Implement `fullscreen' on Android 4.0 and later

* doc/emacs/android.texi (Android Windowing): Document what new
frame parameters are now supported.
* java/org/gnu/emacs/EmacsActivity.java (EmacsActivity): New
field `isFullscreen'.
(detachWindow, attachWindow): Sync fullscreen state.
(onWindowFocusChanged): Add more logging.
(onResume): Restore previous fullscreen state.
(syncFullscreen): New function.
* java/org/gnu/emacs/EmacsWindow.java (EmacsWindow)
(setFullscreen): New function.
* src/android.c (struct android_emacs_window): Add new method.
(android_init_emacs_window): Look up new method.
(android_set_fullscreen): New function.
* src/androidgui.h:
* src/androidterm.c (android_fullscreen_hook): Implement
accordingly.

1 files changed, 21 insertions, 3 deletions

diff --git a/src/androidterm.c b/src/androidterm.c
index 0fbee1e9867..62a8d5d12b3 100644
--- a/src/androidterm.c
+++ b/src/androidterm.c
@@ -1792,12 +1792,30 @@ android_make_frame_visible_invisible (struct frame *f, bool visible)
 static void
 android_fullscreen_hook (struct frame *f)
 {
-  /* Explicitly setting fullscreen is not supported on Android.  */
+  Lisp_Object wanted;
 
   if (!FRAME_PARENT_FRAME (f))
-    store_frame_param (f, Qfullscreen, Qmaximized);
+    {
+      /* Explicitly setting fullscreen is not supported on older
+         Android versions.  */
+
+      wanted = (f->want_fullscreen == FULLSCREEN_BOTH
+                ? Qfullscreen : Qmaximized);
+
+      if (android_set_fullscreen (FRAME_ANDROID_WINDOW (f),
+                                  EQ (wanted, Qfullscreen)))
+        store_frame_param (f, Qfullscreen, Qmaximized);
+      else
+        store_frame_param (f, Qfullscreen, wanted);
+    }
   else
-    store_frame_param (f, Qfullscreen, Qnil);
+    {
+      store_frame_param (f, Qfullscreen, Qnil);
+
+      /* If this is a child frame, don't keep it fullscreen
+         anymore.  */
+      android_set_fullscreen (FRAME_ANDROID_WINDOW (f), false);
+    }
 }
 
 void