From f15f36cc1b292cea5d93c6a6480104d53d44d770 Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Tue, 22 Oct 2019 13:58:59 -0700
Subject: [PATCH] Add ScrollView::scroll_to_important_area

---
 src/view/scroll/core.rs  | 33 +++++++++++++++++----------------
 src/views/scroll_view.rs |  6 ++++++
 2 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/src/view/scroll/core.rs b/src/view/scroll/core.rs
index 947f557..f3c0522 100644
--- a/src/view/scroll/core.rs
+++ b/src/view/scroll/core.rs
@@ -337,22 +337,7 @@ impl Core {
             other => {
                 // The view consumed the event. Maybe something changed?
 
-                // Fix offset?
-                let important = important_area;
-
-                // The furthest top-left we can go
-                let top_left = (important.bottom_right() + (1, 1))
-                    .saturating_sub(self.available_size());
-                // The furthest bottom-right we can go
-                let bottom_right = important.top_left();
-
-                // "top_left < bottom_right" is NOT guaranteed
-                // if the child is larger than the view.
-                let offset_min = Vec2::min(top_left, bottom_right);
-                let offset_max = Vec2::max(top_left, bottom_right);
-
-                self.offset =
-                    self.offset.or_max(offset_min).or_min(offset_max);
+                self.scroll_to_rect(important_area);
 
                 other
             }
@@ -554,6 +539,22 @@ impl Core {
         self.offset = self.offset.or_min(max).or_max(min);
     }
 
+    /// Scrolls until the given rect is in view.
+    pub fn scroll_to_rect(&mut self, important_area: Rect) {
+        // The furthest top-left we can go
+        let top_left = (important_area.bottom_right() + (1, 1))
+            .saturating_sub(self.available_size());
+        // The furthest bottom-right we can go
+        let bottom_right = important_area.top_left();
+
+        // "top_left < bottom_right" is NOT guaranteed
+        // if the child is larger than the view.
+        let offset_min = Vec2::min(top_left, bottom_right);
+        let offset_max = Vec2::max(top_left, bottom_right);
+
+        self.offset = self.offset.or_max(offset_min).or_min(offset_max);
+    }
+
     /// Scroll until the given point is visible.
     pub fn scroll_to(&mut self, pos: Vec2) {
         // The furthest top-left we can go
diff --git a/src/views/scroll_view.rs b/src/views/scroll_view.rs
index 119ea69..06cdb75 100644
--- a/src/views/scroll_view.rs
+++ b/src/views/scroll_view.rs
@@ -155,6 +155,12 @@ where
         self.core.scroll_to_right();
     }
 
+    /// Programmatically scroll until the child's important area is in view.
+    pub fn scroll_to_important_area(&mut self) {
+        let important_area = self.inner.important_area(self.core.last_size());
+        self.core.scroll_to_rect(important_area);
+    }
+
     /// Returns the wrapped view.
     pub fn into_inner(self) -> V {
         self.inner