battery: Add full/empty guessing based on capacity

Assuming we have some estimation for the current battery capacity (i.e.
percentage), we can infer a FULL/EMPTY state. Do so if the battery state
is unknown.

Related: #196

2 files changed, 48 insertions, 4 deletions

diff --git a/src/linux/integration-test.py b/src/linux/integration-test.py
index 2ad5845..ea275e7 100755
--- a/src/linux/integration-test.py
+++ b/src/linux/integration-test.py
@@ -653,6 +653,40 @@ class Tests(dbusmock.DBusTestCase):
         self.assertEqual(self.get_dbus_display_property('State'), UP_DEVICE_STATE_PENDING_CHARGE)
         self.stop_daemon()
 
+    def test_empty_guessing(self):
+        '''One empty batter not reporting a state'''
+
+        self.testbed.add_device('power_supply', 'BAT0', None,
+                                ['type', 'Battery',
+                                 'present', '1',
+                                 'status', 'Unknown',
+                                 'charge_full', '10500000',
+                                 'charge_full_design', '11000000',
+                                 'capacity', '0',
+                                 'voltage_now', '12000000'], [])
+
+        self.start_daemon()
+        self.assertDevs({ 'battery_BAT0': { 'State' : UP_DEVICE_STATE_EMPTY } })
+        self.assertEqual(self.get_dbus_display_property('State'), UP_DEVICE_STATE_EMPTY)
+        self.stop_daemon()
+
+    def test_full_guessing(self):
+        '''One full batter not reporting a state'''
+
+        self.testbed.add_device('power_supply', 'BAT0', None,
+                                ['type', 'Battery',
+                                 'present', '1',
+                                 'status', 'Unknown',
+                                 'charge_full', '10500000',
+                                 'charge_full_design', '11000000',
+                                 'capacity', '99',
+                                 'voltage_now', '12000000'], [])
+
+        self.start_daemon()
+        self.assertDevs({ 'battery_BAT0': { 'State' : UP_DEVICE_STATE_FULLY_CHARGED } })
+        self.assertEqual(self.get_dbus_display_property('State'), UP_DEVICE_STATE_FULLY_CHARGED)
+        self.stop_daemon()
+
     def test_display_state_aggregation(self):
         bat0 = self.testbed.add_device('power_supply', 'BAT0', None,
                                        ['type', 'Battery',
diff --git a/src/up-device-battery.c b/src/up-device-battery.c
index 544dedd..c3dc667 100644
--- a/src/up-device-battery.c
+++ b/src/up-device-battery.c
@@ -323,10 +323,6 @@ up_device_battery_report (UpDeviceBattery *self,
 	if (values->percentage <= 0)
 		values->percentage = values->energy.cur / priv->energy_full * 100;
 
-	/* QUIRK: Some devices keep reporting PENDING_CHARGE even when full */
-	if (values->state == UP_DEVICE_STATE_PENDING_CHARGE && values->percentage >= UP_FULLY_CHARGED_THRESHOLD)
-		values->state = UP_DEVICE_STATE_FULLY_CHARGED;
-
 	/* NOTE: We used to do more for the UNKNOWN state. However, some of the
 	 * logic relies on only one battery device to be present. Plus, it
 	 * requires knowing the AC state.
@@ -343,6 +339,20 @@ up_device_battery_report (UpDeviceBattery *self,
 	/* Do estimations */
 	up_device_battery_estimate (self, &values->state);
 
+	/* QUIRK: Do a FULL/EMPTY guess if the state is still unknown
+	 *        Maybe limit to when we have good estimates
+	 *        (would require rate/current information) */
+	if (values->state == UP_DEVICE_STATE_UNKNOWN) {
+		if (values->percentage >= UP_FULLY_CHARGED_THRESHOLD)
+			values->state = UP_DEVICE_STATE_FULLY_CHARGED;
+		else if (values->percentage < 1.0)
+			values->state = UP_DEVICE_STATE_EMPTY;
+	}
+
+	/* QUIRK: Some devices keep reporting PENDING_CHARGE even when full */
+	if (values->state == UP_DEVICE_STATE_PENDING_CHARGE && values->percentage >= UP_FULLY_CHARGED_THRESHOLD)
+		values->state = UP_DEVICE_STATE_FULLY_CHARGED;
+
 	/* Set the main properties (setting "update-time" last) */
 	g_object_set (self,
 		      "energy", values->energy.cur,