SELECT CASE for identical objects

[Zauberkind]

Greetings,
I am building a state machine whose actions and state transitions depend on a single input (click), and which object the input came from. In this case, the objects are all PowerPoint shapes.
Using a Christmas-tree of IF-THEN-ELSEIF... statements is ugly and hard to read.
Life would be much simpler if I could write:

Code: Select all

Function EventHandler
SELECT CASE Object
CASE IS Object1 ' using the classic VBA <object1> IS <object2>
...
CASE IS Object2
...
CASE ELSE
END SELECT

Life is never that simple.

Also possible, but misleading and inelegant is:

Code: Select all

Function EventHandler(Object)
SELECT CASE TRUE ' TRUE? Why TRUE? where did that come from? you ask.
                 ' Dunno, but zero causes weird results!
CASE Object IS Object1, Object IS Object2
...
CASE Object IS Object3
...
CASE ELSE
END SELECT

Q: Is there an elegant way to do this? in VBA?

TIA for any insights.

Regards
Zk

[Jan Karel Pieterse]

Perhaps TypeName(Object) helps?

[HansV]

I don't think the second code fragment will do what you want - when I tried it, all shapes were considered to be equal.

If you can ensure that each shape has a unique name, you could use

Select Case object.Name

[Zauberkind]

Greetings,

Thanks for the suggestions.

Unfortunately, TypeName(Object) is always msoAutoShape, so that doesn't go far.

The uniqueness of Object Names is enforced by the object model, so that could work. It requires a bit more effort for maintenance, but ...

I find the statement "when I tried it, all shapes were considered to be equal" somewhat disturbing. It conflicts with my observations in PPt 2003. I've hung an example for you to play with. I'd be interested in your results.

Regards,
Zk

[HansV]

Shamefacedly, I have to admit that I tested in Word, mistakenly thinking that the MSOffice shapes behave the same in all Office applications. I was wrong. They behave differently in Word than in PowerPoint.

By the way, it *is* possible to create shapes with the same name:

The result of running

Code: Select all

Sub NameShapes()
    Dim shp As Shape
    For Each shp In ActiveWindow.View.Slide.Shapes
        shp.Name = "Zauberkind"
    Next shp
    For Each shp In ActiveWindow.View.Slide.Shapes
        Debug.Print shp.Name
    Next shp
End Sub

is

Zauberkind
Zauberkind
Zauberkind
Zauberkind

[Jan Karel Pieterse]

And Object.AutoShapeType?

[Zauberkind]

Greetings HansV,

I can hear the theme from Twilight Zone playing in the back of my head...

I copied your code into my presentation and ran it.

The first object was renamed successfully.
The second object threw an exception: "Error 70: Permission Denied"
Is PPT 2003 that different? or was that Word again?

Regards,
Zk

[HansV]

This time I tested in PowerPoint 2010. It doesn't matter whether the presentation is a PowerPoint 97-2003 presentation (.ppt) or a PowerPoint 2007-2010 presentation (.pptm).

S269.png

[Zauberkind]

OK, I'll trade you...

Verweigert.jpg

Regards,
Zk

[HansV]

German is stricter than English, I guess...
But seriously, I have no idea what causes the difference. Sorry!

[Zauberkind]

Hmmm...
I admit to puzzlement, too!
Puzzled about the difference - that's odd; more puzzled about the namespace issue - that seems counter-intuitive.
If I can access .Shapes("ShapeName") using "ShapeName" as an identifier, what do I get if more than one shape has the same name? Or has that indexing method been overtaken by "progress"?
Regards (and )
Zk

[HansV]

If I can access .Shapes("ShapeName") using "ShapeName" as an identifier, what do I get if more than one shape has the same name?

The first one with that name in the order of creation, as far as I can tell.