[folks] bluez: Implement [enable|disable]_persona_store()

[Philip Withnall <pwithnall src gnome org>]

commit 521b2635b09cc4b84536efdd7e22a0771083c814
Author: Philip Withnall <philip tecnocode co uk>
Date:   Fri Dec 20 17:07:30 2013 +0000

    bluez: Implement [enable|disable]_persona_store()
    
    Disable all persona stores by default in the BlueZ backend, since they
    should only be connected to when explicitly requested by the user. This
    can only be programmatically achieved at the moment by calling
    bluez_backend.set_persona_stores(["00:11:22:33:44:55"]), where the
    string is the Bluetooth address of the phone to enable. (Multiple phones
    may be specified.)
    
    This is a partial solution to the problem. A complete solution would
    involve creating PersonaStores for all eligible Bluetooth devices, then
    only allowing prepare() on the ones which are enabled by the user.
    That’s still under discussion in the bug; this is an interim fix to
    ensure folks doesn’t continually cause “do you want to allow your
    computer access to this phone’s address book” messages to pop up on
    people’s phones.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=720274

 backends/bluez/bluez-backend.vala |  119 +++++++++++++++++++++++++++++--------
 1 files changed, 95 insertions(+), 24 deletions(-)
---
diff --git a/backends/bluez/bluez-backend.vala b/backends/bluez/bluez-backend.vala
index 42d9fb9..08a7ebc 100644
--- a/backends/bluez/bluez-backend.vala
+++ b/backends/bluez/bluez-backend.vala
@@ -46,11 +46,18 @@ extern const string BACKEND_NAME;
  *  - Paired and connected
  *
  * The default state for a device is unpaired. The user must explicitly pair
- * their device before folks will begin to use it — folks ignores unpaired
- * devices. Once a device is paired, folks will attempt to do an OBEX PBAP
- * transfer to copy the device’s address book; this will automatically connect
- * the device. After the transfer is complete, the device will go back to being
- * paired and unconnected.
+ * their device and enable it using { link Backend.enable_persona_store} or
+ * { link Backend.set_persona_stores} before folks will begin to use it — folks
+ * ignores unpaired devices. Once a device is paired and enabled, folks will
+ * attempt to do an OBEX PBAP transfer to copy the device’s address book; this
+ * will automatically connect the device. After the transfer is complete, the
+ * device will go back to being paired and unconnected.
+ *
+ * Note that by requiring that devices are explicitly enabled by calling
+ * { link Backend.set_persona_stores}, the BlueZ backend is empty by default
+ * every time libfolks is loaded, until the client explicitly enables a device.
+ * This may change in future, and the state of enabled devices may be retained
+ * between runs.
  *
  * Every time the user explicitly connects to the device, folks will re-download
  * its address book. Currently, folks will not otherwise re-download it (i.e.
@@ -99,6 +106,9 @@ public class Folks.Backends.BlueZ.Backend : Folks.Backend
   /* Map from device D-Bus object path to PersonaStore. */
   private HashMap<string, PersonaStore> _watched_devices;
   private org.bluez.obex.Client? _obex_client = null;
+  /* Set of Bluetooth device addresses for the enabled devices. If a device
+   * isn’t listed here, a PersonaStore will not be created for it. */
+  private SmallSet<string> _enabled_devices;
 
   /**
    * Whether this Backend has been prepared.
@@ -144,41 +154,89 @@ public class Folks.Backends.BlueZ.Backend : Folks.Backend
   /**
    * { inheritDoc}
    *
-   * This method actually does nothing because the backend can't
-   * programmatically disable a persona store since it can only
-   * be disabled if the corresponding device is unpaired by the
-   * user.
-   *
    * @since 0.9.6
    */
   public override void disable_persona_store (Folks.PersonaStore store)
     {
+      var _store = store as BlueZ.PersonaStore;
+      if (_store == null)
+        return;
+
+      debug ("Disabling persona store ‘%s’.", store.id);
+
+      var device_address = store.id;  /* implicit assumption */
+      this._enabled_devices.remove (device_address);
+
+      if (!this._persona_stores.has_key (store.id))
+        return;
+
+      this._remove_persona_store ((!) _store);
     }
 
   /**
    * { inheritDoc}
    *
-   * This method actually does nothing because the backend can't
-   * programmatically add a new persona store since it depends
-   * on new paired devices.
-   *
    * @since 0.9.6
    */
   public override void enable_persona_store (Folks.PersonaStore store)
     {
+      var _store = store as BlueZ.PersonaStore;
+      if (_store == null)
+        return;
+
+      debug ("Enabling persona store ‘%s’.", store.id);
+
+      var device_address = store.id;  /* implicit assumption */
+      this._enabled_devices.add (device_address);
+
+      /* See if any existing device objects correspond to the store. */
+      this._refresh_devices.begin ((o, r) =>
+        {
+          this._refresh_devices.end (r);
+        });
     }
 
   /**
    * { inheritDoc}
    *
-   * This method actually does nothing because the backend can't
-   * programmatically add or remove persona stores since it depends
-   * on paired/unpaired devices.
-   *
    * @since 0.9.6
    */
   public override void set_persona_stores (Set<string>? storeids)
     {
+      if (storeids == null)
+        {
+          /* Use all available devices. */
+          var objs = this._manager.get_objects ();
+
+          foreach (var obj in objs)
+            {
+              var device = obj.get_interface ("org.bluez.Device1") as Device;
+              if (device == null)
+                  continue;
+
+              this._enabled_devices.add (device.address);
+              this._add_device.begin (obj, (o, r) =>
+                {
+                  this._add_device.end (r);
+                });
+            }
+
+          return;
+        }
+
+      /* Clear the set of enabled persona stores and re-populate it with only
+       * the addresses from storeids. */
+      this._enabled_devices.clear ();
+      foreach (var store_id in storeids)
+        {
+          var device_address = store_id;  /* implicit assumption */
+          this._enabled_devices.add (device_address);
+        }
+
+      this._refresh_devices.begin ((o, r) =>
+        {
+          this._refresh_devices.end (r);
+        });
     }
 
   /**
@@ -369,6 +427,24 @@ public class Folks.Backends.BlueZ.Backend : Folks.Backend
     }
 
   /**
+   * Refresh the list of devices from D-Bus.
+   *
+   * Add any new devices which are on D-Bus but aren’t in the BlueZ backend.
+   * This does not currently remove devices which have disappeared from D-Bus.
+   *
+   * @since UNRELEASED
+   */
+  private async void _refresh_devices ()
+    {
+      var objs = this._manager.get_objects ();
+
+      foreach (var obj in objs)
+        {
+          yield this._add_device (obj);
+        }
+    }
+
+  /**
    * Add a device to the backend.
    *
    * @param _obj the device's D-Bus object
@@ -551,12 +627,7 @@ public class Folks.Backends.BlueZ.Backend : Folks.Backend
                   this._device_properties_changed_cb);
 
           /* Add all the existing device objects. */
-          var objs = this._manager.get_objects ();
-
-          foreach (var obj in objs)
-            {
-              yield this._add_device (obj);
-            }
+          yield this._refresh_devices ();
 
           this._is_prepared = true;
           this.notify_property ("is-prepared");