From e467a734a1140bbcc35d828c1dab33d66a55d306 Mon Sep 17 00:00:00 2001
From: Takao Fujiwara <tfujiwar@redhat.com>
Date: Mon, 10 Nov 2014 19:09:08 +0900
Subject: [PATCH] ibusManager: Preload all ibus input sources in user
 configuration

Normally users switch xkb input sources and ibus input sources.
But currently the first input source only is running. It's also good
to preload all ibus engines in the logging session so that users switch
input sources quickly without the launching time of input sources.

The following is the ibus change:
https://github.com/ibus/ibus/commit/cff35929a9

https://bugzilla.gnome.org/show_bug.cgi?id=695428
---
 js/misc/ibusManager.js   | 45 ++++++++++++++++++++++++++++++++++++++--
 js/ui/status/keyboard.js |  4 ++++
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/js/misc/ibusManager.js b/js/misc/ibusManager.js
index 9571e0b44..06d808d3f 100644
--- a/js/misc/ibusManager.js
+++ b/js/misc/ibusManager.js
@@ -1,13 +1,14 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 
 const Gio = imports.gi.Gio;
+const GLib = imports.gi.GLib;
 const Lang = imports.lang;
+const Mainloop = imports.mainloop;
 const Signals = imports.signals;
 
 try {
     var IBus = imports.gi.IBus;
-    if (!('new_async' in IBus.Bus))
-        throw "IBus version is too old";
+    _checkIBusVersion();
     const IBusCandidatePopup = imports.ui.ibusCandidatePopup;
 } catch (e) {
     var IBus = null;
@@ -16,6 +17,22 @@ try {
 
 let _ibusManager = null;
 
+function _checkIBusVersion() {
+    var requiredMajor = 1;
+    var requiredMinor = 5;
+    var requiredMicro = 2;
+
+    if ((IBus.MAJOR_VERSION > requiredMajor) ||
+        (IBus.MAJOR_VERSION == requiredMajor && IBus.MINOR_VERSION > requiredMinor) ||
+        (IBus.MAJOR_VERSION == requiredMajor && IBus.MINOR_VERSION == requiredMinor &&
+         IBus.MICRO_VERSION >= requiredMicro))
+        return;
+
+    throw "Found IBus version %d.%d.%d but required is %d.%d.%d".
+        format(IBus.MAJOR_VERSION, IBus.MINOR_VERSION, IBus.MINOR_VERSION,
+               requiredMajor, requiredMinor, requiredMicro);
+}
+
 function getIBusManager() {
     if (_ibusManager == null)
         _ibusManager = new IBusManager();
@@ -28,6 +45,7 @@ const IBusManager = new Lang.Class({
     // This is the longest we'll keep the keyboard frozen until an input
     // source is active.
     _MAX_INPUT_SOURCE_ACTIVATION_TIME: 4000, // ms
+    _PRELOAD_ENGINES_DELAY_TIME: 30, // sec
 
     _init: function() {
         if (!IBus)
@@ -42,6 +60,7 @@ const IBusManager = new Lang.Class({
         this._ready = false;
         this._registerPropertiesId = 0;
         this._currentEngineName = null;
+        this._preloadEnginesId = 0;
 
         this._ibus = IBus.Bus.new_async();
         this._ibus.connect('connected', Lang.bind(this, this._onConnected));
@@ -176,5 +195,27 @@ const IBusManager = new Lang.Class({
         this._ibus.set_global_engine_async(id, this._MAX_INPUT_SOURCE_ACTIVATION_TIME,
                                            null, callback);
     },
+
+    preloadEngines: function(ids) {
+        if (!IBus || !this._ibus || ids.length == 0)
+            return;
+
+        if (this._preloadEnginesId != 0) {
+            Mainloop.source_remove(this._preloadEnginesId);
+            this._preloadEnginesId = 0;
+        }
+
+        this._preloadEnginesId =
+            Mainloop.timeout_add_seconds(this._PRELOAD_ENGINES_DELAY_TIME,
+                                         Lang.bind(this, function() {
+                                             this._ibus.preload_engines_async(
+                                                 ids,
+                                                 -1,
+                                                 null,
+                                                 null);
+                                             this._preloadEnginesId = 0;
+                                             return GLib.SOURCE_REMOVE;
+                                         }));
+    },
 });
 Signals.addSignalMethods(IBusManager.prototype);
diff --git a/js/ui/status/keyboard.js b/js/ui/status/keyboard.js
index 8cb8cc913..4ae8ba1bd 100644
--- a/js/ui/status/keyboard.js
+++ b/js/ui/status/keyboard.js
@@ -381,6 +381,10 @@ const InputSourceManager = new Lang.Class({
 
         if (this._mruSources.length > 0)
             this._mruSources[0].activate();
+
+        // All ibus engines are preloaded here to reduce the launching time
+        // when users switch the input sources.
+        this._ibusManager.preloadEngines(Object.keys(this._ibusSources));
     },
 
     _makeEngineShortName: function(engineDesc) {