id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
20329	interface has become very slow (since about the time when the	anonymous	team	"==== What steps will reproduce the problem?
1. Start josm (latest or tested) per 2020-12-21 or later.
2. Open the download data data window (ctrl-shift-down) and select the sliding map tab.
3. Not how extreamly slow the map panning is when map is moved. often, at first the position markers are slowly updated, then the map starts to slide.

==== What is the expected result?
Map panning should be fast.

==== What happens instead?
map panning is extremely slow.
This slowness is also present / felt while editing map data after some data is downloaded.
The slowness is not related to plugins as far as i can tell, it was there even before opendata plugin was added.

==== Please provide any additional information below. Attach a screenshot if possible.

{{{
URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-12-28 22:03:23 +0100 (Mon, 28 Dec 2020)
Build-Date:2020-12-30 02:30:55
Revision:17428
Relative:URL: ^/trunk

Identification: JOSM/1.5 (17428 sv) Linux Fedora 32 (Thirty Two)
Memory Usage: 475 MB / 837 MB (203 MB allocated, but free)
Java version: 1.8.0_275-b01, Red Hat, Inc., OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 1280×800 (scaling 1,00×1,00)
Maximum Screen Size: 1280×800
Best cursor sizes: 16×16→16×16, 32×32→32×32
Desktop environment: KDE
Java package: java-1.8.0-openjdk:x86_64-1.8.0.275.b01
Environment variable LANG: sv_SE.UTF-8
apache-commons-compress: apache-commons-compress:noarch-1.19
apache-commons-logging: apache-commons-logging:noarch-1.2
Dataset consistency test: No problems found

Plugins:
+ apache-commons (35524)
+ ejml (35458)
+ geotools (35458)
+ jaxb (35543)
+ jts (35458)
+ opendata (35640)
+ utilsplugin2 (35674)
}}}
"	defect	closed	normal		Core	latest	worksforme	template_report performance