OrganLit/BaseEditForm.vb

Imports System.Windows.Forms

Public Class BaseEditForm
    Enum EditingOrAdding
        Editing
        Adding
        Loading
        NoAction
    End Enum 'EditingOrAdding

    Private mvalEditingOrAdding As EditingOrAdding
    Private mintCurrentSortColumn As Integer
    Private mobjEditFormExistingItemColumnSortRules() As clsGridColumnSortRule

    Private Sub BaseEditForm_FormClosed(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
        MyGlobals.FlushCachedObjects()
    End Sub

    Private Sub BaseEditForm_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Me.DesignMode Then
            MessageBox.Show("The BaseEditForm class must be inherited, and contains methods that must be overridden." + vbCrLf + "They have been declared in the base class and will throw NotImplementedException at runtime if not overridden.")
        End If
        MyGlobals.FlushCachedObjects()
        lvwExistingItemsList.Sorting = SortOrder.None
        mintCurrentSortColumn = 0
        mvalEditingOrAdding = EditingOrAdding.NoAction
        LoadExistingItemsList()
        InitializeDetailControls()
        EnableDisableControls()
        'Dim lobjColumnClickEventArgs As New System.Windows.Forms.ColumnClickEventArgs(0)
        'lvwExistingItemsList_ColumnClick(Me, lobjColumnClickEventArgs)
        lvwExistingItemsList.Height = fraAddEdit.Top - lvwExistingItemsList.Top - 10
    End Sub

    Protected Overridable Sub LoadExistingItemsList()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected Overridable Sub InitializeDetailControls()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected Overridable Sub EmptyOutDetailControls()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected Overridable Function DetailControlsHaveSignificantData() As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return False
    End Function

    Protected Overridable Function DetailControlsHaveDifferentDataThanExistingData(ByVal lstvwExistingItem As ListViewItem) As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return False
    End Function

    Protected Overridable Function DeleteExistingItem(ByVal lstvwItemToDelete As ListViewItem) As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return True
    End Function

    Protected Overridable Function ConfirmOKToDeleteExistingItem(ByVal lstvwItemToDelete As ListViewItem) As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return True
    End Function

    Protected Overridable Function SaveNewItem() As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return True
    End Function

    Protected Overridable Function SaveNewDataForExistingItem(ByVal lstvwExistingItem As ListViewItem) As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return True
    End Function

    Protected Overridable Function LoadExistingDataToDetailControls(ByVal lstvwExistingItem As ListViewItem) As Boolean
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
        Return True
    End Function

    Protected Overridable Sub SetFocusToFirstDetailControlForEdit()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected Overridable Sub UserRequestedToExit()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected Overridable Sub EditOrAddStarting()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected Overridable Sub EditOrAddCompleted()
        If Not Me.DesignMode Then
            Throw New NotImplementedException
        End If
    End Sub

    Protected ReadOnly Property ExistingObjectsListItems() As ListView.ListViewItemCollection
        Get
            Return lvwExistingItemsList.Items
        End Get
    End Property

    Protected ReadOnly Property ExistingObjectsListColumns() As ListView.ColumnHeaderCollection
        Get
            Return lvwExistingItemsList.Columns
        End Get
    End Property

    Protected ReadOnly Property GetEditingOrAdding() As EditingOrAdding
        Get
            Return mvalEditingOrAdding
        End Get
    End Property

    Protected Property MyBaseEditFormColumnSortRules() As clsGridColumnSortRule()
        Get
            Return mobjEditFormExistingItemColumnSortRules
        End Get
        Set(ByVal iValue As clsGridColumnSortRule())
            mobjEditFormExistingItemColumnSortRules = iValue
        End Set
    End Property
    Private Sub EnableDisableControls()
        Select Case mvalEditingOrAdding
            Case EditingOrAdding.Loading
                Exit Sub
            Case EditingOrAdding.Adding, EditingOrAdding.NoAction
                If DetailControlsHaveSignificantData() Then
                    If btnCancel.Enabled = False Then
                        EditOrAddStarting()
                    End If
                    mvalEditingOrAdding = EditingOrAdding.Adding
                    lvwExistingItemsList.Enabled = False
                    btnEdit.Enabled = False
                    btnDelete.Enabled = False
                    btnExit.Enabled = False
                    fraAddEdit.Text = "Add..."
                    btnSave.Enabled = True
                    btnCancel.Enabled = True
                    btnRevert.Enabled = False
                Else
                    If btnCancel.Enabled = True Then
                        EditOrAddCompleted()
                    End If
                    mvalEditingOrAdding = EditingOrAdding.NoAction
                    lvwExistingItemsList.Enabled = True
                    btnEdit.Enabled = True
                    btnDelete.Enabled = True
                    btnExit.Enabled = True
                    fraAddEdit.Text = "Add..."
                    btnSave.Enabled = False
                    btnCancel.Enabled = False
                    btnRevert.Enabled = False
                End If
            Case EditingOrAdding.Editing
                If btnCancel.Enabled = False Then
                    EditOrAddStarting()
                End If
                lvwExistingItemsList.Enabled = False
                btnEdit.Enabled = False
                btnDelete.Enabled = False
                btnExit.Enabled = False
                fraAddEdit.Text = "Edit..."
                btnCancel.Enabled = True
                If DetailControlsHaveDifferentDataThanExistingData(lvwExistingItemsList.SelectedItems(0)) Then
                    btnSave.Enabled = True
                    btnRevert.Enabled = True
                Else
                    btnSave.Enabled = False
                    btnRevert.Enabled = False
                End If
        End Select
        If Not Me.DesignMode Then
            If btnCancel.Enabled Then
                Me.CancelButton = btnCancel
            Else
                Me.CancelButton = Nothing
            End If
            If btnSave.Enabled Then
                Me.AcceptButton = btnSave
            Else
                Me.AcceptButton = Nothing
            End If
        End If
    End Sub


    Private Sub btnEdit_Click1(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnEdit.Click
        DoEditClick()
    End Sub

    Private Sub btnDelete_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        If lvwExistingItemsList.SelectedItems.Count = 0 Then
            MessageBox.Show("Must select an item to delete", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
            Exit Sub
        End If
        If ConfirmOKToDeleteExistingItem(lvwExistingItemsList.SelectedItems(0)) Then
            If DeleteExistingItem(lvwExistingItemsList.SelectedItems(0)) Then
                lvwExistingItemsList.Items.Remove(lvwExistingItemsList.SelectedItems(0))
            End If
        End If
    End Sub

    Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
        EmptyOutDetailControls()
        mvalEditingOrAdding = EditingOrAdding.NoAction
        EnableDisableControls()
        SetFocusToFirstDetailControlForEdit()
    End Sub

    Private Sub btnRevert_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnRevert.Click
        LoadExistingDataToDetailControls(lvwExistingItemsList.SelectedItems(0))
        SetFocusToFirstDetailControlForEdit()
    End Sub

    Private Sub btnSave_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSave.Click
        If mvalEditingOrAdding = EditingOrAdding.Adding Then
            If SaveNewItem() Then
                mvalEditingOrAdding = EditingOrAdding.NoAction
                EmptyOutDetailControls()
                EnableDisableControls()
            End If
        Else
            If SaveNewDataForExistingItem(lvwExistingItemsList.SelectedItems(0)) Then
                mvalEditingOrAdding = EditingOrAdding.NoAction
                EmptyOutDetailControls()
                EnableDisableControls()
            End If
        End If
        SetFocusToFirstDetailControlForEdit()
    End Sub

    Private Sub DoEditClick()
        If lvwExistingItemsList.SelectedItems.Count = 0 Then
            MessageBox.Show("Must select an item to edit", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
            Exit Sub
        End If

        mvalEditingOrAdding = EditingOrAdding.Loading
        If LoadExistingDataToDetailControls(lvwExistingItemsList.SelectedItems(0)) Then
            mvalEditingOrAdding = EditingOrAdding.Editing
            EnableDisableControls()
        Else
            mvalEditingOrAdding = EditingOrAdding.NoAction
            EmptyOutDetailControls()
            Exit Sub
        End If
    End Sub

    Protected Sub DetailDataHasChanged()
        EnableDisableControls()
    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        UserRequestedToExit()
    End Sub

    Private Sub lvwExistingItemsList_ColumnClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ColumnClickEventArgs) Handles lvwExistingItemsList.ColumnClick
        mintCurrentSortColumn = e.Column
        lvwExistingItemsList.ListViewItemSorter = New clsGridSorter(e.Column, mobjEditFormExistingItemColumnSortRules)
    End Sub

    Private Sub lvwExistingItemsList_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles lvwExistingItemsList.DoubleClick
        DoEditClick()
    End Sub

    Private Sub BaseEditForm_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
        lvwExistingItemsList.Height = fraAddEdit.Top - lvwExistingItemsList.Top - 10
    End Sub

    Private Sub fraAddEdit_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles fraAddEdit.Resize
        lvwExistingItemsList.Height = fraAddEdit.Top - lvwExistingItemsList.Top - 10
    End Sub

    Private Sub BaseEditForm_Shown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Shown
        If mobjEditFormExistingItemColumnSortRules Is Nothing Then
            Exit Sub
        End If

        Dim intSavedSortColumn As Integer = mintCurrentSortColumn
        'If there is more than one column, temporarily sort by some other column
        'This is because, when first shown, for some reason, it was sorting only by the first
        'column, with no subsorts.  I'm not sure if this is because .NET thinks that we're already
        'sorted by the first column.
        If mobjEditFormExistingItemColumnSortRules.Length > 1 Then
            Dim intTempSortColumn As Integer
            If mintCurrentSortColumn = 0 Then
                intTempSortColumn = 1
            Else
                intTempSortColumn = 0
            End If
            Dim lobjTempColumnClickEventArgs As New System.Windows.Forms.ColumnClickEventArgs(intTempSortColumn)
            lvwExistingItemsList_ColumnClick(Me, lobjTempColumnClickEventArgs)
        End If

        'Sort by the current column
        Dim lobjColumnClickEventArgs As New System.Windows.Forms.ColumnClickEventArgs(intSavedSortColumn)
        lvwExistingItemsList_ColumnClick(Me, lobjColumnClickEventArgs)
    End Sub

    Public Sub ExistingItemsListSuspendLayout()
        lvwExistingItemsList.SuspendLayout()
    End Sub

    Public Sub ExistingItemsListResumeLayout()
        lvwExistingItemsList.ResumeLayout()
    End Sub

End Class