Internal Navigation

Use internal navigation when the active cursor needs to be moved within the control.

Use internal navigation when manipulating elements within a control.

If a control uses internal navigation to move an element cursor among elements within a control, follow all the rules for control navigation, proceeding as if the elements in the control were controls within a tab group.

Allow the directional keys to move a graphics cursor one unit in the indicated direction, where a unit is generally a pixel.

Allow the directional keys augmented by Ctrl to move a graphics cursor multiple units in the indicated direction.

Allow Home (or Begin) and End to move a graphics cursor to the leftmost and rightmost ends, respectively, of the data being viewed in the control. For information on bidirectional and vertical language support, see Chapter 11.

Allow Ctrl Home (or Ctrl Begin) and Ctrl End to do one of the following:

Do not allow a graphics cursor to wrap from one edge to the opposite edge.

When the purpose of a control is to allow a positional indicator to be set to a value (for example, an arm in a slider), then when the control has focus, allow directional keys to move the positional indicator one unit (not necessarily one pixel) in the corresponding direction.

When the purpose of a control is to allow a positional indicator to be set to a value, allow directional keys augmented by Ctrl to move the positional indicator multiple units in the indicated direction.

If a control with a positional indicator has major and minor tick marks, and if minor tick marks indicate each single unit, then allow directional keys augmented by Ctrl to move to major tick marks.

If a control with a positional indicator has only one degree of freedom, then do one of the following:

If a control with a positional indicator has only one degree of freedom, then allow Home (or Begin) to move the positional indicator to its initial position, and End to move it to its final position.

If vertical and horizontal navigation have different effects on a positional indicator, then allow Home (or Begin) to move the indicator as far as it can go toward the initial or final horizontal positions. Allow Ctrl Home (or Ctrl Begin) and Ctrl End to move the indicator as far as it can go towards the initial or final vertical position.

If you use horizontal or vertical navigation to switch to a value from among a linear sequence of values, then make Home (or Begin) switch to the first such value, and End switch to the last such value.

If the user can use a control to set a value from among a linear sequence of values, then when the control has focus, allow horizontal navigation, vertical navigation, or both, to switch from one value to another.

If additional internal navigation techniques are required, extend the navigation model as needed, but do not deviate from it unnecessarily. Some situations that may require additional navigation techniques are: