HGRIDVIEW

#region Copyright
// Please do not remove this section. If you can improve it further, you may send a copy to the
// author at azharkhan@hotmail.com
//
// Author : Azhar A. Khan
// Date : 08/27/2008
// Filename : HWGridView.cs
// History :
// 08/27/2008 Initial Version
// 08/28/2008 Romoved ApplyFilterCommand call from OnFilterCommand, since it will be called in OnPreRender
#endregion

using System;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace HWControls
{
public delegate void FilterCommandEventHandler(object sender, FilterCommandEventArgs e);

public class FilterCommandEventArgs : EventArgs
{
private string filterExpression;

public FilterCommandEventArgs()
{
}

public FilterCommandEventArgs(string filterExpression)
{
this.filterExpression = filterExpression;
}

public string FilterExpression
{
get
{
return this.filterExpression;
}
set
{
this.filterExpression = value;
}
}
}

[ToolboxData("<{0}:HWGridView runat=server>")]
public class HWGridView : GridView
{

TextBox m_txtPageNo = null;
Hashtable m_txtFilter = new Hashtable();
Hashtable m_ddlFilter = new Hashtable();

private static readonly object EventFilterCommand = new object();
// Events
[Category("Extend GridView Events"), Description("ExtededGridView_OnFilterCommand")]
public event EventHandler FilterCommand
{
add
{
base.Events.AddHandler(EventFilterCommand, value);
}
remove
{
base.Events.RemoveHandler(EventFilterCommand, value);
}
}

public HWGridView()
{
PagerSettings.Position = PagerPosition.TopAndBottom;
}

#region Pager
protected virtual void InitializeTopPager(GridViewRow row,
int columnSpan,
PagedDataSource pagedDataSource)
{
TableCell cell = new TableCell();
if (columnSpan > 1)
{
cell.ColumnSpan = columnSpan;
}
Literal ltrlSpan = new Literal();
ltrlSpan.Text = " " +
pagedDataSource.DataSourceCount.ToString() +
" record(s) found.";
cell.Controls.Add(ltrlSpan);
row.Cells.Add(cell);
}

protected virtual void InitializeBottomPager(GridViewRow row,
int columnSpan,
PagedDataSource pagedDataSource)
{
TableCell goToCell = new TableCell();
goToCell.Style.Add(HtmlTextWriterStyle.Width, "100%");

Table pagerTable = (Table)row.Cells[0].Controls[0];
pagerTable.Rows[0].Cells.Add(goToCell);

Literal ltrlSpanBegin = new Literal();
ltrlSpanBegin.Text = "Page ";

if (m_txtPageNo == null)
{
m_txtPageNo = new TextBox();
m_txtPageNo.Width = new Unit(20);
m_txtPageNo.Style.Add("height", "10px");
m_txtPageNo.Font.Size = new FontUnit("10px");
m_txtPageNo.CssClass = this.PagerStyle.CssClass;
}

Literal ltrlText = new Literal();
ltrlText.Text = " of " + PageCount.ToString();

Button btnGo = new Button();
btnGo.Text = "Go";
btnGo.CommandName = "Page1";
btnGo.CommandArgument = "2";
btnGo.ID = "ctl_PageIndex";
btnGo.Height = new Unit("16px");
btnGo.Font.Size = new FontUnit("10px");
btnGo.CssClass = this.PagerStyle.CssClass;
if (this.PagerStyle.ForeColor!=null) {
btnGo.Style.Add(HtmlTextWriterStyle.Color,
this.PagerStyle.ForeColor.ToString());
}

Literal ltrlSpanEnd = new Literal();
ltrlSpanEnd.Text = "";

goToCell.Controls.Add(ltrlSpanBegin);
goToCell.Controls.Add(m_txtPageNo);
goToCell.Controls.Add(ltrlText);
goToCell.Controls.Add(btnGo);
goToCell.Controls.Add(ltrlSpanEnd);
}

protected override void InitializePager(GridViewRow row,
int columnSpan,
PagedDataSource pagedDataSource)
{
//if (this.TopPagerRow == null &&
if (this.Controls[0].Controls.Count == 0 &&
(this.PagerSettings.Position == PagerPosition.Top ||
this.PagerSettings.Position == PagerPosition.TopAndBottom))
{
InitializeTopPager(row, columnSpan, pagedDataSource);
}
else
{
base.InitializePager(row, columnSpan, pagedDataSource);
InitializeBottomPager(row, columnSpan, pagedDataSource);
}
}

protected virtual void HandlePageCommand(GridViewCommandEventArgs e)
{
TextBox txtPageIndex;
txtPageIndex = (TextBox)((System.Web.UI.Control)e.CommandSource).Parent.Controls[1];
Button btnPageIndex = (Button)((System.Web.UI.Control)e.CommandSource).Parent.Controls[3];
if (txtPageIndex.Text.Length > 0)
{
try
{
int ndx = int.Parse(txtPageIndex.Text);
ndx = ndx - 1;
if (ndx >= PageCount)
ndx = PageCount - 1;
if (ndx < 0)
ndx = 0;
this.PageIndex = ndx;
btnPageIndex.CommandArgument = txtPageIndex.Text;
}
catch (Exception e1)
{
if (e1.Message.Length == 0)
return;
}
}
}

protected override void OnRowCommand(GridViewCommandEventArgs e)
{
switch (e.CommandName)
{
case "Page1":
HandlePageCommand(e);
break;
default:
base.OnRowCommand(e);
break;
}
}
#endregion

#region Filter
protected virtual void AddFilter(int columnIndex,
TableCell headerCell,
DataControlField field)
{
if (headerCell.Controls.Count == 0)
{
LiteralControl ltlHeaderText = new LiteralControl(headerCell.Text);
headerCell.Controls.Add(ltlHeaderText);
}

LiteralControl ltlBreak = new LiteralControl("
");
headerCell.Controls.Add(ltlBreak);
TextBox txtFilter = null;
if (m_txtFilter.Contains(columnIndex))
{
txtFilter = (TextBox)m_txtFilter[columnIndex];
}
else
{
txtFilter = new TextBox();
txtFilter.ID = ID + "_txtFilter" + columnIndex.ToString();// +headerCell.ClientID;
if (field.ItemStyle.Width.Value != 0.0)
{
txtFilter.Style.Add(HtmlTextWriterStyle.Width, Convert.ToString(field.ItemStyle.Width.Value - 40) + "px");
}
else if (field.HeaderStyle.Width.Value != 0.0)
{
txtFilter.Style.Add(HtmlTextWriterStyle.Width, Convert.ToString(field.HeaderStyle.Width.Value - 40) + "px");
}
txtFilter.Style.Add(HtmlTextWriterStyle.Height, "10px");
txtFilter.Style.Add(HtmlTextWriterStyle.FontSize, "9px");
m_txtFilter[columnIndex] = txtFilter;
}

DropDownList ddlFilter;
if (m_ddlFilter.Contains(columnIndex))
{
ddlFilter = (DropDownList)m_ddlFilter[columnIndex];
}
else
{
ddlFilter = new DropDownList();
ddlFilter.ID = ID + "_ddlFilter" + columnIndex.ToString();
ddlFilter.Items.Add(" ");
ddlFilter.Items.Add("=");
ddlFilter.Items.Add("<");
ddlFilter.Items.Add(">");
ddlFilter.Items.Add("<=");
ddlFilter.Items.Add(">=");
ddlFilter.AutoPostBack = true;
ddlFilter.SelectedIndexChanged += new EventHandler(this.HandleFilterCommand);
//ddlFilter.SelectedIndex = 0;
ddlFilter.Style.Add(HtmlTextWriterStyle.Width, "30px");
ddlFilter.Height = new Unit("7px");
ddlFilter.Style.Add(HtmlTextWriterStyle.Height, "8px");
ddlFilter.Style.Add(HtmlTextWriterStyle.FontSize, "8px");
m_ddlFilter[columnIndex] = ddlFilter;
}

headerCell.Controls.Add(txtFilter);
headerCell.Controls.Add(ddlFilter);
}

protected virtual void AddFilters(GridViewRow headerRow,
DataControlField[] fields)
{
for (int i = 0; i < Columns.Count; i++)
{
if (Columns[i].HeaderText.EndsWith(" "))
{
AddFilter(i, headerRow.Cells[i], fields[i]);
}
}
}

protected virtual void AddGlyph(GridView grid, GridViewRow item)
{
Label glyph = new Label();
glyph.EnableTheming = false;
glyph.Font.Name = "webdings";
glyph.Text = (grid.SortDirection == SortDirection.Ascending ? " 5" : " 6");
//glyph.Font.Size = FontUnit.Medium;
//glyph.Text = " " + (grid.SortDirection == SortDirection.Ascending ? "▲" : "▼");
// Find the column you sorted by
for (int i = 0; i < grid.Columns.Count; i++)
{
string colExpr = grid.Columns[i].SortExpression;
if (colExpr != "" && colExpr == grid.SortExpression)
{
item.Cells[i].Controls.Add(glyph);
}
}
}

protected virtual void InitializeHeaderRow(GridViewRow row, DataControlField[] fields)
{
AddGlyph(this, row);
AddFilters(row, fields);
}

protected override void InitializeRow(GridViewRow row, DataControlField[] fields)
{
base.InitializeRow(row, fields);
if (row.RowType == DataControlRowType.Header)
{
InitializeHeaderRow(row, fields);
}
}

protected virtual String GetFilterCommand()
{
String filterCommand = "";
for (int i = 0; i < this.Columns.Count; i++)
{
if (this.Columns[i].HeaderText.EndsWith(" "))
{
DataControlFieldHeaderCell headerCell = (DataControlFieldHeaderCell)this.HeaderRow.Cells[i];
TextBox txtFilter = (TextBox)m_txtFilter[i];
DropDownList ddlFilter = (DropDownList)m_ddlFilter[i];
BoundField aColumn;
if (!(this.Columns[i] is BoundField) || String.IsNullOrEmpty(ddlFilter.SelectedValue.Trim()))
{
continue;
}
aColumn = (BoundField)this.Columns[i];
if (String.IsNullOrEmpty(txtFilter.Text))
{
continue;
}
if (String.IsNullOrEmpty(filterCommand))
{
filterCommand = aColumn.DataField + " " + ddlFilter.SelectedValue + " " + txtFilter.Text;
}
else
{
filterCommand += " AND " + aColumn.DataField + " " + ddlFilter.SelectedValue + " " + txtFilter.Text;
}
}
}

return filterCommand;
}

protected virtual void ApplyFilterCommand(String filterCommand)
{
DataSourceView dsv = this.GetData();
if (dsv is SqlDataSourceView)
{
String selectCommand = ((SqlDataSourceView)dsv).SelectCommand;
if (selectCommand.Contains(filterCommand)) {
return;
}
if (selectCommand.Contains("WHERE"))
{
selectCommand += " AND " + filterCommand;
}
else
{
selectCommand += " WHERE " + filterCommand;
}
((SqlDataSourceView)dsv).SelectCommand = selectCommand;
}
}

protected virtual void OnFilterCommand(FilterCommandEventArgs e)
{
EventHandler handler = (EventHandler)base.Events[EventFilterCommand];
if (handler != null)
{
handler(this, e);
}
}

private void HandleFilterCommand(object sender, EventArgs e)
{
this.RequiresDataBinding = true; //this is required to make sure that unsetting of filter is also handled
FilterCommandEventArgs filterArgs = new FilterCommandEventArgs();
filterArgs.FilterExpression = GetFilterCommand();
this.OnFilterCommand(filterArgs);
}

protected override void OnPreRender(EventArgs e)
{
String filterCommand = GetFilterCommand();

if (String.IsNullOrEmpty(filterCommand) == false)
{
ApplyFilterCommand(filterCommand);
}
base.OnPreRender(e);
}
#endregion
}
}