From 9c51dea6d1bc5c13dcd8e921f425c3a3792641f6 Mon Sep 17 00:00:00 2001
From: Sophie Herold <sophie@hemio.de>
Date: Tue, 7 Feb 2023 23:14:55 +0100
Subject: [PATCH] image: Fix rotation gesture on touchscreens

Use angle-delta instead of total angle. Total angle is
absolute on touchscreens.
---
 src/widgets/image.rs | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/widgets/image.rs b/src/widgets/image.rs
index 04bb93d..748ca72 100644
--- a/src/widgets/image.rs
+++ b/src/widgets/image.rs
@@ -380,12 +380,15 @@ mod imp {
             let rotation_gesture = gtk::GestureRotate::new();
             obj.add_controller(&rotation_gesture);
 
-            rotation_gesture.connect_angle_changed(glib::clone!(@weak obj => move |_, angle, _| {
-                // offset for rotate gesture to take effect
-                if angle.abs().to_degrees() > 20. {
-                    obj.set_rotation(obj.imp().rotation_target.get() + angle.to_degrees());
-                }
-            }));
+            rotation_gesture.connect_angle_changed(
+                glib::clone!(@weak obj => move |gesture, _, _| {
+                    let angle = gesture.angle_delta();
+                    // offset for rotate gesture to take effect
+                    if angle.abs().to_degrees() > 20. {
+                        obj.set_rotation(obj.imp().rotation_target.get() + angle.to_degrees());
+                    }
+                }),
+            );
 
             rotation_gesture.connect_end(glib::clone!(@weak obj => move |_, _| {
                 log::debug!("Rotate gesture ended");