Merge pull request #261 from sajattack/master

implement scroll_to_top and scroll_to_bottom

src/views/scroll_view.rs

@@ -108,6 +108,32 @@ impl<V> ScrollView<V> {
         self.with(|s| s.set_scroll_x(enabled))
     }
     
+    /// Programmatically scroll to the top of the view.
+    pub fn scroll_to_top(&mut self) {
+        let curr_x = self.offset.x;
+        self.set_offset((curr_x,0));   
+    }
+    
+    /// Programmatically scroll to the bottom of the view.
+    pub fn scroll_to_bottom(&mut self) {
+        let max_y = self.inner_size.saturating_sub(self.available_size()).y;
+        let curr_x = self.offset.x; 
+        self.set_offset((curr_x, max_y));
+    }
+    
+    /// Programmatically scroll to the leftmost side of the view.
+    pub fn scroll_to_left(&mut self) {
+        let curr_y = self.offset.y;
+        self.set_offset((0, curr_y));
+    }
+    
+    /// Programmatically scroll to the rightmost side of the view.
+    pub fn scroll_to_right(&mut self) {
+        let max_x = self.inner_size.saturating_sub(self.available_size()).x;
+        let curr_y = self.offset.y;
+        self.set_offset((max_x, curr_y));
+    }
+
     /// Returns for each axis if we are scrolling.
     fn is_scrolling(&self) -> XY<bool> {
         self.inner_size.zip_map(self.last_size, |i, s| i > s)