Rework the way UI can trigger a client quitting

Add a UserInterface::is_ok method and return false on
SIGHUP/stdin closing/socket dropping

This should be cleaner and more robust than the previous SIGHUP
handling code.

Fixes #1594

1 files changed, 2 insertions, 0 deletions

diff --git a/src/json_ui.hh b/src/json_ui.hh
index ad887561..5e53ab42 100644
--- a/src/json_ui.hh
+++ b/src/json_ui.hh
@@ -19,6 +19,8 @@ public:
     JsonUI(const JsonUI&) = delete;
     JsonUI& operator=(const JsonUI&) = delete;
 
+    bool is_ok() const override { return m_stdin_watcher.fd() != -1; }
+
     void draw(const DisplayBuffer& display_buffer,
               const Face& default_face,
               const Face& buffer_padding) override;