This little tool 'Pixie' runs of course in OSX. Apart from curiosity - could we do this with RealBasic - we also rather wanted this function on some older systems running OS9.
And indeed we can do this with RealBasic.
The code in the method listed below does this by doggedly asking for the color of a System.Pixel at a coordinate on the screen. With the color of the pixel of the screen then a small rectangle is drawn onto the receiving canvas to create a magnified view.
Sub UpdateImage(Cnv As Canvas)
Dim mX, mY As Integer // the mouse position in global coords
Dim nX, nY As Integer // the size of the sample we are magnifying
Dim dX, dY As Integer // the mid-point of the magnifying area
Dim CounterX, CounterY As Integer
Dim mag As Integer // magnification factor
mag = App.MagFactor // get from preferences
mX = System.MouseX
mY = System.MouseY
// if the pref is to only update when the mouse moved,
// check for the condition and bail from Sub if so
If App.LiveUpdating = False Then
If mX = LastX And mY = LastY Then
Exit // bail
End if
End If
// still here, so need to update our image so store the current coords
LastX = mX
LastY = mY
// determine the size of the sample we need to take from Screen by
// dividing the target canvas size by the magnification factor
nX = Floor( Cnv.Width / mag )
nY = Floor( Cnv.Height / mag )
// then the midpoint we need to sample around
dX = Round( nX/2 )
dY = Round( nY/2)
// then sample the color of every pixel we need to magnify and draw
// a corresponding square onto the canvas (that was passed as param)
For CounterX = 0 To nX
For CounterY = 0 To nY
magPic.Graphics.ForeColor = System.Pixel(mX+CounterX-dX, mY+CounterY-dY)
magPic.Graphics.FillRect( CounterX*mag, CounterY*mag,mag,mag)
Next
Next
Cnv.Refresh
End Sub
This method is used to make a magnifying window very much like the Pixie tool. The program in this source is localized into Dutch, but we're sure you will be able to figure out what it all means and be able to change it to the language of your choice. Source is provided right here.
The source also includes handling of preferences and remembering window positions. Because it is not possible to change the type of a Window (document, floating) after it has been created, the program uses two windows and shows/hides these depending on the program state.
Activating the program with a mouse click in the system-wide floater also is a bit of a hack. Have a look at the code :)
