irc: keep session alive when closing UI; reuse background session on reopen; rename Leave->Close

Signed-off-by: Slendi <slendi@socopon.com>

main.lua

@@ -26,6 +26,7 @@ local IrcChatView = TextViewer:extend{
     add_default_buttons = true,
     monospace_font = true,
     text_type = "code",
+    keep_running = true, -- keep connection alive when UI is closed
     _connected = false,
     _closing = false,
     _receive_task = nil,
@@ -56,7 +57,7 @@ function IrcChatView:init()
                 end,
             },
             {
-                text = _("Leave"),
+                text = _("Close"),
                 callback = function()
                     self:onClose()
                 end,
@@ -597,6 +598,11 @@ function IrcChatView:handleLine(line)
 end
 
 function IrcChatView:onClose()
+    -- If keep_running, only close the UI; keep socket and receive loop alive in background
+    if self.keep_running then
+        TextViewer.onClose(self)
+        return
+    end
     if self._closing then return end
     self._closing = true
     if self._receive_task then
@@ -998,6 +1004,11 @@ function IRC:connectToServer(server)
     local function open_chat(channel)
         local function do_open()
             local nick = server.nick or self.username or "koreader"
+            -- Reuse background session if already running for this host/port
+            if self._bg_view and self._bg_view._sock then
+                UIManager:show(self._bg_view)
+                return
+            end
             local view = IrcChatView:new{
                 _server = {
                     name = server.name,
@@ -1008,7 +1019,9 @@ function IRC:connectToServer(server)
                 },
                 _channel = channel,
                 _nick = nick,
+                keep_running = true,
             }
+            self._bg_view = view
             UIManager:show(view)
         end
         -- Ensure wifi/network is up before proceeding