1 files changed, 152 insertions, 0 deletions
diff --git a/comm/mail/modules/TagUtils.jsm b/comm/mail/modules/TagUtils.jsm
new file mode 100644
index 0000000000..05747e7b8c
--- /dev/null
+++ b/comm/mail/modules/TagUtils.jsm
@@ -0,0 +1,152 @@
+/* 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/. */
+
+const { MailServices } = ChromeUtils.import(
+  "resource:///modules/MailServices.jsm"
+);
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Color: "resource://gre/modules/Color.sys.mjs",
+});
+
+var EXPORTED_SYMBOLS = ["TagUtils"];
+
+var TagUtils = {
+  loadTagsIntoCSS,
+  addTagToAllDocumentSheets,
+  isColorContrastEnough,
+};
+
+function loadTagsIntoCSS(aDocument) {
+  let tagSheet = findTagColorSheet(aDocument);
+  let tagArray = MailServices.tags.getAllTags();
+  for (let tag of tagArray) {
+    // tag.key is the internal key, like "$label1" for "Important".
+    // For user defined keys with non-ASCII characters, key is
+    // the MUTF-7 encoded name.
+    addTagToSheet(tag.key, tag.color, tagSheet);
+  }
+}
+
+function addTagToAllDocumentSheets(aKey, aColor) {
+  for (let nextWin of Services.wm.getEnumerator("mail:3pane", true)) {
+    addTagToSheet(aKey, aColor, findTagColorSheet(nextWin.document));
+  }
+
+  for (let nextWin of Services.wm.getEnumerator("mailnews:search", true)) {
+    addTagToSheet(aKey, aColor, findTagColorSheet(nextWin.document));
+  }
+}
+
+function addTagToSheet(aKey, aColor, aSheet) {
+  if (!aSheet) {
+    return;
+  }
+
+  // Add rules to sheet.
+  let ruleString1;
+  let ruleString2;
+  let ruleString3;
+  let ruleString4;
+  let selector = MailServices.tags.getSelectorForKey(aKey);
+  if (!aColor) {
+    ruleString1 =
+      ":root[lwt-tree] treechildren::-moz-tree-row(" +
+      selector +
+      ", selected, focus) { background-color: " +
+      "var(--sidebar-highlight-background-color) !important; }";
+    ruleString2 =
+      "treechildren::-moz-tree-cell-text(" +
+      selector +
+      ", selected, focus) { color: SelectedItemText !important; }";
+    ruleString3 =
+      "tree:-moz-lwtheme treechildren::-moz-tree-cell-text(" +
+      selector +
+      ", selected) { color: currentColor !important; }";
+    ruleString4 =
+      ":root[lwt-tree] treechildren::-moz-tree-cell-text(" +
+      selector +
+      ", selected, focus) { color: var(--sidebar-highlight-text-color, " +
+      "var(--sidebar-text-color)) !important; }";
+  } else {
+    ruleString1 =
+      "treechildren::-moz-tree-row(" +
+      selector +
+      ", selected, focus) { background-color: " +
+      aColor +
+      " !important; outline-color: color-mix(in srgb, " +
+      aColor +
+      ", black 25%); }";
+    ruleString2 =
+      "treechildren::-moz-tree-cell-text(" +
+      selector +
+      ") { color: " +
+      aColor +
+      "; }";
+    let textColor = "black";
+    if (!isColorContrastEnough(aColor)) {
+      textColor = "white";
+    }
+    ruleString3 =
+      "treechildren::-moz-tree-cell-text(" +
+      selector +
+      ", selected, focus) { color: " +
+      textColor +
+      " }";
+    ruleString4 =
+      "treechildren::-moz-tree-image(" +
+      selector +
+      ", selected, focus)," +
+      "treechildren::-moz-tree-twisty(" +
+      selector +
+      ", selected, focus) { --select-focus-text-color: " +
+      textColor +
+      "; }";
+  }
+  try {
+    aSheet.insertRule(ruleString1, aSheet.cssRules.length);
+    aSheet.insertRule(ruleString2, aSheet.cssRules.length);
+    aSheet.insertRule(ruleString3, aSheet.cssRules.length);
+    aSheet.insertRule(ruleString4, aSheet.cssRules.length);
+  } catch (ex) {
+    aSheet.ownerNode.addEventListener(
+      "load",
+      () => addTagToSheet(aKey, aColor, aSheet),
+      { once: true }
+    );
+  }
+}
+
+function findTagColorSheet(aDocument) {
+  const cssUri = "chrome://messenger/skin/tagColors.css";
+  let tagSheet = null;
+  for (let sheet of aDocument.styleSheets) {
+    if (sheet.href == cssUri) {
+      tagSheet = sheet;
+      break;
+    }
+  }
+  if (!tagSheet) {
+    console.error("TagUtils.findTagColorSheet: tagColors.css not found");
+  }
+  return tagSheet;
+}
+
+/* Checks if black writing on 'aColor' background has enough contrast */
+function isColorContrastEnough(aColor) {
+  // Is a color set? If not, return "true" to use the default color.
+  if (!aColor) {
+    return true;
+  }
+  // Zero-pad the number just to make sure that it is 8 digits.
+  let colorHex = ("00000000" + aColor).substr(-8);
+  let colorArray = colorHex.match(/../g);
+  let [, cR, cG, cB] = colorArray.map(val => parseInt(val, 16));
+  return new lazy.Color(cR, cG, cB).isContrastRatioAcceptable(
+    new lazy.Color(0, 0, 0),
+    "AAA"
+  );
+}