Changeset 13861 in josm

Timestamp:

2018-05-28T20:25:58+02:00 (6 years ago)

Author:

wiktorn

Message:

Ensure that tiles from lower zoom leveles are loaded

When lower zoom leveles doesn't have any tiles initiate loading and ensure, that
tiles will be loaded and in tile cache. This tiles will be used to render
imagery when no tiles are availble at current tile zoom level.

Duplicate requests for loading will be handled by TileLoader factories so this
should not generate memory load or unnecessary requests to imagery server.

Closes: #13738, #14562

File:

• trunk/src/org/openstreetmap/josm/gui/layer/AbstractTileSourceLayer.java (modified) (1 diff)

trunk/src/org/openstreetmap/josm/gui/layer/AbstractTileSourceLayer.java

@@ -1557 +1557 @@
                 // Instantiating large TileSets is expensive. If there are no loaded tiles, don't bother even trying.
                 if (ts2.allLoadedTiles().isEmpty()) {
-                    newlyMissedTiles.add(missed);
-                    continue;
+                    if (zoomOffset > 0) {
+                        newlyMissedTiles.add(missed);
+                        continue;
+                    } else {
+                        /*
+                         *  We have negative zoom offset. Try to load tiles from lower zoom levels, as they may be not present
+                         *  in tile cache (e.g. when user panned the map or opened layer above zoom level, for which tiles are present.
+                         *  This will ensure, that tileCache is populated with tiles from lower zoom levels so it will be possible to
+                         *  use them to paint overzoomed tiles.
+                         *  See: #14562
+                         */
+                        ts2.loadAllTiles(false);
+                    }
                 }
                 if (ts2.tooLarge()) {