altoslib: Preload maps based on distance rather than number of tiles

This lets you get the specific area requested at all zoom levels,
rather than having further detail only at lower resolution zooms.

Signed-off-by: Keith Packard <keithp@keithp.com>

3 files changed, 65 insertions, 11 deletions

diff --git a/altosdroid/res/layout/map_preload.xml b/altosdroid/res/layout/map_preload.xml
index 1d1fca32..dc613bf2 100644
--- a/altosdroid/res/layout/map_preload.xml
+++ b/altosdroid/res/layout/map_preload.xml
@@ -103,15 +103,15 @@
 	       android:prompt="@string/preload_max_zoom"
 	       android:spinnerMode="dropdown"
 	       />
-      <TextView android:id="@+id/preload_tile_radius_label"
+      <TextView android:id="@+id/preload_radius_label"
 		android:layout_width="fill_parent"
 		android:layout_height="wrap_content"
-		android:text="@string/preload_tile_radius"
+		android:text="@string/preload_radius"
 		/>
-      <Spinner android:id="@+id/preload_tile_radius"
+      <Spinner android:id="@+id/preload_radius"
 	       android:layout_width="fill_parent"
 	       android:layout_height="wrap_content"
-	       android:prompt="@string/preload_tile_radius"
+	       android:prompt="@string/preload_radius"
 	       android:spinnerMode="dropdown"
 	       />
       <Button android:id="@+id/preload_load"
diff --git a/altosdroid/res/values/strings.xml b/altosdroid/res/values/strings.xml
index 8c299a35..36b07bc2 100644
--- a/altosdroid/res/values/strings.xml
+++ b/altosdroid/res/values/strings.xml
@@ -106,7 +106,7 @@
 	<string name="preload_terrain">Terrain</string>
 	<string name="preload_min_zoom">Minimum Zoom</string>
 	<string name="preload_max_zoom">Maximum Zoom</string>
-	<string name="preload_tile_radius">Tile Radius</string>
+	<string name="preload_radius">Radius</string>
 	
 	<string name="preload_load">Load Map</string>
 </resources>
diff --git a/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java b/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
index 1968edae..498b208e 100644
--- a/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
+++ b/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
@@ -61,7 +61,8 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 	private Spinner		known_sites_spinner;
 	private Spinner		min_zoom;
 	private Spinner		max_zoom;
-	private Spinner		tile_radius;
+	private TextView	radius_label;
+	private Spinner		radius;
 
 	private EditText	latitude;
 	private EditText	longitude;
@@ -227,8 +228,17 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		return value(max_zoom);
 	}
 
-	private int radius() {
-		return value(tile_radius);
+	private double value_distance(Spinner spinner) {
+		return (Double) spinner.getSelectedItem();
+	}
+
+	private double radius() {
+		double r = value_distance(radius);
+		if (AltosPreferences.imperial_units())
+			r = AltosConvert.distance.inverse(r);
+		else
+			r = r * 1000;
+		return r;
 	}
 
 	private int bit(CheckBox box, int value) {
@@ -250,11 +260,14 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 			double	lon = longitude();
 			int	min = min_z();
 			int	max = max_z();
-			int	r = radius();
+			double	r = radius();
 			int	t = types();
 
+			AltosDebug.debug("PreloadMap load %f %f %d %d %f %d\n",
+					 lat, lon, min, max, r, t);
 			loader.load(lat, lon, min, max, r, t);
 		} catch (ParseException e) {
+			AltosDebug.debug("PreloadMap load raised exception %s", e.toString());
 		}
 	}
 
@@ -276,6 +289,37 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		spinner.setSelection(spinner_def);
 	}
 
+
+	private void add_distance(Spinner spinner, double[] distances_km, double def_km, double[] distances_mi, double def_mi) {
+
+		ArrayAdapter<Double> adapter = new ArrayAdapter<Double>(this, android.R.layout.simple_spinner_item);
+
+		int	spinner_def = 0;
+		int	pos = 0;
+
+		double[] distances;
+		double	def;
+		if (AltosPreferences.imperial_units()) {
+			distances = distances_mi;
+			def = def_mi;
+		} else {
+			distances = distances_km;
+			def = def_km;
+		}
+
+		for (int i = 0; i < distances.length; i++) {
+			adapter.add(distances[i]);
+			if (distances[i] == def)
+				spinner_def = pos;
+			pos++;
+		}
+
+		spinner.setAdapter(adapter);
+		spinner.setSelection(spinner_def);
+	}
+
+
+
 	class SiteListListener implements OnItemSelectedListener {
 		public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
 			AltosLaunchSite	site = (AltosLaunchSite) parent.getItemAtPosition(pos);
@@ -289,6 +333,11 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		}
 	}
 
+	double[]	radius_mi = { 1, 2, 5, 10, 20 };
+	double		radius_def_mi = 2;
+	double[]	radius_km = { 1, 2, 5, 10, 20, 30 };
+	double		radius_def_km = 2;
+
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
@@ -326,8 +375,13 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		add_numbers(max_zoom,
 			    AltosMap.min_zoom - AltosMap.default_zoom,
 			    AltosMap.max_zoom - AltosMap.default_zoom, 2);
-		tile_radius = (Spinner) findViewById(R.id.preload_tile_radius);
-		add_numbers(tile_radius, 1, 5, 5);
+		radius_label = (TextView) findViewById(R.id.preload_radius_label);
+		radius = (Spinner) findViewById(R.id.preload_radius);
+		if (AltosPreferences.imperial_units())
+			radius_label.setText("Radius (miles)");
+		else
+			radius_label.setText("Radius (km)");
+		add_distance(radius, radius_km, radius_def_km, radius_mi, radius_def_mi);
 
 		progress = (ProgressBar) findViewById(R.id.preload_progress);