From 56ba08b7cbec5fab590d2ac8388e1e0052069b48 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Mon, 13 Jul 2015 15:33:15 +0200
Subject: [PATCH] implement scroll-wheel support for ClickBoxes

---
 libs/gtkmm2ext/auto_spin.cc          | 23 +++++++++++++++++++++++
 libs/gtkmm2ext/click_box.cc          |  7 +++++++
 libs/gtkmm2ext/gtkmm2ext/auto_spin.h |  1 +
 libs/gtkmm2ext/gtkmm2ext/click_box.h |  1 +
 4 files changed, 32 insertions(+)

diff --git a/libs/gtkmm2ext/auto_spin.cc b/libs/gtkmm2ext/auto_spin.cc
index 0f4c371a09..707414df95 100644
--- a/libs/gtkmm2ext/auto_spin.cc
+++ b/libs/gtkmm2ext/auto_spin.cc
@@ -143,6 +143,29 @@ AutoSpin::button_press (GdkEventButton *ev)
 	return TRUE;
 }
 
+gint
+AutoSpin::scroll_event (GdkEventScroll *ev)
+{
+	stop_spinning (0);
+
+	gfloat increment = step_increment;
+
+	if (ev->state & Keyboard::TertiaryModifier) {
+		increment = page_increment;
+	}
+
+	switch (ev->direction) {
+		case GDK_SCROLL_DOWN:
+		case GDK_SCROLL_LEFT:
+			adjust_value (-increment);
+			break;
+		case GDK_SCROLL_RIGHT:
+		case GDK_SCROLL_UP:
+			adjust_value (increment);
+			break;
+	}
+}
+
 void
 AutoSpin::start_spinning (bool decrement, bool page)
 {
diff --git a/libs/gtkmm2ext/click_box.cc b/libs/gtkmm2ext/click_box.cc
index 63ab3db7ba..383fa6e583 100644
--- a/libs/gtkmm2ext/click_box.cc
+++ b/libs/gtkmm2ext/click_box.cc
@@ -62,6 +62,13 @@ ClickBox::button_press_handler (GdkEventButton* ev)
 	return true;
 }
 
+bool
+ClickBox::on_scroll_event (GdkEventScroll* ev)
+{
+	AutoSpin::scroll_event (ev);
+	return true;
+}
+
 bool
 ClickBox::button_release_handler (GdkEventButton* ev)
 {
diff --git a/libs/gtkmm2ext/gtkmm2ext/auto_spin.h b/libs/gtkmm2ext/gtkmm2ext/auto_spin.h
index 8a6c9ab3b0..0f5a9467c6 100644
--- a/libs/gtkmm2ext/gtkmm2ext/auto_spin.h
+++ b/libs/gtkmm2ext/gtkmm2ext/auto_spin.h
@@ -47,6 +47,7 @@ class LIBGTKMM2EXT_API AutoSpin
 	gint button_press (GdkEventButton *);
 	gint stop_spinning (GdkEventButton *ignored_but_here_for_clicked);
 	void start_spinning (bool decrementing, bool use_page);
+	gint scroll_event (GdkEventScroll *);
 
   private:
 	Gtk::Adjustment &adjustment;
diff --git a/libs/gtkmm2ext/gtkmm2ext/click_box.h b/libs/gtkmm2ext/gtkmm2ext/click_box.h
index c2afa2dd12..3b7fd0f498 100644
--- a/libs/gtkmm2ext/gtkmm2ext/click_box.h
+++ b/libs/gtkmm2ext/gtkmm2ext/click_box.h
@@ -57,6 +57,7 @@ class LIBGTKMM2EXT_API ClickBox : public Gtk::DrawingArea, public AutoSpin
 	void style_changed (const Glib::RefPtr<Gtk::Style> &);
 	bool button_press_handler (GdkEventButton *);
 	bool button_release_handler (GdkEventButton *);
+	bool on_scroll_event (GdkEventScroll*);
 
 	sigc::slot<bool, char *, Gtk::Adjustment &> _printer;
 };