adding settings

apps/metronome/metronome.js

@@ -6,8 +6,26 @@ var tindex=0;  //index to iterate through time_diffs
 
 Bangle.setLCDTimeout(undefined);  //do not deaktivate display while running this app
 
+const storage = require("Storage");
+const SETTINGS_FILE = 'metronome.settings.json';
+
+//return setting
+function setting(key) {
+  //define default settings
+  const DEFAULTS = {
+    'beatsperbar': 4,
+  };
+  if (!settings) { loadSettings(); }
+  return (key in settings) ? settings[key] : DEFAULTS[key];
+}
+
+//load settings
+let settings;
+
+function loadSettings() {
+  settings = storage.readJSON(SETTINGS_FILE, 1) || {};
+
 function changecolor() {
-  const maxColors = 2;
   const colors = {
         0: { value: 0xF800, name: "Red" },
         1: { value: 0xFFFF, name: "White" },
@@ -17,21 +35,10 @@ function changecolor() {
         5: { value: 0xFFFF, name: "White" },
         6: { value: 0x03E0, name: "DarkGreen" },
         7: { value: 0xFFFF, name: "White" },
-        8: { value: 0x7BEF, name: "DarkGrey" },
+        8: { value: 0x03E0, name: "DarkGreen" },
-     //   9: { value: 0x001F, name: "Blue" },
-     //   9: { value: 0x001F, name: "Blue" },
-     //   10: { value: 0x07E0, name: "Green" },
-     //   11: { value: 0x07FF, name: "Cyan" },
-        1: { value: 0xF800, name: "Red" },
-     //   13: { value: 0xF81F, name: "Magenta" },
-     //   14: { value: 0xFFE0, name: "Yellow" },
-     //   15: { value: 0xFFFF, name: "White" },
-     //   16: { value: 0xFD20, name: "Orange" },
-     //   17: { value: 0xAFE5, name: "GreenYellow" },
-     //   18: { value: 0xF81F, name: "Pink" },
     };
     g.setColor(colors[cindex].value);
-    if (cindex == maxColors-1) {
+    if (cindex == setting('beatsperbar')-1) {
       cindex = 0;
     }
     else {
@@ -52,6 +59,7 @@ function updateScreen() {
   g.drawString(Math.floor(bpm)+"bpm", 5, 60);
 }
 
+  
 Bangle.on('touch', function(button) {
 // setting bpm by tapping the screen. Uses the mean time difference between several tappings.
     if (tindex < time_diffs.length) {

apps/metronome/settings.js

@@ -0,0 +1,40 @@
+// 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 = 'metronome.settings.json';
+
+  // initialize with default settings...
+  let s = {
+    'beatsperbar': 4,
+  };
+  // ...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': 'Metronome' },
+    '< Back': back,
+    'beats per bar': {
+      value: s.beatsperbar,
+      min: 1,
+      max: 8,
+      step: 1,
+      onchange: save('beatsperbar'),
+    },
+  };
+  E.showMenu(menu);
+});