Refactor pen interface into driver system.

1 files changed, 148 insertions, 0 deletions

diff --git a/src/drivers/Base/Fl_Base_Pen_Events.cxx b/src/drivers/Base/Fl_Base_Pen_Events.cxx
new file mode 100644
index 000000000..f4ebbd8ad
--- /dev/null
+++ b/src/drivers/Base/Fl_Base_Pen_Events.cxx
@@ -0,0 +1,148 @@
+//
+// Implementation of default Pen/Tablet event driver.
+//
+// Copyright 2025 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     https://www.fltk.org/COPYING.php
+//
+// Please see the following page on how to report bugs and issues:
+//
+//     https://www.fltk.org/bugs.php
+//
+
+#include "src/drivers/Base/Fl_Base_Pen_Events.H"
+
+
+class Fl_Widget;
+
+
+namespace Fl {
+
+namespace Pen {
+
+EventData e;
+SubscriberList subscriber_list_;
+std::shared_ptr<Subscriber> pushed_;
+std::shared_ptr<Subscriber> below_pen_;
+
+} // namespace Pen
+
+} // namespace Fl
+
+
+using namespace Fl::Pen;
+
+
+// ---- SubscriberList implementation ------------------------------------------
+
+/* Remove subscribers that have a nullptr as a widget */
+void Fl::Pen::SubscriberList::cleanup() {
+  for (auto it = begin(); it != end(); ) {
+    if (!it->second->widget()) {
+      it = erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+
+/* Add a new subscriber, or return an existing one. */
+std::shared_ptr<Subscriber> Fl::Pen::SubscriberList::add(Fl_Widget *w) {
+  cleanup();
+  auto it = find(w);
+  if (it == end()) {
+    auto sub = std::make_shared<Subscriber>(w);
+    insert(std::make_pair(w, sub));
+    return sub;
+  } else {
+    return it->second;
+  }
+}
+
+/* Remove a subscriber from the list. */
+void Fl::Pen::SubscriberList::remove(Fl_Widget *w) {
+  auto it = find(w);
+  if (it != end()) {
+    it->second->clear();
+    erase(it);
+  }
+}
+
+// ---- Driver implementation --------------------------------------------------
+// Override the methods below to handle subscriptions and queries by user apps.
+
+void Fl::Pen::Driver::subscribe(Fl_Widget* widget) {
+  if (widget == nullptr) return;
+  subscriber_list_.add(widget);
+}
+
+void Fl::Pen::Driver::unsubscribe(Fl_Widget* widget) {
+  if (widget == nullptr) return;
+  subscriber_list_.remove(widget);
+}
+
+void Fl::Pen::Driver::release() {
+  pushed_ = nullptr;
+  below_pen_ = nullptr;
+}
+
+Trait Fl::Pen::Driver::traits() {
+  return Trait::NONE;
+}
+
+Trait Fl::Pen::Driver::pen_traits(int pen_id) {
+  (void)pen_id;
+  return Trait::NONE;
+}
+
+// ---- Fl::Pen API ------------------------------------------------------------
+
+void Fl::Pen::subscribe(Fl_Widget* widget) {
+  driver.subscribe(widget);
+}
+
+void Fl::Pen::unsubscribe(Fl_Widget* widget) {
+  driver.unsubscribe(widget);
+}
+
+void Fl::Pen::release() {
+  driver.release();
+}
+
+Trait Fl::Pen::driver_traits() {
+  return driver.traits();
+}
+
+Trait Fl::Pen::pen_traits(int pen_id) {
+  return driver.pen_traits(pen_id);
+}
+
+double Fl::Pen::event_x() { return e.x; }
+
+double Fl::Pen::event_y() { return e.y; }
+
+double Fl::Pen::event_x_root() { return e.rx; }
+
+double Fl::Pen::event_y_root() { return e.ry; }
+
+int Fl::Pen::event_pen_id() { return e.pen_id; }
+
+double Fl::Pen::event_pressure() { return e.pressure; }
+
+double Fl::Pen::event_barrel_pressure() { return e.barrel_pressure; }
+
+double Fl::Pen::event_tilt_x() { return e.tilt_x; }
+
+double Fl::Pen::event_tilt_y() { return e.tilt_y; }
+
+double Fl::Pen::event_twist() { return e.twist; }
+
+double Fl::Pen::event_proximity() { return e.proximity; }
+
+State Fl::Pen::event_state() { return e.state; }
+
+State Fl::Pen::event_trigger() { return e.trigger; }