From 7e724934a515d05d46621de6e744dac6a3070761 Mon Sep 17 00:00:00 2001
From: Benedikt Terhechte <terhechte@gmail.com>
Date: Fri, 3 Mar 2023 12:05:51 +0100
Subject: [PATCH] add support for popovers

---
 examples/popover.rs      | 195 +++++++++++++++++++++++++++++++++++++++
 src/appkit/app/mod.rs    |  13 ++-
 src/appkit/window/mod.rs |  15 ++-
 src/geometry.rs          |   8 ++
 src/view/mod.rs          |   2 +
 src/view/popover/mod.rs  |  95 +++++++++++++++++++
 6 files changed, 325 insertions(+), 3 deletions(-)
 create mode 100644 examples/popover.rs
 create mode 100644 src/view/popover/mod.rs

diff --git a/examples/popover.rs b/examples/popover.rs
new file mode 100644
index 0000000..8fd92f8
--- /dev/null
+++ b/examples/popover.rs
@@ -0,0 +1,195 @@
+//! This example showcases how to use a `Popover`.
+//! This requires multiple types:
+//! - A Window with a Controller / View
+//! - A Popover
+//! - Another Controller / View
+
+use cacao::appkit::menu::{Menu, MenuItem};
+use cacao::appkit::window::{Window, WindowConfig, WindowController, WindowDelegate};
+use cacao::appkit::{App, AppDelegate};
+use cacao::button::Button;
+use cacao::geometry::{Edge, Rect};
+use cacao::layout::{Layout, LayoutConstraint};
+use cacao::notification_center::Dispatcher;
+use cacao::text::{Font, Label};
+use cacao::view::{Popover, PopoverConfig, View, ViewController, ViewDelegate};
+
+struct BasicApp {
+    window: WindowController<MyWindow>,
+}
+
+impl AppDelegate for BasicApp {
+    fn did_finish_launching(&self) {
+        App::set_menu(vec![
+            Menu::new(
+                "",
+                vec![
+                    MenuItem::Services,
+                    MenuItem::Separator,
+                    MenuItem::Hide,
+                    MenuItem::HideOthers,
+                    MenuItem::ShowAll,
+                    MenuItem::Separator,
+                    MenuItem::Quit,
+                ],
+            ),
+            Menu::new("File", vec![MenuItem::CloseWindow]),
+            Menu::new("View", vec![MenuItem::EnterFullScreen]),
+            Menu::new(
+                "Window",
+                vec![
+                    MenuItem::Minimize,
+                    MenuItem::Zoom,
+                    MenuItem::Separator,
+                    MenuItem::new("Bring All to Front"),
+                ],
+            ),
+        ]);
+
+        App::activate();
+
+        self.window.show();
+    }
+
+    fn should_terminate_after_last_window_closed(&self) -> bool {
+        true
+    }
+}
+
+#[derive(Default)]
+struct MyWindow {
+    controller: Option<ViewController<PopoverExampleContentView>>,
+}
+
+impl WindowDelegate for MyWindow {
+    const NAME: &'static str = "MyWindow";
+
+    fn did_load(&mut self, window: Window) {
+        window.set_minimum_content_size(400., 400.);
+        window.set_title("A Basic Window!?");
+        let view = PopoverExampleContentView::new();
+        let controller = ViewController::new(view);
+        window.set_content_view_controller(&controller);
+        self.controller = Some(controller);
+    }
+
+    fn will_close(&self) {
+        println!("Closing now!");
+    }
+}
+
+impl MyWindow {
+    pub fn on_message(&self, message: Msg) {
+        if let Some(delegate) = self.controller.as_ref().map(|e| &e.view).and_then(|v| v.delegate.as_ref()) {
+            delegate.on_message(message);
+        }
+    }
+}
+
+fn main() {
+    App::new(
+        "com.test.window-delegate",
+        BasicApp {
+            window: WindowController::with(WindowConfig::default(), MyWindow::default()),
+        },
+    )
+    .run();
+}
+
+#[derive(Clone, Debug)]
+pub enum Msg {
+    Click,
+}
+
+#[derive(Debug, Default)]
+struct PopoverExampleContentView {
+    view: Option<View>,
+    button: Option<Button>,
+    popover: Option<Popover<PopoverExampleContentViewController>>,
+}
+
+impl PopoverExampleContentView {
+    pub fn new() -> Self {
+        Self {
+            view: None,
+            button: None,
+            popover: None,
+        }
+    }
+
+    pub fn on_message(&self, message: Msg) {
+        match message {
+            Msg::Click => {
+                let Some(ref popover) = self.popover else { return };
+                let Some(ref button) = self.button else { return };
+                popover.show_popover(Rect::zero(), button, Edge::MaxY);
+            },
+        }
+    }
+}
+
+impl ViewDelegate for PopoverExampleContentView {
+    const NAME: &'static str = "PopoverExampleContentView";
+
+    fn did_load(&mut self, view: cacao::view::View) {
+        let mut button = Button::new("Show");
+        button.set_action(|| dispatch_ui(Msg::Click));
+
+        let controller = PopoverExampleContentViewController::new();
+        let config = PopoverConfig {
+            animates: false,
+            ..Default::default()
+        };
+        let popover = Popover::new(controller, config);
+        self.popover = Some(popover);
+
+        view.add_subview(&button);
+
+        LayoutConstraint::activate(&[
+            button.center_x.constraint_equal_to(&view.center_x),
+            button.center_y.constraint_equal_to(&view.center_y),
+        ]);
+
+        self.view = Some(view);
+        self.button = Some(button);
+    }
+}
+
+pub fn dispatch_ui(message: Msg) {
+    println!("Dispatching UI message: {:?}", message);
+    App::<BasicApp, Msg>::dispatch_main(message);
+}
+
+impl Dispatcher for BasicApp {
+    type Message = Msg;
+
+    // Handles a message that came over on the main (UI) thread.
+    fn on_ui_message(&self, message: Self::Message) {
+        if let Some(d) = &self.window.window.delegate {
+            d.on_message(message)
+        }
+    }
+}
+
+#[derive(Debug)]
+struct PopoverExampleContentViewController {
+    pub label: Label,
+}
+
+impl PopoverExampleContentViewController {
+    fn new() -> Self {
+        let label = Label::new();
+        let font = Font::system(20.);
+        label.set_font(&font);
+        label.set_text("Hello");
+        Self { label }
+    }
+}
+
+impl ViewDelegate for PopoverExampleContentViewController {
+    const NAME: &'static str = "PopoverExampleContentViewController";
+
+    fn did_load(&mut self, view: View) {
+        view.add_subview(&self.label);
+    }
+}
diff --git a/src/appkit/app/mod.rs b/src/appkit/app/mod.rs
index 4f41791..3ff2b6e 100644
--- a/src/appkit/app/mod.rs
+++ b/src/appkit/app/mod.rs
@@ -63,13 +63,15 @@ pub use enums::*;
 mod traits;
 pub use traits::AppDelegate;
 
+use super::window::Window;
+
 pub(crate) static APP_PTR: &str = "rstAppPtr";
 
 /// A handler to make some boilerplate less annoying.
 #[inline]
-fn shared_application<F: Fn(id)>(handler: F) {
+fn shared_application<T, F: Fn(id) -> T>(handler: F) -> T {
     let app: id = unsafe { msg_send![register_app_class(), sharedApplication] };
-    handler(app);
+    handler(app)
 }
 
 /// A wrapper for `NSApplication` in AppKit/Cocoa, and `UIApplication` in UIKit/Cocoa Touch.
@@ -298,6 +300,13 @@ impl App {
         });
     }
 
+    pub fn main_window() -> Window {
+        shared_application(|app| unsafe {
+            let window: id = msg_send![app, mainWindow];
+            Window::existing(window)
+        })
+    }
+
     /// Terminates the application, firing the requisite cleanup delegate methods in the process.
     ///
     /// This is typically called when the user chooses to quit via the App menu.
diff --git a/src/appkit/window/mod.rs b/src/appkit/window/mod.rs
index 7fc3034..bae5d57 100644
--- a/src/appkit/window/mod.rs
+++ b/src/appkit/window/mod.rs
@@ -23,6 +23,7 @@ use crate::foundation::{id, nil, to_bool, NSInteger, NSString, NSUInteger, NO, Y
 use crate::layout::Layout;
 use crate::objc_access::ObjcAccess;
 use crate::utils::{os, Controller};
+use crate::view::View;
 
 mod class;
 use class::register_window_class_with_delegate;
@@ -109,7 +110,14 @@ impl Window {
 
         Window {
             objc: objc,
-            delegate: None
+            delegate: None,
+        }
+    }
+
+    pub(crate) unsafe fn existing(window: *mut Object) -> Window {
+        Window {
+            objc: ShareId::from_ptr(window),
+            delegate: None,
         }
     }
 }
@@ -291,6 +299,11 @@ impl<T> Window<T> {
         }
     }
 
+    /// Return the objc ContentView from the window
+    pub(crate) unsafe fn content_view(&self) -> id {
+        let id: *mut Object = msg_send![&*self.objc, contentView];
+        id
+    }
     /// Given a view, sets it as the content view for this window.
     pub fn set_content_view<L: Layout + 'static>(&self, view: &L) {
         view.with_backing_obj_mut(|backing_node| unsafe {
diff --git a/src/geometry.rs b/src/geometry.rs
index a0f3bfe..4e3fbcf 100644
--- a/src/geometry.rs
+++ b/src/geometry.rs
@@ -41,6 +41,14 @@ impl Rect {
     }
 }
 
+#[derive(Debug, Eq, PartialEq, Copy, Clone)]
+#[repr(u32)]
+pub enum Edge {
+    MinX = 0,
+    MinY = 1,
+    MaxX = 2,
+    MaxY = 3,
+}
 impl From<Rect> for CGRect {
     fn from(rect: Rect) -> CGRect {
         CGRect::new(&CGPoint::new(rect.left, rect.top), &CGSize::new(rect.width, rect.height))
diff --git a/src/view/mod.rs b/src/view/mod.rs
index d6ee81d..e99a53d 100644
--- a/src/view/mod.rs
+++ b/src/view/mod.rs
@@ -77,6 +77,8 @@ mod splitviewcontroller;
 #[cfg(feature = "appkit")]
 pub use splitviewcontroller::SplitViewController;
 
+mod popover;
+pub use popover::*;
 mod traits;
 pub use traits::ViewDelegate;
 
diff --git a/src/view/popover/mod.rs b/src/view/popover/mod.rs
new file mode 100644
index 0000000..454c0ac
--- /dev/null
+++ b/src/view/popover/mod.rs
@@ -0,0 +1,95 @@
+use core_graphics::geometry::CGRect;
+use objc::runtime::Object;
+use objc::{class, msg_send, sel, sel_impl};
+use objc_id::ShareId;
+
+use crate::appkit::toolbar::ToolbarItem;
+use crate::appkit::window::Window;
+use crate::appkit::App;
+use crate::foundation::{id, nil, NSString};
+use crate::geometry::{Edge, Rect};
+use crate::layout::Layout;
+use crate::utils::{os, CGSize, Controller};
+use crate::view::{View, ViewController, ViewDelegate};
+
+#[derive(Debug, Eq, PartialEq)]
+#[repr(i64)]
+pub enum PopoverBehaviour {
+    /// Your application assumes responsibility for closing the popover.
+    ApplicationDefined = 0,
+    /// The system will close the popover when the user interacts with a user interface element outside the popover.
+    Transient = 1,
+    /// The system will close the popover when the user interacts with user interface elements in the window containing the popover's positioning view.
+    Semitransient = 2,
+}
+
+#[derive(Debug)]
+pub struct PopoverConfig {
+    pub content_size: CGSize,
+    pub animates: bool,
+    pub behaviour: PopoverBehaviour,
+}
+
+impl Default for PopoverConfig {
+    fn default() -> Self {
+        Self {
+            content_size: CGSize {
+                width: 320.0,
+                height: 320.0,
+            },
+            animates: true,
+            behaviour: PopoverBehaviour::Transient,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Popover<Content> {
+    /// A reference to the underlying Objective-C NSPopover
+    pub objc: ShareId<Object>,
+
+    /// The wrapped ViewController.
+    pub view_controller: ViewController<Content>,
+}
+
+impl<Content> Popover<Content>
+where
+    Content: ViewDelegate + 'static,
+{
+    pub fn new(content: Content, config: PopoverConfig) -> Self {
+        let view_controller = ViewController::new(content);
+        let objc = unsafe {
+            let pop: id = msg_send![class!(NSPopover), new];
+            let _: () = msg_send![pop, setContentSize: config.content_size];
+            let _: () = msg_send![pop, setBehavior: config.behaviour as i64];
+            let _: () = msg_send![pop, setAnimates: config.animates];
+            let _: () = msg_send![pop, setContentViewController: &*view_controller.objc];
+
+            ShareId::from_ptr(pop)
+        };
+
+        Popover { objc, view_controller }
+    }
+}
+
+impl<Content> Popover<Content> {
+    /// Show a popover relative to a view
+    pub fn show_popover<V: Layout>(&self, relative_to: Rect, view: &V, edge: Edge) {
+        let rect: CGRect = relative_to.into();
+        unsafe {
+            view.with_backing_obj_mut(|obj| {
+                let _: () = msg_send![&*self.objc, showRelativeToRect:rect ofView: &*obj preferredEdge: edge as u32];
+            });
+        }
+    }
+
+    /// Show the popover relative to the content view of the main window
+    pub fn show_popover_main(&self, rect: Rect, edge: Edge) {
+        let window = App::main_window();
+        unsafe {
+            let content_view = window.content_view();
+            let rect: CGRect = rect.into();
+            let _: () = msg_send![&*self.objc, showRelativeToRect:rect ofView: content_view preferredEdge: edge as u32];
+        }
+    }
+}