From f2b1fac6797b4ed846c0b8e42447225ecd0cb4bd Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Mon, 29 Jun 2020 18:00:57 -0700
Subject: [PATCH] Fix bad initial focus

---
 cursive-core/src/views/fixed_layout.rs | 46 ++++++++++++++++++++++----
 cursive-core/src/views/stack_view.rs   |  2 +-
 examples/src/bin/fixed_layout.rs       | 17 +++++++---
 3 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/cursive-core/src/views/fixed_layout.rs b/cursive-core/src/views/fixed_layout.rs
index 10a7334..def2c9a 100644
--- a/cursive-core/src/views/fixed_layout.rs
+++ b/cursive-core/src/views/fixed_layout.rs
@@ -7,11 +7,28 @@ use crate::{Printer, Vec2, View, With};
 /// Arranges its children in a fixed layout.
 ///
 /// Usually meant to use an external layout engine.
+///
+/// # Examples
+///
+/// ```rust
+/// use cursive_core::{
+///     views::{FixedLayout, TextView, Button},
+///     Rect,
+/// };
+///
+/// let layout = FixedLayout::new()
+///     .child(Rect::from_size((0,0), (1,1)), TextView::new("/"))
+///     .child(Rect::from_size((14,0), (1,1)), TextView::new(r"\"))
+///     .child(Rect::from_size((0,2), (1,1)), TextView::new(r"\"))
+///     .child(Rect::from_size((14,2), (1,1)), TextView::new("/"))
+///     .child(Rect::from_size((3,1), (11,1)), Button::new("Clickme", |s| s.quit()));
+/// ````
 pub struct FixedLayout {
     children: Vec<Child>,
     focus: usize,
 }
 
+/// Represents a child view inside the FixedLayout.
 struct Child {
     view: Box<dyn View>,
     position: Rect,
@@ -123,7 +140,21 @@ impl FixedLayout {
         }
     }
 
-    fn move_focus(&mut self, target: Absolute) -> EventResult {
+    fn move_focus_rel(&mut self, target: Relative) -> EventResult {
+        let source = Direction::Rel(target.swap());
+        for (i, c) in
+            Self::iter_mut(source, &mut self.children).skip(self.focus + 1)
+        {
+            if c.view.take_focus(source) {
+                self.focus = i;
+                return EventResult::Consumed(None);
+            }
+        }
+
+        EventResult::Ignored
+    }
+
+    fn move_focus_abs(&mut self, target: Absolute) -> EventResult {
         let source = Direction::Abs(target.opposite());
         let (orientation, rel) = target.split();
 
@@ -198,6 +229,7 @@ impl View for FixedLayout {
     }
 
     fn on_event(&mut self, event: Event) -> EventResult {
+        eprintln!("Self focus: {:?}", self.focus);
         if self.is_empty() {
             return EventResult::Ignored;
         }
@@ -212,11 +244,12 @@ impl View for FixedLayout {
 
         match result {
             EventResult::Ignored => match event {
-                Event::Key(Key::Tab) => unimplemented!(),
-                Event::Key(Key::Left) => self.move_focus(Absolute::Left),
-                Event::Key(Key::Right) => self.move_focus(Absolute::Right),
-                Event::Key(Key::Up) => self.move_focus(Absolute::Up),
-                Event::Key(Key::Down) => self.move_focus(Absolute::Down),
+                Event::Shift(Key::Tab) => self.move_focus_rel(Relative::Front),
+                Event::Key(Key::Tab) => self.move_focus_rel(Relative::Back),
+                Event::Key(Key::Left) => self.move_focus_abs(Absolute::Left),
+                Event::Key(Key::Right) => self.move_focus_abs(Absolute::Right),
+                Event::Key(Key::Up) => self.move_focus_abs(Absolute::Up),
+                Event::Key(Key::Down) => self.move_focus_abs(Absolute::Down),
                 _ => EventResult::Ignored,
             },
             res => res,
@@ -243,6 +276,7 @@ impl View for FixedLayout {
 
     fn take_focus(&mut self, source: Direction) -> bool {
         // TODO: what if source = None?
+        eprintln!("Self focus: {:?}", self.focus);
         match source {
             Direction::Abs(Absolute::None) => {
                 // For now, take focus if any view is focusable.
diff --git a/cursive-core/src/views/stack_view.rs b/cursive-core/src/views/stack_view.rs
index cb99c29..5235c55 100644
--- a/cursive-core/src/views/stack_view.rs
+++ b/cursive-core/src/views/stack_view.rs
@@ -648,7 +648,7 @@ impl View for StackView {
             // The text view takes focus because it's scrolling, but it only
             // knows that after a call to `layout()`.
             if layer.virgin {
-                layer.view.take_focus(Direction::none());
+                layer.view.take_focus(Direction::front());
                 layer.virgin = false;
             }
         }
diff --git a/examples/src/bin/fixed_layout.rs b/examples/src/bin/fixed_layout.rs
index 900d785..def7985 100644
--- a/examples/src/bin/fixed_layout.rs
+++ b/examples/src/bin/fixed_layout.rs
@@ -1,12 +1,21 @@
+use cursive::{
+    views::{Button, FixedLayout, TextView},
+    Rect,
+};
 fn main() {
     let mut siv = cursive::default();
 
     siv.add_layer(
         cursive::views::Dialog::around(
-            cursive::views::FixedLayout::new().child(
-                cursive::Rect::from_size((0, 0), (10, 1)),
-                cursive::views::TextView::new("abc"),
-            ),
+            FixedLayout::new()
+                .child(Rect::from_size((0, 0), (1, 1)), TextView::new("/"))
+                .child(Rect::from_size((14, 0), (1, 1)), TextView::new(r"\"))
+                .child(Rect::from_size((0, 2), (1, 1)), TextView::new(r"\"))
+                .child(Rect::from_size((14, 2), (1, 1)), TextView::new("/"))
+                .child(
+                    Rect::from_size((2, 1), (11, 1)),
+                    Button::new("Click me!", |s| s.quit()),
+                ),
         )
         .button("Quit", |s| s.quit()),
     );