draft: flickable list

Author: igagis

src/ruis/widget/base/touch/flickable.cpp

@@ -178,8 +178,6 @@ ruis::event_status flickable::on_mouse_move(const mouse_move_event& event)
 							 .pointer_id = this->cur_pointer_id}
 						);
 					}
-
-					this->flickable_scroll_by(-delta);
 				}
 			}
 			return event_status::consumed;

src/ruis/widget/group/list.cpp

@@ -353,77 +353,96 @@ void list::notify_scroll_pos_changed(size_t old_index, real old_offset)
 	}
 }
 
-void list::scroll_by(real delta)
+real list::scroll_by(real delta)
 {
 	size_t old_index = this->pos_index;
 	real old_offset = this->pos_offset;
 
+	// list's longitudinal direction index
 	unsigned long_index = this->get_long_index();
 
-	//	TRACE(<< "delta = " << delta << std::endl)
+	real scrolled_by = 0;
 
 	if (delta >= 0) {
 		for (auto& c : this->children()) {
 			auto wd = c.get().rect().d[long_index] - this->pos_offset;
 			if (wd > delta) {
 				this->pos_offset += delta;
 				delta -= wd;
+				scrolled_by += delta;
 				break;
 			}
 
 			delta -= wd;
+			scrolled_by += wd;
 			this->pos_offset = 0;
 			++this->pos_index;
 		}
 
 		if (delta > 0) {
-			ASSERT(this->pos_index > this->added_index + this->children().size(), [&](auto& o) {
-				o << "this->pos_index = " << this->pos_index << " this->added_index = " << this->added_index
-				  << " this->children().size() = " << this->children().size();
-			})
+			utki::assert(
+				this->pos_index > this->added_index + this->children().size(),
+				[&](auto& o) {
+					o << "this->pos_index = " << this->pos_index << " this->added_index = " << this->added_index
+					  << " this->children().size() = " << this->children().size();
+				},
+				SL
+			);
 			for (; this->pos_index < this->first_tail_item_index;) {
 				auto w = this->get_provider().get_widget(this->pos_index);
 				vec2 d = dims_for_widget(w.get(), this->rect().d);
-				this->push_back(w); // this is just optimization, to avoid creating same widget twice
+
+				// this is just optimization, to avoid creating same widget twice
+				this->push_back(std::move(w));
+
 				if (d[long_index] > delta) {
 					this->pos_offset = delta;
 					break;
 				}
 				delta -= d[long_index];
-				ASSERT(this->pos_offset == 0)
+				scrolled_by += d[long_index];
+				utki::assert(this->pos_offset == 0, SL);
 				++this->pos_index;
 			}
 		}
 	} else {
 		delta = -delta;
 		if (delta <= this->pos_offset) {
 			this->pos_offset -= delta;
+			scrolled_by -= delta;
 		} else {
-			ASSERT(this->added_index == this->pos_index)
+			utki::assert(this->added_index == this->pos_index, SL);
 			delta -= this->pos_offset;
+			scrolled_by -= this->pos_offset;
 			this->pos_offset = 0;
 			for (; this->pos_index > 0;) {
-				ASSERT(this->added_index == this->pos_index)
+				utki::assert(this->added_index == this->pos_index, SL);
 				--this->pos_index;
 				auto w = this->get_provider().get_widget(this->pos_index);
 				vec2 d = dims_for_widget(w.get(), this->rect().d);
+
+				// this is just optimization, to avoid creating same widget twice
 				this->insert(
-					w,
+					std::move(w), //
 					this->children().begin()
-				); // this is just optimization, to avoid creating same widget twice
+				);
+
 				--this->added_index;
 				if (d[long_index] > delta) {
 					this->pos_offset = d[long_index] - delta;
 					break;
 				}
 				delta -= d[long_index];
+				scrolled_by -= d[long_index];
 			}
 		}
 	}
 
 	this->update_children_list();
 
 	this->notify_scroll_pos_changed(old_index, old_offset);
+
+	return scrolled_by;
 }
 
 ruis::vec2 list::measure(const ruis::vec2& quotum) const

src/ruis/widget/group/list.hpp

@@ -126,8 +126,9 @@ class list :
 	/**
 	 * @brief Scroll the list by given number of pixels.
 	 * @param delta - number of pixels to scroll, can be positive or negative.
+	 * @return number of pixels actually scrolled by.
 	 */
-	void scroll_by(real delta);
+	real scroll_by(real delta);
 
 	/**
 	 * @brief Model change signal.
@@ -152,6 +153,10 @@ class list :
 		return this->children();
 	}
 
+protected:
+	using container::on_mouse_move;
+	using container::on_mouse_button;
+
 private:
 	void update_children_list();
 

src/ruis/widget/group/touch/list.cpp

@@ -0,0 +1,53 @@
+/*
+ruis - GUI framework
+
+Copyright (C) 2012-2026  Ivan Gagis <igagis@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* ================ LICENSE END ================ */
+
+#include "list.hpp"
+
+using namespace ruis::touch;
+
+ruis::event_status list::on_mouse_button(const mouse_button_event& event)
+{
+	return this->flickable::on_mouse_button(event);
+}
+
+ruis::event_status list::on_mouse_move(const mouse_move_event& event)
+{
+	return this->flickable::on_mouse_move(event);
+}
+
+ruis::event_status list::flickable_on_mouse_button(const mouse_button_event& event)
+{
+	return this->ruis::list::on_mouse_button(event);
+}
+
+ruis::event_status list::flickable_on_mouse_move(const mouse_move_event& event)
+{
+	return this->ruis::list::on_mouse_move(event);
+}
+
+ruis::vec2 list::flickable_scroll_by(const vec2& delta)
+{
+	if (this->is_vertical()) {
+		return vec2(0, this->scroll_by(delta.y()));
+	} else {
+		return vec2(this->scroll_by(delta.x()), 0);
+	}
+}

src/ruis/widget/group/touch/list.hpp

@@ -0,0 +1,52 @@
+/*
+ruis - GUI framework
+
+Copyright (C) 2012-2026  Ivan Gagis <igagis@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* ================ LICENSE END ================ */
+
+#pragma once
+
+#include "../../base/touch/flickable.hpp"
+#include "../list.hpp"
+
+namespace ruis::touch {
+
+class list :
+	public ruis::list, //
+	private flickable
+{
+public:
+	list(
+		utki::shared_ref<ruis::context> context, //
+		all_parameters params
+	);
+
+	event_status on_mouse_button(const mouse_button_event& event) override;
+	event_status on_mouse_move(const mouse_move_event& event) override;
+
+private:
+	event_status flickable_on_mouse_button(const mouse_button_event& event) override;
+	event_status flickable_on_mouse_move(const mouse_move_event& event) override;
+	vec2 flickable_scroll_by(const vec2& delta) override;
+};
+
+namespace make {
+// TODO: add list() factory
+} // namespace make
+
+} // namespace ruis::touch

src/ruis/widget/group/touch/scroll_area.hpp

@@ -46,4 +46,8 @@ class scroll_area :
 	vec2 flickable_scroll_by(const vec2& delta) override;
 };
 
+namespace make {
+// TDOO: add scroll_area() factory
+} // namespace make
+
 } // namespace ruis::touch