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, 158 insertions, 3 deletions

diff --git a/src/android.c b/src/android.c
index d7bd06f1f34..125bb5209c3 100644
--- a/src/android.c
+++ b/src/android.c
@@ -2457,7 +2457,7 @@ NATIVE_NAME (sendExpose) (JNIEnv *env, jobject object,
   return event_serial;
 }
 
-JNIEXPORT jboolean JNICALL
+JNIEXPORT jlong JNICALL
 NATIVE_NAME (sendDndDrag) (JNIEnv *env, jobject object,
                            jshort window, jint x, jint y)
 {
@@ -2477,7 +2477,7 @@ NATIVE_NAME (sendDndDrag) (JNIEnv *env, jobject object,
   return event_serial;
 }
 
-JNIEXPORT jboolean JNICALL
+JNIEXPORT jlong JNICALL
 NATIVE_NAME (sendDndUri) (JNIEnv *env, jobject object,
                           jshort window, jint x, jint y,
                           jstring string)
@@ -2514,7 +2514,7 @@ NATIVE_NAME (sendDndUri) (JNIEnv *env, jobject object,
   return event_serial;
 }
 
-JNIEXPORT jboolean JNICALL
+JNIEXPORT jlong JNICALL
 NATIVE_NAME (sendDndText) (JNIEnv *env, jobject object,
                            jshort window, jint x, jint y,
                            jstring string)
@@ -2551,6 +2551,85 @@ NATIVE_NAME (sendDndText) (JNIEnv *env, jobject object,
   return event_serial;
 }
 
+JNIEXPORT jlong JNICALL
+NATIVE_NAME (sendNotificationDeleted) (JNIEnv *env, jobject object,
+                                       jstring tag)
+{
+  JNI_STACK_ALIGNMENT_PROLOGUE;
+
+  union android_event event;
+  const char *characters;
+
+  event.notification.type = ANDROID_NOTIFICATION_DELETED;
+  event.notification.serial = ++event_serial;
+  event.notification.window = ANDROID_NONE;
+
+  /* TAG is guaranteed to be an ASCII string, of which the JNI character
+     encoding is a superset.  */
+  characters = (*env)->GetStringUTFChars (env, tag, NULL);
+  if (!characters)
+    return 0;
+
+  event.notification.tag = strdup (characters);
+  (*env)->ReleaseStringUTFChars (env, tag, characters);
+  if (!event.notification.tag)
+    return 0;
+
+  event.notification.action = NULL;
+  event.notification.length = 0;
+
+  android_write_event (&event);
+  return event_serial;
+}
+
+JNIEXPORT jlong JNICALL
+NATIVE_NAME (sendNotificationAction) (JNIEnv *env, jobject object,
+                                      jstring tag, jstring action)
+{
+  JNI_STACK_ALIGNMENT_PROLOGUE;
+
+  union android_event event;
+  const void *characters;
+  jsize length;
+  uint16_t *buffer;
+
+  event.notification.type = ANDROID_NOTIFICATION_ACTION;
+  event.notification.serial = ++event_serial;
+  event.notification.window = ANDROID_NONE;
+
+  /* TAG is guaranteed to be an ASCII string, of which the JNI character
+     encoding is a superset.  */
+  characters = (*env)->GetStringUTFChars (env, tag, NULL);
+  if (!characters)
+    return 0;
+
+  event.notification.tag = strdup (characters);
+  (*env)->ReleaseStringUTFChars (env, tag, characters);
+  if (!event.notification.tag)
+    return 0;
+
+  length = (*env)->GetStringLength (env, action);
+  buffer = malloc (length * sizeof *buffer);
+  characters = (*env)->GetStringChars (env, action, NULL);
+
+  if (!characters)
+    {
+      /* The JVM has run out of memory; return and let the out of memory
+         error take its course.  */
+      xfree (event.notification.tag);
+      return 0;
+    }
+
+  memcpy (buffer, characters, length * sizeof *buffer);
+  (*env)->ReleaseStringChars (env, action, characters);
+
+  event.notification.action = buffer;
+  event.notification.length = length;
+
+  android_write_event (&event);
+  return event_serial;
+}
+
 JNIEXPORT jboolean JNICALL
 NATIVE_NAME (shouldForwardMultimediaButtons) (JNIEnv *env,
                                               jobject object)
@@ -6310,6 +6389,82 @@ android_exception_check_4 (jobject object, jobject object1,
   memory_full (0);
 }
 
+/* Like android_exception_check_4, except it takes more than four local
+   reference arguments.  */
+
+void
+android_exception_check_5 (jobject object, jobject object1,
+                           jobject object2, jobject object3,
+                           jobject object4)
+{
+  if (likely (!(*android_java_env)->ExceptionCheck (android_java_env)))
+    return;
+
+  __android_log_print (ANDROID_LOG_WARN, __func__,
+                       "Possible out of memory error. "
+                       " The Java exception follows:  ");
+  /* Describe exactly what went wrong.  */
+  (*android_java_env)->ExceptionDescribe (android_java_env);
+  (*android_java_env)->ExceptionClear (android_java_env);
+
+  if (object)
+    ANDROID_DELETE_LOCAL_REF (object);
+
+  if (object1)
+    ANDROID_DELETE_LOCAL_REF (object1);
+
+  if (object2)
+    ANDROID_DELETE_LOCAL_REF (object2);
+
+  if (object3)
+    ANDROID_DELETE_LOCAL_REF (object3);
+
+  if (object4)
+    ANDROID_DELETE_LOCAL_REF (object4);
+
+  memory_full (0);
+}
+
+
+/* Like android_exception_check_5, except it takes more than five local
+   reference arguments.  */
+
+void
+android_exception_check_6 (jobject object, jobject object1,
+                           jobject object2, jobject object3,
+                           jobject object4, jobject object5)
+{
+  if (likely (!(*android_java_env)->ExceptionCheck (android_java_env)))
+    return;
+
+  __android_log_print (ANDROID_LOG_WARN, __func__,
+                       "Possible out of memory error. "
+                       " The Java exception follows:  ");
+  /* Describe exactly what went wrong.  */
+  (*android_java_env)->ExceptionDescribe (android_java_env);
+  (*android_java_env)->ExceptionClear (android_java_env);
+
+  if (object)
+    ANDROID_DELETE_LOCAL_REF (object);
+
+  if (object1)
+    ANDROID_DELETE_LOCAL_REF (object1);
+
+  if (object2)
+    ANDROID_DELETE_LOCAL_REF (object2);
+
+  if (object3)
+    ANDROID_DELETE_LOCAL_REF (object3);
+
+  if (object4)
+    ANDROID_DELETE_LOCAL_REF (object4);
+
+  if (object5)
+    ANDROID_DELETE_LOCAL_REF (object5);
+
+  memory_full (0);
+}
+
 /* Check for JNI problems based on the value of OBJECT.
 
    Signal out of memory if OBJECT is NULL.  OBJECT1 means the