y 

n/a 

n 

Required 

_ 

_ 

_ 

4-13: 

The selection models support keyboard selection modes according to the following rules:  

• Single selection supports only add mode.

• Browse selection supports only normal mode.

• Multiple selection supports only add mode.

• Range selection supports normal mode. If it also supports add mode, normal mode is the default.

• Discontiguous selection supports both normal mode and add mode. Normal mode is the default.

Selection must be available from the keyboard. In normal mode, used for making simple contiguous selections from the keyboard, the location cursor is never disjoint from the current selection. In add mode, used for making more complex and possibly disjoint selections, the location cursor can move independently of the current selection. 

Required 

_ 

_ 

_ 

4-14: 

If a collection supports both normal mode and add mode, Shift+F8 switches from one mode to the other. Mouse-based selection does not change when the keyboard selection mode changes. In editable components, add mode is a temporary mode that is exited when the user performs an operation on the selection or deselects the selection.  

Shift+F8 provides a convenient means of switching between normal mode and add mode. 

y 

n/a 

n 

Required 

_ 

_ 

_ 

4-15: 

In a collection that uses single selection, the navigation keys move the location cursor independently from the selected element. If the user presses the Select key or the Spacebar on an unselected element, the element with the location cursor is selected, and any other selection in the collection is deselected.  

Single selection supports only add mode. Pressing the Select key or the Spacebar is similar to clicking BSelect. 

y 

n/a 

n 

Required 

_ 

_ 

_ 

4-16: 

In a collection that uses browse selection, the navigation keys move the location cursor and select the cursored element, deselecting any other element. If the application has deselected all elements or if the cursor is left disjoint from the selection, the Select key or the Spacebar selects the cursored element and deselects any other element. 

Browse selection supports only normal mode. A navigation operation is similar to dragging BSelect. 

y 

n/a 

n 

Required 

_ 

_ 

_ 

4-17: 

In a collection that uses multiple selection, the navigation keys move the location cursor independently from the current selection. The Select key or the Spacebar on an unselected element adds the element to the current selection. Pressing the Select key or the Spacebar on a selected element removes the element from the current selection. 

Multiple selection supports only add mode. Pressing the Select key or the Spacebar is similar to clicking BSelect. 

y 

n/a 

n 

Required 

_ 

_ 

_ 

4-18: 

In a collection that uses range selection and is in normal mode, the navigation keys move the location cursor and deselect the current selection. If the cursor is on an element, it is selected. The anchor moves with the location cursor. 

Text-like collections can use a different model in which the navigation keys leave the anchor at its current location, except that, if the current selection is not empty, it is deselected and the anchor is moved to the location of the cursor prior to navigation.  

Range selection supports normal mode, and, if the collection also supports add mode, normal mode is the default. 

Required 

_ 

_ 

_ 

4-19: 

In a collection that uses range selection, whether in normal mode or add mode, the Select key or Spacebar (except in a text component) moves the anchor to the cursor, deselects the current selection, and, if the cursor is on an element, selects the element. Unless the anchor is on a deselected item, Shift+Select or Shift+Spacebar (except in text) extends the selection from the anchor to the cursor, based on the extension model used by Shift+BSelect (Reselect, Enlarge Only, or Balance Beam.  

In range selection, pressing the Select key or Spacebar is similar to clicking BSelect, and pressing Shift+Select or Shift+Spacebar extends the range as with Shift+BSelect. 

Required 

_ 

_ 

_ 

4-20: 

In a collection that uses range selection and is in normal mode, using Shift in conjunction with the navigation keys extends the selection, based on the extension model used by Shift+BSelect. If the current selection is empty, the anchor is first moved to the cursor. The cursor is then moved according to the navigation keys, and the selection is extended based on the extension model used by Shift+BSelect.  

In range selection, shifted navigation extends the selection in a similar manner to dragging Shift+BSelect. 

Required 

_ 

_ 

_ 

4-21: 

In a collection that uses range selection and is in add mode, the navigation keys move the location cursor but leave the anchor unchanged. Shifted navigation moves the location cursor according to the navigation keys, and the selection is extended based on the extension model used by Shift+BSelect.  

Shifted navigation in add mode is similar to shifted navigation in normal mode, except that when the selection is empty the anchor does not move to the cursor prior to navigation. 

y 

n/a 

n 

Required 

_ 

_ 

_ 

4-22: 

In a collection that uses discontiguous selection and is in normal mode, all keyboard operations have the same effect as in the range selection model.  

Normal mode does not permit multiple discontiguous selections. 

Required 

_ 

_ 

_ 

4-23: 

In a collection that uses discontiguous selection and is in add mode, the Select key or Spacebar moves the anchor to the location cursor and initiates toggling. If the cursor is on an element, the selection state of that element is toggled, but the selection state of all other elements remains unchanged. Shift+Select or Shift+Spacebar and shifted navigation operations extend the selection between the anchor and the location cursor, based on the toggle mechanism used by Control+BSelect (Anchor Toggle or Full Toggle).  

Add mode permits use of the keyboard to make multiple discontiguous selections.