Port Android battery status to Android 4.4 and earlier

* java/org/gnu/emacs/EmacsService.java (EmacsService)
(queryBattery19): New function.
(queryBattery): Call it on old systems.  Also, return AC line
status and temperature.
* lisp/battery.el (battery-android): Implement more format
directives.
* src/android.c (android_query_battery): Handle new status
fields.
* src/android.h (struct android_battery_state): Add `plugged'
and `temperature'.
* src/androidfns.c (Fandroid_query_battery): Return new fields.

1 files changed, 59 insertions, 6 deletions

diff --git a/java/org/gnu/emacs/EmacsService.java b/java/org/gnu/emacs/EmacsService.java
index 848ad4de789..9c48c56ca26 100644
--- a/java/org/gnu/emacs/EmacsService.java
+++ b/java/org/gnu/emacs/EmacsService.java
@@ -40,6 +40,7 @@ import android.content.ClipboardManager;
 import android.content.Context;
 import android.content.ContentResolver;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager.ApplicationInfoFlags;
 import android.content.pm.PackageManager;
@@ -738,6 +739,36 @@ public final class EmacsService extends Service
       }
   }
 
+  private long[]
+  queryBattery19 ()
+  {
+    IntentFilter filter;
+    Intent battery;
+    long capacity, chargeCounter, currentAvg, currentNow;
+    long status, remaining, plugged, temp;
+
+    filter = new IntentFilter (Intent.ACTION_BATTERY_CHANGED);
+    battery = registerReceiver (null, filter);
+
+    if (battery == null)
+      return null;
+
+    capacity = battery.getIntExtra (BatteryManager.EXTRA_LEVEL, 0);
+    chargeCounter
+      = (battery.getIntExtra (BatteryManager.EXTRA_SCALE, 0)
+         / battery.getIntExtra (BatteryManager.EXTRA_LEVEL, 100) * 100);
+    currentAvg = 0;
+    currentNow = 0;
+    status = battery.getIntExtra (BatteryManager.EXTRA_STATUS, 0);
+    remaining = -1;
+    plugged = battery.getIntExtra (BatteryManager.EXTRA_PLUGGED, 0);
+    temp = battery.getIntExtra (BatteryManager.EXTRA_TEMPERATURE, 0);
+
+    return new long[] { capacity, chargeCounter, currentAvg,
+                        currentNow, remaining, status, plugged,
+                        temp, };
+  }
+
   /* Return the status of the battery.  See struct
      android_battery_status for the order of the elements
      returned.
@@ -750,14 +781,16 @@ public final class EmacsService extends Service
     Object tem;
     BatteryManager manager;
     long capacity, chargeCounter, currentAvg, currentNow;
-    long status, remaining;
+    long status, remaining, plugged, temp;
     int prop;
+    IntentFilter filter;
+    Intent battery;
 
-    /* Android 4.4 or earlier require applications to listen to
-       changes to the battery instead of querying for its status.  */
+    /* Android 4.4 or earlier require applications to use a different
+       API to query the battery status.  */
 
     if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
-      return null;
+      return queryBattery19 ();
 
     tem = getSystemService (Context.BATTERY_SERVICE);
     manager = (BatteryManager) tem;
@@ -776,7 +809,8 @@ public final class EmacsService extends Service
        only return ``charging'' or ``discharging''.  */
 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
-      status = manager.getIntProperty (BatteryManager.BATTERY_PROPERTY_STATUS);
+      status
+        = manager.getIntProperty (BatteryManager.BATTERY_PROPERTY_STATUS);
     else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
       status = (manager.isCharging ()
                 ? BatteryManager.BATTERY_STATUS_CHARGING
@@ -789,8 +823,27 @@ public final class EmacsService extends Service
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P)
       remaining = manager.computeChargeTimeRemaining ();
 
+    plugged = -1;
+    temp = -1;
+
+    /* Now obtain additional information from the battery manager.  */
+
+    filter = new IntentFilter (Intent.ACTION_BATTERY_CHANGED);
+    battery = registerReceiver (null, filter);
+
+    if (battery != null)
+      {
+        plugged = battery.getIntExtra (BatteryManager.EXTRA_PLUGGED, 0);
+        temp = battery.getIntExtra (BatteryManager.EXTRA_TEMPERATURE, 0);
+
+        /* Make status more reliable.  */
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
+          status = battery.getIntExtra (BatteryManager.EXTRA_STATUS, 0);
+      }
+
     return new long[] { capacity, chargeCounter, currentAvg,
-                        currentNow, remaining, status, };
+                        currentNow, remaining, status, plugged,
+                        temp, };
   }
 
   /* Display the specified STRING in a small dialog box on the main