The window whose callback to set.
The new callback, or null to remove the currently set callback.
The previously set callback, or null if no callback was set or an error occurred.
@callback_signature
void function_name(GLFWwindow* window, unsigned int codepoint, int mods)
For more information about the callback parameters, see the function pointer type.
@deprecated Scheduled for removal in version 4.0.
Errors: Possible errors include @ref GLFW_NOT_INITIALIZED.
This function must only be called from the main thread.
@sa @ref input_char
Added in version 3.1.
Ingroup: input
Sets the Unicode character with modifiers callback.
This function sets the character with modifiers callback of the specified window, which is called when a Unicode character is input regardless of what modifier keys are used.
The character with modifiers callback is intended for implementing custom Unicode character input. For regular Unicode text input, see the character callback. Like the character callback, the character with modifiers callback deals with characters and is keyboard layout dependent. Characters do not map 1:1 to physical keys, as a key may produce zero, one or more characters. If you want to know whether a specific physical key was pressed or released, see the key callback instead.