1 files changed, 166 insertions, 0 deletions
diff --git a/comm/mail/base/content/toolbarIconColor.js b/comm/mail/base/content/toolbarIconColor.js
new file mode 100644
index 0000000000..591c86096d
--- /dev/null
+++ b/comm/mail/base/content/toolbarIconColor.js
@@ -0,0 +1,166 @@
+/**
+ * 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/. */
+
+var { AppConstants } = ChromeUtils.importESModule(
+  "resource://gre/modules/AppConstants.sys.mjs"
+);
+
+var ToolbarIconColor = {
+  _windowState: {
+    active: false,
+    fullscreen: false,
+    tabsintitlebar: false,
+  },
+
+  init() {
+    this._initialized = true;
+
+    window.addEventListener("activate", this);
+    window.addEventListener("deactivate", this);
+    window.addEventListener("toolbarvisibilitychange", this);
+    window.addEventListener("windowlwthemeupdate", this);
+
+    // If the window isn't active now, we assume that it has never been active
+    // before and will soon become active such that inferFromText will be
+    // called from the initial activate event.
+    if (Services.focus.activeWindow == window) {
+      this.inferFromText("activate");
+    }
+  },
+
+  uninit() {
+    this._initialized = false;
+
+    window.removeEventListener("activate", this);
+    window.removeEventListener("deactivate", this);
+    window.removeEventListener("toolbarvisibilitychange", this);
+    window.removeEventListener("windowlwthemeupdate", this);
+  },
+
+  handleEvent(event) {
+    switch (event.type) {
+      case "activate":
+      case "deactivate":
+      case "windowlwthemeupdate":
+        this.inferFromText(event.type);
+        break;
+      case "toolbarvisibilitychange":
+        this.inferFromText(event.type, event.visible);
+        break;
+    }
+  },
+
+  // A cache of luminance values for each toolbar to avoid unnecessary calls to
+  // getComputedStyle().
+  _toolbarLuminanceCache: new Map(),
+
+  // A cache of the current sidebar color to avoid unnecessary conditions and
+  // luminance calculations.
+  _sidebarColorCache: null,
+
+  inferFromText(reason, reasonValue) {
+    if (!this._initialized) {
+      return;
+    }
+
+    function parseRGB(aColorString) {
+      let rgb = aColorString.match(/^rgba?\((\d+), (\d+), (\d+)/);
+      rgb.shift();
+      return rgb.map(x => parseInt(x));
+    }
+
+    switch (reason) {
+      case "activate": // falls through.
+      case "deactivate":
+        this._windowState.active = reason === "activate";
+        break;
+      case "fullscreen":
+        this._windowState.fullscreen = reasonValue;
+        break;
+      case "windowlwthemeupdate":
+        // Theme change, we'll need to recalculate all color values.
+        this._toolbarLuminanceCache.clear();
+        this._sidebarColorCache = null;
+        break;
+      case "toolbarvisibilitychange":
+        // Toolbar changes dont require reset of the cached color values.
+        break;
+      case "tabsintitlebar":
+        this._windowState.tabsintitlebar = reasonValue;
+        break;
+    }
+
+    let toolbarSelector = "toolbox > toolbar:not([collapsed=true])";
+    if (AppConstants.platform == "macosx") {
+      toolbarSelector += ":not([type=menubar])";
+    }
+    toolbarSelector += ", .toolbar";
+
+    // The getComputedStyle calls and setting the brighttext are separated in
+    // two loops to avoid flushing layout and making it dirty repeatedly.
+    let cachedLuminances = this._toolbarLuminanceCache;
+    let luminances = new Map();
+    for (let toolbar of document.querySelectorAll(toolbarSelector)) {
+      // Toolbars *should* all have ids, but guard anyway to avoid blowing up.
+      let cacheKey =
+        toolbar.id && toolbar.id + JSON.stringify(this._windowState);
+      // Lookup cached luminance value for this toolbar in this window state.
+      let luminance = cacheKey && cachedLuminances.get(cacheKey);
+      if (isNaN(luminance)) {
+        let [r, g, b] = parseRGB(getComputedStyle(toolbar).color);
+        luminance = 0.2125 * r + 0.7154 * g + 0.0721 * b;
+        if (cacheKey) {
+          cachedLuminances.set(cacheKey, luminance);
+        }
+      }
+      luminances.set(toolbar, luminance);
+    }
+
+    const luminanceThreshold = 127; // In between 0 and 255
+    for (let [toolbar, luminance] of luminances) {
+      if (luminance <= luminanceThreshold) {
+        toolbar.removeAttribute("brighttext");
+      } else {
+        toolbar.setAttribute("brighttext", "true");
+      }
+    }
+
+    // On Linux, we need to detect if the OS theme caused a text color change in
+    // the sidebar icons and properly update the brighttext attribute.
+    if (
+      reason == "activate" &&
+      AppConstants.platform == "linux" &&
+      Services.prefs.getCharPref("extensions.activeThemeID", "") ==
+        "default-theme@mozilla.org"
+    ) {
+      let folderTree = document.getElementById("folderTree");
+      if (!folderTree) {
+        return;
+      }
+
+      let sidebarColor = getComputedStyle(folderTree).color;
+      // Interrupt if the sidebar color didn't change.
+      if (sidebarColor == this._sidebarColorCache) {
+        return;
+      }
+
+      this._sidebarColorCache = sidebarColor;
+
+      let mainWindow = document.getElementById("messengerWindow");
+      if (!mainWindow) {
+        return;
+      }
+
+      let [r, g, b] = parseRGB(sidebarColor);
+      let luminance = 0.2125 * r + 0.7154 * g + 0.0721 * b;
+
+      if (luminance <= 110) {
+        mainWindow.removeAttribute("lwt-tree-brighttext");
+      } else {
+        mainWindow.setAttribute("lwt-tree-brighttext", "true");
+      }
+    }
+  },
+};