[gnome-boxes] Unified way to set & flush deferred property changes

[Christophe Fergeau <teuf src gnome org>]

commit 2c36aebcbff282af5538388dcfb075e39e5bd307
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Fri Aug 31 05:48:21 2012 +0300

    Unified way to set & flush deferred property changes
    
    Add new API to Boxes.Property class to easily schedule deferred changes
    to it and to flush it when needed.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=672554

 src/i-properties-provider.vala |   36 ++++++++++++++++++++++++++++++++++++
 src/libvirt-machine.vala       |   19 +++++--------------
 src/properties.vala            |   13 +++++++++++++
 3 files changed, 54 insertions(+), 14 deletions(-)
---
diff --git a/src/i-properties-provider.vala b/src/i-properties-provider.vala
index b0195fb..a471133 100644
--- a/src/i-properties-provider.vala
+++ b/src/i-properties-provider.vala
@@ -6,9 +6,45 @@ private class Boxes.Property: GLib.Object {
     public Gtk.Widget widget { get; construct set; }
     public bool reboot_required { get; set; }
 
+    public uint defer_interval { get; set; default = 1; } // In seconds
+
+    private uint deferred_change_id;
+    private SourceFunc? _deferred_change;
+    public SourceFunc? deferred_change {
+        get {
+            return _deferred_change;
+        }
+
+        owned set {
+            if (deferred_change_id != 0) {
+                Source.remove (deferred_change_id);
+                deferred_change_id = 0;
+            }
+
+            _deferred_change = (owned) value;
+            if (_deferred_change == null)
+                return;
+
+            deferred_change_id = Timeout.add_seconds (defer_interval, () => {
+                flush ();
+
+                return false;
+            });
+        }
+    }
+
     public Property (string description, Gtk.Widget widget) {
         base (description: description, widget: widget);
     }
+
+    public void flush () {
+        if (deferred_change == null)
+            return;
+
+        deferred_change ();
+
+        deferred_change = null;
+    }
 }
 
 private delegate void PropertyStringChanged (Boxes.Property property, string value) throws Boxes.Error;
diff --git a/src/libvirt-machine.vala b/src/libvirt-machine.vala
index 17393d7..c1b6fbe 100644
--- a/src/libvirt-machine.vala
+++ b/src/libvirt-machine.vala
@@ -48,8 +48,6 @@ private class Boxes.LibvirtMachine: Boxes.Machine {
         double net_write;
     }
 
-    private uint ram_update_timeout = 0;
-    private uint storage_update_timeout = 0;
     private uint stats_update_timeout;
     private Cancellable stats_cancellable;
 
@@ -523,10 +521,7 @@ private class Boxes.LibvirtMachine: Boxes.Machine {
 
     private void on_ram_changed (Boxes.Property property, uint64 value) {
         // Ensure that we don't end-up changing RAM like a 1000 times a second while user moves the slider..
-        if (ram_update_timeout != 0)
-            Source.remove (ram_update_timeout);
-
-        ram_update_timeout = Timeout.add_seconds (1, () => {
+        property.deferred_change = () => {
             try {
                 var config = domain.get_config (GVir.DomainXMLFlags.INACTIVE);
                 config.memory = value;
@@ -539,11 +534,11 @@ private class Boxes.LibvirtMachine: Boxes.Machine {
                          value,
                          error.message);
             }
-            ram_update_timeout = 0;
+
             update_ram_property (property);
 
             return false;
-        });
+        };
     }
 
     public async void start () {
@@ -615,10 +610,7 @@ private class Boxes.LibvirtMachine: Boxes.Machine {
 
     private void on_storage_changed (Boxes.Property property, uint64 value) {
         // Ensure that we don't end-up changing storage like a 1000 times a second while user moves the slider..
-        if (storage_update_timeout != 0)
-            Source.remove (storage_update_timeout);
-
-        storage_update_timeout = Timeout.add_seconds (1, () => {
+        property.deferred_change = () => {
             if (storage_volume == null)
                 return false;
 
@@ -637,9 +629,8 @@ private class Boxes.LibvirtMachine: Boxes.Machine {
                          value,
                          error.message);
             }
-            storage_update_timeout = 0;
 
             return false;
-        });
+        };
     }
 }
diff --git a/src/properties.vala b/src/properties.vala
index aa96ac2..01de259 100644
--- a/src/properties.vala
+++ b/src/properties.vala
@@ -118,6 +118,11 @@ private class Boxes.Properties: Boxes.UI {
             grid.show_all ();
             widget = grid;
         }
+
+        public void flush_changes () {
+            foreach (var property in properties)
+                property.flush ();
+        }
     }
 
     public Properties () {
@@ -261,6 +266,14 @@ private class Boxes.Properties: Boxes.UI {
             populate ();
             opacity = 255;
             break;
+        default:
+            if (previous_ui_state == UIState.PROPERTIES)
+                for (var i = 0; i < PropertiesPage.LAST; i++) {
+                    var page = notebook.get_data<PageWidget> (@"boxes-property-$i");
+
+                    page.flush_changes ();
+                }
+            break;
         }
         fade_actor (actor, opacity);
     }