'===========================================================================
' Subject: SCROLLABLE VIEWPORT FOR PICTURE    Date: 03-13-99 (19:15)       
'  Author: Joel Paula                         Code: VBWIN                  
'  Origin: CapeCanaveral/Lab/1961/          Packet: VBWIN.ABC
'===========================================================================
Scrollable Viewport for a Picture

It's easy to make a scrollable viewport for a picture in both VB3 VB4. In addition
to a picture, you can also use other objects that grow. First, create a new form.
Place a picture box on the form, name it "picParent," and resize it. This will be the
viewport. Place a picture box inside the other picture box (picParent) and name it
"picPICTURE." The value of the Left and Top properties must be zero. This one
will contain the picture you want to view.

Next, place a vertical scrollbar on the right of the picParent Picture. Name it
"vsbPict." This scrollbar should have the same Top and Height values as
picParent. Do the same with a horizontal scrollbar. Place it on the bottom of
"picParent"-the Left and Width values should be equal to picParent. Name it
"hsbPic." In both scrollbars, set the LargeChange property to the height and width
of picParent, respectively. Then place this code on the declarations section of
Form1. You can also copy this code to the Scroll event:

Private Sub hsbPIC_Change()
        picPicture.Left =hsbPIC.Value
End Sub
Private Sub vsbPIC_Change()
        picPicture.Top =vsbPIC.Value
End Sub
Private Sub picPicture_Resize()
        If picPicture.Height > picParent.Height Then
                vsbPIC.Max =picParent.Height - picPicture.Height
        Else
                vsbPIC.Max = 0
        End If
        If picPicture.Width > picParent.Width Then
                hsbPIC.Max =picParent.Width - picPicture.Width
        Else
                hsbPIC.Max =0
        End If
                vsbPIC.Value = 0
                hsbPIC.Value = 0
End Sub

Every time you load a new picture, the scrollbars will adjust to its size. Write the
code to load the pictures, and write other code to deal with exceptions to the
rules.

-Joel Paula, Carcavelos, Portugal
