forgot to commit openos

data/openos/boot/93_term.lua

@@ -0,0 +1,46 @@
+local event = require("event")
+
+local function components_changed(ename, address, type)
+  local tty = require("tty")
+  local window = tty.window
+  if not window then
+    return
+  end
+
+  if ename == "component_available" or ename == "component_unavailable" then
+    type = address
+  end
+
+  if ename == "component_removed" or ename == "component_unavailable" then
+     -- address can be type, when ename is *_unavailable, but *_removed works here and that's all we need
+    if type == "gpu" and window.gpu.address == address then
+      window.gpu = nil
+      window.keyboard = nil
+    elseif type == "keyboard" then
+      -- we could check if this was our keyboard
+      -- i.e. if address == window.keyboard
+      -- but it is also simple for the terminal to
+      -- recheck what kb to use
+      window.keyboard = nil
+    end
+    if (type == "screen" or type == "gpu") and not tty.isAvailable() then
+      event.push("term_unavailable")
+    end
+  elseif (ename == "component_added" or ename == "component_available") and type == "keyboard" then
+  -- we need to clear the current terminals cached keyboard (if any) when
+  -- a new keyboard becomes available. This is in case the new keyboard was
+  -- attached to the terminal's window. The terminal library has the code to
+  -- determine what the best keyboard to use is, but here we'll just set the
+  -- cache to nil to force term library to reload it. An alternative to this
+  -- method would be to make sure the terminal library doesn't cache the
+  -- wrong keybaord to begin with but, users may actually expect that any
+  -- primary keyboard is a valid keyboard (weird, in my opinion)
+    window.keyboard = nil
+  end
+end
+
+event.listen("component_removed",     components_changed)
+event.listen("component_added",       components_changed)
+event.listen("component_available",   components_changed)
+event.listen("component_unavailable", components_changed)
+