// FancyPagerTemplate.cs
//
// Copyright (c) 2007 Gonzalo Paniagua
// 
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
// Author: Gonzalo Paniagua (gonzalo.mono@gmail.com)
//
using System;
using System.Drawing;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;

public class FancyPagerTemplate : ITemplate {
	const string PreviousString = "\u25c4";
	const string NextString = "\u25ba";

	GridView m_gridView;

	public FancyPagerTemplate() {
	}

	public FancyPagerTemplate(GridView gv) {
		m_gridView = gv;
	}

	public GridView GridView {
		get { return m_gridView; }
		set { m_gridView = value; }
	}

	#region ITemplate Members

	public void InstantiateIn(Control container) {
		Table tbl = new Table();
		TableRow row = new TableRow();
		TableCell cell = new TableCell();
		cell.Controls.Add(BuildLinkButton("prevArrow", PreviousString, OnPreviousClicked, OnPreRenderPrevious));
		row.Cells.Add(cell);
		cell = new TableCell();
		cell.Controls.Add(new LiteralControl(" Page "));
		row.Cells.Add(cell);
		int pageCount = m_gridView.PageCount;
		cell = new TableCell();
		cell.Controls.Add(BuildPageInputTextBox(m_gridView.PageIndex, pageCount, OnPageTextChanged));
		row.Cells.Add(cell);
		cell = new TableCell();
		cell.Controls.Add(new LiteralControl(String.Format(" / {0} ", pageCount)));
		row.Cells.Add(cell);
		cell = new TableCell();
		cell.Controls.Add(BuildLinkButton("nextArrow", NextString, OnNextClicked, OnPreRenderNext));
		row.Cells.Add(cell);
		container.Controls.Add(tbl);
		tbl.Rows.Add(row);
	}

	#endregion

	static LinkButton BuildLinkButton(string id, string text, EventHandler onClick, EventHandler onPreRender) {
		LinkButton link = new LinkButton();
		link.ID = id;
		link.Text = text; 
		link.Click += onClick;
		link.PreRender += onPreRender;
		return link;
	}

	static TextBox BuildPageInputTextBox(int currentPage, int totalPages, EventHandler onTextChanged) {
		TextBox tb = new TextBox();
		tb.ID = "tbPage";
		tb.TextChanged += onTextChanged;
		tb.Style.Add("width", String.Format("{0}em", ((double)GetNumberOfDigits(totalPages) / 2)));
		tb.Text = (currentPage + 1).ToString();
		tb.AutoPostBack = true;
		return tb;
	}

	static int GetNumberOfDigits(int number) {
		int ndigits = 1;
		while(number > 0) {
			number /= 10;
			ndigits++;
		}
		return ndigits;
	}

	#region Event handlers
	public void OnPreviousClicked(object sender, EventArgs e) {
		if(m_gridView.PageIndex > 0) {
			m_gridView.PageIndex--;
		}
	}

	public void OnNextClicked(object sender, EventArgs e) {
		if(m_gridView.PageIndex < m_gridView.PageCount - 1) {
			m_gridView.PageIndex++;
		}
	}

	void OnPreRenderPrevious(object sender, EventArgs e) {
		if(m_gridView.PageIndex == 0) {
			LinkButton btn = (LinkButton)sender;
			btn.ForeColor = Color.FromArgb(0xbb, 0xbb, 0xbb);
			btn.Enabled = false;
		}
	}

	void OnPreRenderNext(object sender, EventArgs e) {
		if(m_gridView.PageIndex == m_gridView.PageCount - 1) {
			LinkButton btn = (LinkButton)sender;
			btn.ForeColor = Color.FromArgb(0xbb, 0xbb, 0xbb);
			btn.Enabled = false;
		}
	}

	void OnPageTextChanged(object sender, EventArgs e) {
		TextBox tb = (TextBox)sender;
		int new_page;
		if(!Int32.TryParse(tb.Text, out new_page)) {
			tb.Text = (m_gridView.PageIndex + 1).ToString();
		} else if(new_page <= 0 || new_page > m_gridView.PageCount) {
			tb.Text = (m_gridView.PageIndex + 1).ToString();
		} else {
			m_gridView.PageIndex = new_page - 1;
		}
		/* Use this if the pager is inside a UpdatePanel
		 * Replace 'ScriptManager1' if needed.
		ScriptManager manager = (ScriptManager)tb.Page.Master.FindControl("ScriptManager1");
		if(manager != null) {
			manager.SetFocus(tb.ClientID);
		}
		*/
	}
	#endregion
}