Changeset 4329 in josm

Timestamp:

Aug 21, 2011 5:45:53 PM (21 months ago)

Author:

hansendc

Message:

fix map flicker in TMSLayer drawing code when zooming out

I'm seeing the map flicker and black-out during zoom-out operations. It
only seems to happen when I _start_ zoomed in to an area. I believe
it's because there are no visible tiles in upper zoom levels and
displayZoomLevel gets set to 2 when the while loop goes a bit nuts.
Thus, no tiles get drawn since it's so far away from my actual zoom
level and it takes a moment for repaint to get called.

This patch will not bother moving displayZoomLevel unless we've
unquestionably _found_ some more visible tiles in another zoom level.

File:

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

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

@@ -1166 +1166 @@
             }
             // Find highest zoom level with at least one visible tile
-            while (displayZoomLevel > dts.minZoom &&
-                    !dts.getTileSetInfo(displayZoomLevel).hasVisibleTiles) {
-                displayZoomLevel--;
+            for (int tmpZoom = zoom; tmpZoom > dts.minZoom; tmpZoom--) {
+                if (dts.getTileSetInfo(tmpZoom).hasVisibleTiles) {
+                    displayZoomLevel = tmpZoom;
+                    break;
+                }
             }
             // Do binary search between currentZoomLevel and displayZoomLevel