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Dialog Controls And Navigation

The various controls in a dialog box respond to tab and cursor key movement. How the navigation between controls works is sensitive to the tab stop and group attribute settings associated with the controls. Sometimes the interaction is not terribly obvious and that’s why we’re going to have this little talk. Once we are finished with the talk, you’ll make dialog boxes that are things of simple joy and beauty. Now pay attention. There’s going to be a pop quiz later.

Organize Control Tab Order

The first thing to pay attention to is tab order. Set your controls so that they follow a logical order. Users expect that the tab order starts at the upper left corner, goes off to the right and works its way down to the bottom. The last things in the tab order are the buttons that close down the dialog.

As you are no doubt aware, tab order is determined by viewing a dialog box in Resource View and hitting the Layout\Tab Order command or simply using the Control D sequence. The default arrangement for a dialog puts the OK button in the number one slot and the Cancel at number two. This is just plain wrong and will cause your users to hate and loath you for such degenerate behavior.

Insert A Control In Tab Order

Here’s an ordering tip that you may be unaware of: let’s take the situation where you’ve created a true work of art with a billion controls on it and then you go and add another one somewhere in the middle. How do you get this new control to merge into the middle of the tab order without having to go through the entire list from the beginning? Get into tab order mode (Ctrl D) and shift click on the control that is to precede the newly inserted control. That tells the resource editor that you want to keep the tab order the way it is but to jump up in the list to the clicked upon control. The next control you click on with be inserted into the list in the same manner in which we are already familiar with.

Group Flag

The purpose of the group flag is to limit the effects of radio buttons and cursor movement.

Radio Buttons

If you have a set of radio buttons then the first button gets a group flag and the control that follows that last radio button gets another group flag. Up and down cursors, once focus goes into the radio group, will be limited to those controls that are fenced by the controls with the group attribute.

Push Buttons

Push buttons will also shift focus in reaction to the cursor keys so you will want to fence them in as well or you’ll end up with users cursoring into places that they can’t cursor out of. This isn’t a serious condition, obviously, but it is indicative that someone was a bit sloppy and will serve to indicate that the person (that would be you, hint hint) who coded the dialog is a poser who isn’t as sharp as he’d like everyone to believe.

Here’s a real simple example. Let’s say that you have a listbox as the first control in the tab order and OK and Cancel follow with their default attributes. All of the controls have Tab Stop checked. When the dialog starts up, the user can tab to OK. A cursor down will move the focus to Cancel. Further cursor downs are ignored. Cursor up gets back to OK and another cursor up shifts focus to the listbox. All cursor up and down keystrokes from this point on are routed to the listbox which applies them to the currently selected line.

The fix for this minor annoyance is to check the Group checkbox in the OK button’s properties.