From 28cd51c2651a9479c55956fccbf3d535a0d21c4e Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Thu, 2 Jul 2020 23:58:54 -0700
Subject: [PATCH] Add Cursive::dump

---
 cursive-core/src/cursive.rs               | 60 ++++++++++++++++++++---
 cursive-core/src/dump.rs                  | 22 +++++++++
 cursive-core/src/lib.rs                   | 14 +++++-
 cursive-core/src/views/enableable_view.rs |  2 +
 cursive-core/src/views/hideable_view.rs   |  2 +
 cursive-core/src/views/last_size_view.rs  |  2 +
 cursive-core/src/views/layer.rs           |  6 ++-
 cursive-core/src/views/named_view.rs      |  4 +-
 cursive-core/src/views/on_event_view.rs   |  7 +--
 cursive-core/src/views/padded_view.rs     |  2 +-
 cursive-core/src/views/panel.rs           |  6 ++-
 cursive-core/src/views/resized_view.rs    |  4 +-
 cursive-core/src/views/scroll_view.rs     | 14 ++++--
 cursive-core/src/views/shadow_view.rs     |  6 ++-
 cursive-core/src/views/tracked_view.rs    | 18 ++-----
 15 files changed, 126 insertions(+), 43 deletions(-)
 create mode 100644 cursive-core/src/dump.rs

diff --git a/cursive-core/src/cursive.rs b/cursive-core/src/cursive.rs
index 9d05b4f..4e221df 100644
--- a/cursive-core/src/cursive.rs
+++ b/cursive-core/src/cursive.rs
@@ -6,14 +6,15 @@ use std::time::Duration;
 
 use crossbeam_channel::{self, Receiver, Sender};
 
-use crate::backend;
-use crate::direction;
-use crate::event::{Event, EventResult};
-use crate::printer::Printer;
-use crate::theme;
-use crate::view::{self, Finder, IntoBoxedView, Position, View};
-use crate::views::{self, LayerPosition};
-use crate::Vec2;
+use crate::{
+    backend, direction,
+    event::{Event, EventResult},
+    printer::Printer,
+    theme,
+    view::{self, Finder, IntoBoxedView, Position, View},
+    views::{self, LayerPosition},
+    Dump, Vec2,
+};
 
 static DEBUG_VIEW_NAME: &str = "_cursive_debug_view";
 
@@ -1035,6 +1036,49 @@ impl Cursive {
     pub fn backend_name(&self) -> &str {
         self.backend.name()
     }
+
+    /// Dump the current state of the Cursive root.
+    ///
+    /// This will stop the backend and clean up the terminal.
+    ///
+    /// It will save everything, including:
+    /// * The view tree
+    /// * Callbacks
+    /// * Menubar
+    /// * User data
+    /// * Callback sink
+    pub fn dump(mut self) -> crate::Dump {
+        Dump {
+            cb_sink: self.cb_sink.clone(),
+            cb_source: self.cb_source.clone(),
+            fps: self.fps,
+            menubar: std::mem::take(&mut self.menubar),
+            root_view: std::mem::take(&mut self.root),
+            theme: self.theme.clone(),
+            user_data: std::mem::replace(&mut self.user_data, Box::new(())),
+        }
+    }
+
+    /// Restores the state from a previous dump.
+    ///
+    /// This will discard everything from this `Cursive` instance.
+    /// In particular:
+    /// * All current views will be dropped, replaced by the dump.
+    /// * All callbacks will be replaced.
+    /// * Menubar will be replaced.
+    /// * User Data will be replaced.
+    /// * The callback channel will be replaced - any previous call to
+    ///   `cb_sink` on this instance will be disconnected.
+    pub fn restore(&mut self, dump: Dump) {
+        self.cb_sink = dump.cb_sink;
+        self.cb_source = dump.cb_source;
+        self.fps = dump.fps;
+        self.menubar = dump.menubar;
+        self.root = dump.root_view;
+        self.theme = dump.theme;
+        self.user_data = dump.user_data;
+        self.clear();
+    }
 }
 
 impl Drop for Cursive {
diff --git a/cursive-core/src/dump.rs b/cursive-core/src/dump.rs
new file mode 100644
index 0000000..6fa3512
--- /dev/null
+++ b/cursive-core/src/dump.rs
@@ -0,0 +1,22 @@
+use crate::{theme::Theme, views, Cursive};
+use crossbeam_channel::{Receiver, Sender};
+use std::any::Any;
+use std::num::NonZeroU32;
+
+/// Represents a dump of everything from a `Cursive` instance.
+///
+/// See [`Cursive::dump()`](../cursive.html#method.dump)
+pub struct Dump {
+    pub(crate) cb_sink: Sender<Box<dyn FnOnce(&mut Cursive) + Send>>,
+    pub(crate) cb_source: Receiver<Box<dyn FnOnce(&mut Cursive) + Send>>,
+
+    pub(crate) fps: Option<NonZeroU32>,
+
+    pub(crate) menubar: views::Menubar,
+    pub(crate) root_view:
+        views::OnEventView<views::ScreensView<views::StackView>>,
+
+    pub(crate) theme: Theme,
+
+    pub(crate) user_data: Box<dyn Any>,
+}
diff --git a/cursive-core/src/lib.rs b/cursive-core/src/lib.rs
index 48c7d69..11c1c80 100644
--- a/cursive-core/src/lib.rs
+++ b/cursive-core/src/lib.rs
@@ -17,13 +17,21 @@ macro_rules! new_default(
             }
         }
     };
-    ($c:ty) => {
+    ($c:ident) => {
         impl Default for $c {
             fn default() -> Self {
                 Self::new()
             }
         }
-    }
+    };
+    ($c:ident<$t:ident: Default>) => {
+        impl <$t> Default for $c<$t>
+        where $t: Default {
+            fn default() -> Self {
+                Self::new($t::default())
+            }
+        }
+    };
 );
 
 #[macro_use]
@@ -44,6 +52,7 @@ pub mod traits;
 pub mod vec;
 
 mod cursive;
+mod dump;
 mod printer;
 mod rect;
 mod with;
@@ -52,6 +61,7 @@ mod xy;
 mod div;
 
 pub use self::cursive::{CbSink, Cursive, ScreenId};
+pub use self::dump::Dump;
 pub use self::printer::Printer;
 pub use self::rect::Rect;
 pub use self::vec::Vec2;
diff --git a/cursive-core/src/views/enableable_view.rs b/cursive-core/src/views/enableable_view.rs
index 991f953..dbf6cd8 100644
--- a/cursive-core/src/views/enableable_view.rs
+++ b/cursive-core/src/views/enableable_view.rs
@@ -31,6 +31,8 @@ pub struct EnableableView<V> {
     enabled: bool,
 }
 
+new_default!(EnableableView<V: Default>);
+
 impl<V> EnableableView<V> {
     /// Creates a new `EnableableView` around `view`.
     ///
diff --git a/cursive-core/src/views/hideable_view.rs b/cursive-core/src/views/hideable_view.rs
index 59907cb..ce6ce4a 100644
--- a/cursive-core/src/views/hideable_view.rs
+++ b/cursive-core/src/views/hideable_view.rs
@@ -17,6 +17,8 @@ pub struct HideableView<V> {
     invalidated: bool,
 }
 
+new_default!(HideableView<V: Default>);
+
 impl<V> HideableView<V> {
     /// Creates a new HideableView around `view`.
     ///
diff --git a/cursive-core/src/views/last_size_view.rs b/cursive-core/src/views/last_size_view.rs
index 1694fc9..730fcbe 100644
--- a/cursive-core/src/views/last_size_view.rs
+++ b/cursive-core/src/views/last_size_view.rs
@@ -10,6 +10,8 @@ pub struct LastSizeView<T> {
     pub size: Vec2,
 }
 
+new_default!(LastSizeView<V: Default>);
+
 impl<T> LastSizeView<T> {
     /// Wraps the given view.
     pub fn new(view: T) -> Self {
diff --git a/cursive-core/src/views/layer.rs b/cursive-core/src/views/layer.rs
index 0aa037a..22bc5f0 100644
--- a/cursive-core/src/views/layer.rs
+++ b/cursive-core/src/views/layer.rs
@@ -8,12 +8,14 @@ use crate::Printer;
 ///
 /// [`StackView`]: crate::views::StackView
 #[derive(Debug)]
-pub struct Layer<T: View> {
+pub struct Layer<T> {
     view: T,
     color: ColorStyle,
 }
 
-impl<T: View> Layer<T> {
+new_default!(Layer<T: Default>);
+
+impl<T> Layer<T> {
     /// Wraps the given view.
     pub fn new(view: T) -> Self {
         Self::with_color(view, ColorStyle::primary())
diff --git a/cursive-core/src/views/named_view.rs b/cursive-core/src/views/named_view.rs
index 6a99ee8..a7c2ca7 100644
--- a/cursive-core/src/views/named_view.rs
+++ b/cursive-core/src/views/named_view.rs
@@ -10,7 +10,7 @@ use std::rc::Rc;
 /// This lets other views refer to this one using a string identifier.
 ///
 /// See [`Identifiable`](crate::view::Identifiable) for an easy way to wrap any view with it.
-pub struct NamedView<V: View> {
+pub struct NamedView<V> {
     view: Rc<RefCell<V>>,
     id: String,
 }
@@ -22,7 +22,7 @@ pub struct NamedView<V: View> {
 /// [`RefMut`]: std::cell::RefMut
 pub type ViewRef<V> = OwningHandle<RcRef<RefCell<V>>, RefMut<'static, V>>;
 
-impl<V: View> NamedView<V> {
+impl<V> NamedView<V> {
     /// Wraps `view` in a new `NamedView`.
     pub fn new<S: Into<String>>(id: S, view: V) -> Self {
         NamedView {
diff --git a/cursive-core/src/views/on_event_view.rs b/cursive-core/src/views/on_event_view.rs
index 64fcdbe..2a2ab86 100644
--- a/cursive-core/src/views/on_event_view.rs
+++ b/cursive-core/src/views/on_event_view.rs
@@ -38,11 +38,13 @@ use std::rc::Rc;
 ///                         .on_event('q', |s| s.quit())
 ///                         .on_event(event::Key::Esc, |s| s.quit());
 /// ```
-pub struct OnEventView<T: View> {
+pub struct OnEventView<T> {
     view: T,
     callbacks: Vec<(EventTrigger, Action<T>)>,
 }
 
+new_default!(OnEventView<T: Default>);
+
 type InnerCallback<T> = Rc<Box<dyn Fn(&mut T, &Event) -> Option<EventResult>>>;
 
 struct Action<T> {
@@ -65,7 +67,7 @@ enum TriggerPhase {
     AfterChild,
 }
 
-impl<T: View> OnEventView<T> {
+impl<T> OnEventView<T> {
     /// Wraps the given view in a new OnEventView.
     pub fn new(view: T) -> Self {
         OnEventView {
@@ -83,7 +85,6 @@ impl<T: View> OnEventView<T> {
         self.callbacks
             .retain(move |&(ref trigger, _)| !trigger.has_tag(&event));
     }
-
     /// Registers a callback when the given event is ignored by the child.
     ///
     /// Chainable variant.
diff --git a/cursive-core/src/views/padded_view.rs b/cursive-core/src/views/padded_view.rs
index dddbe13..c508ef9 100644
--- a/cursive-core/src/views/padded_view.rs
+++ b/cursive-core/src/views/padded_view.rs
@@ -25,7 +25,7 @@ pub struct PaddedView<V> {
     margins: Margins,
 }
 
-impl<V: View> PaddedView<V> {
+impl<V> PaddedView<V> {
     /// Wraps `view` in a new `PaddedView` with the given margins.
     pub fn new(margins: Margins, view: V) -> Self {
         PaddedView { view, margins }
diff --git a/cursive-core/src/views/panel.rs b/cursive-core/src/views/panel.rs
index a381a98..3a33ecc 100644
--- a/cursive-core/src/views/panel.rs
+++ b/cursive-core/src/views/panel.rs
@@ -10,7 +10,7 @@ use unicode_width::UnicodeWidthStr;
 
 /// Draws a border around a wrapped view.
 #[derive(Debug)]
-pub struct Panel<V: View> {
+pub struct Panel<V> {
     // Inner view
     view: V,
 
@@ -24,7 +24,9 @@ pub struct Panel<V: View> {
     invalidated: bool,
 }
 
-impl<V: View> Panel<V> {
+new_default!(Panel<V: Default>);
+
+impl<V> Panel<V> {
     /// Creates a new panel around the given view.
     pub fn new(view: V) -> Self {
         Panel {
diff --git a/cursive-core/src/views/resized_view.rs b/cursive-core/src/views/resized_view.rs
index f382bc7..4e7746c 100644
--- a/cursive-core/src/views/resized_view.rs
+++ b/cursive-core/src/views/resized_view.rs
@@ -23,7 +23,7 @@ use crate::XY;
 /// ```
 ///
 /// See also [`Boxable`](crate::view::Boxable) for an easy way to wrap any view.
-pub struct ResizedView<T: View> {
+pub struct ResizedView<T> {
     /// Constraint on each axis
     size: XY<SizeConstraint>,
 
@@ -34,7 +34,7 @@ pub struct ResizedView<T: View> {
     view: T,
 }
 
-impl<T: View> ResizedView<T> {
+impl<T> ResizedView<T> {
     /// Creates a new `ResizedView` with the given width and height requirements.
     ///
     /// `None` values will use the wrapped view's preferences.
diff --git a/cursive-core/src/views/scroll_view.rs b/cursive-core/src/views/scroll_view.rs
index 077121e..a4279a8 100644
--- a/cursive-core/src/views/scroll_view.rs
+++ b/cursive-core/src/views/scroll_view.rs
@@ -17,12 +17,11 @@ pub struct ScrollView<V> {
     on_scroll: Rc<dyn Fn(&mut Self, Rect) -> EventResult>,
 }
 
+new_default!(ScrollView<V: Default>);
+
 impl_scroller!(ScrollView<V>::core);
 
-impl<V> ScrollView<V>
-where
-    V: View,
-{
+impl<V> ScrollView<V> {
     /// Creates a new ScrollView around `view`.
     pub fn new(inner: V) -> Self {
         ScrollView {
@@ -189,7 +188,10 @@ where
     }
 
     /// Programmatically scroll until the child's important area is in view.
-    pub fn scroll_to_important_area(&mut self) -> EventResult {
+    pub fn scroll_to_important_area(&mut self) -> EventResult
+    where
+        V: View,
+    {
         let important_area = self.inner.important_area(self.core.last_size());
         self.core.scroll_to_rect(important_area);
 
@@ -256,6 +258,7 @@ where
     pub fn set_on_scroll_change_inner<F>(&mut self, on_scroll: F)
     where
         F: FnMut(&mut Self, Rect) -> EventResult + 'static,
+        V: 'static,
     {
         self.set_on_scroll_inner(Self::skip_unchanged(on_scroll, || {
             EventResult::Ignored
@@ -266,6 +269,7 @@ where
     pub fn set_on_scroll_change<F>(&mut self, on_scroll: F)
     where
         F: FnMut(&mut Cursive, Rect) + 'static,
+        V: 'static,
     {
         self.set_on_scroll(Self::skip_unchanged(on_scroll, || ()));
     }
diff --git a/cursive-core/src/views/shadow_view.rs b/cursive-core/src/views/shadow_view.rs
index c5cb569..5965af5 100644
--- a/cursive-core/src/views/shadow_view.rs
+++ b/cursive-core/src/views/shadow_view.rs
@@ -8,14 +8,16 @@ use crate::Vec2;
 /// Wrapper view that adds a shadow.
 ///
 /// It reserves a 1 pixel border on each side.
-pub struct ShadowView<T: View> {
+pub struct ShadowView<T> {
     view: T,
     top_padding: bool,
     left_padding: bool,
     // TODO: invalidate if we change the padding? wrap_needs_relayout?
 }
 
-impl<T: View> ShadowView<T> {
+new_default!(ShadowView<T: Default>);
+
+impl<T> ShadowView<T> {
     /// Wraps the given view.
     pub fn new(view: T) -> Self {
         ShadowView {
diff --git a/cursive-core/src/views/tracked_view.rs b/cursive-core/src/views/tracked_view.rs
index bbc0394..554046f 100644
--- a/cursive-core/src/views/tracked_view.rs
+++ b/cursive-core/src/views/tracked_view.rs
@@ -1,18 +1,19 @@
 use crate::view::{View, ViewWrapper};
-use crate::views::NamedView;
 use crate::Printer;
 use crate::Vec2;
 use std::cell::Cell;
 
 /// Wrapper around a view that remembers its position.
-pub struct TrackedView<T: View> {
+pub struct TrackedView<T> {
     /// Wrapped view.
     pub view: T,
     /// Last position the view was located.
     offset: Cell<Vec2>,
 }
 
-impl<T: View> TrackedView<T> {
+new_default!(TrackedView<T: Default>);
+
+impl<T> TrackedView<T> {
     /// Return the last offset at which the view was drawn.
     pub fn offset(&self) -> Vec2 {
         self.offset.get()
@@ -26,17 +27,6 @@ impl<T: View> TrackedView<T> {
         }
     }
 
-    /// Same as [`with_name`](TrackedView::with_name)
-    #[deprecated(note = "`with_id` is being renamed to `with_name`")]
-    pub fn with_id(self, id: &str) -> NamedView<Self> {
-        self.with_name(id)
-    }
-
-    /// Wraps itself in a `NamedView` for easy retrieval.
-    pub fn with_name(self, name: &str) -> NamedView<Self> {
-        NamedView::new(name, self)
-    }
-
     inner_getters!(self.view: T);
 }