Handle spacebar events.

Space/Shift-space scrolls the files list up/down.

BUG=25195555

Change-Id: Ib6351831db77a930920610106cc1da2b710532c6

packages/DocumentsUI/src/com/android/documentsui/dirlist/FocusManager.java

@@ -54,6 +54,18 @@ class FocusManager implements View.OnFocusChangeListener {
      * @return Whether the event was handled.
      */
     public boolean handleKey(DocumentHolder doc, int keyCode, KeyEvent event) {
+        boolean extendSelection = false;
+        // Translate space/shift-space into PgDn/PgUp
+        if (keyCode == KeyEvent.KEYCODE_SPACE) {
+            if (event.isShiftPressed()) {
+                keyCode = KeyEvent.KEYCODE_PAGE_UP;
+            } else {
+                keyCode = KeyEvent.KEYCODE_PAGE_DOWN;
+            }
+        } else {
+            extendSelection = event.isShiftPressed();
+        }
+
         if (Events.isNavigationKeyCode(keyCode)) {
             // Find the target item and focus it.
             int endPos = findTargetPosition(doc.itemView, keyCode, event);