Drag, Drop and Restrict

I have just read a problem inside foxite where when a user accidentally moves the mouse beyond the form boundaries, then drag and drop fails because the objects disappear on the areas beyond the form. 

The solution to that is to restrict the drag and drop movements within your form, or dimension within objects in your form.  Here are two samples showing how to achieve that:

Sample 1:

* Restricting drag and drop within the form

Local oForm As Form

oForm = Createobject('TestForm')

oForm.Show(1)

Return

Define Class TestForm As Form

      AutoCenter = .T.

      Width = 900

      Height = 440

      Caption = 'Drag, Drop & Restrict Inside Form'

      Add Object container1 As Mycontainer With Top = 30, Left = 50

Enddefine

Define Class Mycontainer As Container

      Height = 100

      Width = 100

      Procedure MouseMove

      Lparameters nButton, nShift, nXCoord, nYCoord

      If m.nButton = 1 And Between(m.nYCoord,0,Thisform.Height-This.Height) And ;

                  BETWEEN(m.nXCoord,0,Thisform.Width-This.Width)

            This.Move(m.nXCoord, m.nYCoord)

      Endif

      Endproc

Enddefine

Sample 2:

* Restricing within objects on form, in this case above or below the lines

Local oForm As Form

oForm = Createobject('TestForm')

oForm.Show(1)

Return

Define Class TestForm As Form

      AutoCenter = .T.

      Width = 900

      Height = 440

      Caption = 'Drag, Drop & Restrict'

      Add Object Shape1 As shape With Top = 30, Left = 0, Width = 900, height = 1

      Add Object Shape2 As shape With Top = 200, Left = 0, Width = 900, height = 1

      Add Object Command1 As MyButton With Caption='Move Me outside of the lines', Top = 35, Left = 5, width = 200, height = 30

Enddefine

Define Class MyButton As CommandButton

      Procedure MouseMove

            Lparameters nButton, nShift, nXCoord, nYCoord

            If m.nButton = 1 AND BETWEEN(m.nYCoord,30,171)

                  This.Move(m.nXCoord, m.nYCoord)

                  WAIT WINDOW m.nYCoord nowait

            Endif

      Endproc

Enddefine

In case you need it.  Cheers!