macOS: Improve set_cursor (#740)

* Improve set_cursor on macOS

* Check for nil

CHANGELOG.md

@@ -18,6 +18,7 @@
 - Added support for generating dummy `DeviceId`s and `WindowId`s to better support unit testing.
 - On macOS, fixed unsoundness in drag-and-drop that could result in drops being rejected.
 - On macOS, implemented `WindowEvent::Refresh`.
+- On macOS, all `MouseCursor` variants are now implemented and the cursor will no longer reset after unfocusing.
 
 # Version 0.18.0 (2018-11-07)
 

src/platform/macos/util/cursor.rs

@@ -0,0 +1,149 @@
+use cocoa::{
+    appkit::NSImage, base::{id, nil, YES},
+    foundation::{NSDictionary, NSPoint, NSString},
+};
+use objc::runtime::Sel;
+
+use super::IntoOption;
+use MouseCursor;
+
+pub enum Cursor {
+    Native(&'static str),
+    Undocumented(&'static str),
+    WebKit(&'static str),
+}
+
+impl From<MouseCursor> for Cursor {
+    fn from(cursor: MouseCursor) -> Self {
+        match cursor {
+            MouseCursor::Arrow | MouseCursor::Default => Cursor::Native("arrowCursor"),
+            MouseCursor::Hand => Cursor::Native("pointingHandCursor"),
+            MouseCursor::Grabbing | MouseCursor::Grab => Cursor::Native("closedHandCursor"),
+            MouseCursor::Text => Cursor::Native("IBeamCursor"),
+            MouseCursor::VerticalText => Cursor::Native("IBeamCursorForVerticalLayout"),
+            MouseCursor::Copy => Cursor::Native("dragCopyCursor"),
+            MouseCursor::Alias => Cursor::Native("dragLinkCursor"),
+            MouseCursor::NotAllowed | MouseCursor::NoDrop => Cursor::Native("operationNotAllowedCursor"),
+            MouseCursor::ContextMenu => Cursor::Native("contextualMenuCursor"),
+            MouseCursor::Crosshair => Cursor::Native("crosshairCursor"),
+            MouseCursor::EResize => Cursor::Native("resizeRightCursor"),
+            MouseCursor::NResize => Cursor::Native("resizeUpCursor"),
+            MouseCursor::WResize => Cursor::Native("resizeLeftCursor"),
+            MouseCursor::SResize => Cursor::Native("resizeDownCursor"),
+            MouseCursor::EwResize | MouseCursor::ColResize => Cursor::Native("resizeLeftRightCursor"),
+            MouseCursor::NsResize | MouseCursor::RowResize => Cursor::Native("resizeUpDownCursor"),
+
+            // Undocumented cursors: https://stackoverflow.com/a/46635398/5435443
+            MouseCursor::Help => Cursor::Undocumented("_helpCursor"),
+            MouseCursor::ZoomIn => Cursor::Undocumented("_zoomInCursor"),
+            MouseCursor::ZoomOut => Cursor::Undocumented("_zoomOutCursor"),
+            MouseCursor::NeResize => Cursor::Undocumented("_windowResizeNorthEastCursor"),
+            MouseCursor::NwResize => Cursor::Undocumented("_windowResizeNorthWestCursor"),
+            MouseCursor::SeResize => Cursor::Undocumented("_windowResizeSouthEastCursor"),
+            MouseCursor::SwResize => Cursor::Undocumented("_windowResizeSouthWestCursor"),
+            MouseCursor::NeswResize => Cursor::Undocumented("_windowResizeNorthEastSouthWestCursor"),
+            MouseCursor::NwseResize => Cursor::Undocumented("_windowResizeNorthWestSouthEastCursor"),
+
+            // While these are available, the former just loads a white arrow,
+            // and the latter loads an ugly deflated beachball!
+            // MouseCursor::Move => Cursor::Undocumented("_moveCursor"),
+            // MouseCursor::Wait => Cursor::Undocumented("_waitCursor"),
+
+            // An even more undocumented cursor...
+            // https://bugs.eclipse.org/bugs/show_bug.cgi?id=522349
+            // This is the wrong semantics for `Wait`, but it's the same as
+            // what's used in Safari and Chrome.
+            MouseCursor::Wait | MouseCursor::Progress => Cursor::Undocumented("busyButClickableCursor"),
+
+            // For the rest, we can just snatch the cursors from WebKit...
+            // They fit the style of the native cursors, and will seem
+            // completely standard to macOS users.
+            // https://stackoverflow.com/a/21786835/5435443
+            MouseCursor::Move | MouseCursor::AllScroll => Cursor::WebKit("move"),
+            MouseCursor::Cell => Cursor::WebKit("cell"),
+        }
+    }
+}
+
+impl Default for Cursor {
+    fn default() -> Self {
+        Cursor::Native("arrowCursor")
+    }
+}
+
+impl Cursor {
+    pub unsafe fn load(&self) -> id {
+        match self {
+            Cursor::Native(cursor_name) => {
+                let sel = Sel::register(cursor_name);
+                msg_send![class!(NSCursor), performSelector:sel]
+            },
+            Cursor::Undocumented(cursor_name) => {
+                let class = class!(NSCursor);
+                let sel = Sel::register(cursor_name);
+                let sel = if msg_send![class, respondsToSelector:sel] {
+                    sel
+                } else {
+                    warn!("Cursor `{}` appears to be invalid", cursor_name);
+                    sel!(arrowCursor)
+                };
+                msg_send![class, performSelector:sel]
+            },
+            Cursor::WebKit(cursor_name) => load_webkit_cursor(cursor_name)
+                .unwrap_or_else(|message| {
+                    warn!("{}", message);
+                    Self::default().load()
+                }),
+        }
+    }
+}
+
+// Note that loading `busybutclickable` with this code won't animate the frames;
+// instead you'll just get them all in a column.
+unsafe fn load_webkit_cursor(cursor_name_str: &str) -> Result<id, String> {
+    static CURSOR_ROOT: &'static str = "/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/HIServices.framework/Versions/A/Resources/cursors";
+    let cursor_root = NSString::alloc(nil).init_str(CURSOR_ROOT);
+    let cursor_name = NSString::alloc(nil).init_str(cursor_name_str);
+    let cursor_pdf = NSString::alloc(nil).init_str("cursor.pdf");
+    let cursor_plist = NSString::alloc(nil).init_str("info.plist");
+    let key_x = NSString::alloc(nil).init_str("hotx");
+    let key_y = NSString::alloc(nil).init_str("hoty");
+
+    let cursor_path: id = msg_send![cursor_root,
+        stringByAppendingPathComponent:cursor_name
+    ];
+    let pdf_path: id = msg_send![cursor_path,
+        stringByAppendingPathComponent:cursor_pdf
+    ];
+    let info_path: id = msg_send![cursor_path,
+        stringByAppendingPathComponent:cursor_plist
+    ];
+
+    let image = NSImage::alloc(nil)
+        .initByReferencingFile_(pdf_path)
+        // This will probably never be `None`, since images are loaded lazily...
+        .into_option()
+        // because of that, we need to check for validity.
+        .filter(|image| image.isValid() == YES)
+        .ok_or_else(||
+            format!("Failed to read image for `{}` cursor", cursor_name_str)
+        )?;
+    let info = NSDictionary::dictionaryWithContentsOfFile_(nil, info_path)
+        .into_option()
+        .ok_or_else(||
+            format!("Failed to read info for `{}` cursor", cursor_name_str)
+        )?;
+    let x = info.valueForKey_(key_x);
+    let y = info.valueForKey_(key_y);
+    let point = NSPoint::new(
+        msg_send![x, doubleValue],
+        msg_send![y, doubleValue],
+    );
+    let cursor: id = msg_send![class!(NSCursor), alloc];
+    let cursor: id = msg_send![cursor, initWithImage:image hotSpot:point];
+    cursor
+        .into_option()
+        .ok_or_else(||
+            format!("Failed to initialize `{}` cursor", cursor_name_str)
+        )
+}

src/platform/macos/util/into_option.rs

@@ -0,0 +1,14 @@
+use cocoa::base::{id, nil};
+
+pub trait IntoOption: Sized {
+    fn into_option(self) -> Option<Self>;
+}
+
+impl IntoOption for id {
+    fn into_option(self) -> Option<Self> {
+        match self != nil {
+            true => Some(self),
+            false => None,
+        }
+    }
+}

src/platform/macos/util/mod.rs

@@ -1,3 +1,8 @@
+mod cursor;
+mod into_option;
+
+pub use self::{cursor::Cursor, into_option::IntoOption};
+
 use cocoa::appkit::NSWindowStyleMask;
 use cocoa::base::{id, nil};
 use cocoa::foundation::{NSRect, NSUInteger};

src/platform/macos/view.rs

@@ -5,7 +5,7 @@ use std::{slice, str};
 use std::boxed::Box;
 use std::collections::VecDeque;
 use std::os::raw::*;
-use std::sync::Weak;
+use std::sync::{Arc, Mutex, Weak};
 
 use cocoa::base::{id, nil};
 use cocoa::appkit::{NSEvent, NSView, NSWindow};
@@ -22,15 +22,19 @@ use platform::platform::window::{get_window_id, IdRef};
 struct ViewState {
     window: id,
     shared: Weak<Shared>,
+    cursor: Arc<Mutex<util::Cursor>>,
     ime_spot: Option<(f64, f64)>,
     raw_characters: Option<String>,
     is_key_down: bool,
 }
 
-pub fn new_view(window: id, shared: Weak<Shared>) -> IdRef {
+pub fn new_view(window: id, shared: Weak<Shared>) -> (IdRef, Weak<Mutex<util::Cursor>>) {
+    let cursor = Default::default();
+    let cursor_access = Arc::downgrade(&cursor);
     let state = ViewState {
         window,
         shared,
+        cursor,
         ime_spot: None,
         raw_characters: None,
         is_key_down: false,
@@ -39,7 +43,7 @@ pub fn new_view(window: id, shared: Weak<Shared>) -> IdRef {
         // This is free'd in `dealloc`
         let state_ptr = Box::into_raw(Box::new(state)) as *mut c_void;
         let view: id = msg_send![VIEW_CLASS.0, alloc];
-        IdRef::new(msg_send![view, initWithWinit:state_ptr])
+        (IdRef::new(msg_send![view, initWithWinit:state_ptr]), cursor_access)
     }
 }
 
@@ -75,6 +79,10 @@ lazy_static! {
             sel!(drawRect:),
             draw_rect as extern fn(&Object, Sel, NSRect),
         );
+        decl.add_method(
+            sel!(resetCursorRects),
+            reset_cursor_rects as extern fn(&Object, Sel),
+        );
         decl.add_method(sel!(hasMarkedText), has_marked_text as extern fn(&Object, Sel) -> BOOL);
         decl.add_method(
             sel!(markedRange),
@@ -179,6 +187,20 @@ extern fn draw_rect(this: &Object, _sel: Sel, rect: NSRect) {
     }
 }
 
+extern fn reset_cursor_rects(this: &Object, _sel: Sel) {
+    unsafe {
+        let state_ptr: *mut c_void = *this.get_ivar("winitState");
+        let state = &mut *(state_ptr as *mut ViewState);
+
+        let bounds: NSRect = msg_send![this, bounds];
+        let cursor = state.cursor.lock().unwrap().load();
+        let _: () = msg_send![this,
+            addCursorRect:bounds
+            cursor:cursor
+        ];
+    }
+}
+
 extern fn has_marked_text(this: &Object, _sel: Sel) -> BOOL {
     //println!("hasMarkedText");
     unsafe {

src/platform/macos/window.rs

@@ -3,7 +3,7 @@ use std::cell::{Cell, RefCell};
 use std::f64;
 use std::ops::Deref;
 use std::os::raw::c_void;
-use std::sync::Weak;
+use std::sync::{Mutex, Weak};
 use std::sync::atomic::{Ordering, AtomicBool};
 
 use cocoa::appkit::{
@@ -547,6 +547,7 @@ pub struct Window2 {
     pub window: IdRef,
     pub delegate: WindowDelegate,
     pub input_context: IdRef,
+    cursor: Weak<Mutex<util::Cursor>>,
     cursor_hidden: AtomicBool,
 }
 
@@ -714,7 +715,7 @@ impl Window2 {
                 return Err(OsError(format!("Couldn't create NSWindow")));
             },
         };
-        let view = match Window2::create_view(*window, Weak::clone(&shared)) {
+        let (view, cursor) = match Window2::create_view(*window, Weak::clone(&shared)) {
             Some(view) => view,
             None => {
                 let _: () = unsafe { msg_send![autoreleasepool, drain] };
@@ -772,6 +773,7 @@ impl Window2 {
             window: window,
             delegate: WindowDelegate::new(delegate_state),
             input_context,
+            cursor,
             cursor_hidden: Default::default(),
         };
 
@@ -950,9 +952,9 @@ impl Window2 {
         }
     }
 
-    fn create_view(window: id, shared: Weak<Shared>) -> Option<IdRef> {
+    fn create_view(window: id, shared: Weak<Shared>) -> Option<(IdRef, Weak<Mutex<util::Cursor>>)> {
         unsafe {
-            let view = new_view(window, shared);
+            let (view, cursor) = new_view(window, shared);
             view.non_nil().map(|view| {
                 view.setWantsBestResolutionOpenGLSurface_(YES);
 
@@ -967,7 +969,7 @@ impl Window2 {
 
                 window.setContentView_(*view);
                 window.makeFirstResponder_(*view);
-                view
+                (view, cursor)
             })
         }
     }
@@ -1074,40 +1076,14 @@ impl Window2 {
     }
 
     pub fn set_cursor(&self, cursor: MouseCursor) {
-        let cursor_name = match cursor {
+        let cursor = util::Cursor::from(cursor);
-            MouseCursor::Arrow | MouseCursor::Default => "arrowCursor",
+        if let Some(cursor_access) = self.cursor.upgrade() {
-            MouseCursor::Hand => "pointingHandCursor",
+            *cursor_access.lock().unwrap() = cursor;
-            MouseCursor::Grabbing | MouseCursor::Grab => "closedHandCursor",
+        }
-            MouseCursor::Text => "IBeamCursor",
-            MouseCursor::VerticalText => "IBeamCursorForVerticalLayout",
-            MouseCursor::Copy => "dragCopyCursor",
-            MouseCursor::Alias => "dragLinkCursor",
-            MouseCursor::NotAllowed | MouseCursor::NoDrop => "operationNotAllowedCursor",
-            MouseCursor::ContextMenu => "contextualMenuCursor",
-            MouseCursor::Crosshair => "crosshairCursor",
-            MouseCursor::EResize => "resizeRightCursor",
-            MouseCursor::NResize => "resizeUpCursor",
-            MouseCursor::WResize => "resizeLeftCursor",
-            MouseCursor::SResize => "resizeDownCursor",
-            MouseCursor::EwResize | MouseCursor::ColResize => "resizeLeftRightCursor",
-            MouseCursor::NsResize | MouseCursor::RowResize => "resizeUpDownCursor",
-
-            // TODO: Find appropriate OSX cursors
-            MouseCursor::NeResize | MouseCursor::NwResize |
-            MouseCursor::SeResize | MouseCursor::SwResize |
-            MouseCursor::NwseResize | MouseCursor::NeswResize |
-
-            MouseCursor::Cell |
-            MouseCursor::Wait | MouseCursor::Progress | MouseCursor::Help |
-            MouseCursor::Move | MouseCursor::AllScroll | MouseCursor::ZoomIn |
-            MouseCursor::ZoomOut => "arrowCursor",
-        };
-        let sel = Sel::register(cursor_name);
-        let cls = class!(NSCursor);
         unsafe {
-            use objc::Message;
+            let _: () = msg_send![*self.window,
-            let cursor: id = cls.send_message(sel, ()).unwrap();
+                invalidateCursorRectsForView:*self.view
-            let _: () = msg_send![cursor, set];
+            ];
         }
     }