gridviewhelper.vb

gridviewhelpervb cla

	#End Region


	#Region "Core"

	Private Sub RowDataBoundHandler(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
		For Each g As GridViewGroup In mGroups
			' The last group values are caught here
			If e.Row.RowType = DataControlRowType.Footer Then
				g.CalculateSummaries()
				GenerateGroupSummary(g, e.Row)
				RaiseEvent GroupEnd(g.Name, g.ActualValues, e.Row)
ElseIf e.Row.RowType = DataControlRowType.DataRow Then
				ProcessGroup(g, e)
				If g.IsSuppressGroup Then
					e.Row.Visible = False
				End If
ElseIf e.Row.RowType = DataControlRowType.Pager Then
				' Workaround to strange behavior (ColumnSpan not rendered)
				' when AllowPaging=true
				' Found at: http://aspadvice.com/blogs/joteke/archive/2006/02/11/15130.aspx
				Dim originalCell As TableCell = e.Row.Cells(0)
				Dim newCell As New TableCell()
				newCell.Visible = False
				e.Row.Cells.AddAt(0, newCell)
				originalCell.ColumnSpan = Me.GetVisibleColumnCount()
			End If
		Next

		' This will deal only with general summaries
		For Each s As GridViewSummary In mGeneralSummaries
			If e.Row.RowType = DataControlRowType.Header Then
				' Essentially this isn't required, but it prevents wrong calc
				' in case of RowDataBound event be called twice (for each row)
				s.Reset()
ElseIf e.Row.RowType = DataControlRowType.DataRow Then
				s.AddValue(DataBinder.Eval(e.Row.DataItem, s.Column))
ElseIf e.Row.RowType = DataControlRowType.Footer Then
				s.Calculate()
			End If
		Next

		If e.Row.RowType = DataControlRowType.Footer Then
			' Automatic generation of summary
			GenerateGeneralSummaries(e)

				' Triggers event footerdatabound
			RaiseEvent FooterDataBound(e.Row)
		End If
	End Sub

	Private Sub ProcessGroup(ByVal g As GridViewGroup, ByVal e As GridViewRowEventArgs)
		Dim groupHeaderText As String = [String].Empty

		' Check if it's still in the same group values
		If Not EvaluateEquals(g, e.Row.DataItem) Then
			' Check if a group ends or if it is the first group values starting...
			If g.ActualValues IsNot Nothing Then
				g.CalculateSummaries()
				GenerateGroupSummary(g, e.Row)

					' Triggers event GroupEnd
				RaiseEvent GroupEnd(g.Name, g.ActualValues, e.Row)
			End If

			' Another group values starts now
			g.Reset()
			g.SetActualValues(GetGroupRowValues(g, e.Row.DataItem))

			' If group is automatic inserts a group header
			If g.Automatic Then
				For v As Integer = 0 To g.ActualValues.Length - 1
					If g.ActualValues(v) Is Nothing Then
						Continue For
					End If
					groupHeaderText += g.ActualValues(v).ToString()
					If g.ActualValues.Length - v > 1 Then
						groupHeaderText += " - "
					End If
				Next

				Dim newRow As GridViewRow = InsertGridRow(e.Row)
				newRow.Cells(0).Text = groupHeaderText

					' Triggers event GroupHeader
				RaiseEvent GroupHeader(g.Name, g.ActualValues, newRow)
			End If

				' Triggers event GroupStart
			RaiseEvent GroupStart(g.Name, g.ActualValues, e.Row)
		End If

		g.AddValueToSummaries(e.Row.DataItem)
	End Sub

	Private Function GetFormatedString(ByVal preferredFormat As String, ByVal secondFormat As String, ByVal value As Object) As String
        Dim formatx As String = preferredFormat

        If IsNothing(value) Or IsDBNull(value) Then Return ""

        If formatx.Length = 0 Then
            formatx = secondFormat
        End If

        If formatx.Length > 0 Then
            Dim t As String = Format(Integer.Parse(value), "# ### ##0")
            If t = formatx Then t = ""
            Return t
        Else
            Return value.ToString()
        End If
    End Function

	Private Sub GenerateGroupSummary(ByVal g As GridViewGroup, ByVal row As GridViewRow)
		Dim colIndex As Integer
		Dim colValue As Object

		If Not HasAutoSummary(g.Summaries) AndAlso Not HasSuppressGroup() Then
			Return
		End If

		' Inserts a new row 
		Dim newRow As GridViewRow = InsertGridRow(row, g)

		For Each s As GridViewSummary In g.Summaries
			If s.Automatic Then
				colIndex = GetVisibleColumnIndex(s.Column)
				colIndex = ResolveCellIndex(newRow, colIndex)
				newRow.Cells(colIndex).Text = Me.GetFormatedString(s.FormatString, Me.GetColumnFormat(GetColumnIndex(s.Column)), s.Value)
			End If
		Next

		' If it is a suppress group must set the grouped values in the cells
		' of the inserted row
		If g.IsSuppressGroup Then
			For i As Integer = 0 To g.Columns.Length - 1
				colValue = g.ActualValues(i)
				If colValue IsNot Nothing Then
					colIndex = GetVisibleColumnIndex(g.Columns(i))
					colIndex = ResolveCellIndex(newRow, colIndex)
					newRow.Cells(colIndex).Text = colValue.ToString()
				End If
			Next
		End If
		RaiseEvent GroupSummary(g.Name, g.ActualValues, newRow)

		' Triggers event GroupSummary

	End Sub

	''' <summary>
	''' Generates the general summaries in the grid. 
	''' </summary>
	''' <param name="e">GridViewRowEventArgs</param>
	Private Sub GenerateGeneralSummaries(ByVal e As GridViewRowEventArgs)
		Dim colIndex As Integer
		Dim row As GridViewRow

		If Not HasAutoSummary(Me.mGeneralSummaries) Then
			RaiseEvent GeneralSummary(e.Row)
			' Triggers event GeneralSummary

			Return
		End If

		If useFooter Then
			row = e.Row
		Else
			row = InsertGridRow(e.Row, Nothing)
		End If

		For Each s As GridViewSummary In mGeneralSummaries
			If Not s.Automatic Then
				Continue For
			End If

			If useFooter Then
				colIndex = GetColumnIndex(s.Column)
			Else
				colIndex = GetVisibleColumnIndex(s.Column)
			End If

			colIndex = ResolveCellIndex(row, colIndex)
			row.Cells(colIndex).Text = Me.GetFormatedString(s.FormatString, Me.GetColumnFormat(GetColumnIndex(s.Column)), s.Value)
		Next
		RaiseEvent GeneralSummary(row)

		' Triggers event GeneralSummary

	End Sub

	''' <summary>
	''' Identifies the equivalent index on a row that contains cells with colspan
	''' </summary>
	''' <param name="row"></param>
	''' <param name="colIndex"></param>
	''' <returns></returns>
	Private Function ResolveCellIndex(ByVal row As GridViewRow, ByVal colIndex As Integer) As Integer
		Dim colspansum As Integer = 0
		Dim realIndex As Integer
		For i As Integer = 0 To row.Cells.Count - 1

			realIndex = i + colspansum
			If realIndex = colIndex Then
				Return i
			End If

			If row.Cells(i).ColumnSpan > 1 Then
				colspansum = colspansum + row.Cells(i).ColumnSpan - 1
			End If
		Next

		Return -1
	End Function

	Private Function ColumnHasSummary(ByVal colindex As Integer, ByVal g As GridViewGroup) As Boolean
		Dim list As List(Of GridViewSummary)
		Dim column As String = Me.GetDataFieldName(mGrid.Columns(colindex))

		If g Is Nothing Then
			list = Me.mGeneralSummaries
		Else
			list = g.Summaries
		End If

		For Each s As GridViewSummary In list
			If column.ToLower() = s.Column.ToLower() Then
				Return True
			End If
		Next
		Return False
	End Function

	Private Function ColumnHasSummary(ByVal column As String, ByVal g As GridViewGroup) As Boolean
		Dim list As List(Of GridViewSummary)

		If g Is Nothing Then
			list = Me.mGeneralSummaries
		Else
			list = g.Summaries
		End If

		For Each s As GridViewSummary In list
			If column.ToLower() = s.Column.ToLower() Then
				Return True
			End If
		Next
		Return False
	End Function

	#End Region


	#Region "Public Helper functions"

	Public Function GetRealIndexFromVisibleColumnIndex(ByVal visibleIndex As Integer) As Integer
		Dim visibles As Integer = 0
		For i As Integer = 0 To mGrid.Columns.Count - 1
			If mGrid.Columns(i).Visible Then
				If visibleIndex = visibles Then
					Return i
				End If
				visibles += 1
			End If
		Next

		' Not found....
		Return -1
	End Function

	Public Function GetVisibleColumnIndex(ByVal columnName As String) As Integer
		Dim visibles As Integer = 0
		For i As Integer = 0 To mGrid.Columns.Count - 1
			If GetDataFieldName(mGrid.Columns(i)).ToLower() = columnName.ToLower() Then
				Return visibles
			End If

			If mGrid.Columns(i).Visible Then
				visibles += 1
			End If
		Next

		' Not found....
		Return -1
	End Function

	Public Function GetColumnIndex(ByVal columnName As String) As Integer
		For i As Integer = 0 To mGrid.Columns.Count - 1
			If GetDataFieldName(mGrid.Columns(i)).ToLower() = columnName.ToLower() Then
				Return i
			End If
		Next

		' Not found....
		Return -1
	End Function

	Public Function GetDataFieldName(ByVal field As DataControlField) As String
		' TO DO: Enable search in HyperLinkField, ButtonField...

		If TypeOf field Is BoundField Then
			Return TryCast(field, BoundField).DataField
		Else
			' It hopes that SortExpression is set (and it's equal to column name)
			Return field.SortExpression
		End If
	End Function

	Public Function GetColumnFormat(ByVal colIndex As Integer) As String
		' TO DO: Enable search in HyperLinkField, ButtonField...

		If TypeOf mGrid.Columns(colIndex) Is BoundField Then
			Return TryCast(mGrid.Columns(colIndex), BoundField).DataFormatString
		Else
			Return [String].Empty
		End If
	End Function

	Public Function GetVisibleColumnCount() As Integer
		Dim ret As Integer = 0
		For i As Integer = 0 To mGrid.Columns.Count - 1

			If mGrid.Columns(i).Visible Then
				ret += 1
			End If
		Next

		Return ret
	End Function

	''' <summary>
	''' This method must be called to hide columns that doesn't 
	''' have any summary operation when we are using a suppress group
	''' </summary>
	Public Sub HideColumnsWithoutGroupSummary()
		Dim colname As String
		Dim colChecked As Boolean

		For Each dcf As DataControlField In mGrid.Columns
			colChecked = False
			colname = GetDataFieldName(dcf).ToLower()

			For Each g As GridViewGroup In mGroups
				For j As Integer = 0 To g.Columns.Length - 1
					' Check if it's part of the group columns
					If colname = g.Columns(j).ToLower() Then
						colChecked = True
						Exit For
					End If
				Next

				If colChecked Then
					Exit For
				End If

				' Check if it's part of a group summary
				colChecked = ColumnHasSummary(colname, g)

				If colChecked Then
					Exit For
				End If
			Next

			If colChecked Then
				Continue For
			End If


			dcf.Visible = False
		Next
	End Sub


	''' <summary>
	''' Legacy name...
	''' </summary>
	Public Sub SetInvisibleColumnsWithoutGroupSummary()
		Me.HideColumnsWithoutGroupSummary()
	End Sub

	''' <summary>
	'''  Inserts a grid row with one cell only
	''' </summary>
	''' <param name="beforeRow"></param>
	''' <returns></returns>
	Public Function InsertGridRow(ByVal beforeRow As GridViewRow) As GridViewRow
		Dim visibleColumns As Integer = Me.GetVisibleColumnCount()

		Dim tbl As Table = DirectCast(mGrid.Controls(0), Table)
		Dim newRowIndex As Integer = tbl.Rows.GetRowIndex(beforeRow)
		Dim newRow As New GridViewRow(newRowIndex, newRowIndex, DataControlRowType.DataRow, DataControlRowState.Normal)

		newRow.Cells.Add(New TableCell())
		If visibleColumns > 1 Then
			newRow.Cells(0).ColumnSpan = visibleColumns
		End If

		tbl.Controls.AddAt(newRowIndex, newRow)

		Return newRow
	End Function

	Public Sub ApplyGroupSort()
		mGrid.Sort(Me.GetSequentialGroupColumns(), groupSortDir)
	End Sub

	#End Region
End Class