Fix broken egui_router transition and improve swiping (#91)

* Fix broken egui_router transition and improve swiping

* Disable by default

* Comment

* Fix

Author: lucasmerlin

crates/egui_router/src/router.rs

@@ -5,7 +5,7 @@ use crate::transition::{ActiveTransition, ActiveTransitionResult};
 use crate::{
     CurrentTransition, Request, RouteState, RouterError, RouterResult, TransitionConfig, ID,
 };
-use egui::{scroll_area, Id, Sense, Ui};
+use egui::{scroll_area, Id, NumExt, Sense, Ui};
 use matchit::MatchError;
 use std::borrow::Cow;
 use std::collections::BTreeMap;
@@ -396,13 +396,16 @@ impl<State: 'static, H: History + Default> EguiRouter<State, H> {
 
                                 // Start a manual backward transition
                                 if self.current_transition.is_none() {
-                                    self.current_transition = Some(CurrentTransition {
-                                        active_transition: ActiveTransition::backward_manual(
+                                    let mut transition = CurrentTransition {
+                                        active_transition: ActiveTransition::manual(
                                             self.backward_transition.clone(),
                                         )
                                         .with_default_duration(self.default_duration),
                                         leaving_route: None,
-                                    });
+                                    };
+                                    // Initialize progress to 1.0 (fully showing current page)
+                                    transition.active_transition.set_progress(1.0);
+                                    self.current_transition = Some(transition);
                                 }
                             }
                         }
@@ -422,7 +425,8 @@ impl<State: 'static, H: History + Default> EguiRouter<State, H> {
                         // Update the transition progress
                         if let Some(transition) = &mut self.current_transition {
                             let screen_width = content_rect.width();
-                            let progress = (new_distance / screen_width).min(1.0);
+                            // let progress = 1.0 - (new_distance / screen_width).at_most(1.0);
+                            let progress = 1.0 - (new_distance / screen_width).at_most(1.0);
                             transition.active_transition.set_progress(progress);
                         }
                     }
@@ -442,15 +446,17 @@ impl<State: 'static, H: History + Default> EguiRouter<State, H> {
                         || velocity >= FLICK_VELOCITY_THRESHOLD;
 
                     if should_navigate_back {
+                        let popped = self.history.pop();
                         // Complete the back navigation
                         if let Some(transition) = &mut self.current_transition {
-                            transition.active_transition.resume_automatic();
+                            let progress = transition.active_transition.progress();
+                            transition.active_transition =
+                                ActiveTransition::backward(self.backward_transition.clone());
+                            transition.active_transition.set_progress(1.0 - progress);
+                            transition.leaving_route = popped;
                         }
                         // Actually perform the back navigation
                         self.history_kind.back().ok();
-                        if self.history.len() > 1 {
-                            self.history.pop();
-                        }
                     } else {
                         // Cancel the gesture - animate back to the current page
                         self.current_transition = None;

crates/egui_router/src/router_builder.rs

@@ -52,7 +52,7 @@ impl<State: 'static, H: History + Default> RouterBuilder<State, H> {
             loading_ui: Arc::new(Box::new(|ui, _| {
                 ui.spinner();
             })),
-            swipe_back_gesture_enabled: true,
+            swipe_back_gesture_enabled: false,
             swipe_back_edge_width: 40.0,
             swipe_back_threshold: 0.4,
         }
@@ -241,7 +241,7 @@ impl<State: 'static, H: History + Default> RouterBuilder<State, H> {
         self
     }
 
-    /// Enable or disable the iOS-style swipe-to-go-back gesture (enabled by default)
+    /// Enable or disable the iOS-style swipe-to-go-back gesture (disabled by default)
     pub fn swipe_back_gesture(mut self, enabled: bool) -> Self {
         self.swipe_back_gesture_enabled = enabled;
         self

crates/egui_router/src/transition.rs

@@ -193,24 +193,24 @@ impl ActiveTransition {
         }
     }
 
-    pub fn backward_manual(config: TransitionConfig) -> Self {
+    pub fn manual(config: TransitionConfig) -> Self {
         Self {
             duration: config.duration,
             easing: config.easing,
             progress: 0.0,
             in_: config.in_,
             out: config.out,
-            backward: true,
+            backward: false,
             manual_control: true,
         }
     }
 
-    pub fn set_progress(&mut self, progress: f32) {
-        self.progress = progress.clamp(0.0, 1.0);
+    pub fn progress(&self) -> f32 {
+        self.progress
     }
 
-    pub fn resume_automatic(&mut self) {
-        self.manual_control = false;
+    pub fn set_progress(&mut self, progress: f32) {
+        self.progress = progress.clamp(0.0, 1.0);
     }
 
     pub fn with_default_duration(mut self, duration: Option<f32>) -> Self {
@@ -242,32 +242,36 @@ impl ActiveTransition {
             (self.easing)(t)
         };
 
+        let eased_t_rev = if self.manual_control {
+            1.0 - t
+        } else {
+            (self.easing)(1.0 - t)
+        };
+
         if self.backward {
-            // Render previous page first (underneath, revealed as current slides away)
+            with_temp_auto_id(ui, in_id, |ui| {
+                let mut out_ui =
+                    self.out
+                        .create_child_ui(ui, eased_t, Id::new("router_child").with(in_id));
+                content_in(&mut out_ui, state);
+            });
+
             if let Some((out_id, content_out)) = content_out {
                 with_temp_auto_id(ui, out_id, |ui| {
-                    let mut out_ui =
-                        self.out
-                            .create_child_ui(ui, eased_t, Id::new("router_child").with(out_id));
-                    content_out(&mut out_ui, state);
+                    let mut in_ui = self.in_.create_child_ui(
+                        ui,
+                        eased_t_rev,
+                        Id::new("router_child").with(out_id),
+                    );
+                    content_out(&mut in_ui, state);
                 });
             }
-
-            // Render current page second (on top, sliding to the right)
-            with_temp_auto_id(ui, in_id, |ui| {
-                let mut in_ui = self.in_.create_child_ui(
-                    ui,
-                    1.0 - eased_t,
-                    Id::new("router_child").with(in_id),
-                );
-                content_in(&mut in_ui, state);
-            });
         } else {
             if let Some((out_id, content_out)) = content_out {
                 with_temp_auto_id(ui, out_id, |ui| {
                     let mut out_ui = self.out.create_child_ui(
                         ui,
-                        1.0 - eased_t,
+                        eased_t_rev,
                         Id::new("router_child").with(out_id),
                     );
                     content_out(&mut out_ui, state);
@@ -282,7 +286,7 @@ impl ActiveTransition {
             });
         }
 
-        if self.progress >= 1.0 {
+        if self.progress >= 1.0 && !self.manual_control {
             ActiveTransitionResult::Done
         } else {
             ActiveTransitionResult::Continue