options: load and save params

scripts/params.js

@@ -0,0 +1,44 @@
+import { browser } from './browser.js'
+
+export const fields = [
+  'randomSeed',
+  'halfPatternSize',
+  'scaleFactor',
+  'gridSize',
+  'density',
+  'red',
+  'green',
+  'blue',
+]
+
+export function getParamsFromStorage () {
+  return browser.storage.local.get(['params'])
+    .then(({params}) => params)
+}
+
+export function setParamsToStorage (params) {
+  return browser.storage.local.set({params})
+}
+
+export function assureParams(params) {
+  const assureNumber = (rawValue) => (defaultValue) => (min, max) => {
+    let value = Number(rawValue)
+
+    if (isNaN(value)) return defaultValue
+    value = Math.max(min, value)
+    value = Math.min(max, value)
+
+    return value
+  }
+
+  return {
+    randomSeed: assureNumber(params.randomSeed)(0)(0, Infinity),
+    halfPatternSize: assureNumber(params.halfPatternSize)(16)(0, Infinity),
+    scaleFactor: assureNumber(params.scaleFactor)(16)(0, Infinity),
+    gridSize: assureNumber(params.gridSize)(3)(0, Infinity),
+    density: assureNumber(params.density)(0.5)(0, 1),
+    red: assureNumber(params.red)(255)(0, 255),
+    green: assureNumber(params.green)(255)(0, 255),
+    blue: assureNumber(params.blue)(255)(0, 255),
+  }
+}