widbars: new widget

apps.json

@@ -4557,5 +4557,20 @@
     { "name": "sensible.app.js", "url": "sensible.js" },
     { "name": "sensible.img", "url": "sensible-icon.js", "evaluate": true }
   ]
-}
+},
+  {
+    "id": "widbars",
+    "name": "Bars Widget",
+    "version": "0.01",
+    "description": "Display several measurements as vertical bars.",
+    "icon": "icon.png",
+    "screenshots": [{"url":"screenshot.png"}],
+    "readme": "README.md",
+    "type": "widget",
+    "tags": "widget",
+    "supports": ["BANGLEJS","BANGLEJS2"],
+    "storage": [
+      {"name":"widbars.wid.js","url":"widget.js"}
+    ]
+  }
 ]

apps/widbars/ChangeLog

@@ -0,0 +1 @@
+0.01: New Widget!

apps/widbars/README.md

@@ -0,0 +1,14 @@
+# Bars Widget
+
+A simple widget that display several measurements as vertical bars.
+
+![Screenshot](screenshot.png)
+
+## Measurements from left to right:
+
+- Current heart rate, on a scale from 0-200 bpm (*red*)<br>
+  Only if available: this widget does not turn on HRM monitoring by itself.
+- Device temperature, on a scale from 0-50 °C (*yellow*)  
+- Flash storage space used (*blue/cyan*)    
+- Memory usage (*magenta*) 
+- Battery charge (*green*)

apps/widbars/widget.js

@@ -0,0 +1,62 @@
+(() => {
+  const h=24, // widget height
+        w=3,  // width of single bar
+        bars=3; // number of bars
+
+  // We show HRM if available, but don't turn it on
+  let bpm,rst,con=10; // always ignore HRM with confidence below 10%
+  function noHrm() { // last value is no longer valid
+    if (rst) clearTimeout(rst);
+    rst=bpm=undefined; con=10;
+    WIDGETS["bars"].draw();
+  }
+  Bangle.on('HRM', hrm=>{
+    if (hrm.confidence>con || hrm.confidence>=80) {
+      bpm=hrm.confidence;
+      con=hrm.confidence;
+      WIDGETS["bars"].draw();
+      if (rst) clearTimeout(rst);
+      rst = setTimeout(noHrm, 10*60*1000); // forget HRM after 10 minutes
+    }
+  });
+
+  /**
+   * Draw a bar
+   *
+   * @param {int} x left
+   * @param {int} y top (of full bar)
+   * @param {string} col Color
+   * @param {number} f Fraction of bar to draw
+   */
+  function bar(x,y, col,f) {
+    if (!f)  f = 0; // for f=NaN: set it to 0 -> don't even draw the bottom pixel
+    if (f>1) f = 1;
+    if (f<0) f = 0;
+    const top = Math.round((h-1)*(1-f));
+    // use Math.min/max to make sure we stay within widget boundaries for f=0/f=1
+    if (top) g             .clearRect(x,y,     x+w-1,y+top-1); // erase above bar
+    if (f)   g.setColor(col).fillRect(x,y+top, x+w-1,y+h-1);   // even for f=0.001 this is still 1 pixel high
+  }
+  function draw() {
+    g.reset();
+    const x = this.x, y = this.y,
+      m = process.memory();
+    let b=0;
+    bar(x+(w*b++),y,'#f00'/*red    */,bpm/200); // >200 seems very unhealthy; if we have no valid bpm this will just be empty space
+    bar(x+(w*b++),y,'#ff0'/*yellow */,E.getTemperature()/50); // you really don't want to wear a watch that's hotter than 50°C
+    bar(x+(w*b++),y,g.theme.dark?'#0ff':'#00f'/*cyan/blue*/,1-(require('Storage').getFree() / process.env.STORAGE));
+    bar(x+(w*b++),y,'#f0f'/*magenta*/,m.usage/m.total);
+    bar(x+(w*b++),y,'#0f0'/*green  */,E.getBattery()/100);
+  }
+
+  let redraw;
+  Bangle.on('lcdPower', on => {
+    if (redraw) clearInterval(redraw)
+    redraw = undefined;
+    if (on) {
+      WIDGETS["bars"].draw();
+      redraw = setInterval(()=>WIDGETS["bars"].draw, 10*1000); // redraw every 10 seconds
+    }
+  });
+  WIDGETS["bars"]={area:"tr",width: bars*w,draw:draw};
+})()