Replace explicit pref observer with lazy preference getters. Tag mcp-graveyard/UXP#361.

2 files changed, 11 insertions, 33 deletions

diff --git a/toolkit/components/reader/ReaderMode.jsm b/toolkit/components/reader/ReaderMode.jsm
index ebc3334958..0302054462 100644
--- a/toolkit/components/reader/ReaderMode.jsm
+++ b/toolkit/components/reader/ReaderMode.jsm
@@ -38,15 +38,6 @@ this.ReaderMode = {
 
   DEBUG: 0,
 
-  // Don't try to parse the page if it has too many elements (for memory and
-  // performance reasons)
-  get maxElemsToParse() {
-    delete this.parseNodeLimit;
-
-    Services.prefs.addObserver("reader.parse-node-limit", this, false);
-    return this.parseNodeLimit = Services.prefs.getIntPref("reader.parse-node-limit");
-  },
-
   /**
    * Enter the reader mode by going forward one step in history if applicable,
    * if not, append the about:reader page in the history instead.
@@ -548,3 +539,8 @@ this.ReaderMode = {
     return readingSpeed.get(lang) || readingSpeed.get("en");
   },
 };
+
+// Don't try to parse the page if it has too many elements (for memory and
+// performance reasons)
+XPCOMUtils.defineLazyPreferenceGetter(
+  ReaderMode, "maxElemsToParse", "reader.parse-node-limit", 0);
diff --git a/toolkit/components/reader/Readerable.js b/toolkit/components/reader/Readerable.js
index 71c23eb5b2..cee8adc088 100644
--- a/toolkit/components/reader/Readerable.js
+++ b/toolkit/components/reader/Readerable.js
@@ -23,30 +23,7 @@ var Readerable = {
   DEBUG: 0,
 
   get isEnabledForParseOnLoad() {
-    delete this.isEnabledForParseOnLoad;
-
-    // Listen for future pref changes.
-    Services.prefs.addObserver("reader.parse-on-load.", this, false);
-
-    return this.isEnabledForParseOnLoad = this._getStateForParseOnLoad();
-  },
-
-  _getStateForParseOnLoad() {
-    let isEnabled = Services.prefs.getBoolPref("reader.parse-on-load.enabled");
-    let isForceEnabled = Services.prefs.getBoolPref("reader.parse-on-load.force-enabled");
-    return isForceEnabled || isEnabled;
-  },
-
-  observe(aMessage, aTopic, aData) {
-    switch (aTopic) {
-      case "nsPref:changed":
-        if (aData.startsWith("reader.parse-on-load.")) {
-          this.isEnabledForParseOnLoad = this._getStateForParseOnLoad();
-        } else if (aData === "reader.parse-node-limit") {
-          this.parseNodeLimit = Services.prefs.getIntPref(aData);
-        }
-        break;
-    }
+    return this.isEnabled || this.isForceEnabled;
   },
 
   log(msg) {
@@ -112,3 +89,8 @@ var Readerable = {
     return true;
   },
 };
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  Readerable, "isEnabled", "reader.parse-on-load.enabled", true);
+XPCOMUtils.defineLazyPreferenceGetter(
+  Readerable, "isForceEnabled", "reader.parse-on-load.force-enabled", false);