lookingGlass: use new history manager implementation

This starts saving lookingGlass history in gsettings, and also adds
the ability to clear the text field by pressing 'down' on the last
entry, like the run dialog and readline allow.

https://bugzilla.gnome.org/show_bug.cgi?id=642237

data/org.gnome.shell.gschema.xml.in

@@ -45,6 +45,10 @@
       <default>[]</default>
       <_summary>History for command (Alt-F2) dialog</_summary>
     </key>
+    <key name="looking-glass-history" type="as">
+      <default>[]</default>
+      <_summary>History for the looking glass dialog</_summary>
+    </key>
     <child name="clock" schema="org.gnome.shell.clock"/>
     <child name="calendar" schema="org.gnome.shell.calendar"/>
     <child name="recorder" schema="org.gnome.shell.recorder"/>

js/ui/lookingGlass.js

@@ -14,6 +14,7 @@ const Mainloop = imports.mainloop;
 const Gettext = imports.gettext.domain('gnome-shell');
 const _ = Gettext.gettext;
 
+const History = imports.misc.history;
 const ExtensionSystem = imports.ui.extensionSystem;
 const Link = imports.ui.link;
 const Tweener = imports.ui.tweener;
@@ -37,6 +38,8 @@ var commandHeader = 'const Clutter = imports.gi.Clutter; ' +
                        'const it = Main.lookingGlass.getIt(); ' +
                     'const r = Lang.bind(Main.lookingGlass, Main.lookingGlass.getResult); ';
 
+const HISTORY_KEY = 'looking-glass-history';
+
 function Notebook() {
     this._init();
 }
@@ -671,18 +674,10 @@ function LookingGlass() {
 
 LookingGlass.prototype = {
     _init : function() {
-        this._idleHistorySaveId = 0;
-        let historyPath = global.userdatadir + '/lookingglass-history.txt';
-        this._historyFile = Gio.file_new_for_path(historyPath);
-        this._savedText = null;
-        this._historyNavIndex = -1;
-        this._history = [];
         this._borderPaintTarget = null;
         this._borderPaintId = 0;
         this._borderDestroyId = 0;
 
-        this._readHistory();
-
         this._open = false;
 
         this._offset = 0;
@@ -779,31 +774,23 @@ LookingGlass.prototype = {
             if (text == '')
                 return true;
             this._evaluate(text);
-            this._historyNavIndex = -1;
             return true;
         }));
+
+        this._history = new History.HistoryManager(HISTORY_KEY);
+        this._history.connect('changed', Lang.bind(this, function(history, text) {
+            this._entry.text = text;
+        }));
+
         this._entry.clutter_text.connect('key-press-event', Lang.bind(this, function(o, e) {
             let symbol = e.get_key_symbol();
             if (symbol == Clutter.Up) {
-                if (this._historyNavIndex >= this._history.length - 1)
+                this._history.prevItem(o.get_text());
-                    return true;
-                this._historyNavIndex++;
-                if (this._historyNavIndex == 0)
-                    this._savedText = this._entry.text;
-                this._entry.text = this._history[this._history.length - this._historyNavIndex - 1];
                 return true;
             } else if (symbol == Clutter.Down) {
-                if (this._historyNavIndex <= 0)
+                this._history.nextItem(o.get_text());
-                    return true;
-                this._historyNavIndex--;
-                if (this._historyNavIndex < 0)
-                    this._entry.text = this._savedText;
-                else
-                    this._entry.text = this._history[this._history.length - this._historyNavIndex - 1];
                 return true;
             } else {
-                this._historyNavIndex = -1;
-                this._savedText = null;
                 return false;
             }
         }));
@@ -821,29 +808,6 @@ LookingGlass.prototype = {
             + 'font-family: "' + fontDesc.get_family() + '";';
     },
 
-    _readHistory: function () {
-        if (!this._historyFile.query_exists(null))
-            return;
-        let [result, contents, length, etag] = this._historyFile.load_contents(null);
-        this._history = contents.split('\n').filter(function (e) { return e != ''; });
-    },
-
-    _queueHistorySave: function() {
-        if (this._idleHistorySaveId > 0)
-            return;
-        this._idleHistorySaveId = Mainloop.timeout_add_seconds(5, Lang.bind(this, this._doSaveHistory));
-    },
-
-    _doSaveHistory: function () {
-        this._idleHistorySaveId = false;
-        let output = this._historyFile.replace(null, true, Gio.FileCreateFlags.NONE, null);
-        let dataOut = new Gio.DataOutputStream({ base_stream: output });
-        dataOut.put_string(this._history.join('\n'), null);
-        dataOut.put_string('\n', null);
-        dataOut.close(null);
-        return false;
-    },
-
     _pushResult: function(command, obj) {
         let index = this._results.length + this._offset;
         let result = new Result('>>> ' + command, obj, index);
@@ -874,8 +838,7 @@ LookingGlass.prototype = {
     },
 
     _evaluate : function(command) {
-        this._history.push(command);
+        this._history.addItem(command);
-        this._queueHistorySave();
 
         let fullCmd = commandHeader + command;
 
@@ -962,6 +925,7 @@ LookingGlass.prototype = {
         this.actor.show();
         this.actor.lower(Main.chrome.actor);
         this._open = true;
+        this._history.lastItem();
 
         Tweener.removeTweens(this.actor);
 
@@ -979,7 +943,6 @@ LookingGlass.prototype = {
 
         this._objInspector.actor.hide();
 
-        this._historyNavIndex = -1;
         this._open = false;
         Tweener.removeTweens(this.actor);