recovery: Initial dialog implementation

Implement two types of dialogs: info and error.  Info dialogs are intended
to show that an operation is in progress and cannot be interrupted.  Error
dialogs are intended to show that an error occurred.  The user must respond
by dismissing the dialog with any input (a swipe or keypress).

Dialogs may be initiated internally within the UI code or externally via a
named local socket.  Dialogs created via socket are presumed to be info
and may not be dismissed.  When the client socket is closed, the dialog
automatically dismisses.

Initial implementation shows dialogs for adb backup and restore.  Future
work will show dialogs for all errors and lengthy operations.

Change-Id: Icefea12ec0fd70fb487d54aa2eb1cae9dd451355

2 files changed, 18 insertions, 0 deletions

diff --git a/minui/events.cpp b/minui/events.cpp
index 3b2262a..4e9d80b 100644
--- a/minui/events.cpp
+++ b/minui/events.cpp
@@ -137,6 +137,23 @@ int ev_add_fd(int fd, ev_callback cb, void* data) {
     return ret;
 }
 
+int ev_del_fd(int fd)
+{
+    unsigned n;
+    for (n = 0; n < ev_count; ++n) {
+        if (ev_fdinfo[n].fd == fd) {
+            epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, fd, NULL);
+            if (n != ev_count-1) {
+                ev_fdinfo[n] = ev_fdinfo[ev_count-1];
+            }
+            ev_count--;
+            ev_misc_count--;
+            return 0;
+        }
+    }
+    return -1;
+}
+
 void ev_exit(void) {
     while (ev_count > 0) {
         close(ev_fdinfo[--ev_count].fd);
diff --git a/minui/minui.h b/minui/minui.h
index d714632..7dec2d7 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -67,6 +67,7 @@ typedef int (*ev_set_key_callback)(int code, int value, void* data);
 int ev_init(ev_callback input_cb, void* data);
 void ev_exit();
 int ev_add_fd(int fd, ev_callback cb, void* data);
+int ev_del_fd(int fd);
 void ev_iterate_available_keys(std::function<void(int)> f);
 int ev_sync_key_state(ev_set_key_callback set_key_cb, void* data);