* VB-CODE (2)
Tip 72: Positioning the Cursor over a Control That Receives Focus

May 1, 1995

Abstract
The Default property of a Command Button can be used to place the
focus on the control at run time. If this property is set to True, the
Command Button receives the focus; if it is set to False, the Command
Button does not have the focus. In addition, the SetFocus method can
be used to shift the focus to a specific control or form. However, the
mouse pointer's position is not changed. This article explains how you
can position the mouse pointer over the control that has just received
the focus.

Using SetCursorPos to Change Cursor Position
Whenever you use the SetFocus method to move the focus to a different
control or form, the mouse pointer's position is not changed. In many
situations, it would be nice if the position of the mouse pointer
could follow the control that has the focus. We can implement this
feature in a Visual Basic® application by using the SetCursorPos
function provided in the Windows® application programming interface
(API). The Declare statement for the SetCursorPos function is:

Declare Sub SetCursorPos Lib "User" (ByVal X As Integer, ByVal Y As Integer)

As you can see, this function takes two arguments. The X argument
represents the horizontal position of the cursor and the Y argument
represents the vertical position of the cursor. To successfully move
the cursor using SetCursorPos, you must first determine the correct
coordinates to use with the function.
How do we actually determine the position of a control on the screen?
First, we know that the Command Button control has both Width and
Height properties that tell us the exact size of the control; ditto
for the Form control. To calculate the approximate coordinates of the
center point of the Command Button, we can add the left position of
the Command Button to the Form's left position, and divide this value
by the half the width of the Command Button, which gives us the center
position of the Command Button.

However, we also need to adjust the values we calculate for the width
of the form's border and title bar. The final step is to divide this
value we have just calculated by the TwipsPerPixelX and TwipsPerPixelY
values to obtain the control's true center position on the screen. It
is then a simple matter to call the SetCursorPos function to move the
mouse pointer to this new location.
Each time a control receives the focus, the GotFocus event for that
control is triggered. In addition, the focus can be shifted to a
control by clicking that control. In this case, the Click event is
triggered. By including code that positions the mouse pointer at the
center of the control in these two events, you can successfully
position the cursor over any control as soon as it receives the focus.

Example Program
The program below shows how to move the mouse pointer to the control
that has just received the focus.

 1. Create a new project in Visual Basic. Form1 is created by default.
 2. Add the following Declare statement to the General Declarations
    section of Form1 (note that this Declare statement should be typed
    as one single line of code):

Declare Sub SetCursorPos Lib "User" (ByVal X As Integer, ByVal Y As Integer)

 3. Add a Label control to Form1. Label1 is created by default. Set
    its Caption property to "Save Changes?"
 4. Add a Command Button control to Form1. Command1 is created by
    default. Set its Caption property to "Yes".
 5. Add the following code to the Click event for Command1:

Sub Command1_Click()
    Dim X As Integer, Y As Integer
    X = (Form1.Left + Command2.Left + Command2.Width / 2 + 60) /
         Screen.TwipsPerPixelX
    Y = (Form1.Top + Command2.Top + Command2.Height / 2 + 360) /
         Screen.TwipsPerPixelY
    SetCursorPos X, Y
    Command2.SetFocus
End Sub

 6. Add a second Command Button control to Form1. Command2 is created
    by default. Set its Caption property to "No".
 7. Add the following code to the GotFocus event for Command2:

Sub Command2_GotFocus()
    Dim X As Integer, Y As Integer
    X = (Form1.Left + Command2.Left + Command2.Width / 2 + 60) /
          Screen.TwipsPerPixelX
    Y = (Form1.Top + Command2.Top + Command2.Height / 2 + 360) /
         Screen.TwipsPerPixelY
    SetCursorPos X, Y
End Sub

Run the program by pressing the F5 function key. Notice that the Yes
Command Button has the focus. Press the TAB key once. The focus has
now been placed on the No Command Button. In addition, the mouse
pointer is positioned over the second Command Button.
Run the program a second time. Using the mouse, click the No Command
Button. The Command Button receives the focus and the mouse pointer
is positioned over the button. This demonstrates that no matter which
one is used to move the focusthe TAB key or the mouse the mouse
pointer can be programmed to follow control that has the focus.