michael@0: package org.mozilla.gecko.db;
michael@0: 
michael@0: import android.database.Cursor;
michael@0: import android.database.CursorWrapper;
michael@0: import android.util.SparseArray;
michael@0: 
michael@0: import org.mozilla.gecko.db.BrowserContract.Bookmarks;
michael@0: import org.mozilla.gecko.db.BrowserDB.URLColumns;
michael@0: 
michael@0: /**
michael@0:  * {@TopSitesCursorWrapper} is a cursor wrapper that merges
michael@0:  * the top and pinned sites cursors into one. It ensures the
michael@0:  * cursor will contain at least a given minimum number of
michael@0:  * entries.
michael@0:  */
michael@0: public class TopSitesCursorWrapper extends CursorWrapper {
michael@0: 
michael@0:     private static class PinnedSite {
michael@0:         public final String title;
michael@0:         public final String url;
michael@0: 
michael@0:         public PinnedSite(String title, String url) {
michael@0:             this.title = (title == null ? "" : title);
michael@0:             this.url = (url == null ? "" : url);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     // The cursor for the top sites query
michael@0:     private final Cursor topCursor;
michael@0: 
michael@0:     // Associates pinned sites and their respective positions
michael@0:     private SparseArray<PinnedSite> pinnedSites;
michael@0: 
michael@0:     // Current position of the cursor
michael@0:     private int currentPosition = -1;
michael@0: 
michael@0:     // The size of the cursor wrapper
michael@0:     private final int count;
michael@0: 
michael@0:     public TopSitesCursorWrapper(Cursor pinnedCursor, Cursor topCursor, int minSize) {
michael@0:         super(topCursor);
michael@0: 
michael@0:         setPinnedSites(pinnedCursor);
michael@0:         this.topCursor = topCursor;
michael@0: 
michael@0:         count = Math.max(minSize, pinnedSites.size() + topCursor.getCount());
michael@0:     }
michael@0: 
michael@0:     public void setPinnedSites(Cursor c) {
michael@0:         pinnedSites = new SparseArray<PinnedSite>();
michael@0: 
michael@0:         if (c == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         try {
michael@0:             if (c.getCount() <= 0) {
michael@0:                 return;
michael@0:             }
michael@0: 
michael@0:             c.moveToPosition(0);
michael@0:             do {
michael@0:                 final int pos = c.getInt(c.getColumnIndex(Bookmarks.POSITION));
michael@0:                 final String url = c.getString(c.getColumnIndex(URLColumns.URL));
michael@0:                 final String title = c.getString(c.getColumnIndex(URLColumns.TITLE));
michael@0:                 pinnedSites.put(pos, new PinnedSite(title, url));
michael@0:             } while (c.moveToNext());
michael@0:         } finally {
michael@0:             c.close();
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public boolean hasPinnedSites() {
michael@0:         return (pinnedSites != null && pinnedSites.size() > 0);
michael@0:     }
michael@0: 
michael@0:     public PinnedSite getPinnedSite(int position) {
michael@0:         if (!hasPinnedSites()) {
michael@0:             return null;
michael@0:         }
michael@0: 
michael@0:         return pinnedSites.get(position);
michael@0:     }
michael@0: 
michael@0:     public boolean isPinned() {
michael@0:         return (pinnedSites.get(currentPosition) != null);
michael@0:     }
michael@0: 
michael@0:     private int getPinnedBefore(int position) {
michael@0:         int numFound = 0;
michael@0:         if (!hasPinnedSites()) {
michael@0:             return numFound;
michael@0:         }
michael@0: 
michael@0:         for (int i = 0; i < position; i++) {
michael@0:             if (pinnedSites.get(i) != null) {
michael@0:                 numFound++;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         return numFound;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public int getPosition() {
michael@0:         return currentPosition;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public int getCount() {
michael@0:         return count;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean isAfterLast() {
michael@0:         return (currentPosition >= count);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean isBeforeFirst() {
michael@0:         return (currentPosition < 0);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean isLast() {
michael@0:         return (currentPosition == count - 1);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean moveToNext() {
michael@0:         return moveToPosition(currentPosition + 1);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean moveToPrevious() {
michael@0:         return moveToPosition(currentPosition - 1);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean move(int offset) {
michael@0:         return moveToPosition(currentPosition + offset);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean moveToFirst() {
michael@0:         return moveToPosition(0);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean moveToLast() {
michael@0:         return moveToPosition(count - 1);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean moveToPosition(int position) {
michael@0:         currentPosition = position;
michael@0: 
michael@0:         // Move the real cursor as if we were stepping through it to this position.
michael@0:         // Account for pinned sites, and be careful to update its position to the
michael@0:         // minimum or maximum position, even if we're moving beyond its bounds.
michael@0:         final int before = getPinnedBefore(position);
michael@0:         final int p2 = position - before;
michael@0: 
michael@0:         if (p2 <= -1) {
michael@0:             super.moveToPosition(-1);
michael@0:         } else if (p2 >= topCursor.getCount()) {
michael@0:             super.moveToPosition(topCursor.getCount());
michael@0:         } else {
michael@0:             super.moveToPosition(p2);
michael@0:         }
michael@0: 
michael@0:         return (!isBeforeFirst() && !isAfterLast());
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public long getLong(int columnIndex) {
michael@0:         if (hasPinnedSites()) {
michael@0:             final PinnedSite site = getPinnedSite(currentPosition);
michael@0: 
michael@0:             if (site != null) {
michael@0:                 return 0;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         if (!super.isBeforeFirst() && !super.isAfterLast()) {
michael@0:             return super.getLong(columnIndex);
michael@0:         }
michael@0: 
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public int getInt(int columnIndex) {
michael@0:         if (hasPinnedSites()) {
michael@0:             final PinnedSite site = getPinnedSite(currentPosition);
michael@0: 
michael@0:             if (site != null) {
michael@0:                 return 0;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         if (!super.isBeforeFirst() && !super.isAfterLast()) {
michael@0:             return super.getInt(columnIndex);
michael@0:         }
michael@0: 
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public String getString(int columnIndex) {
michael@0:         if (hasPinnedSites()) {
michael@0:             final PinnedSite site = getPinnedSite(currentPosition);
michael@0: 
michael@0:             if (site != null) {
michael@0:                 if (columnIndex == topCursor.getColumnIndex(URLColumns.URL)) {
michael@0:                     return site.url;
michael@0:                 } else if (columnIndex == topCursor.getColumnIndex(URLColumns.TITLE)) {
michael@0:                     return site.title;
michael@0:                 }
michael@0: 
michael@0:                 return "";
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         if (!super.isBeforeFirst() && !super.isAfterLast()) {
michael@0:             return super.getString(columnIndex);
michael@0:         }
michael@0: 
michael@0:         return "";
michael@0:     }
michael@0: }