widdevst: add option to draw only when peripherals are on

apps/widdevst/README.md

@@ -13,3 +13,7 @@ at fixed positions, and two bars
 - bottom to top: usage of RAM
 
 in green if below 50%, orange if between 50% and 80%, and red if above 80%.
+
+The widget will redraw more frequently when unlocked.
+
+It can be configured to avoid redrawing if all monitored peripherals are off, waiting until it hears from them (meaning you won't see regular RAM/Storage updates, but save battery by avoiding drawing). This can be configured by writing `{"redrawBars":0}` to `widdevst.settings.json`.

apps/widdevst/metadata.json

@@ -9,5 +9,8 @@
   "readme": "README.md",
   "storage": [
     {"name": "widdevst.wid.js", "url": "wid.js"}
+  ],
+  "data":[
+    {"name": "widdevst.settings.json"}
   ]
 }

apps/widdevst/wid.js

@@ -1,6 +1,9 @@
 (() => {
   var stat = {date: 0};
   var d = Date.now();
+  var settings = require("Storage").readJSON("widdevst.settings.json", 1)||{};
+  var redrawBars = "redrawBars" in settings ? settings.redrawBars : false;
+  delete settings;
 
   WIDGETS.devst = {area: "tr", width: 22, draw: function() {
     d = Date.now();
@@ -29,7 +32,7 @@
     g.setColor(col(stat.sto)); g.drawRect(x + 2, y + 21, x + 2 + stat.sto * 18, y + 22);
     g.setColor(col(t)); g.drawRect(x + 1, y + 21 - t * 20, x + 2, y + 21);
     // if there's nothing active, don't queue a redraw (rely on Bangle.on(...) below)
-    if (again) setTimeout(draw, drawTime());
+    if (redrawBars || again) setTimeout(draw, drawTime());
   }};
 
   function col(p) {