DragSortListView.removeCheckState

Method similar to moveCheckState but for moving check statuses up one step
when a list item was removed.

Author: Mattias Flodin

library/src/com/mobeta/android/dslv/DragSortListView.java

@@ -2499,6 +2499,40 @@ public void moveCheckState(int from, int to) {
         }
     }
 
+    /**
+     * Use this when an item has been deleted, to move the check state of all
+     * preceding items up one step. If you have a choiceMode which is not none,
+     * this method must be called when the order of items changes in an
+     * underlying adapter which does not have stable IDs (see
+     * {@link ListAdapter#hasStableIds()}). This is because without IDs, the
+     * ListView has no way of knowing which items have moved where, and cannot
+     * update the check state accordingly.
+     * 
+     * See also further comments on {@link #moveCheckState(int, int)}.
+     * 
+     * @param position
+     */
+    public void removeCheckState(int position) {
+        SparseBooleanArray cip = getCheckedItemPositions();
+        
+        if (cip.size() == 0)
+            return;
+        int[] runStart = new int[cip.size()];
+        int[] runEnd = new int[cip.size()];
+        int rangeStart = position;
+        int rangeEnd = cip.keyAt(cip.size()-1)+1;
+        int runCount = buildRunList(cip, rangeStart, rangeEnd, runStart, runEnd);
+        for (int i=0; i!=runCount; i++) {
+            if (!(runStart[i] == position || (runEnd[i] < runStart[i] && runEnd[i] > position))) {
+                // Only set a new check mark in front of this run if it does
+                // not contain the deleted position. If it does, we only need
+                // to make it one check mark shorter at the end.
+                setItemChecked(rotate(runStart[i], - 1, rangeStart, rangeEnd), true);
+            }
+            setItemChecked(rotate(runEnd[i], - 1, rangeStart, rangeEnd), false);
+        }
+    }
+
     private static int buildRunList(SparseBooleanArray cip, int rangeStart,
             int rangeEnd, int[] runStart, int[] runEnd) {
         int runCount = 0;