Implement notification callbacks on Android

* doc/lispref/os.texi (Desktop Notifications): Document that
:on-cancel, :on-action and :actions are now supported on
Android.

* java/org/gnu/emacs/EmacsActivity.java (onNewIntent): New
function.

* java/org/gnu/emacs/EmacsDesktopNotification.java
(NOTIFICATION_ACTION, NOTIFICATION_TAG, NOTIFICATION_DISMISSED):
New constants.  <actions, titles>: New fields.
(insertActions): New function.
(display1, display): Insert actions on Jelly Bean and up, and
arrange to be notified when the notification is dismissed.
(CancellationReceiver): New class.

* java/org/gnu/emacs/EmacsNative.java (sendNotificationDeleted)
(sendNotificationAction): New functions.

* src/android.c (sendDndDrag, sendDndUri, sendDndText): Correct
return types.
(sendNotificationDeleted, sendNotificationAction)
(android_exception_check_5, android_exception_check_6): New
functions.

* src/android.h:

* src/androidgui.h (struct android_notification_event): New
structure.
(union android_event): New member for notification events.

* src/androidselect.c (android_init_emacs_desktop_notification):
Update JNI signatures.
(android_notifications_notify_1, Fandroid_notifications_notify):
New arguments ACTIONS, ACTION_CB and CANCEL_CB.  Convert and
record them as appropriate.
(android_notification_deleted, android_notification_action): New
functions.
(syms_of_androidselect): Prepare a hash table of outstanding
notifications.
<QCactions, QCon_action, QCon_cancel> New defsyms.

* src/androidterm.c (handle_one_android_event)
<ANDROID_NOTIFICATION_DELETED>
<ANDROID_NOTIFICATION_ACTION>: Dispatch event contents to
androidselect.c for processing.

* src/androidterm.h:

* src/androidvfs.c (java_string_class): Export.

* src/keyboard.c (kbd_buffer_get_event) <NOTIFICATION_EVENT>:
Call callback specified by the event.

* src/termhooks.h (enum event_kind) [HAVE_ANDROID]: New
enum NOTIFICATION_EVENT.

1 files changed, 29 insertions, 0 deletions

diff --git a/src/androidgui.h b/src/androidgui.h
index 73b60c483d3..d89aee51055 100644
--- a/src/androidgui.h
+++ b/src/androidgui.h
@@ -251,6 +251,8 @@ enum android_event_type
     ANDROID_DND_DRAG_EVENT,
     ANDROID_DND_URI_EVENT,
     ANDROID_DND_TEXT_EVENT,
+    ANDROID_NOTIFICATION_DELETED,
+    ANDROID_NOTIFICATION_ACTION,
   };
 
 struct android_any_event
@@ -535,6 +537,29 @@ struct android_dnd_event
   size_t length;
 };
 
+struct android_notification_event
+{
+  /* Type of the event.  */
+  enum android_event_type type;
+
+  /* The event serial.  */
+  unsigned long serial;
+
+  /* The window that gave rise to the event (None).  */
+  android_window window;
+
+  /* The identifier of the notification whose status changed.
+     Must be deallocated with `free'.  */
+  char *tag;
+
+  /* The action that was activated, if any.  Must be deallocated with
+     `free'.  */
+  unsigned short *action;
+
+  /* Length of that data.  */
+  size_t length;
+};
+
 union android_event
 {
   enum android_event_type type;
@@ -571,6 +596,10 @@ union android_event
      protocol, whereas there exist several competing X protocols
      implemented in terms of X client messages.  */
   struct android_dnd_event dnd;
+
+  /* X provides no equivalent interface for displaying
+     notifications.  */
+  struct android_notification_event notification;
 };
 
 enum