push column picker immediately to new column

instead of pushing to temporary column first

Signed-off-by: kernelkind <kernelkind@gmail.com>

src/route.rs

@@ -61,6 +61,7 @@ pub struct Router<R: Clone> {
     routes: Vec<R>,
     pub returning: bool,
     pub navigating: bool,
+    replacing: bool,
 }
 
 impl<R: Clone> Router<R> {
@@ -70,10 +71,12 @@ impl<R: Clone> Router<R> {
         }
         let returning = false;
         let navigating = false;
+        let replacing = false;
         Router {
             routes,
             returning,
             navigating,
+            replacing,
         }
     }
 
@@ -82,6 +85,13 @@ impl<R: Clone> Router<R> {
         self.routes.push(route);
     }
 
+    // Route to R. Then when it is successfully placed, should call `remove_previous_route`
+    pub fn route_to_replaced(&mut self, route: R) {
+        self.navigating = true;
+        self.replacing = true;
+        self.routes.push(route);
+    }
+
     /// Go back, start the returning process
     pub fn go_back(&mut self) -> Option<R> {
         if self.returning || self.routes.len() == 1 {
@@ -100,6 +110,20 @@ impl<R: Clone> Router<R> {
         self.routes.pop()
     }
 
+    pub fn remove_previous_route(&mut self) -> Option<R> {
+        let num_routes = self.routes.len();
+        if num_routes <= 1 {
+            return None;
+        }
+        self.returning = false;
+        self.replacing = false;
+        Some(self.routes.remove(num_routes - 2))
+    }
+
+    pub fn is_replacing(&self) -> bool {
+        self.replacing
+    }
+
     pub fn top(&self) -> &R {
         self.routes.last().expect("routes can't be empty")
     }