Handle arrow keys and enter in emulator text fields

frontend/ui/widget/inputtext.lua

@@ -543,30 +543,47 @@ end
 -- is shown. Mostly likely to be in the emulator, but could be Android + BT
 -- keyboard, or a "coder's keyboard" Android input method.
 function InputText:onKeyPress(key)
-    if key["Backspace"] then
-        self:delChar()
-    elseif key["Del"] then
-        self:rightChar()
-        self:delChar()
-    elseif key["Left"] then
-        self:leftChar()
-    elseif key["Right"] then
-        self:rightChar()
-    elseif key["End"] then
-        self:goToEnd()
-    elseif key["Home"] then
-        self:goToHome()
+
+    local handled = true
+
+    if not key["Ctrl"] and not key["Shift"] and not key["Alt"] then
+        if key["Backspace"] then
+            self:delChar()
+        elseif key["Del"] then
+            self:rightChar()
+            self:delChar()
+        elseif key["Left"] then
+            self:leftChar()
+        elseif key["Right"] then
+            self:rightChar()
+        elseif key["Up"] then
+            self:upLine()
+        elseif key["Down"] then
+            self:downLine()
+        elseif key["End"] then
+            self:goToEnd()
+        elseif key["Home"] then
+            self:goToHome()
+        elseif key["Press"] then
+            self:addChars("\n")
+        elseif key["Tab"] then
+            self:addChars("    ")
+        else
+            handled = false
+        end
     elseif key["Ctrl"] and not key["Shift"] and not key["Alt"] then
         if key["U"] then
             self:delToStartOfLine()
         elseif key["H"] then
             self:delChar()
+        else
+            handled = false
         end
     else
-        return false
+        handled = false
     end
 
-    return true
+    return handled
 end
 
 -- Handle text coming directly as text from the Device layer (eg. soft keyboard