package hong.specialEffects.wheel; import java.util.LinkedList; import java.util.List; import android.view.View; import android.widget.LinearLayout; /** * Recycle stores wheel items to reuse. */ public class WheelRecycle { // Cached items private List<View> items; // Cached empty items private List<View> emptyItems; // Wheel view private WheelView wheel; /** * Constructor * @param wheel the wheel view */ public WheelRecycle(WheelView wheel) { this.wheel = wheel; } /** * Recycles items from specified layout. * There are saved only items not included to specified range. * All the cached items are removed from original layout. * * @param layout the layout containing items to be cached * @param firstItem the number of first item in layout * @param range the range of current wheel items * @return the new value of first item number */ public int recycleItems(LinearLayout layout, int firstItem, ItemsRange range) { int index = firstItem; for (int i = 0; i < layout.getChildCount();) { if (!range.contains(index)) { recycleView(layout.getChildAt(i), index); layout.removeViewAt(i); if (i == 0) { // first item firstItem++; } } else { i++; // go to next item } index++; } return firstItem; } /** * Gets item view * @return the cached view */ public View getItem() { return getCachedView(items); } /** * Gets empty item view * @return the cached empty view */ public View getEmptyItem() { return getCachedView(emptyItems); } /** * Clears all views */ public void clearAll() { if (items != null) { items.clear(); } if (emptyItems != null) { emptyItems.clear(); } } /** * Adds view to specified cache. Creates a cache list if it is null. * @param view the view to be cached * @param cache the cache list * @return the cache list */ private List<View> addView(View view, List<View> cache) { if (cache == null) { cache = new LinkedList<View>(); } cache.add(view); return cache; } /** * Adds view to cache. Determines view type (item view or empty one) by index. * @param view the view to be cached * @param index the index of view */ private void recycleView(View view, int index) { int count = wheel.getViewAdapter().getItemsCount(); if ((index < 0 || index >= count) && !wheel.isCyclic()) { // empty view emptyItems = addView(view, emptyItems); } else { while (index < 0) { index = count + index; } index %= count; items = addView(view, items); } } /** * Gets view from specified cache. * @param cache the cache * @return the first view from cache. */ private View getCachedView(List<View> cache) { if (cache != null && cache.size() > 0) { View view = cache.get(0); cache.remove(0); return view; } return null; } }