persist remaining time for auto fetching

fixes #38

randomwallpaper@iflow.space/extension.js

@@ -43,6 +43,10 @@ function enable() {
 function disable() {
 	// disable Extension
 	panelEntry.destroy();
+
+	// cleanup the timer singleton
+	let timer = new Timer.AFTimer();
+	timer.cleanup();
 }
 
 var RandomWallpaperEntry = new Lang.Class({

randomwallpaper@iflow.space/schemas/org.gnome.shell.extensions.space.iflow.randomwallpaper.gschema.xml

@@ -50,10 +50,10 @@
             <description>Stores the history objects as stringified JSONs</description>
         </key>
 
-        <key type='i' name='minutes-elapsed'>
+        <key type='x' name='timer-last-trigger'>
             <default>0</default>
-            <summary>Elapsed Time</summary>
-            <description>The time that already elapsed.</description>
+            <summary>Timestamp of the last timer trigger.</summary>
+            <description>A JS timestamp of the last timer callback trigger. Zero if no last change registered.</description>
         </key>
 
         <key type='b' name='change-lock-screen'>

randomwallpaper@iflow.space/timer.js

@@ -3,6 +3,7 @@ const GLib = imports.gi.GLib;
 
 const Self = imports.misc.extensionUtils.getCurrentExtension();
 const Prefs = Self.imports.settings;
+const LoggerModule = Self.imports.logger;
 
 let _afTimerInstance = null;
 
@@ -17,7 +18,6 @@ var AFTimer = function() {
 /**
  * Timer for the auto fetch feature.
  *
- * TODO: find way to store elapsed time on shutdown/logout/gnome-shell-restart/etc.
  * @type {Lang}
  */
 var _AFTimer = new Lang.Class({
@@ -25,45 +25,20 @@ var _AFTimer = new Lang.Class({
 
     _timeout: null,
     _timoutEndCallback: null,
-    _timestamp: null,
+    _minutes: 30,
 
     _init: function() {
         this._settings = new Prefs.Settings();
     },
 
-    /**
-     * Side effect is that the elapsed minutes will be stored in the GSettings.
-     */
-    _minutesElapsed: function() {
-        let timestamp = this._timestamp;
-        if (!timestamp) {
-            return 0;
-        }
-
-        let now = new Date().getTime();
-        let elapsed = this._settings.get('minutes-elapsed', 'int');
-
-        let diffMin = Math.floor((now-timestamp)/(60*1000));
-
-        if (diffMin >= 1) {
-            elapsed += diffMin;
-            this._settings.set('minutes-elapsed', 'int', elapsed);
-            this._timestamp += diffMin*60*1000;
-        }
-
-        return elapsed;
-    },
-
     isActive: function () {
         return this._settings.get('auto-fetch', 'boolean');
     },
 
     remainingMinutes: function() {
-        let hours = this._settings.get('hours', 'int');
-        let minutes = hours * 60 + this._settings.get('minutes', 'int');
         let minutesElapsed = this._minutesElapsed();
-
-        return (minutes - minutesElapsed);
+        let diff = this._minutes - minutesElapsed;
+        return Math.max(diff, 0);
     },
 
     registerCallback: function(callback) {
@@ -71,27 +46,30 @@ var _AFTimer = new Lang.Class({
     },
 
     /**
-     * Starts a new timer.
+     * Starts a new timer with the given minutes.
      *
+     * @param minutes
      * @return void
      */
-    begin: function() {
-        this.end(); // stop any running timer
+    start: function(minutes) {
+        this.cleanup();
 
-        this._timestamp = new Date().getTime();
-
-        let millisToWait = this.remainingMinutes() * 60 * 1000;
-        if (millisToWait <= 0) {
-            return;
+        this._minutes = minutes;
+        let lastChanged = this._settings.get('timer-last-trigger', 'int64');
+        if (lastChanged === 0) {
+            this.reset();
         }
 
-        this._timeout = GLib.timeout_add(GLib.PRIORITY_DEFAULT, millisToWait, function() {
-            this.end();
+        let millisToWait = this.remainingMinutes() * 60 * 1000;
+        this._timeout = GLib.timeout_add(GLib.PRIORITY_DEFAULT, millisToWait, () => {
             if (this._timoutEndCallback) {
                 this._timoutEndCallback();
             }
-            this.begin(); // restart timer
-        }.bind(this));
+
+            this._settings.set('timer-last-trigger', 'int64', new Date().getTime());
+
+            this.start(minutes); // restart timer
+        });
     },
 
     /**
@@ -99,20 +77,43 @@ var _AFTimer = new Lang.Class({
      *
      * @return void
      */
-    end: function() {
-        this._settings.set('minutes-elapsed', 'int', 0);
-        if (this._timeout) {
-            GLib.source_remove(this._timeout)
+    stop: function() {
+        this._settings.set('timer-last-trigger', 'int64', 0);
+        this.cleanup();
+    },
+
+    /**
+     * Cleanup the timeout callback if it exists.
+     *
+     * @return void
+     */
+    cleanup: function() {
+        if (this._timeout) { // only remove if a timeout is active
+            GLib.source_remove(this._timeout);
             this._timeout = null;
         }
     },
 
-    // currently not used
-    pause: function() {
-        if (this._timeout) {
-            GLib.source_remove(this._timeout)
-            this._minutesElapsed();
+    /**
+     * Reset the timer.
+     *
+     * @return void
+     */
+    reset: function() {
+        this._settings.set('timer-last-trigger', 'int64', new Date().getTime());
+        this.cleanup();
+    },
+
+    _minutesElapsed: function() {
+        let now = new Date().getTime();
+        let lastChanged = this._settings.get('timer-last-trigger', 'int64');
+
+        if (lastChanged === 0) {
+            return 0;
         }
+
+        let elapsed = Math.max(now - lastChanged, 0);
+        return Math.floor(elapsed / (60 * 1000));
     }
 
 });

randomwallpaper@iflow.space/wallpaperController.js

@@ -40,6 +40,8 @@ var WallpaperController = new Lang.Class({
 	_stopLoadingHooks: [],
 
 	_init: function (extensionMeta) {
+		this.logger = new LoggerModule.Logger('RWG3', 'WallpaperController');
+
 		this.extensionMeta = extensionMeta;
 		this.wallpaperlocation = this.extensionMeta.path + '/wallpapers/';
 
@@ -61,8 +63,6 @@ var WallpaperController = new Lang.Class({
 		this._unsplashAdapter = new SourceAdapter.UnsplashAdapter();
 		this._wallhavenAdapter = new SourceAdapter.WallhavenAdapter();
 		this._genericJsonAdapter = new SourceAdapter.GenericJsonAdapter();
-
-		this.logger = new LoggerModule.Logger('RWG3', 'WallpaperController');
 	},
 
 	_updateHistory: function () {
@@ -78,9 +78,9 @@ var WallpaperController = new Lang.Class({
 
 		if (this._autoFetch.active) {
 			this._timer.registerCallback(this.fetchNewWallpaper.bind(this));
-			this._timer.begin();
+			this._timer.start(this._autoFetch.duration);
 		} else {
-			this._timer.end();
+			this._timer.stop();
 		}
 	},
 
@@ -220,7 +220,7 @@ var WallpaperController = new Lang.Class({
 		this._startLoadingHooks.forEach((element) => {
 			element();
 		});
-		this._timer.begin(); // reset timer
+		this._timer.reset(); // reset timer
 
 		this._requestRandomImageFromAdapter((historyElement) => {
 			this.logger.info("Requesting image: " + historyElement.source.imageDownloadUrl);