Handle scroll events in RichtTextLabel

[KoBeWi]

Allows scrolling RichTextLabel inside ScrollContainer.

Before:

godot_23r9S1xFxA.mp4

After:

godot.windows.editor.dev.x86_64_RdaT5zqTkq.mp4

The code is adapted from ScrollContainer.

godot/scene/gui/scroll_container.cpp

Lines 119 to 163 in 1917bc3

	if (mb->get_button_index() == MouseButton::WHEEL_UP) {
	// By default, the vertical orientation takes precedence. This is an exception.
	if ((h_scroll_enabled && mb->is_shift_pressed()) || v_scroll_hidden) {
	h_scroll->scroll(-h_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	} else if (v_scroll_enabled) {
	v_scroll->scroll(-v_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	}
	}
	if (mb->get_button_index() == MouseButton::WHEEL_DOWN) {
	if ((h_scroll_enabled && mb->is_shift_pressed()) || v_scroll_hidden) {
	h_scroll->scroll(h_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	} else if (v_scroll_enabled) {
	v_scroll->scroll(v_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	}
	}
	bool h_scroll_hidden = !h_scroll->is_visible() && horizontal_scroll_mode != SCROLL_MODE_SHOW_NEVER;
	if (mb->get_button_index() == MouseButton::WHEEL_LEFT) {
	// By default, the horizontal orientation takes precedence. This is an exception.
	if ((v_scroll_enabled && mb->is_shift_pressed()) || h_scroll_hidden) {
	v_scroll->scroll(-v_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	} else if (h_scroll_enabled) {
	h_scroll->scroll(-h_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	}
	}
	if (mb->get_button_index() == MouseButton::WHEEL_RIGHT) {
	if ((v_scroll_enabled && mb->is_shift_pressed()) || h_scroll_hidden) {
	v_scroll->scroll(v_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	} else if (h_scroll_enabled) {
	h_scroll->scroll(h_scroll->get_page() / 8 * mb->get_factor());
	scroll_value_modified = true;
	}
	}
	if (scroll_value_modified && (v_scroll->get_value() != prev_v_scroll || h_scroll->get_value() != prev_h_scroll)) {
	accept_event(); // Accept event if scroll changed.
	return;
	}

[akien-mga]

Thanks!