Gpx approximation in progress

OsmAnd-java/src/main/java/net/osmand/LocationsHolder.java

@@ -25,15 +25,15 @@ public class LocationsHolder {
 		this.locationType = resolveLocationType(locations);
 		switch (locationType) {
 			case LOCATION_TYPE_LATLON:
-				latLonList = (List<LatLon>) locations;
+				latLonList = new ArrayList<>((List<LatLon>) locations);
 				size = locations.size();
 				break;
 			case LOCATION_TYPE_LOCATION:
-				locationList = (List<Location>) locations;
+				locationList = new ArrayList<>((List<Location>) locations);
 				size = locations.size();
 				break;
 			case LOCATION_TYPE_WPTPT:
-				wptPtList = (List<WptPt>) locations;
+				wptPtList = new ArrayList<>((List<WptPt>) locations);
 				size = locations.size();
 				break;
 		}

OsmAnd-java/src/main/java/net/osmand/router/RoutePlannerFrontEnd.java

@@ -4,6 +4,7 @@ package net.osmand.router;
 import net.osmand.LocationsHolder;
 import net.osmand.NativeLibrary;
 import net.osmand.PlatformUtil;
+import net.osmand.ResultMatcher;
 import net.osmand.binary.BinaryMapIndexReader;
 import net.osmand.binary.BinaryMapRouteReaderAdapter;
 import net.osmand.binary.BinaryMapRouteReaderAdapter.RouteRegion;
@@ -63,16 +64,28 @@ public class RoutePlannerFrontEnd {
 		public int routeGapDistance;
 		public int routeDistanceUnmatched;
 
+		public boolean calculationCancelled;
+		private boolean calculationDone;
+
 		public GpxRouteApproximation(RoutingContext ctx) {
 			this.ctx = ctx;
 		}
 		
+		public GpxRouteApproximation(GpxRouteApproximation gctx) {
+			this.ctx = gctx.ctx;
+			this.routeDistance = gctx.routeDistance;
+		}
+
 		@Override
 		public String toString() {
 			return String.format(">> GPX approximation (%d of %d m route calcs, %d route points searched) for %d m: %d m umatched",
 					routeCalculations, routeDistCalculations, routePointsSearched, routeDistance, routeDistanceUnmatched);
 		}
 
+		public boolean isCalculationDone() {
+			return calculationDone;
+		}
+
 		public double distFromLastPoint(LatLon startPoint) {
 			if (result.size() > 0) {
 				return MapUtils.getDistance(getLastPoint(), startPoint);
@@ -97,6 +110,15 @@ public class RoutePlannerFrontEnd {
 		public List<RouteSegmentResult> stepBackRoute;
 		public int targetInd = -1;
 		public boolean straightLine = false;
+
+		public GpxPoint() {
+		}
+
+		public GpxPoint(GpxPoint point) {
+			this.ind = point.ind;
+			this.loc = point.loc;
+			this.cumDist = point.cumDist;
+		}
 	}
 
 	public RoutingContext buildRoutingContext(RoutingConfiguration config, NativeLibrary nativeLibrary, BinaryMapIndexReader[] map, RouteCalculationMode rm) {
@@ -206,7 +228,6 @@ public class RoutePlannerFrontEnd {
 		return null;
 	}
 
-
 	public List<RouteSegmentResult> searchRoute(final RoutingContext ctx, LatLon start, LatLon end, List<LatLon> intermediates) throws IOException, InterruptedException {
 		return searchRoute(ctx, start, end, intermediates, null);
 	}
@@ -215,11 +236,8 @@ public class RoutePlannerFrontEnd {
 		useSmartRouteRecalculation = use;
 	}
 
-	public GpxRouteApproximation searchGpxRoute(GpxRouteApproximation gctx, List<GpxPoint> gpxPoints) throws IOException, InterruptedException {
+	public GpxRouteApproximation searchGpxRoute(GpxRouteApproximation gctx, List<GpxPoint> gpxPoints, ResultMatcher<GpxRouteApproximation> resultMatcher) throws IOException, InterruptedException {
 		long timeToCalculate = System.nanoTime();
-		if (gctx.ctx.calculationProgress == null) {
-			gctx.ctx.calculationProgress = new RouteCalculationProgress();
-		}
 		gctx.ctx.keepNativeRoutingContext = true;
 		GpxPoint start = null;
 		GpxPoint prev = null;
@@ -227,7 +245,7 @@ public class RoutePlannerFrontEnd {
 			gctx.ctx.calculationProgress.totalIterations = (int) (gpxPoints.get(gpxPoints.size() - 1).cumDist / gctx.MAXIMUM_STEP_APPROXIMATION + 1); 
 			start = gpxPoints.get(0); 
 		}
-		while (start != null) {
+		while (start != null && !gctx.calculationCancelled) {
 			double routeDist = gctx.MAXIMUM_STEP_APPROXIMATION;
 			GpxPoint next = findNextGpxPointWithin(gctx, gpxPoints, start, routeDist);
 			boolean routeFound = false;
@@ -287,10 +305,14 @@ public class RoutePlannerFrontEnd {
 		gctx.ctx.deleteNativeRoutingContext();
 		BinaryRoutePlanner.printDebugMemoryInformation(gctx.ctx);
 		calculateGpxRoute(gctx, gpxPoints);
-		if (!gctx.result.isEmpty()) {
+		if (!gctx.result.isEmpty() && !gctx.calculationCancelled) {
 			new RouteResultPreparation().printResults(gctx.ctx, gpxPoints.get(0).loc, gpxPoints.get(gpxPoints.size() - 1).loc, gctx.result);
 			System.out.println(gctx);
 		}
+		if (resultMatcher != null) {
+			resultMatcher.publish(gctx);
+		}
+		gctx.calculationDone = true;
 		return gctx;
 	}
 
@@ -343,7 +365,7 @@ public class RoutePlannerFrontEnd {
 		reg.initRouteEncodingRule(0, "highway", RouteResultPreparation.UNMATCHED_HIGHWAY_TYPE);
 		List<LatLon> lastStraightLine = null;
 		GpxPoint straightPointStart = null;
-		for (int i = 0; i < gpxPoints.size(); ) {
+		for (int i = 0; i < gpxPoints.size() && !gctx.calculationCancelled; ) {
 			GpxPoint pnt = gpxPoints.get(i);
 			if (pnt.routeToTarget != null && !pnt.routeToTarget.isEmpty()) {
 				LatLon startPoint = pnt.routeToTarget.get(0).getStartPoint();
@@ -402,7 +424,7 @@ public class RoutePlannerFrontEnd {
 	private void cleanupResultAndAddTurns(GpxRouteApproximation gctx) {
 		// cleanup double joints
 		int LOOK_AHEAD = 4;
-		for(int i = 0; i < gctx.result.size(); i++) {
+		for(int i = 0; i < gctx.result.size() && !gctx.calculationCancelled; i++) {
 			RouteSegmentResult s = gctx.result.get(i);
 			for(int j = i + 2; j <= i + LOOK_AHEAD && j < gctx.result.size(); j++) {
 				RouteSegmentResult e = gctx.result.get(j);
@@ -419,8 +441,10 @@ public class RoutePlannerFrontEnd {
 			r.setTurnType(null);
 			r.setDescription("");
 		}
+		if (!gctx.calculationCancelled) {
 			preparation.prepareTurnResults(gctx.ctx, gctx.result);
 		}
+	}
 
 	private void addStraightLine(GpxRouteApproximation gctx, List<LatLon> lastStraightLine, GpxPoint strPnt, RouteRegion reg) {
 		RouteDataObject rdo = new RouteDataObject(reg);

OsmAnd/res/layout/fragment_gpx_approximation_bottom_sheet_dialog.xml

@@ -18,8 +18,6 @@
 			android:layout_width="match_parent"
 			android:layout_height="match_parent">
 
-			<include layout="@layout/plan_route_progress_bar"/>
-
 			<net.osmand.plus.LockableScrollView
 				android:id="@+id/route_menu_bottom_scroll"
 				android:layout_width="match_parent"
@@ -37,6 +35,9 @@
 				</LinearLayout>
 
 			</net.osmand.plus.LockableScrollView>
+
+			<include layout="@layout/plan_route_progress_bar"/>
+
 		</FrameLayout>
 
 	</LinearLayout>

OsmAnd/src/net/osmand/AndroidUtils.java

@@ -54,6 +54,7 @@ import androidx.annotation.ColorInt;
 import androidx.annotation.ColorRes;
 import androidx.annotation.DrawableRes;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.appcompat.content.res.AppCompatResources;
 import androidx.core.content.ContextCompat;
 import androidx.core.content.FileProvider;
@@ -169,11 +170,11 @@ public class AndroidUtils {
 		return intent.resolveActivity(context.getPackageManager()) != null;
 	}
 
-	public static boolean isActivityNotDestroyed(Activity activity) {
+	public static boolean isActivityNotDestroyed(@Nullable Activity activity) {
 		if (Build.VERSION.SDK_INT >= 17) {
-			return !activity.isFinishing() && !activity.isDestroyed();
+			return activity != null && !activity.isFinishing() && !activity.isDestroyed();
 		}
-		return !activity.isFinishing();
+		return activity != null && !activity.isFinishing();
 	}
 
 	public static Spannable replaceCharsWithIcon(String text, Drawable icon, String[] chars) {

OsmAnd/src/net/osmand/plus/measurementtool/GpxApproximationFragment.java

@@ -7,6 +7,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 import android.widget.LinearLayout;
+import android.widget.ProgressBar;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -15,18 +16,25 @@ import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 
 import net.osmand.AndroidUtils;
+import net.osmand.LocationsHolder;
 import net.osmand.PlatformUtil;
+import net.osmand.ResultMatcher;
+import net.osmand.plus.OsmandApplication;
 import net.osmand.plus.R;
 import net.osmand.plus.UiUtilities;
 import net.osmand.plus.activities.MapActivity;
 import net.osmand.plus.base.ContextMenuScrollFragment;
 import net.osmand.plus.helpers.AndroidUiHelper;
+import net.osmand.plus.routing.GpxApproximator;
 import net.osmand.plus.settings.backend.ApplicationMode;
+import net.osmand.router.RoutePlannerFrontEnd.GpxRouteApproximation;
 
 import org.apache.commons.logging.Log;
 
-import static net.osmand.plus.measurementtool.ProfileCard.*;
+import java.io.IOException;
-import static net.osmand.plus.measurementtool.SliderCard.*;
+
+import static net.osmand.plus.measurementtool.ProfileCard.ProfileCardListener;
+import static net.osmand.plus.measurementtool.SliderCard.SliderCardListener;
 
 public class GpxApproximationFragment extends ContextMenuScrollFragment
 		implements SliderCardListener, ProfileCardListener {
@@ -36,9 +44,16 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 	public static final String DISTANCE_THRESHOLD_KEY = "distance_threshold";
 	public static final String SNAP_TO_ROAD_APP_MODE_STRING_KEY = "snap_to_road_app_mode";
 
+	public static final int REQUEST_CODE = 1100;
+
 	private int menuTitleHeight;
 	private ApplicationMode snapToRoadAppMode = ApplicationMode.CAR;
-	private int distanceThreshold = 30;
+	private int distanceThreshold = 50;
+
+	private LocationsHolder locationsHolder;
+	@Nullable
+	private GpxApproximator gpxApproximator;
+	private ProgressBar progressBar;
 
 	@Override
 	public int getMainLayoutId() {
@@ -85,6 +100,43 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 			distanceThreshold = savedInstanceState.getInt(DISTANCE_THRESHOLD_KEY);
 			snapToRoadAppMode = ApplicationMode.valueOfStringKey(
 					savedInstanceState.getString(SNAP_TO_ROAD_APP_MODE_STRING_KEY), ApplicationMode.CAR);
+			try {
+				gpxApproximator = new GpxApproximator(requireMyApplication(), snapToRoadAppMode, distanceThreshold, locationsHolder);
+			} catch (Exception e) {
+				LOG.error(e.getMessage(), e);
+			}
+		} else {
+			try {
+				gpxApproximator = new GpxApproximator(requireMyApplication(), locationsHolder);
+			} catch (Exception e) {
+				LOG.error(e.getMessage(), e);
+			}
+		}
+
+		if (gpxApproximator != null) {
+			gpxApproximator.setApproximationProgress(new GpxApproximator.GpxApproximationProgressCallback() {
+
+				@Override
+				public void start() {
+					if (isResumed()) {
+						startProgress();
+					}
+				}
+
+				@Override
+				public void updateProgress(int progress) {
+					if (isResumed()) {
+						GpxApproximationFragment.this.updateProgress(progress);
+					}
+				}
+
+				@Override
+				public void finish() {
+					if (isResumed()) {
+						finishProgress();
+					}
+				}
+			});
 		}
 
 		if (isPortrait()) {
@@ -93,6 +145,12 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 		updateCards();
 		updateButtons(mainView);
 
+		progressBar = mainView.findViewById(R.id.progress_bar);
+		if (progressBar != null) {
+			requireMapActivity().setupRouteCalculationProgressBar(progressBar);
+			progressBar.setIndeterminate(false);
+		}
+
 		if (!isPortrait()) {
 			int widthNoShadow = getLandscapeNoShadowWidth();
 			FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(widthNoShadow, ViewGroup.LayoutParams.WRAP_CONTENT);
@@ -102,6 +160,8 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 		enterGpxApproximationMode();
 		runLayoutListener();
 
+		calculateGpxApproximation();
+
 		return mainView;
 	}
 
@@ -159,7 +219,7 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 			public void onClick(View v) {
 				Fragment fragment = getTargetFragment();
 				if (fragment instanceof GpxApproximationFragmentListener) {
-					((GpxApproximationFragmentListener) fragment).onApplyGpxApproximation(snapToRoadAppMode, distanceThreshold);
+					((GpxApproximationFragmentListener) fragment).onApplyGpxApproximation();
 				}
 				dismiss();
 			}
@@ -226,13 +286,13 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 		return (menuState & (MenuState.HEADER_ONLY | MenuState.HALF_SCREEN)) != 0;
 	}
 
-	public static void showInstance(@NonNull FragmentManager fm, @Nullable Fragment targetFragment, @NonNull ApplicationMode initialAppMode, int initialDistanceThreshold) {
+	public static void showInstance(@NonNull FragmentManager fm, @Nullable Fragment targetFragment, @NonNull LocationsHolder locationsHolder) {
 		try {
 			if (!fm.isStateSaved()) {
 				GpxApproximationFragment fragment = new GpxApproximationFragment();
-				fragment.setTargetFragment(targetFragment, 0);
+				fragment.setRetainInstance(true);
-				fragment.snapToRoadAppMode = initialAppMode;
+				fragment.setTargetFragment(targetFragment, REQUEST_CODE);
-				fragment.distanceThreshold = initialDistanceThreshold;
+				fragment.setLocationsHolder(locationsHolder);
 				fm.beginTransaction()
 						.replace(R.id.fragmentContainer, fragment, TAG)
 						.addToBackStack(TAG)
@@ -254,29 +314,94 @@ public class GpxApproximationFragment extends ContextMenuScrollFragment
 		}
 	}
 
-	@Override
+	public void calculateGpxApproximation() {
-	public void onSliderChange(int sliderValue) {
+		if (gpxApproximator != null) {
-		Fragment fragment = getTargetFragment();
+			try {
-		if (fragment instanceof GpxApproximationFragmentListener) {
+				gpxApproximator.setMode(snapToRoadAppMode);
-			((GpxApproximationFragmentListener) fragment).onChangeGpxApproxDistanceThreshold(snapToRoadAppMode, sliderValue);
+				gpxApproximator.setPointApproximation(distanceThreshold);
-			distanceThreshold = sliderValue;
+				approximateGpx();
+			} catch (Exception e) {
+				LOG.error(e.getMessage(), e);
+			}
 		}
 	}
 
+	@Override
+	public void onSliderChange(int sliderValue) {
+		distanceThreshold = sliderValue;
+		calculateGpxApproximation();
+	}
+
 	@Override
 	public void onProfileSelect(ApplicationMode applicationMode) {
+		snapToRoadAppMode = applicationMode;
+		calculateGpxApproximation();
+	}
+
+	public LocationsHolder getLocationsHolder() {
+		return locationsHolder;
+	}
+
+	public void setLocationsHolder(LocationsHolder locationsHolder) {
+		this.locationsHolder = locationsHolder;
+	}
+
+	public void startProgress() {
+		if (progressBar != null) {
+			progressBar.setProgress(0);
+			progressBar.setVisibility(View.VISIBLE);
+		}
+	}
+
+	public void finishProgress() {
+		if (progressBar != null) {
+			progressBar.setVisibility(View.GONE);
+		}
+	}
+
+	public void updateProgress(int progress) {
+		if (progressBar != null) {
+			if (progressBar.getVisibility() != View.VISIBLE) {
+				progressBar.setVisibility(View.VISIBLE);
+			}
+			progressBar.setProgress(progress);
+		}
+	}
+
+	private void approximateGpx() {
+		if (gpxApproximator != null) {
+			gpxApproximator.calculateGpxApproximation(new ResultMatcher<GpxRouteApproximation>() {
+				@Override
+				public boolean publish(final GpxRouteApproximation gpxApproximation) {
+					OsmandApplication app = getMyApplication();
+					if (app != null) {
+						app.runInUIThread(new Runnable() {
+							@Override
+							public void run() {
 								Fragment fragment = getTargetFragment();
 								if (fragment instanceof GpxApproximationFragmentListener) {
-			((GpxApproximationFragmentListener) fragment).onChangeGpxApproxDistanceThreshold(applicationMode, distanceThreshold);
+									((GpxApproximationFragmentListener) fragment).onGpxApproximationDone(gpxApproximation);
-			snapToRoadAppMode = applicationMode;
+								}
+							}
+						});
+						return true;
+					}
+					return false;
+				}
+
+				@Override
+				public boolean isCancelled() {
+					return false;
+				}
+			});
 		}
 	}
 
 	public interface GpxApproximationFragmentListener {
 
-		void onChangeGpxApproxDistanceThreshold(ApplicationMode mode, int distanceThreshold);
+		void onGpxApproximationDone(GpxRouteApproximation gpxApproximation);
 
-		void onApplyGpxApproximation(ApplicationMode mode, int distanceThreshold);
+		void onApplyGpxApproximation();
 
 		void onCancelGpxApproximation();
 	}

OsmAnd/src/net/osmand/plus/measurementtool/MeasurementToolFragment.java

@@ -61,6 +61,7 @@ import net.osmand.plus.activities.MapActivity;
 import net.osmand.plus.activities.TrackActivity;
 import net.osmand.plus.base.BaseOsmAndFragment;
 import net.osmand.plus.helpers.AndroidUiHelper;
+import net.osmand.plus.measurementtool.GpxApproximationFragment.GpxApproximationFragmentListener;
 import net.osmand.plus.measurementtool.NewGpxData.ActionType;
 import net.osmand.plus.measurementtool.OptionsBottomSheetDialogFragment.OptionsFragmentListener;
 import net.osmand.plus.measurementtool.RouteBetweenPointsBottomSheetDialogFragment.RouteBetweenPointsFragmentListener;
@@ -73,7 +74,6 @@ import net.osmand.plus.measurementtool.command.ClearPointsCommand;
 import net.osmand.plus.measurementtool.command.MovePointCommand;
 import net.osmand.plus.measurementtool.command.RemovePointCommand;
 import net.osmand.plus.measurementtool.command.ReorderPointCommand;
-import net.osmand.plus.routing.GpxApproximator;
 import net.osmand.plus.settings.backend.ApplicationMode;
 import net.osmand.plus.settings.backend.OsmandSettings;
 import net.osmand.plus.views.controls.ReorderItemTouchHelperCallback;
@@ -84,7 +84,6 @@ import net.osmand.plus.views.mapwidgets.MapInfoWidgetsFactory.TopToolbarView;
 import net.osmand.router.RoutePlannerFrontEnd.GpxRouteApproximation;
 
 import java.io.File;
-import java.io.IOException;
 import java.lang.ref.WeakReference;
 import java.text.MessageFormat;
 import java.text.SimpleDateFormat;
@@ -94,7 +93,6 @@ import java.util.List;
 import java.util.Locale;
 
 import static net.osmand.IndexConstants.GPX_FILE_EXT;
-import static net.osmand.plus.measurementtool.GpxApproximationFragment.GpxApproximationFragmentListener;
 import static net.osmand.plus.measurementtool.MeasurementEditingContext.CalculationType;
 import static net.osmand.plus.measurementtool.MeasurementEditingContext.ExportAsGpxListener;
 import static net.osmand.plus.measurementtool.MeasurementEditingContext.SnapToRoadProgressListener;
@@ -104,7 +102,7 @@ import static net.osmand.plus.measurementtool.SelectFileBottomSheet.SelectFileLi
 import static net.osmand.plus.measurementtool.StartPlanRouteBottomSheet.StartPlanRouteListener;
 
 public class MeasurementToolFragment extends BaseOsmAndFragment implements RouteBetweenPointsFragmentListener,
-		GpxApproximationFragmentListener, OptionsFragmentListener {
+		OptionsFragmentListener, GpxApproximationFragmentListener {
 
 	public static final String TAG = MeasurementToolFragment.class.getSimpleName();
 
@@ -138,7 +136,6 @@ public class MeasurementToolFragment extends BaseOsmAndFragment implements Route
 	private boolean gpxPointsAdded;
 
 	private MeasurementEditingContext editingCtx = new MeasurementEditingContext();
-	private GpxApproximator gpxApproximator;
 
 	private LatLon initialPoint;
 
@@ -547,39 +544,6 @@ public class MeasurementToolFragment extends BaseOsmAndFragment implements Route
 		return R.color.status_bar_transparent_gradient;
 	}
 
-	private void approximateGpx() {
-		if (gpxApproximator != null) {
-			try {
-				GpxRouteApproximation gpxApproximation = gpxApproximator.calculateGpxApproximation();
-				displayApproximatedPoints(gpxApproximation);
-			} catch (IOException e) {
-			} catch (InterruptedException e) {
-			}
-		}
-	}
-
-	@Override
-	public void onChangeGpxApproxDistanceThreshold(ApplicationMode mode, int distanceThreshold) {
-		if (gpxApproximator != null) {
-			try {
-				gpxApproximator.setMode(mode);
-				gpxApproximator.setPointApproximation(distanceThreshold);
-				approximateGpx();
-			} catch (IOException e) {
-			}
-		}
-	}
-
-	@Override
-	public void onApplyGpxApproximation(ApplicationMode mode, int distanceThreshold) {
-
-	}
-
-	@Override
-	public void onCancelGpxApproximation() {
-
-	}
-
 	@Nullable
 	private MapActivity getMapActivity() {
 		Activity activity = getActivity();
@@ -659,13 +623,8 @@ public class MeasurementToolFragment extends BaseOsmAndFragment implements Route
 				case SnapTrackWarningBottomSheet.CONTINUE_REQUEST_CODE:
 					MapActivity mapActivity = getMapActivity();
 					if (mapActivity != null) {
-						try {
-							gpxApproximator = new GpxApproximator(requireMyApplication(), new LocationsHolder(editingCtx.getPoints()));
 						GpxApproximationFragment.showInstance(mapActivity.getSupportFragmentManager(),
-									this, gpxApproximator.getMode(), (int) gpxApproximator.getPointApproximation());
+								this, new LocationsHolder(editingCtx.getPoints()));
-						} catch (IOException e) {
-
-						}
 					}
 					break;
 			}
@@ -1098,7 +1057,7 @@ public class MeasurementToolFragment extends BaseOsmAndFragment implements Route
 		}
 	}
 
-	private void displayApproximatedPoints(GpxRouteApproximation gpxApproximation) {
+	public void displayApproximatedPoints(GpxRouteApproximation gpxApproximation) {
 		MeasurementToolLayer measurementLayer = getMeasurementLayer();
 		if (measurementLayer != null) {
 			editingCtx.setPoints(gpxApproximation);
@@ -1968,4 +1927,19 @@ public class MeasurementToolFragment extends BaseOsmAndFragment implements Route
 			return NO_COLOR;
 		}
 	}
+
+	@Override
+	public void onGpxApproximationDone(GpxRouteApproximation gpxApproximation) {
+		displayApproximatedPoints(gpxApproximation);
+	}
+
+	@Override
+	public void onApplyGpxApproximation() {
+
+	}
+
+	@Override
+	public void onCancelGpxApproximation() {
+
+	}
 }

OsmAnd/src/net/osmand/plus/measurementtool/SliderCard.java

@@ -46,10 +46,20 @@ public class SliderCard extends BaseCard {
 				if (fromUser) {
 					String valueStr = getStringValueWithMetric((int) value);
 					thresholdDistanceValue.setText(valueStr);
-					if (listener != null) {
-						listener.onSliderChange((int) value);
 				}
 			}
+		});
+		slider.addOnSliderTouchListener(new Slider.OnSliderTouchListener() {
+			@Override
+			public void onStartTrackingTouch(@NonNull Slider slider) {
+
+			}
+
+			@Override
+			public void onStopTrackingTouch(@NonNull Slider slider) {
+				if (listener != null) {
+					listener.onSliderChange((int) slider.getValue());
+				}
 			}
 		});
 	}

OsmAnd/src/net/osmand/plus/routing/GpxApproximator.java

@@ -1,18 +1,35 @@
 package net.osmand.plus.routing;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import net.osmand.LocationsHolder;
+import net.osmand.PlatformUtil;
+import net.osmand.ResultMatcher;
 import net.osmand.data.LatLon;
 import net.osmand.plus.OsmandApplication;
+import net.osmand.plus.measurementtool.GpxApproximationFragment;
 import net.osmand.plus.routing.RouteProvider.RoutingEnvironment;
 import net.osmand.plus.settings.backend.ApplicationMode;
+import net.osmand.router.RouteCalculationProgress;
+import net.osmand.router.RoutePlannerFrontEnd;
 import net.osmand.router.RoutePlannerFrontEnd.GpxPoint;
 import net.osmand.router.RoutePlannerFrontEnd.GpxRouteApproximation;
+import net.osmand.search.core.SearchResult;
+
+import org.apache.commons.logging.Log;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
 
 public class GpxApproximator {
 
+	protected static final Log log = PlatformUtil.getLog(GpxApproximator.class);
+
 	private OsmandApplication ctx;
 	private RoutingHelper routingHelper;
 
@@ -23,8 +40,21 @@ public class GpxApproximator {
 	private List<GpxPoint> points;
 	private LatLon start;
 	private LatLon end;
+	private double pointApproximation = 50;
 
-	public GpxApproximator(OsmandApplication ctx, LocationsHolder locationsHolder) throws IOException {
+	private ThreadPoolExecutor singleThreadedExecutor;
+	private GpxApproximationProgressCallback approximationProgress;
+
+	public interface GpxApproximationProgressCallback {
+
+		void start();
+
+		void updateProgress(int progress);
+
+		void finish();
+	}
+
+	public GpxApproximator(@NonNull OsmandApplication ctx, @NonNull LocationsHolder locationsHolder) throws IOException {
 		this.ctx = ctx;
 		this.locationsHolder = locationsHolder;
 		this.routingHelper = ctx.getRoutingHelper();
@@ -33,26 +63,48 @@ public class GpxApproximator {
 			start = locationsHolder.getLatLon(0);
 			end = locationsHolder.getLatLon(locationsHolder.getSize() - 1);
 			prepareEnvironment(ctx, mode);
-			this.points = routingHelper.generateGpxPoints(env, gctx, locationsHolder);
 		}
+		init();
 	}
 
-	public GpxApproximator(OsmandApplication ctx, ApplicationMode mode, double pointApproximation, LocationsHolder locationsHolder) throws IOException {
+	public GpxApproximator(@NonNull OsmandApplication ctx, @NonNull ApplicationMode mode, double pointApproximation, @NonNull LocationsHolder locationsHolder) throws IOException {
 		this.ctx = ctx;
+		this.locationsHolder = locationsHolder;
+		this.pointApproximation = pointApproximation;
 		this.routingHelper = ctx.getRoutingHelper();
 		this.mode = mode;
 		if (locationsHolder.getSize() > 1) {
 			start = locationsHolder.getLatLon(0);
 			end = locationsHolder.getLatLon(locationsHolder.getSize() - 1);
 			prepareEnvironment(ctx, mode);
-			gctx.MINIMUM_POINT_APPROXIMATION = pointApproximation;
-			this.points = routingHelper.generateGpxPoints(env, gctx, locationsHolder);
 		}
+		init();
 	}
 
-	private void prepareEnvironment(OsmandApplication ctx, ApplicationMode mode) throws IOException {
+	private void init() {
+		singleThreadedExecutor = new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
+	}
+
+	private void prepareEnvironment(@NonNull OsmandApplication ctx, @NonNull ApplicationMode mode) throws IOException {
 		this.env = routingHelper.getRoutingEnvironment(ctx, mode, start, end);
-		this.gctx = new GpxRouteApproximation(env.getCtx());
+	}
+
+	private GpxRouteApproximation getNewGpxApproximationContext(@Nullable GpxRouteApproximation gctx) {
+		GpxRouteApproximation newContext = gctx != null ? new GpxRouteApproximation(gctx) : new GpxRouteApproximation(env.getCtx());
+		newContext.ctx.calculationProgress = new RouteCalculationProgress();
+		newContext.MINIMUM_POINT_APPROXIMATION = pointApproximation;
+		return newContext;
+	}
+
+	private List<GpxPoint> getPoints() {
+		if (points == null) {
+			points = routingHelper.generateGpxPoints(env, getNewGpxApproximationContext(null), locationsHolder);
+		}
+		List<GpxPoint> points = new ArrayList<>(this.points.size());
+		for (GpxPoint p : this.points) {
+			points.add(new GpxPoint(p));
+		}
+		return points;
 	}
 
 	public ApplicationMode getMode() {
@@ -68,18 +120,82 @@ public class GpxApproximator {
 	}
 
 	public double getPointApproximation() {
-		return gctx.MINIMUM_POINT_APPROXIMATION;
+		return pointApproximation;
 	}
 
 	public void setPointApproximation(double pointApproximation) {
-		gctx.MINIMUM_POINT_APPROXIMATION = pointApproximation;
+		this.pointApproximation = pointApproximation;
 	}
 
 	public LocationsHolder getLocationsHolder() {
 		return locationsHolder;
 	}
 
-	public GpxRouteApproximation calculateGpxApproximation() throws IOException, InterruptedException {
+	public GpxApproximationProgressCallback getApproximationProgress() {
-		return routingHelper.calculateGpxApproximation(env, gctx, points);
+		return approximationProgress;
+	}
+
+	public void setApproximationProgress(GpxApproximationProgressCallback approximationProgress) {
+		this.approximationProgress = approximationProgress;
+	}
+
+	public void calculateGpxApproximation(@NonNull final ResultMatcher<GpxRouteApproximation> resultMatcher) {
+		if (gctx != null) {
+			gctx.calculationCancelled = true;
+		}
+		final GpxRouteApproximation gctx = getNewGpxApproximationContext(this.gctx);
+		this.gctx = gctx;
+		startProgress();
+		updateProgress(gctx);
+		singleThreadedExecutor.submit(new Runnable() {
+			@Override
+			public void run() {
+				try {
+					routingHelper.calculateGpxApproximation(env, gctx, getPoints(), resultMatcher);
+				} catch (Exception e) {
+					resultMatcher.publish(null);
+					log.error(e.getMessage(), e);
+				}
+			}
+		});
+	}
+
+	private void startProgress() {
+		final GpxApproximationProgressCallback approximationProgress = this.approximationProgress;
+		if (approximationProgress != null) {
+			approximationProgress.start();
+		}
+	}
+
+	private void finishProgress() {
+		final GpxApproximationProgressCallback approximationProgress = this.approximationProgress;
+		if (approximationProgress != null) {
+			approximationProgress.finish();
+		}
+	}
+
+	private void updateProgress(@NonNull final GpxRouteApproximation gctx) {
+		final GpxApproximationProgressCallback approximationProgress = this.approximationProgress;
+		if (approximationProgress != null) {
+			ctx.runInUIThread(new Runnable() {
+
+				@Override
+				public void run() {
+					RouteCalculationProgress calculationProgress = gctx.ctx.calculationProgress;
+					if (gctx.isCalculationDone() && GpxApproximator.this.gctx == gctx) {
+						finishProgress();
+					}
+					if (!gctx.isCalculationDone() && calculationProgress != null && !calculationProgress.isCancelled) {
+						float pr = calculationProgress.getLinearProgress();
+						approximationProgress.updateProgress((int) pr);
+						if (GpxApproximator.this.gctx != gctx) {
+							// different calculation started
+						} else {
+							updateProgress(gctx);
+						}
+					}
+				}
+			}, 300);
+		}
 	}
 }

OsmAnd/src/net/osmand/plus/routing/RouteProvider.java

@@ -15,6 +15,7 @@ import net.osmand.GPXUtilities.WptPt;
 import net.osmand.Location;
 import net.osmand.LocationsHolder;
 import net.osmand.PlatformUtil;
+import net.osmand.ResultMatcher;
 import net.osmand.binary.BinaryMapIndexReader;
 import net.osmand.data.LatLon;
 import net.osmand.data.LocationPoint;
@@ -716,13 +717,8 @@ public class RouteProvider {
 		return env.router.generateGpxPoints(gctx, locationsHolder);
 	}
 
-	public GpxRouteApproximation calculateGpxPointsApproximation(RoutingEnvironment env, GpxRouteApproximation gctx, List<GpxPoint> points) throws IOException, InterruptedException {
+	public GpxRouteApproximation calculateGpxPointsApproximation(RoutingEnvironment env, GpxRouteApproximation gctx, List<GpxPoint> points, ResultMatcher<GpxRouteApproximation> resultMatcher) throws IOException, InterruptedException {
-		if (points != null && points.size() > 1) {
+		return env.router.searchGpxRoute(gctx, points, resultMatcher);
-			if (!Algorithms.isEmpty(points)) {
-				return env.router.searchGpxRoute(gctx, points);
-			}
-		}
-		return null;
 	}
 
 	protected RoutingEnvironment calculateRoutingEnvironment(RouteCalculationParams params, boolean calcGPXRoute, boolean skipComplex) throws IOException {

OsmAnd/src/net/osmand/plus/routing/RoutingHelper.java

@@ -7,6 +7,7 @@ import net.osmand.GPXUtilities.WptPt;
 import net.osmand.Location;
 import net.osmand.LocationsHolder;
 import net.osmand.PlatformUtil;
+import net.osmand.ResultMatcher;
 import net.osmand.ValueHolder;
 import net.osmand.binary.RouteDataObject;
 import net.osmand.data.LatLon;
@@ -1364,8 +1365,8 @@ public class RoutingHelper {
 		return provider.generateGpxPoints(env, gctx, locationsHolder);
 	}
 
-	public GpxRouteApproximation calculateGpxApproximation(RoutingEnvironment env, GpxRouteApproximation gctx, List<GpxPoint> points) throws IOException, InterruptedException {
+	public GpxRouteApproximation calculateGpxApproximation(RoutingEnvironment env, GpxRouteApproximation gctx, List<GpxPoint> points, ResultMatcher<GpxRouteApproximation> resultMatcher) throws IOException, InterruptedException {
-		return provider.calculateGpxPointsApproximation(env, gctx, points);
+		return provider.calculateGpxPointsApproximation(env, gctx, points, resultMatcher);
 	}
 
 	public void notifyIfRouteIsCalculated() {