Implement tooltip_reuse_hidden_frame for Android

* java/org/gnu/emacs/EmacsWindow.java
(findSuitableActivityContext): Return Activity rather than
Context.
(mapWindow): Provide window token manually.

* src/androidfns.c (Fx_show_tip, Fx_hide_tip): Respect
tooltip_reuse_hidden_frame.

java/org/gnu/emacs/EmacsWindow.java

@@ -27,6 +27,8 @@
 import java.util.LinkedHashMap;
 import java.util.Map;
 
+import android.app.Activity;
+
 import android.content.ClipData;
 import android.content.ClipDescription;
 import android.content.Context;
@@ -362,6 +364,9 @@ private static class Coordinate
     requestViewLayout ();
   }
 
+  /* Return WM layout parameters for an override redirect window with
+     the geometry provided here.  */
+
   private WindowManager.LayoutParams
   getWindowLayoutParams ()
   {
@@ -384,15 +389,15 @@ private static class Coordinate
     return params;
   }
 
-  private Context
+  private Activity
   findSuitableActivityContext ()
   {
     /* Find a recently focused activity.  */
     if (!EmacsActivity.focusedActivities.isEmpty ())
       return EmacsActivity.focusedActivities.get (0);
 
-    /* Return the service context, which probably won't work.  */
-    return EmacsService.SERVICE;
+    /* Resort to the last activity to be focused.  */
+    return EmacsActivity.lastFocusedActivity;
   }
 
   public synchronized void
@@ -416,7 +421,7 @@ private static class Coordinate
 	    {
 	      EmacsWindowAttachmentManager manager;
 	      WindowManager windowManager;
-	      Context ctx;
+	      Activity ctx;
 	      Object tem;
 	      WindowManager.LayoutParams params;
 
@@ -447,11 +452,23 @@ private static class Coordinate
                        activity using the system window manager.  */
 
 		  ctx = findSuitableActivityContext ();
+
+		  if (ctx == null)
+		    {
+		      Log.w (TAG, "failed to attach override-redirect window"
+			     + " for want of activity");
+		      return;
+		    }
+
 		  tem = ctx.getSystemService (Context.WINDOW_SERVICE);
 		  windowManager = (WindowManager) tem;
 
-		  /* Calculate layout parameters.  */
+		  /* Calculate layout parameters and propagate the
+		     activity's token into it.  */
+
 		  params = getWindowLayoutParams ();
+		  params.token = (ctx.findViewById (android.R.id.content)
+				  .getWindowToken ());
 		  view.setLayoutParams (params);
 
 		  /* Attach the view.  */

src/androidfns.c

@@ -2287,6 +2287,57 @@ DEFUN ("x-show-tip", Fx_show_tip, Sx_show_tip, 1, 6, 0,
 
 	  goto start_timer;
 	}
+      else if (tooltip_reuse_hidden_frame && BASE_EQ (frame, tip_last_frame))
+	{
+	  bool delete = false;
+	  Lisp_Object tail, elt, parm, last;
+
+	  /* Check if every parameter in PARMS has the same value in
+	     tip_last_parms.  This may destruct tip_last_parms which,
+	     however, will be recreated below.  */
+	  for (tail = parms; CONSP (tail); tail = XCDR (tail))
+	    {
+	      elt = XCAR (tail);
+	      parm = CAR (elt);
+	      /* The left, top, right and bottom parameters are handled
+		 by compute_tip_xy so they can be ignored here.  */
+	      if (!EQ (parm, Qleft) && !EQ (parm, Qtop)
+		  && !EQ (parm, Qright) && !EQ (parm, Qbottom))
+		{
+		  last = Fassq (parm, tip_last_parms);
+		  if (NILP (Fequal (CDR (elt), CDR (last))))
+		    {
+		      /* We lost, delete the old tooltip.  */
+		      delete = true;
+		      break;
+		    }
+		  else
+		    tip_last_parms
+		      = call2 (Qassq_delete_all, parm, tip_last_parms);
+		}
+	      else
+		tip_last_parms
+		  = call2 (Qassq_delete_all, parm, tip_last_parms);
+	    }
+
+	  /* Now check if every parameter in what is left of
+	     tip_last_parms with a non-nil value has an association in
+	     PARMS.  */
+	  for (tail = tip_last_parms; CONSP (tail); tail = XCDR (tail))
+	    {
+	      elt = XCAR (tail);
+	      parm = CAR (elt);
+	      if (!EQ (parm, Qleft) && !EQ (parm, Qtop) && !EQ (parm, Qright)
+		  && !EQ (parm, Qbottom) && !NILP (CDR (elt)))
+		{
+		  /* We lost, delete the old tooltip.  */
+		  delete = true;
+		  break;
+		}
+	    }
+
+	  android_hide_tip (delete);
+	}
       else
 	android_hide_tip (true);
     }
@@ -2453,7 +2504,7 @@ DEFUN ("x-hide-tip", Fx_hide_tip, Sx_hide_tip, 0, 0, 0,
 #endif /* 0 */
   return Qnil;
 #else /* !ANDROID_STUBIFY */
-  return android_hide_tip (true);
+  return android_hide_tip (!tooltip_reuse_hidden_frame);
 #endif /* ANDROID_STUBIFY */
 }