From 1551fbb543e5eece4a42cf9dcbe068942ea7b73f Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Mon, 22 Jan 2018 09:20:32 -0800
Subject: [PATCH] Add View::as_any and View::as_any_mut

---
 examples/key_codes.rs      |  3 +++
 examples/logs.rs           |  3 +++
 src/view/mod.rs            | 15 +++++++++++++++
 src/view/view_wrapper.rs   |  2 ++
 src/views/button.rs        |  2 ++
 src/views/canvas.rs        |  2 ++
 src/views/checkbox.rs      |  2 ++
 src/views/dialog.rs        |  2 ++
 src/views/dummy.rs         |  2 ++
 src/views/edit_view.rs     |  2 ++
 src/views/linear_layout.rs |  2 ++
 src/views/list_view.rs     |  3 +++
 src/views/menu_popup.rs    |  2 ++
 src/views/menubar.rs       |  2 ++
 src/views/progress_bar.rs  |  2 ++
 src/views/radio.rs         |  3 +++
 src/views/select_view.rs   |  3 +++
 src/views/slider_view.rs   |  2 ++
 src/views/stack_view.rs    |  4 ++++
 src/views/text_area.rs     |  2 ++
 src/views/text_view.rs     |  2 ++
 21 files changed, 62 insertions(+)

diff --git a/examples/key_codes.rs b/examples/key_codes.rs
index ff64bc3..2b345b4 100644
--- a/examples/key_codes.rs
+++ b/examples/key_codes.rs
@@ -1,3 +1,4 @@
+#[macro_use]
 extern crate cursive;
 
 use cursive::{Cursive, Printer};
@@ -30,6 +31,8 @@ impl KeyCodeView {
 }
 
 impl View for KeyCodeView {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         // We simply draw every event from the history.
         for (y, line) in self.history.iter().enumerate() {
diff --git a/examples/logs.rs b/examples/logs.rs
index 871f348..c1f33a0 100644
--- a/examples/logs.rs
+++ b/examples/logs.rs
@@ -1,3 +1,4 @@
+#[macro_use]
 extern crate cursive;
 
 use cursive::{Cursive, Printer};
@@ -80,6 +81,8 @@ impl BufferView {
 }
 
 impl View for BufferView {
+    view_any!();
+
     fn layout(&mut self, _: Vec2) {
         // Before drawing, we'll want to update the buffer
         self.update();
diff --git a/src/view/mod.rs b/src/view/mod.rs
index 76fd604..ca21b01 100644
--- a/src/view/mod.rs
+++ b/src/view/mod.rs
@@ -35,6 +35,15 @@
 //!   no matter what the request is. This means calling `View::layout()` with
 //!   a size returned by `required_size` is **never** an error.
 
+/// Helper macro to implement `View::as_any` and `View::as_any_mut`
+#[macro_export]
+macro_rules! view_any {
+    () => {
+        fn as_any(&self) -> &::std::any::Any { self }
+        fn as_any_mut(&mut self) -> &mut ::std::any::Any { self }
+    }
+}
+
 #[macro_use]
 mod view_wrapper;
 
@@ -73,6 +82,12 @@ pub trait View: Any {
         EventResult::Ignored
     }
 
+    /// Downcast self to a `Any`.
+    fn as_any(&self) -> &Any;
+
+    /// Downcast self to a mutable `Any`.
+    fn as_any_mut(&mut self) -> &mut Any;
+
     /// Returns the minimum size the view requires with the given restrictions.
     ///
     /// If the view is flexible (it has multiple size options), it can try
diff --git a/src/view/view_wrapper.rs b/src/view/view_wrapper.rs
index c26dc02..208649e 100644
--- a/src/view/view_wrapper.rs
+++ b/src/view/view_wrapper.rs
@@ -119,6 +119,8 @@ impl<U: View + ?Sized, T: Deref<Target = U> + DerefMut + 'static> ViewWrapper
 
 // The main point of implementing ViewWrapper is to have View for free.
 impl<T: ViewWrapper> View for T {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         self.wrap_draw(printer);
     }
diff --git a/src/views/button.rs b/src/views/button.rs
index a0ec0fc..9f5ab11 100644
--- a/src/views/button.rs
+++ b/src/views/button.rs
@@ -126,6 +126,8 @@ impl Button {
 }
 
 impl View for Button {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         if printer.size.x == 0 {
             return;
diff --git a/src/views/canvas.rs b/src/views/canvas.rs
index 8d5d7af..5766079 100644
--- a/src/views/canvas.rs
+++ b/src/views/canvas.rs
@@ -173,6 +173,8 @@ impl<T> Canvas<T> {
 }
 
 impl<T: 'static> View for Canvas<T> {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         (self.draw)(&self.state, printer);
     }
diff --git a/src/views/checkbox.rs b/src/views/checkbox.rs
index 6f8aef4..3fd5ea8 100644
--- a/src/views/checkbox.rs
+++ b/src/views/checkbox.rs
@@ -105,6 +105,8 @@ impl Checkbox {
 }
 
 impl View for Checkbox {
+    view_any!();
+
     fn required_size(&mut self, _: Vec2) -> Vec2 {
         Vec2::new(3, 1)
     }
diff --git a/src/views/dialog.rs b/src/views/dialog.rs
index 3d7662d..17cabc8 100644
--- a/src/views/dialog.rs
+++ b/src/views/dialog.rs
@@ -423,6 +423,8 @@ impl Dialog {
 }
 
 impl View for Dialog {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         // This will be the buttons_height used by the buttons.
         let buttons_height = match self.draw_buttons(printer) {
diff --git a/src/views/dummy.rs b/src/views/dummy.rs
index 5b88176..2123a50 100644
--- a/src/views/dummy.rs
+++ b/src/views/dummy.rs
@@ -7,5 +7,7 @@ use view::View;
 pub struct DummyView;
 
 impl View for DummyView {
+    view_any!();
+
     fn draw(&self, _: &Printer) {}
 }
diff --git a/src/views/edit_view.rs b/src/views/edit_view.rs
index 4a2b775..4faee7c 100644
--- a/src/views/edit_view.rs
+++ b/src/views/edit_view.rs
@@ -434,6 +434,8 @@ fn make_small_stars(length: usize) -> &'static str {
 }
 
 impl View for EditView {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         assert_eq!(
             printer.size.x,
diff --git a/src/views/linear_layout.rs b/src/views/linear_layout.rs
index 9047859..f88606c 100644
--- a/src/views/linear_layout.rs
+++ b/src/views/linear_layout.rs
@@ -297,6 +297,8 @@ fn try_focus(
 }
 
 impl View for LinearLayout {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         // Use pre-computed sizes
         // eprintln!("Pre loop!");
diff --git a/src/views/list_view.rs b/src/views/list_view.rs
index 8c60b56..e419cd2 100644
--- a/src/views/list_view.rs
+++ b/src/views/list_view.rs
@@ -261,6 +261,9 @@ fn try_focus(
 }
 
 impl View for ListView {
+    view_any!();
+
+
     fn draw(&self, printer: &Printer) {
         if self.children.is_empty() {
             return;
diff --git a/src/views/menu_popup.rs b/src/views/menu_popup.rs
index 365ec13..7da673e 100644
--- a/src/views/menu_popup.rs
+++ b/src/views/menu_popup.rs
@@ -199,6 +199,8 @@ impl MenuPopup {
 }
 
 impl View for MenuPopup {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         if !printer.size.fits((2, 2)) {
             return;
diff --git a/src/views/menubar.rs b/src/views/menubar.rs
index abb83fc..b39dee3 100644
--- a/src/views/menubar.rs
+++ b/src/views/menubar.rs
@@ -259,6 +259,8 @@ fn show_child(s: &mut Cursive, offset: Vec2, menu: Rc<MenuTree>) {
 }
 
 impl View for Menubar {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         // Draw the bar at the top
         printer.with_color(ColorStyle::primary(), |printer| {
diff --git a/src/views/progress_bar.rs b/src/views/progress_bar.rs
index 44538e4..b0f2bdb 100644
--- a/src/views/progress_bar.rs
+++ b/src/views/progress_bar.rs
@@ -193,6 +193,8 @@ impl ProgressBar {
 }
 
 impl View for ProgressBar {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         // Now, the bar itself...
         let available = printer.size.x;
diff --git a/src/views/radio.rs b/src/views/radio.rs
index 15cd4e3..0f5a247 100644
--- a/src/views/radio.rs
+++ b/src/views/radio.rs
@@ -154,6 +154,9 @@ impl<T> RadioButton<T> {
 }
 
 impl<T: 'static> View for RadioButton<T> {
+    view_any!();
+
+
     fn required_size(&mut self, _: Vec2) -> Vec2 {
         self.req_size()
     }
diff --git a/src/views/select_view.rs b/src/views/select_view.rs
index 4244e9f..be529f6 100644
--- a/src/views/select_view.rs
+++ b/src/views/select_view.rs
@@ -570,6 +570,9 @@ impl SelectView<String> {
 }
 
 impl<T: 'static> View for SelectView<T> {
+    view_any!();
+
+
     fn draw(&self, printer: &Printer) {
         self.last_offset.set(printer.offset);
 
diff --git a/src/views/slider_view.rs b/src/views/slider_view.rs
index 01476ef..13f7fce 100644
--- a/src/views/slider_view.rs
+++ b/src/views/slider_view.rs
@@ -112,6 +112,8 @@ impl SliderView {
 }
 
 impl View for SliderView {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         match self.orientation {
             Orientation::Vertical => {
diff --git a/src/views/stack_view.rs b/src/views/stack_view.rs
index acf5b86..63177dc 100644
--- a/src/views/stack_view.rs
+++ b/src/views/stack_view.rs
@@ -71,6 +71,8 @@ impl<T: View> ChildWrapper<T> {
 
 // TODO: use macros to make this less ugly?
 impl<T: View> View for ChildWrapper<T> {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         match *self {
             ChildWrapper::Shadow(ref v) => v.draw(printer),
@@ -322,6 +324,8 @@ impl<R: Deref<Target = Child>, I: Iterator<Item = R>> Iterator
 }
 
 impl View for StackView {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         let last = self.layers.len();
         printer.with_color(ColorStyle::primary(), |printer| {
diff --git a/src/views/text_area.rs b/src/views/text_area.rs
index 3e72e43..ea0a12c 100644
--- a/src/views/text_area.rs
+++ b/src/views/text_area.rs
@@ -396,6 +396,8 @@ impl TextArea {
 }
 
 impl View for TextArea {
+    view_any!();
+
     fn required_size(&mut self, constraint: Vec2) -> Vec2 {
         // Make sure our structure is up to date
         self.soft_compute_rows(constraint);
diff --git a/src/views/text_view.rs b/src/views/text_view.rs
index 72c9c75..d175f3f 100644
--- a/src/views/text_view.rs
+++ b/src/views/text_view.rs
@@ -448,6 +448,8 @@ impl TextView {
 }
 
 impl View for TextView {
+    view_any!();
+
     fn draw(&self, printer: &Printer) {
         let h = self.rows.len();
         // If the content is smaller than the view, align it somewhere.