How I enable Cut, Copy and Paste buttons and menu items

[cafeenman]

I like the way I did this. Basically it's set up on a Timer set to 250 milliseconds. So every quarter second it's getting checked. You can see the slight delay but I don't want to make the Timer too frequent for fear of making the program sluggish doing that kind of thing.

Private Sub Timer1()

If Not Visible Then Exit Sub

With tbrCustomers

  .Buttons("Cut").Enabled = CanCut(ActiveControl)
  .Buttons("Copy").Enabled = CanCopy(ActiveControl)
  .Buttons("Paste").Enabled = CanPaste(ActiveControl)

End With

End Sub

Public Function CanCopy(ByRef Control As Control) As Boolean
Dim f As Boolean

' Determines if text can be Copied from a Control.
' ComboBoxes must have their Style set to 0 (DropDownCombo)

On Error GoTo errHandler

CanCopy = False

If Control Is Nothing Then Exit Function

f = TypeName(Control) = "ComboBox"

If f Then

  If Control.Style <> 0 Then f = False

End If

If Control.Enabled Then

  If Not IsTextControl(Control) And Not f Then Exit Function
  If Not TextSelected(Control) Then Exit Function
  
  CanCopy = True

End If

Exit Function


errHandler:
Dim nErrorHandlerResult As Long

nErrorHandlerResult = ErrorHandler(Error, Err, "Control.Name = " & Control.NAME, NAME & ".CanCopy(Public Function)")

End Function
Public Function CanCut(ByRef Control As Control) As Boolean
Dim f As Boolean

' Determines if text can be Cut from a Control.
' ComboBoxes must have their Style set to 0 (DropDownCombo)

On Error GoTo errHandler

CanCut = False

If Control Is Nothing Then Exit Function

f = TypeName(Control) = "ComboBox"

If f Then

  If Control.Style <> 0 Then f = False

End If

If Control.Enabled Then

  If Not IsTextControl(Control) And Not f Then Exit Function

  If Not TextSelected(Control) Then Exit Function

  If TypeName(Control) = "TextBox" Or TypeName(Control) = "RichTextBox" Then

    If Control.Locked Then Exit Function

  End If

  CanCut = True

End If

Exit Function


errHandler:
Dim nErrorHandlerResult As Long

nErrorHandlerResult = ErrorHandler(Error, Err, "Control.Name = " & Control.NAME, NAME & ".CanCut(Public Function)")

End Function
Public Function CanPaste(ByRef Control As Control) As Boolean
Dim f As Boolean

' Determines if text can be Pasted into a Control.
' ComboBoxes must have their Style set to 0 (DropDownCombo)

On Error GoTo errHandler

CanPaste = False

If Control Is Nothing Then Exit Function

If Control.Enabled = False Then Exit Function

If Len(Clipboard.GetText) = 0 Then Exit Function

If TypeName(Control) = "ComboBox" Then

  f = (Control.Style = 0)

End If

If Not IsTextControl(Control) And Not f Then Exit Function

If TypeName(Control) = "TextBox" Or TypeName(Control) = "RichTextBox" Then

  If Control.Locked Then Exit Function

End If

CanPaste = True

Exit Function


errHandler:
Dim nErrorHandlerResult As Long

If Err = 521 Then Exit Function ' "Another application is using the Clipboard and won't release it to your application."

nErrorHandlerResult = ErrorHandler(Error, Err, "Control.Name = " & Control.NAME, NAME & ".CanPaste(Public Function)")

End Function

Public Function IsTextControl(ByRef Control As Control) As Boolean

On Error Resume Next

IsTextControl = False

If TypeName(Control) = "TextBox" Or TypeName(Control) = "RichTextBox" Then

  IsTextControl = True

End If

End Function

Public Function TextSelected(ByRef Control As Control) As Boolean

' Returns whether Text is Selected or not.

On Error GoTo errHandler

TextSelected = Len(Control.SelText)

Exit Function


errHandler:

TextSelected = False

End Function