Touch gestures construction - zOrder in groups

In the next few posts I thought I’d take a look at some interesting aspects of the Touch Gesture shapes from a Visio shape development perspective.

To kick things off, this post will look at one way to achieve blending circles, without any [apparent] overlap…

Intersecting geometry

If you look at the TouchPoints shape you’ll see it has three basic forms, the first of which are four apparently blended circles:

With a static shape, this is fairly easy to reproduce using the Shape / Operations tools, but it gets a little more challenging if you want to allow the user to manipulate the position of the circles (with the yellow control handles in this case).  There are a number of ways you could tackle this - using Pythagoras’ theorem, for example, to calculate the intersecting geometry points, but there’s a simpler method.

If you stack a series of solid white ‘inner’ circle shapes on top of similarly positioned outer circles, the former set will obscure the overlapping parts of the latter set.  To create a single shape, you then group them together into a single grouped shape.  An exploded view might look like this (I’ve coloured the white inner circles blue for clarity):

If you also look at the Drawing Explorer you can see the structure (and I’ve identified the respective shapes below that.

Shape Assembly

Building the shape then is basically as follows:

1. Layout each of the circle shapes in the positions you want them to appear
2. Select what you intend to be the group shape click Home / Arrange / Group / Convert to Group
3. Open the ShapeSheet for your new group shape and set its LockCalcWH cell in the Protection section to True
4. In the same ShapeSheet set the DisplayMode cell, in the Group section, to 1 (DisplayModeBack) and then close the ShapeSheet
5. Now run through each of your circle shapes bringing them to the front, in back to front order.  So starting with the your group shape (ie the one you want right at the back), select it and click Home / Arrange / Bring forward / Bring to front (Shift + Ctrl+F) and then repeat the process for each of the black outer circle shapes followed by the white inner circle ones.
6. Now that your shapes are in the correct order you can add the shapes to the group shapes by selecting all of them (include the group shape itself) and clicking Home / Arrange / Group / Add to Group

z-order is a useful tool for creating various effects within shapes and with Visio 2010 you can now access the z-order 'bands' via the ShapeSheet. To find out more about this new feature, check out:

• DisplayLevel Cell (Shape Layout Section)