Index: /trunk/src/org/openstreetmap/josm/gui/layer/WMSLayer.java =================================================================== --- /trunk/src/org/openstreetmap/josm/gui/layer/WMSLayer.java (revision 5968) +++ /trunk/src/org/openstreetmap/josm/gui/layer/WMSLayer.java (revision 5969) @@ -97,5 +97,11 @@ } - private static final ObjectFactory OBJECT_FACTORY = null; // Fake reference to keep build scripts from removing ObjectFactory class. This class is not used directly but it's necessary for jaxb to work + // Fake reference to keep build scripts from removing ObjectFactory class. This class is not used directly but it's necessary for jaxb to work + private static final ObjectFactory OBJECT_FACTORY = null; + + // these values correspond to the zoom levels used throughout OSM and are in meters/pixel from zoom level 0 to 18. + // taken from http://wiki.openstreetmap.org/wiki/Zoom_levels + private static final Double[] snapLevels = { 156412.0, 78206.0, 39103.0, 19551.0, 9776.0, 4888.0, + 2444.0, 1222.0, 610.984, 305.492, 152.746, 76.373, 38.187, 19.093, 9.547, 4.773, 2.387, 1.193, 0.596 }; public static final BooleanProperty PROP_ALPHA_CHANNEL = new BooleanProperty("imagery.wms.alpha_channel", true); @@ -107,5 +113,6 @@ public int messageNum = 5; //limit for messages per layer - protected String resolution; + protected double resolution; + protected String resolutionText; protected int imageSize; protected int dax = 10; @@ -117,4 +124,5 @@ protected final int serializeFormatVersion = 5; protected boolean autoDownloadEnabled = true; + protected boolean autoResolutionEnabled = true; protected boolean settingsChanged; public WmsCache cache; @@ -180,8 +188,9 @@ } } - if(this.info.getPixelPerDegree() == 0.0) { - this.info.setPixelPerDegree(getPPD()); - } - resolution = Main.map.mapView.getDist100PixelText(); + + // if automatic resolution is enabled, ensure that the first zoom level + // is already snapped. Otherwise it may load tiles that will never get + // used again when zooming. + updateResolutionSetting(this, autoResolutionEnabled); final MouseAdapter adapter = new MouseAdapter() { @@ -287,7 +296,7 @@ @Override public String getToolTipText() { if(autoDownloadEnabled) - return tr("WMS layer ({0}), automatically downloading in zoom {1}", getName(), resolution); + return tr("WMS layer ({0}), automatically downloading in zoom {1}", getName(), resolutionText); else - return tr("WMS layer ({0}), downloading in zoom {1}", getName(), resolution); + return tr("WMS layer ({0}), downloading in zoom {1}", getName(), resolutionText); } @@ -303,4 +312,8 @@ @Override public void paint(Graphics2D g, final MapView mv, Bounds b) { if(info.getUrl() == null || (usesInvalidUrl && !isInvalidUrlConfirmed)) return; + + if (autoResolutionEnabled && getBestZoom() != mv.getDist100Pixel()) { + changeResolution(this, true); + } settingsChanged = false; @@ -478,8 +491,9 @@ new BookmarkWmsAction(), SeparatorLayerAction.INSTANCE, - new ZoomToNativeResolution(), new StartStopAction(), new ToggleAlphaAction(), + new ToggleAutoResolutionAction(), new ChangeResolutionAction(), + new ZoomToNativeResolution(), new ReloadErrorTilesAction(), new DownloadAction(), @@ -667,4 +681,66 @@ } + /** + * Finds the most suitable resolution for the current zoom level, but prefers + * higher resolutions. Snaps to values defined in snapLevels. + * @return + */ + private static double getBestZoom() { + // not sure why getDist100Pixel returns values corresponding to + // the snapLevels, which are in meters per pixel. It works, though. + double dist = Main.map.mapView.getDist100Pixel(); + for(int i = snapLevels.length-2; i >= 0; i--) { + if(snapLevels[i+1]/3 + snapLevels[i]*2/3 > dist) + return snapLevels[i+1]; + } + return snapLevels[0]; + } + + /** + * Updates the given layer’s resolution settings to the current zoom level. Does + * not update existing tiles, only new ones will be subject to the new settings. + * + * @param layer + * @param snap Set to true if the resolution should snap to certain values instead of + * matching the current zoom level perfectly + */ + private static void updateResolutionSetting(WMSLayer layer, boolean snap) { + if(snap) { + layer.resolution = getBestZoom(); + layer.resolutionText = MapView.getDistText(layer.resolution); + } else { + layer.resolution = Main.map.mapView.getDist100Pixel(); + layer.resolutionText = Main.map.mapView.getDist100PixelText(); + } + layer.info.setPixelPerDegree(layer.getPPD()); + } + + /** + * Updates the given layer’s resolution settings to the current zoom level and + * updates existing tiles. If round is true, tiles will be updated gradually, if + * false they will be removed instantly (and redrawn only after the new resolution + * image has been loaded). + * @param layer + * @param snap Set to true if the resolution should snap to certain values instead of + * matching the current zoom level perfectly + */ + private static void changeResolution(WMSLayer layer, boolean snap) { + updateResolutionSetting(layer, snap); + + layer.settingsChanged = true; + + // Don’t move tiles off screen when the resolution is rounded. This + // prevents some flickering when zooming with auto-resolution enabled + // and instead gradually updates each tile. + if(!snap) { + for(int x = 0; x layers = LayerListDialog.getInstance().getModel().getSelectedLayers(); for (Layer l: layers) { - changeResolution((WMSLayer) l); + changeResolution((WMSLayer) l, false); } Main.map.mapView.repaint(); @@ -762,4 +827,29 @@ return item; } + @Override + public boolean supportLayers(List layers) { + return layers.size() == 1 && layers.get(0) instanceof WMSLayer; + } + } + + + public class ToggleAutoResolutionAction extends AbstractAction implements LayerAction { + public ToggleAutoResolutionAction() { + super(tr("Automatically change resolution")); + } + + @Override + public void actionPerformed(ActionEvent ev) { + JCheckBoxMenuItem checkbox = (JCheckBoxMenuItem) ev.getSource(); + autoResolutionEnabled = checkbox.isSelected(); + } + + @Override + public Component createMenuComponent() { + JCheckBoxMenuItem item = new JCheckBoxMenuItem(this); + item.setSelected(autoResolutionEnabled); + return item; + } + @Override public boolean supportLayers(List layers) {