Add settings

apps/openseachart/app.js

@@ -5,18 +5,15 @@ var fix = {};
 var last_course = -1;
 var cur_course = -1;
 var course_marker_len = g.getWidth()/4;
-    
+
+var settings = require("Storage").readJSON('openseacsettings.json', 1) || {};
+
 function redraw() {
   g.setClipRect(0,y1,g.getWidth()-1,y2);
   m.draw();
   drawMarker();
-  if (WIDGETS["gpsrec"] && WIDGETS["gpsrec"].plotTrack) {
-    g.flip(); // force immediate draw on double-buffered screens - track will update later
-    g.setColor(0.75,0.2,0);
-    WIDGETS["gpsrec"].plotTrack(m);
-  }
   g.setClipRect(0,0,g.getWidth()-1,g.getHeight()-1);
-  if (cur_course!=-1) drawCourseMarker(cur_course);
+  if (settings.drawcourse && cur_course!=-1) drawCourseMarker(cur_course);
 }
 
 function drawMarker() {
@@ -43,16 +40,16 @@ Bangle.on('GPS',function(f) {
     txt += " - NO FIX";
   else {
     if (fix.satellites>3 && fix.speed>2) { // only uses fixes w/ more than 3 sats and speed > 2kph
-      if (cur_course!=-1) cur_course = 0.8*cur_course + 0.2*fix.course;
-      else cur_course = fix.course;
+      cur_course = fix.course;
       if (Math.abs(cur_course-last_course)>10 && Math.abs(cur_course-last_course)<350) {
-	last_course = cur_course;
-	redraw();
+	      last_course = cur_course;
+	      redraw();
       }
     }
   }
   g.drawString(txt,g.getWidth()/2,y1 + 4);
   drawMarker();
+  if (settings.autocenter) recenter();
 });
 Bangle.setGPSPower(1, "app");
 

apps/openseachart/settings.js

@@ -0,0 +1,41 @@
+// This file should contain exactly one function, which shows the app's settings
+/**
+ * @param {function} back Use back() to return to settings menu
+ */
+(function(back) {
+  const SETTINGS_FILE = 'openseacsettings.json'
+  // initialize with default settings...
+  let s = {
+    'drawcourse': true,
+    'autocenter': false,
+  }
+  // ...and overwrite them with any saved values
+  // This way saved values are preserved if a new version adds more settings
+  const storage = require('Storage')
+  const saved = storage.readJSON(SETTINGS_FILE, 1) || {}
+  for (const key in saved) {
+    s[key] = saved[key];
+  }
+  // creates a function to safe a specific setting, e.g.  save('color')(1)
+  function save(key) {
+    return function (value) {
+      s[key] = value;
+      storage.write(SETTINGS_FILE, s);
+    }
+  }
+  const menu = {
+    '': { 'title': 'OpenSeaChart' },
+    '< Back': back,
+    'Draw course': {
+      value: s.drawcourse,
+      format: boolFormat,
+      onchange: save('drawcourse'),
+    },
+    'Auto center': {
+      value: s.autocenter,
+      format: boolFormat,
+      onchange: save('autoconnect'),
+    }
+  }
+  E.showMenu(menu);
+})