reset the Pager's current row to the first
	// item in the page so that any regions that use the built-in
	// pager data references get refreshed to the correct data values.

	var rows = this.getData(true);
	if (rows && rows.length && rows[this.pageOffset])
		this.curRowID = rows[this.pageOffset].ds_RowID;

	var self = this;

	// Re-apply our non-destructive filter on the ds:
	this.filter(this.getFilterFunc());
};

Spry.Data.PagedView.prototype.getPageCount = function()
{
	return parseInt((this.getData(true).length + this.pageSize - 1) / this.pageSize);
};

Spry.Data.PagedView.prototype.getCurrentPage = function()
{
	return parseInt((this.pageOffset + this.pageSize) / this.pageSize) - this.adjustmentValue;
};

Spry.Data.PagedView.prototype.goToPage = function(pageNum)
{
	pageNum = parseInt(pageNum);

	var numPages = this.getPageCount();
	if ((pageNum + this.adjustmentValue) < 1 || (pageNum + this.adjustmentValue) > numPages)
		return;
	var newOffset = (pageNum - 1 + this.adjustmentValue) * this.pageSize;
	this.filterDataSet(newOffset);
};

// XXX FIX THIS!!! XXX
// Move this method into Spry.Data.DataSet. We define it locally
// here so that folks can still use this class with Spry 1.4.
Spry.Data.PagedView.prototype.getRowNumber = function(row, unfiltered)
{
	if (row)
	{
		var rows = this.getData(unfiltered);
		if (rows && rows.length)
		{
			var numRows = rows.length;
			for (var i = 0; i < numRows; i++)
			{
				if (this.data[i] == row)
					return i;
			}
		}
	}
	return -1;
};

Spry.Data.PagedView.prototype.goToPageContainingRowID = function(rowID)
{
	this.goToPageContainingRowNumber(this.getRowNumber(this.getRowByID(rowID), true));
};

Spry.Data.PagedView.prototype.goToPageContainingRowNumber = function(rowNumber)
{
	// rowNumber should be the zero based index of the row in the
	// unfiltered data set!

	this.goToPage(this.getPageForRowNumber(rowNumber));
};

Spry.Data.PagedView.prototype.goToPageContainingItemNumber = function(itemNumber)
{
	// Item number is the same as the unfiltered row number plus one, so just subract
	// one to get the row number we need.

	this.goToPageContainingRowNumber(itemNumber - 1);
};

Spry.Data.PagedView.prototype.firstPage = function()
{
	this.goToPage(1 - this.adjustmentValue);
};

Spry.Data.PagedView.prototype.lastPage = function()
{
	this.goToPage(this.getPageCount() - this.adjustmentValue);
};

Spry.Data.PagedView.prototype.previousPage = function()
{
	this.goToPage(this.getCurrentPage() - 1);
};

Spry.Data.PagedView.prototype.nextPage = function()
{
	this.goToPage(this.getCurrentPage() + 1);
};

Spry.Data.PagedView.prototype.getPageForRowID = function(rowID)
{
	return this.getPageForRowNumber(this.getRowNumber(this.getRowByID(rowID), true));
};

Spry.Data.PagedView.prototype.getPageForRowNumber = function(rowNumber)
{
	return parseInt(rowNumber / this.pageSize) + 1 - this.adjustmentValue;
};

Spry.Data.PagedView.prototype.getPageForItemNumber = function(itemNumber)
{
	return this.getPageForRowNumber(itemNumber - 1);
};

Spry.Data.PagedView.prototype.setPageSize = function(pageSize)
{
	if (this.pageSize == pageSize)
		return;

	if (pageSize < 1)
	{
		// The caller is trying to shut off paging. Remove the filter
		// we installed on the data set.

		this.pageSize = 0;
		this.pageOffset = 0;
		this.updatePagerColumns();
		this.filter(null);
	}
	else if (this.pageSize < 1)
	{
		this.pageSize = pageSize;
		this.pageOffset = 0;
		this.pageStop = this.pageOffset + this.pageSize;
		this.updatePagerColumns();
		this.filterDataSet(this.pageOffset);
	}
	else
	{
		// The caller is adjusting the pageSize, so go to the page
		// that contains the current pageOffset.

		this.pageSize = pageSize;
		this.updatePagerColumns();
		this.goToPage(this.getPageForRowNumber(this.pageOffset));
	}
};