fix (I hope) OOM errors when there are a ton of games by doing

snapshot creation and loading sequentially on a single thread so that
peak memory consumed by bitmap operations is lower.  Remove snapshots
from GameSummary: the db is the only source now.

xwords4/android/XWords4/src/org/eehouse/android/xw4/BoardCanvas.java

@@ -82,7 +82,7 @@ public class BoardCanvas extends Canvas implements DrawCtx {
     private int m_trayOwner = -1;
     private int m_pendingScore;
     private int m_dictPtr = 0;
-    private String[] m_dictChars;
+    protected String[] m_dictChars;
     private boolean m_hasSmallScreen;
     private int m_backgroundUsed = 0x00000000;
 
@@ -118,7 +118,7 @@ public class BoardCanvas extends Canvas implements DrawCtx {
         int descentFor( int ht ) { return (int)(ht * m_descentProportion); }
         int widthFor( int width ) { return (int)(width / m_widthProportion); }
     }
-    private FontDims m_fontDims;
+    protected FontDims m_fontDims;
 
     public BoardCanvas( Activity activity, Bitmap bitmap, JNIThread jniThread,
                         BoardDims dims )

xwords4/android/XWords4/src/org/eehouse/android/xw4/DBUtils.java

@@ -135,7 +135,7 @@ public class DBUtils {
                              DBHelper.DICTLANG, DBHelper.GAMEID,
                              DBHelper.SCORES, DBHelper.HASMSGS,
                              DBHelper.LASTPLAY_TIME, DBHelper.REMOTEDEVS,
-                             DBHelper.LASTMOVE, DBHelper.THUMBNAIL
+                             DBHelper.LASTMOVE
         };
         String selection = String.format( ROW_ID_FMT, lock.getRowid() );
 
@@ -184,18 +184,6 @@ public class DBUtils {
                 summary.lastMoveTime = 
                     cursor.getInt(cursor.getColumnIndex(DBHelper.LASTMOVE));
 
-                if ( BuildConstants.THUMBNAIL_SUPPORTED ) {
-                    byte[] data =
-                        cursor.getBlob( cursor.
-                                        getColumnIndex(DBHelper.THUMBNAIL));
-                    if ( null != data ) {
-                        Bitmap thumb = 
-                            BitmapFactory.decodeByteArray( data, 0, 
-                                                           data.length );
-                        summary.setThumbnail( thumb );
-                    }
-                }
-
                 String scoresStr = 
                     cursor.getString( cursor.getColumnIndex(DBHelper.SCORES));
                 int[] scores = new int[summary.nPlayers];
@@ -322,8 +310,6 @@ public class DBUtils {
             }
 
             values.put( DBHelper.SERVERROLE, summary.serverRole.ordinal() );
-
-            addThumb( summary.getThumbnail(), values );
         }
 
         initDB( context );
@@ -447,7 +433,15 @@ public class DBUtils {
             long rowid = lock.getRowid();
             String selection = String.format( ROW_ID_FMT, rowid );
             ContentValues values = new ContentValues();
-            addThumb( thumb, values );
+
+            if ( null == thumb ) {
+                values.putNull( DBHelper.THUMBNAIL );
+            } else {
+                ByteArrayOutputStream bas = new ByteArrayOutputStream();
+                thumb.compress( CompressFormat.PNG, 0, bas );
+                values.put( DBHelper.THUMBNAIL, bas.toByteArray() );
+            }
+
             initDB( context );
             synchronized( s_dbHelper ) {
                 SQLiteDatabase db = s_dbHelper.getWritableDatabase();
@@ -957,15 +951,32 @@ public class DBUtils {
         s_groupsCache = null;
     }
 
-    private static void addThumb( Bitmap thumb, ContentValues values )
+    public static Bitmap getThumb( Context context, long rowid )
     {
-        if ( null == thumb ) {
+        Bitmap thumb = null;
-            values.putNull( DBHelper.THUMBNAIL );
+        if ( BuildConstants.THUMBNAIL_SUPPORTED ) {
-        } else {
+            byte[] data = null;
-            ByteArrayOutputStream bas = new ByteArrayOutputStream();
+            String[] columns = { DBHelper.THUMBNAIL };
-            thumb.compress( CompressFormat.PNG, 0, bas );
+            String selection = String.format( ROW_ID_FMT, rowid );
-            values.put( DBHelper.THUMBNAIL, bas.toByteArray() );
+
+            initDB( context );
+            synchronized( s_dbHelper ) {
+                SQLiteDatabase db = s_dbHelper.getReadableDatabase();
+                Cursor cursor = db.query( DBHelper.TABLE_NAME_SUM, columns, 
+                                          selection, null, null, null, null );
+                if ( 1 == cursor.getCount() && cursor.moveToFirst() ) {
+                    data = cursor.getBlob( cursor.
+                                           getColumnIndex(DBHelper.THUMBNAIL));
+                }
+                cursor.close();
+                db.close();
+            }
+
+            if ( null != data ) {
+                thumb = BitmapFactory.decodeByteArray( data, 0, data.length );
+            }
         }
+        return thumb;
     }
 
     // Return map of string (group name) to info about all games in

xwords4/android/XWords4/src/org/eehouse/android/xw4/GameListItem.java

@@ -30,6 +30,7 @@ import android.os.AsyncTask;
 import android.os.Handler;
 import android.util.AttributeSet;
 import android.view.View;
+import java.util.concurrent.LinkedBlockingQueue;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
@@ -310,7 +311,6 @@ public class GameListItem extends LinearLayout
 
             if ( BuildConstants.THUMBNAIL_SUPPORTED ) {
                 m_thumb = (ImageView)findViewById( R.id.thumbnail );
-                m_thumb.setImageBitmap( summary.getThumbnail() );
             }
 
             tview = (TextView)findViewById( R.id.role );
@@ -340,11 +340,9 @@ public class GameListItem extends LinearLayout
 
     private void makeThumbnailIf( boolean expanded )
     {
-        if ( expanded && null != m_activity && null != m_summary
+        if ( expanded && null != m_activity
-             && null == m_summary.getThumbnail()
              && XWPrefs.getThumbEnabled( m_context ) ) {
-            m_summary.setThumbnail( GameUtils.loadMakeBitmap( m_activity,
+            enqueueGetThumbnail( this, m_rowid );
-                                                              m_rowid ) );
         }
     }
 
@@ -412,4 +410,67 @@ public class GameListItem extends LinearLayout
         toggleSelected();
     }
 
+    private static class ThumbQueueElem {
+        public ThumbQueueElem( GameListItem item, long rowid ) {
+            m_item = item;
+            m_rowid = rowid;
+        }
+        long m_rowid;
+        GameListItem m_item;
+    }
+    private static LinkedBlockingQueue<ThumbQueueElem> s_queue
+        = new LinkedBlockingQueue<ThumbQueueElem>();
+    private static Thread s_thumbThread;
+
+    private static void enqueueGetThumbnail( GameListItem item, long rowid )
+    {
+        if ( BuildConstants.THUMBNAIL_SUPPORTED ) {
+            s_queue.add( new ThumbQueueElem( item, rowid ) );
+
+            synchronized( GameListItem.class ) {
+                if ( null == s_thumbThread ) {
+                    s_thumbThread = makeThumbThread();
+                    s_thumbThread.start();
+                }
+            }
+        }
+    }
+
+    private static Thread makeThumbThread()
+    {
+        return new Thread( new Runnable() {
+                public void run()
+                {
+                    for ( ; ; ) {
+                        ThumbQueueElem elem;
+                        try {
+                            elem = s_queue.take();
+                        } catch ( InterruptedException ie ) {
+                            DbgUtils.logf( "interrupted; killing "
+                                           + "s_thumbThread" );
+                            break;
+                        }
+                        Activity activity = elem.m_item.m_activity;
+                        long rowid = elem.m_rowid;
+                        Bitmap thumb = DBUtils.getThumb( activity, rowid );
+                        if ( null == thumb ) {
+                            // loadMakeBitmap puts in DB
+                            thumb = GameUtils.loadMakeBitmap( activity, rowid );
+                        }
+
+                        final GameListItem item = elem.m_item;
+                        final Bitmap ft = thumb;
+                        activity.runOnUiThread( new Runnable() {
+                                public void run() {
+                                    ImageView iview = item.m_thumb;
+                                    if ( null != iview ) {
+                                        iview.setImageBitmap( ft );
+                                    }
+                                }
+                            });
+                    }
+                }
+            });
+    }
+
 }

xwords4/android/XWords4/src/org/eehouse/android/xw4/ThumbCanvas.java

@@ -24,6 +24,8 @@ import android.app.Activity;
 import android.graphics.Bitmap;
 import android.graphics.Rect;
 
+import org.eehouse.android.xw4.jni.XwJNI;
+
 public class ThumbCanvas extends BoardCanvas {
 
     public ThumbCanvas( Activity activity, Bitmap bitmap )
@@ -47,4 +49,17 @@ public class ThumbCanvas extends BoardCanvas {
         return false;
     }
 
+    // Unlike superclass, where the game was loaded on the main thread
+    // but dictChanged() is called on the JNI thread, this instance
+    // will have been created on the same background thread that's
+    // calling us.  So don't switch threads for the dict_getChars()
+    // call
+    @Override
+    public void dictChanged( final int dictPtr )
+    {
+        if ( 0 != dictPtr ) {
+            m_fontDims = null;
+            m_dictChars = XwJNI.dict_getChars( dictPtr );
+        }
+    }
 }

xwords4/android/XWords4/src/org/eehouse/android/xw4/jni/GameSummary.java

@@ -21,7 +21,6 @@
 package org.eehouse.android.xw4.jni;
 
 import android.content.Context;
-import android.graphics.Bitmap;
 import android.text.TextUtils;
 
 import junit.framework.Assert;
@@ -69,7 +68,6 @@ public class GameSummary {
     private CurGameInfo m_gi;
     private Context m_context;
     private String[] m_remotePhones;
-    private Bitmap m_thumb;
 
     private GameSummary() {}
 
@@ -89,16 +87,6 @@ public class GameSummary {
         m_gi = gi;
     }
 
-    public void setThumbnail( Bitmap thumb )
-    {
-        m_thumb = thumb;
-    }
-
-    public Bitmap getThumbnail()
-    {
-        return m_thumb;
-    }
-
     public boolean inNetworkGame()
     {
         return null != relayID;