Weather: refactoring and reduced ram usage

These changes reduce the memory usage of the ram widget by up to 70
JSVars, depending on the weather.

apps.json

@@ -571,7 +571,7 @@
   { "id": "weather",
     "name": "Weather",
     "icon": "icon.png",
-    "version":"0.07",
+    "version":"0.08",
     "description": "Show Gadgetbridge weather report",
     "readme": "readme.md",
     "tags": "widget,outdoors",

apps/weather/ChangeLog

@@ -3,4 +3,5 @@
 0.04: Adjust "weather unknown" message according to Bluetooth connection.
 0.05: Add wind direction.
 0.06: Use setUI for launcher.
-0.07: Add theme support and unknown icon.
+0.07: Add theme support and unknown icon.
+0.08: Refactor and reduce widget ram usage.

apps/weather/app.js

@@ -1,5 +1,6 @@
 (() => {
   const weather = require('weather');
+  let current = weather.get();
 
   function formatDuration(millis) {
     let pluralize = (n, w) => n + " " + w + (n == 1 ? "" : "s");
@@ -10,16 +11,15 @@
   }
 
   function draw() {
-    let w = weather.current;
     g.reset();
     g.clearRect(0, 24, 239, 239);
 
-    weather.drawIcon(w.txt, 65, 90, 55);
+    weather.drawIcon(current.txt, 65, 90, 55);
     const locale = require("locale");
 
     g.reset();
 
-    const temp = locale.temp(w.temp-273.15).match(/^(\D*\d*)(.*)$/);
+    const temp = locale.temp(current.temp-273.15).match(/^(\D*\d*)(.*)$/);
     let width = g.setFont("Vector", 40).stringWidth(temp[1]);
     width += g.setFont("Vector", 20).stringWidth(temp[2]);
     g.setFont("Vector", 40).setFontAlign(-1, -1, 0);
@@ -31,19 +31,19 @@
     g.setFontAlign(-1, 0, 0);
     g.drawString("Humidity", 135, 130);
     g.setFontAlign(1, 0, 0);
-    g.drawString(w.hum+"%", 225, 130);
-    if ('wind' in w) {
+    g.drawString(current.hum+"%", 225, 130);
+    if ('wind' in current) {
       g.setFontAlign(-1, 0, 0);
       g.drawString("Wind", 135, 142);
       g.setFontAlign(1, 0, 0);
-      g.drawString(locale.speed(w.wind)+' '+w.wrose.toUpperCase(), 225, 142);
+      g.drawString(locale.speed(current.wind)+' '+current.wrose.toUpperCase(), 225, 142);
     }
 
     g.setFont("6x8", 2).setFontAlign(0, 0, 0);
-    g.drawString(w.loc, 120, 170);
+    g.drawString(current.loc, 120, 170);
 
     g.setFont("6x8", 1).setFontAlign(0, 0, 0);
-    g.drawString(w.txt.charAt(0).toUpperCase()+w.txt.slice(1), 120, 190);
+    g.drawString(current.txt.charAt(0).toUpperCase()+current.txt.slice(1), 120, 190);
 
     drawUpdateTime();
 
@@ -51,8 +51,8 @@
   }
 
   function drawUpdateTime() {
-    if (!weather.current || !weather.current.time) return;
-    let text = `Last update received ${formatDuration(Date.now() - weather.current.time)} ago`;
+    if (!current || !current.time) return;
+    let text = `Last update received ${formatDuration(Date.now() - current.time)} ago`;
     g.reset();
     g.clearRect(0, 202, 239, 210);
     g.setFont("6x8", 1).setFontAlign(0, 0, 0);
@@ -60,8 +60,9 @@
   }
 
   function update() {
+    current = weather.get();
     NRF.removeListener("connect", update);
-    if (weather.current) {
+    if (current) {
       draw();
     } else if (NRF.getSecurityStatus().connected) {
       E.showMessage("Weather unknown\n\nIs Gadgetbridge\nweather reporting\nset up on your\nphone?");

apps/weather/lib.js

@@ -1,6 +1,6 @@
 const storage = require('Storage');
 
-let expiryTimeout = undefined;
+let expiryTimeout;
 function scheduleExpiry(json) {
   if (expiryTimeout) {
     clearTimeout(expiryTimeout);
@@ -9,53 +9,35 @@ function scheduleExpiry(json) {
   let expiry = "expiry" in json ? json.expiry : 2*3600000;
   if (json.weather && json.weather.time && expiry) {
     let t = json.weather.time + expiry - Date.now();
-    expiryTimeout = setTimeout(() => {
-      expiryTimeout = undefined;
-
-      let json = storage.readJSON('weather.json')||{};
-      delete json.weather;
-      storage.write('weather.json', json);
-
-      exports.current = undefined;
-      exports.emit("update");
-    }, t);
+    expiryTimeout = setTimeout(update, t);
   }
 }
 
-/**
- * Convert numeric direction into human-readable label
- *
- * @param {number} deg - Direction in degrees
- * @return {string|null} - Nearest compass point
- */
-function compassRose(deg) {
-  if (typeof deg === 'undefined') return null;
-  while (deg<0 || deg>360) {
-    deg = (deg+360)%360;
-  }
-  return ['n','ne','e','se','s','sw','w','nw','n'][Math.floor((deg+22.5)/45)];
-}
-
-function setCurrentWeather(json) {
-  scheduleExpiry(json);
-  exports.current = json.weather;
-}
-
 function update(weatherEvent) {
-  let weather = Object.assign({}, weatherEvent);
-  weather.time = Date.now();
-  if ('wdir' in weather) {
-    weather.wrose = compassRose(weather.wdir);
-  }
-  delete weather.t;
-
   let json = storage.readJSON('weather.json')||{};
-  json.weather = weather;
+  
+  if (weatherEvent) {
+    let weather = weatherEvent.clone();
+    delete weather.t;
+    weather.time = Date.now();
+    if (weather.wdir != null) {
+      // Convert numeric direction into human-readable label
+      let deg = weather.wdir;
+      while (deg<0 || deg>360) {
+        deg = (deg+360)%360;
+      }
+      weather.wrose = ['n','ne','e','se','s','sw','w','nw','n'][Math.floor((deg+22.5)/45)];
+    }
+
+    json.weather = weather;
+  }
+  else {
+    delete json.weather;
+  }
+
   storage.write('weather.json', json);
-
-  setCurrentWeather(json);
-
-  exports.emit("update");
+  scheduleExpiry(json);
+  exports.emit("update", json.weather);
 }
 
 const _GB = global.GB;
@@ -64,7 +46,11 @@ global.GB = (event) => {
   if (_GB) setTimeout(_GB, 0, event);
 };
 
-setCurrentWeather(storage.readJSON('weather.json')||{});
+exports.get = function() {
+  return storage.readJSON('weather.json').weather;
+}
+
+scheduleExpiry(storage.readJSON('weather.json')||{});
 
 exports.drawIcon = function(cond, x, y, r) {
   function drawSun(x, y, r) {

apps/weather/widget.js

@@ -1,45 +1,23 @@
 (() => {
   const weather = require('weather');
 
-  function draw() {
-    const w = weather.current;
-    if (!w) return;
-    g.reset();
-    g.clearRect(this.x, this.y, this.x+this.width-1, this.y+23);
-    if (w.txt) {
-      weather.drawIcon(w.txt, this.x+10, this.y+8, 7.5);
-    }
-    if (w.temp) {
-      let t = require('locale').temp(w.temp-273.15);  // applies conversion
-      t = t.match(/[\d\-]*/)[0]; // but we have no room for units
-      g.reset();
-      g.setFontAlign(0, 1); // center horizontally at bottom of widget
-      g.setFont('6x8', 1);
-      g.drawString(t, this.x+10, this.y+24);
-    }
-  }
-
   var dirty = false;
 
-  function update() {
-    if (!WIDGETS["weather"].width) {
-      WIDGETS["weather"].width = 20;
-      Bangle.drawWidgets();
-    } else if (Bangle.isLCDOn()) {
-      WIDGETS["weather"].draw();
-    } else {
-      dirty = true;
+  weather.on("update", w => {
+    if (w) {
+      if (!WIDGETS["weather"].width) {
+        WIDGETS["weather"].width = 20;
+        Bangle.drawWidgets();
+      } else if (Bangle.isLCDOn()) {
+        WIDGETS["weather"].draw();
+      } else {
+        dirty = true;
+      }
+    }
+    else {
+      WIDGETS["weather"].width = 0;
+      Bangle.drawWidgets();
     }
-  }
-
-  function hide() {
-    WIDGETS["weather"].width = 0;
-    Bangle.drawWidgets();
-  }
-
-  weather.on("update", () => {
-    if (weather.current) update();
-    else hide();
   });
 
   Bangle.on('lcdPower', on => {
@@ -51,7 +29,23 @@
 
   WIDGETS["weather"] = {
     area: "tl",
-    width: weather.current ? 20 : 0,
-    draw: draw,
+    width: weather.get() ? 20 : 0,
+    draw: function() {
+      const w = weather.get();
+      if (!w) return;
+      g.reset();
+      g.clearRect(this.x, this.y, this.x+this.width-1, this.y+23);
+      if (w.txt) {
+        weather.drawIcon(w.txt, this.x+10, this.y+8, 7.5);
+      }
+      if (w.temp) {
+        let t = require('locale').temp(w.temp-273.15);  // applies conversion
+        t = t.match(/[\d\-]*/)[0]; // but we have no room for units
+        g.reset();
+        g.setFontAlign(0, 1); // center horizontally at bottom of widget
+        g.setFont('6x8', 1);
+        g.drawString(t, this.x+10, this.y+24);
+      }
+    },
   };
 })();