apply current tag if position active only, expect match results > 0 on request navigation act

src/app/browser/window/tab/item/page/search/form.rs

@@ -80,9 +80,10 @@ impl Form {
             let navigation = navigation.clone();
             let result = result.clone();
             let subject = subject.clone();
-            move |_| match subject.borrow().as_ref() {
+            move |this| match subject.borrow().as_ref() {
                 Some(subject) => {
-                    if let Some((mut start, _)) = navigation.forward(subject) {
+                    if !this.text().is_empty() {
+                        let (mut start, _) = navigation.forward(subject);
                         result.update(navigation.position(), navigation.total());
                         scroll_to_iter(&subject.text_view, &mut start)
                     }
@@ -121,13 +122,11 @@ impl Form {
             let result = result.clone();
             let subject = subject.clone();
             move |_| match subject.borrow().as_ref() {
-                Some(subject) => match navigation.back(subject) {
+                Some(subject) => {
-                    Some((mut start, _)) => {
+                    let (mut start, _) = navigation.back(subject);
-                        result.update(navigation.position(), navigation.total());
+                    result.update(navigation.position(), navigation.total());
-                        scroll_to_iter(&subject.text_view, &mut start)
+                    scroll_to_iter(&subject.text_view, &mut start)
-                    }
+                }
-                    None => todo!(),
-                },
                 None => todo!(),
             }
         });
@@ -137,13 +136,11 @@ impl Form {
             let result = result.clone();
             let subject = subject.clone();
             move |_| match subject.borrow().as_ref() {
-                Some(subject) => match navigation.forward(subject) {
+                Some(subject) => {
-                    Some((mut start, _)) => {
+                    let (mut start, _) = navigation.forward(subject);
-                        result.update(navigation.position(), navigation.total());
+                    result.update(navigation.position(), navigation.total());
-                        scroll_to_iter(&subject.text_view, &mut start)
+                    scroll_to_iter(&subject.text_view, &mut start)
-                    }
+                }
-                    None => todo!(),
-                },
                 None => todo!(),
             }
         });

src/app/browser/window/tab/item/page/search/form/navigation.rs

@@ -53,13 +53,18 @@ impl Navigation {
 
     // Actions
 
+    /// Update widget state, including child components
     pub fn update(&self, matches: Vec<(TextIter, TextIter)>) {
         self.back.update(!matches.is_empty());
         self.forward.update(!matches.is_empty());
         self.model.replace(Model::new(matches));
     }
 
-    pub fn back(&self, subject: &Subject) -> Option<(TextIter, TextIter)> {
+    /// Navigate back in matches, apply tags to buffer
+    /// * return `start`/`end` iters to scroll up the widget
+    /// * user should not activate this function on empty results
+    ///   expected all actions / buttons deactivated in this case
+    pub fn back(&self, subject: &Subject) -> (TextIter, TextIter) {
         let buffer = subject.text_view.buffer();
 
         buffer.remove_tag(
@@ -68,16 +73,25 @@ impl Navigation {
             &buffer.end_iter(),
         );
 
-        match self.model.borrow_mut().back() {
+        let mut model = self.model.borrow_mut();
-            Some((start, end)) => {
+
-                buffer.apply_tag(&subject.tag.current, start, end);
+        let (start, end) = match model.back() {
-                Some((*start, *end))
+            Some((start, end)) => (*start, *end),
-            }
+            None => todo!(), // unexpected
-            None => None,
+        };
+
+        if model.position().is_some() {
+            buffer.apply_tag(&subject.tag.current, &start, &end);
         }
+
+        (start, end)
     }
 
-    pub fn forward(&self, subject: &Subject) -> Option<(TextIter, TextIter)> {
+    /// Navigate forward in matches, apply tags to buffer
+    /// * return `start`/`end` iters to scroll down the widget
+    /// * user should not activate this function on empty results
+    ///   expected all actions / buttons deactivated in this case
+    pub fn forward(&self, subject: &Subject) -> (TextIter, TextIter) {
         let buffer = subject.text_view.buffer();
 
         buffer.remove_tag(
@@ -86,15 +100,22 @@ impl Navigation {
             &buffer.end_iter(),
         );
 
-        match self.model.borrow_mut().next() {
+        let mut model = self.model.borrow_mut();
-            Some((start, end)) => {
+
-                buffer.apply_tag(&subject.tag.current, start, end);
+        let (start, end) = match model.next() {
-                Some((*start, *end))
+            Some((start, end)) => (*start, *end),
-            }
+            None => todo!(), // unexpected
-            None => None,
+        };
+
+        if model.position().is_some() {
+            buffer.apply_tag(&subject.tag.current, &start, &end);
         }
+
+        (start, end)
     }
 
+    // Getters
+
     pub fn position(&self) -> Option<usize> {
         self.model.borrow().position()
     }