Color picking not working on Windows

[KoBeWi]

Godot version

4.0 11e1c83

System information

Windows 10 x64

Issue description

The color never changes. Not for the property, nor for the button. According to the discussion in #63886, this is a Windows-specific issue.

Steps to reproduce

1. Be on Windows
2. Open ColorPicker
3. Click the eyedrop button
4. Try to pick some color

Minimal reproduction project

N/A

[duianto]

v4.0.beta5.official [89a33d2], Win 10 22H2

It does work if the Color popup is closed with esc after clicking on the eye dropper icon:

• click on the color property in the inspector to open the color popup
• click on the eye dropper icon
• press esc to close the color popup
• click on a new color

godot_4_color_picker_windows.mp4

When this is fixed, so that the eye dropper works while the color popup is open,
then the eye dropper probably should be canceled when the color popup is closed with esc.

[Sauermann]

While investigating this issue I tracked it to this:

godot/scene/gui/color_picker.cpp

Lines 1408 to 1429 in 6318320

	void ColorPicker::_screen_pick_pressed() {
	if (!is_inside_tree()) {
	return;
	}
	Viewport *r = get_tree()->get_root();
	if (!screen) {
	screen = memnew(Control);
	r->add_child(screen);
	screen->set_as_top_level(true);
	screen->set_anchors_and_offsets_preset(Control::PRESET_FULL_RECT);
	screen->set_default_cursor_shape(CURSOR_POINTING_HAND);
	screen->connect("gui_input", callable_mp(this, &ColorPicker::_screen_input));
	// It immediately toggles off in the first press otherwise.
	screen->call_deferred(SNAME("connect"), "hidden", Callable(btn_pick, "set_pressed").bind(false));
	} else {
	screen->show();
	}
	screen->move_to_front();
	// TODO: show modal no longer works, needs to be converted to a popup.
	//screen->show_modal();
	}

Is it possible, that this is related to the Control->Window conversion?

I verified, that this problem also exists in v4.0.alpha1.official [31a7ddb] on Linux X11:

• I can't pick colors
• The color under the mouse cursor is not used

In v4.0.beta.custom_build [6318320] on Linux X11:

• I can't pick colors
• The color under the mouse cursor is used for previewing it in the color-picker (so at least some kind of progress has happened since v4.alpha1).

[stmSi]

I saw weird things happening while debugging ColorPicker::_screen_input. The first Mouse Click Event doesn't not enter yet... after u click again.... two clicks events enter continuously.

1. First comment out this so that u can capture screen click events as long as u want. (in _notification)

---

2. insert these lines (in _screen_input)

---

3. select color picker and click it. nothings happens. click again... "LEFT" will print 2 TIMES

---

4. Color will set successfully.

[nezvers]

Godot 4 Beta 15 on Windows eyedropper does not pick a color.

[Sauermann]

The relevant code section has this comment:
// TODO: show modal no longer works, needs to be converted to a popup.

So I did some experiment with popups. Current status is that I ran into the problem that Popups can not be made transparent reliably (previously the Control screen simply was transparent). So I believe, that it is currently not possible to solve this by a simple replacement Control->Window

In a second attempt I tried to solve this with the Drag & Drop mechanic. This might be possible, but becomes quite complex.

[JohanAR]

I've considered a couple of alternative ideas, that may or may not work in reality..

1. Use some OS-specific code for eye dropping a colour instead of trying to implement it using Godot objects.
2. Hide the ColorPicker popup while using the eyedropper, and open it again after the user has clicked the main window. Possibly with some kind of decoration, like a thick frame around the window, or a small notification e.g. "click to pick a colour, or Esc to cancel", to give some kind of indication that the popup didn't just disappear.
3. Remove eye dropper. Maybe people aren't using it anyway?