How do HSlider and VSlider send controller echo events?

Miles_Van_Dusen · October 29, 2025, 3:29pm

Godot Version

4.3

Question

Hey There! I’m in the process of generating my own echo events for controller input, because my understanding is that Godot does not do this by default. However in doing this I discovered that HSlider and VSlider both send echo events on their own when I hold down the control stick or DPad. How is this being done? Can I replicate this behavior for my universal controller or will this cause issues when I build my own echo event generator? Thanks for your insight, this is a puzzling one.

mrcdk · October 29, 2025, 6:33pm

You can check the code, Godot is open source

It does it internally keeping its own timer. It first checks if the input event is a gamepad one:

github.com/godotengine/godot

scene/gui/slider.cpp

534591047


      
          	Input *input = Input::get_singleton();
          	Ref<InputEventJoypadMotion> joypadmotion_event = p_event;
          	Ref<InputEventJoypadButton> joypadbutton_event = p_event;
          	bool is_joypad_event = (joypadmotion_event.is_valid() || joypadbutton_event.is_valid());

If it is and it wasn’t just pressed then it enables its internal process:

github.com/godotengine/godot

scene/gui/slider.cpp

534591047


      
          			if (is_joypad_event) {
          				if (!input->is_action_just_pressed_by_event("ui_left", p_event, true)) {
          					return;
          				}
          				set_process_internal(true);
          			}

And then it change the value keeping track of its own internal timer:

github.com/godotengine/godot

scene/gui/slider.cpp

534591047


      
          		case NOTIFICATION_INTERNAL_PROCESS: {
          			Input *input = Input::get_singleton();
          
          			if (input->is_action_just_released("ui_left") || input->is_action_just_released("ui_right") || input->is_action_just_released("ui_up") || input->is_action_just_released("ui_down")) {
          				gamepad_event_delay_ms = DEFAULT_GAMEPAD_EVENT_DELAY_MS;
          				set_process_internal(false);
          				return;
          			}
          
          			gamepad_event_delay_ms -= get_process_delta_time();
          			if (gamepad_event_delay_ms <= 0) {
          				gamepad_event_delay_ms = GAMEPAD_EVENT_REPEAT_RATE_MS + gamepad_event_delay_ms;
          				if (orientation == HORIZONTAL) {
          					if (input->is_action_pressed("ui_left")) {
          						if (is_layout_rtl()) {
          							set_value(get_value() + (custom_step >= 0 ? custom_step : get_step()));
          						} else {
          							set_value(get_value() - (custom_step >= 0 ? custom_step : get_step()));
          						}
          					}

This file has been truncated. show original

Here’s the constants it’s using:

github.com/godotengine/godot

scene/gui/slider.h

534591047


      
          	const float DEFAULT_GAMEPAD_EVENT_DELAY_MS = 0.5;
          	const float GAMEPAD_EVENT_REPEAT_RATE_MS = 1.0 / 20;
          	float gamepad_event_delay_ms = DEFAULT_GAMEPAD_EVENT_DELAY_MS;