[Fixed 2.6] Error While Removing Notifier From Textfield

[It-Alien]

here it is the code causing the error described here

I have one unresolved issue with the code, though: I had to put two buttons to actually perfomr the conversion because putting conversion code into the change notifiers of the two textfield would create a feedback loop (user change text in Dec textfield => the Dec notifier triggers and changes the text of Hex textfield => Hex notifier triggers and changes the text of the Dec textfield).

So I have tried the following:

• I have put the two notifiers in one variable each.
• I have initially added the respective notifier variable to the constructor of each textfield
• each notifier contained code which firstly removes the notifier from the other textfield, then changed the other textfield value, and finally added the removed notifier again.

this for some reason didn’t work because of an exception. surpsisingly, the raised exception occurred on a remove_notifier() call saying that the notifier was already present. Maybe a wrong copy&paste in the exception message?

I think this may be a bug, but seeing that GUI elements have no “has_notifier()” method, this may also be a design choice which prevents from removing a notifier under certain circumstances?

try putting an hex into the first textfield and press enter. remove_notifier() on line 22 will cause an error saying that the notifier has been already added

  
--[[============================================================================  
gui.lua  
============================================================================]]--  
  
--------------------------------------------------------------------------------  
-- GUI  
--------------------------------------------------------------------------------  
  
local MARGIN_DEFAULT = renoise.ViewBuilder.DEFAULT_CONTROL_MARGIN  
  
vb = nil   
dialog = nil  
  
local dec_to_hex = nil  
local hex_to_dec = nil  
  
--notifiers  
hex_to_dec = function()  
  
 local hex_value = todec(vb.views.txtHex.text)  
  
 vb.views.txtDec:remove_notifier(dec_to_hex)  
  
 if hex_value == 'NaN' then  
 renoise.app():show_warning('Invalid hexadecimal number!')  
 vb.views.txtDec.text = ''  
 vb.views.txtHex.text = ''  
 else  
 vb.views.txtDec.text = hex_value  
 end  
  
 vb.views.txtDec:add_notifier(dec_to_hex)  
  
end  
  
dec_to_hex = function()  
  
 local dec_value = tonumber(vb.views.txtDec.text)  
  
 vb.views.txtHex:remove_notifier(hex_to_dec)  
  
 if dec_value ~= nil then  
 vb.views.txtHex.text = bit.tohex(dec_value)  
 else  
 renoise.app():show_warning('Invalid decimal number!')  
 vb.views.txtDec.text = ''  
 vb.views.txtHex.text = ''  
 end  
  
 vb.views.txtHex:add_notifier(hex_to_dec)  
  
end  
  
--end notifiers  
  
  
function show_dialog()  
  
 if (dialog and dialog.visible) then  
 -- already showing a dialog. bring it to front:  
 dialog:show()  
 return  
 end  
  
 local MARGIN_DEFAULT = renoise.ViewBuilder.DEFAULT_CONTROL_MARGIN  
 local SPACING_DEFAULT = renoise.ViewBuilder.DEFAULT_CONTROL_SPACING  
  
 local TEXT_LABEL_WIDTH = 80  
 local CONTROL_WIDTH = 100  
 local CONTENT_WIDTH = TEXT_LABEL_WIDTH + CONTROL_WIDTH  
  
 local DIALOG_BUTTON_HEIGHT = renoise.ViewBuilder.DEFAULT_DIALOG_BUTTON_HEIGHT  
 local CONTROL_HEIGHT = renoise.ViewBuilder.DEFAULT_CONTROL_HEIGHT  
  
 vb = renoise.ViewBuilder()  
  
 -- create_global_properties  
  
 local row_Txt = vb:row {  
 vb:textfield {  
 id = "txtHex",  
 width = TEXT_LABEL_WIDTH,  
 notifier = hex_to_dec  
 },  
 vb:text {  
 id="lblHex",  
 text="< Hex - Dec >"  
 },  
 vb:textfield {  
 id = "txtDec",  
 width = TEXT_LABEL_WIDTH,  
 notifier = dec_to_hex  
 }  
 }   
  
 local dialog_content = vb:column {  
 id = "colContainer",  
 margin = MARGIN_DEFAULT,  
 spacing = SPACING_DEFAULT,  
 row_Txt  
 }  
  
 dialog = renoise.app():show_custom_dialog (  
 "Hex-Dec Converter",  
 dialog_content  
 )  
  
end  
  

[taktik]

Thanks. “textfield:remove_notifier” indeed tried to add a notifier Will be fixed in the next update. This only applies to vb:textfield and vb:multiline_textfield.