import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

devtools/client/shared/theme.js

@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Colors for themes taken from:
+ * https://developer.mozilla.org/en-US/docs/Tools/DevToolsColors
+ */
+
+const Services = require("Services");
+const { gDevTools } = require("devtools/client/framework/devtools");
+
+const variableFileContents = require("raw!devtools/client/themes/variables.css");
+
+const THEME_SELECTOR_STRINGS = {
+  light: ":root.theme-light {",
+  dark: ":root.theme-dark {",
+  firebug: ":root.theme-firebug {"
+};
+
+/**
+ * Takes a theme name and returns the contents of its variable rule block.
+ * The first time this runs fetches the variables CSS file and caches it.
+ */
+function getThemeFile(name) {
+  // If there's no theme expected for this name, use `light` as default.
+  let selector = THEME_SELECTOR_STRINGS[name] ||
+                 THEME_SELECTOR_STRINGS.light;
+
+  // This is a pretty naive way to find the contents between:
+  // selector {
+  //   name: val;
+  // }
+  // There is test coverage for this feature (browser_theme.js)
+  // so if an } is introduced in the variables file it will catch that.
+  let theme = variableFileContents;
+  theme = theme.substring(theme.indexOf(selector));
+  theme = theme.substring(0, theme.indexOf("}"));
+
+  return theme;
+}
+
+/**
+ * Returns the string value of the current theme,
+ * like "dark" or "light".
+ */
+const getTheme = exports.getTheme = () => {
+  return Services.prefs.getCharPref("devtools.theme");
+};
+
+/**
+ * Returns a color indicated by `type` (like "toolbar-background", or
+ * "highlight-red"), with the ability to specify a theme, or use whatever the
+ * current theme is if left unset. If theme not found, falls back to "light"
+ * theme. Returns null if the type cannot be found for the theme given.
+ */
+/* eslint-disable no-unused-vars */
+const getColor = exports.getColor = (type, theme) => {
+  let themeName = theme || getTheme();
+  let themeFile = getThemeFile(themeName);
+  let match = themeFile.match(new RegExp("--theme-" + type + ": (.*);"));
+
+  // Return the appropriate variable in the theme, or otherwise, null.
+  return match ? match[1] : null;
+};
+
+/**
+ * Mimics selecting the theme selector in the toolbox;
+ * sets the preference and emits an event on gDevTools to trigger
+ * the themeing.
+ */
+const setTheme = exports.setTheme = (newTheme) => {
+  let oldTheme = getTheme();
+
+  Services.prefs.setCharPref("devtools.theme", newTheme);
+  gDevTools.emit("pref-changed", {
+    pref: "devtools.theme",
+    newValue: newTheme,
+    oldValue: oldTheme
+  });
+};
+/* eslint-enable */