In my last post, I outlined why I felt that tab order is an easy way to measure your GUI's complexity, and in this post I intend to show you how. Bad tab order is on my top 5 pet peeve list, so it's one of the first things I look for in an application. As you can see, even the simplest of UI's can be over engineered, and layout metrics that are purely concerned with user interaction wont pick it up. Turning on the View > Tab Order will show that the devil truly lies in the detail.

Nested panels adjacent to more nested panels will make for some mind exploding tab ordering, as shown in the example above. This is definitely panel overkill, or panelcake as I have affectionately dubbed it, and the main culprits include the ToolStripContainer, the SplitContainer, the TableLayoutPanels, and finally the GroupBoxes. The depth is so great, the tab order obscures the design!

YAGNI applies to GUI's too, so lets rescue this poor innocent interface...

In Visual Studio 2005, I press the Ctrl + W, U key chord to bring up the document outline viewer. This tool is absolute gold for rearranging hairy container hierarchies.

Step 2, set the window style to Fixed Window. Unless there is a compelling reason to be able to resize then there is no point in offering it. If it is needed, then careful use of Anchor and Dock properties will suffice for the most part. TableLayoutPanels should be used sparingly. YAGNI all the way.

Next, I lose the ToolStripContainer. Its function is to provide a drop target for ToolStrips and MenuStrips on the outer extremities of your Form. Does the user need to move the menu or tool strips from the top position? Nice idea, but probably not.

I continue to carve into the UI, removing all of the table layout panels and the split container until I am left with the fewest amount of controls to represent the data I need the user to edit. Careful choices for anchoring replicate much of the TableLayoutPanels functionality. Some grouping is beneficial to the user, and doesn't hurt when you need to alter the visibility state of groups of controls. What I am left with is a form that achieves the same end as the original, trimmed of unneeded function.

The acid test is that I can set the tab order in roughly 10 clicks of the mouse button. Not to mention the fact that you can see what you are doing.