Add drag-resizing with cursor feature

CHANGELOG.md

@@ -14,6 +14,7 @@
 - On Wayland, bump `smithay-client-toolkit` to 0.15.
 - On Wayland, implement `request_user_attention` with `xdg_activation_v1`.
 - On X11, emit missing `WindowEvent::ScaleFactorChanged` when the only monitor gets reconnected.
+- On Windows, added `drag_resize_window` method
 
 # 0.25.0 (2021-05-15)
 

FEATURES.md

@@ -193,21 +193,22 @@ Legend:
 |Video mode query |✔️    |✔️    |✔️       |✔️          |❌     |✔️      |**N/A**|
 
 ### Input handling
-|Feature                 |Windows   |MacOS   |Linux x11|Linux Wayland|Android|iOS    |WASM      |
-|----------------------- | -----    | ----   | ------- | ----------- | ----- | ----- | -------- |
-|Mouse events            |✔️       |▢[#63]  |✔️       |✔️          |**N/A**|**N/A**|✔️        |
-|Mouse set location      |✔️       |✔️      |✔️       |❓           |**N/A**|**N/A**|**N/A**|
-|Cursor grab             |✔️       |▢[#165] |▢[#242]  |✔️         |**N/A**|**N/A**|❓        |
-|Cursor icon             |✔️       |✔️      |✔️       |✔️           |**N/A**|**N/A**|✔️        |
-|Touch events            |✔️       |❌      |✔️       |✔️          |✔️    |✔️     |❌        |
-|Touch pressure          |✔️       |❌      |❌       |❌          |❌    |✔️     |❌        |
-|Multitouch              |✔️       |❌      |✔️       |✔️          |✔️    |✔️     |❌        |
-|Keyboard events         |✔️       |✔️      |✔️       |✔️          |❓     |❌     |✔️        |
-|Drag & Drop             |▢[#720]  |▢[#720] |▢[#720]  |❌[#306]    |**N/A**|**N/A**|❓        |
-|Raw Device Events       |▢[#750]  |▢[#750] |▢[#750]  |❌          |❌    |❌     |❓        |
-|Gamepad/Joystick events |❌[#804] |❌      |❌       |❌          |❌    |❌     |❓        |
-|Device movement events  |❓        |❓       |❓       |❓           |❌    |❌     |❓        |
-|Drag window with cursor |✔️         |✔️       |✔️        |✔️            |**N/A**|**N/A**|**N/A**   |
+|Feature                   |Windows   |MacOS    |Linux x11|Linux Wayland|Android |iOS     |WASM     |
+|-----------------------   | -----    | ----    | -------  | ---------- |-----   |-----   | ------- |
+|Mouse events              |✔️        |▢[#63]  |✔️       |✔️          |**N/A** |**N/A** |✔️      |
+|Mouse set location        |✔️        |✔️      |✔️       |❓           |**N/A** |**N/A** |**N/A** |
+|Cursor grab               |✔️        |▢[#165] |▢[#242]  |✔️          |**N/A** |**N/A** |❓       |
+|Cursor icon               |✔️        |✔️      |✔️       |✔️          |**N/A** |**N/A** |✔️      |
+|Touch events              |✔️        |❌      |✔️       |✔️          |✔️      |✔️     |❌      |
+|Touch pressure            |✔️        |❌      |❌       |❌          |❌      |✔️     |❌      |
+|Multitouch                |✔️        |❌      |✔️       |✔️          |✔️      |✔️     |❌      |
+|Keyboard events           |✔️        |✔️      |✔️       |✔️          |❓       |❌     |✔️      |
+|Drag & Drop               |▢[#720]   |▢[#720] |▢[#720]  |❌[#306]    |**N/A** |**N/A** |❓       |
+|Raw Device Events         |▢[#750]   |▢[#750] |▢[#750]  |❌          |❌      |❌     |❓       |
+|Gamepad/Joystick events   |❌[#804]  |❌      |❌       |❌          |❌      |❌     |❓       |
+|Device movement events    |❓         |❓      |❓        |❓           |❌      |❌     |❓       |
+|Drag window with cursor   |✔️        |✔️      |✔️       |✔️          |**N/A** |**N/A** |**N/A**  |
+|Resize window with cursor |✔️        |❌      |❌       |❌          |**N/A** |**N/A** |**N/A**  |
 
 ### Pending API Reworks
 Changes in the API that have been agreed upon but aren't implemented across all platforms.

examples/borderless.rs

@@ -0,0 +1,156 @@
+use simple_logger::SimpleLogger;
+use winit::{
+    dpi::LogicalSize,
+    event::{
+        ElementState, Event, KeyboardInput, MouseButton, StartCause, VirtualKeyCode, WindowEvent,
+    },
+    event_loop::{ControlFlow, EventLoop},
+    window::{CursorIcon, ResizeDirection, WindowBuilder},
+};
+
+#[derive(PartialEq, Eq, Clone, Copy)]
+enum CursorLocation {
+    Caption,
+    Top,
+    Bottom,
+    Right,
+    Left,
+    TopRight,
+    TopLeft,
+    BottomRight,
+    BottomLeft,
+    Default,
+}
+
+impl CursorLocation {
+    // Conversion to appropriate cursor Icon
+    fn get_cursor_icon(&self) -> CursorIcon {
+        match self {
+            CursorLocation::Top | CursorLocation::Bottom => CursorIcon::NsResize,
+            CursorLocation::Right | CursorLocation::Left => CursorIcon::EwResize,
+            CursorLocation::TopRight | CursorLocation::BottomLeft => CursorIcon::NeswResize,
+            CursorLocation::TopLeft | CursorLocation::BottomRight => CursorIcon::NwseResize,
+            _ => CursorIcon::Arrow,
+        }
+    }
+
+    // Conversion to a resize direction
+    fn to_resize_direction(&self) -> Option<ResizeDirection> {
+        match self {
+            CursorLocation::Top => Some(ResizeDirection::Top),
+            CursorLocation::Bottom => Some(ResizeDirection::Bottom),
+            CursorLocation::Right => Some(ResizeDirection::Right),
+            CursorLocation::Left => Some(ResizeDirection::Left),
+            CursorLocation::TopRight => Some(ResizeDirection::TopRight),
+            CursorLocation::TopLeft => Some(ResizeDirection::TopLeft),
+            CursorLocation::BottomRight => Some(ResizeDirection::BottomRight),
+            CursorLocation::BottomLeft => Some(ResizeDirection::BottomLeft),
+            _ => None,
+        }
+    }
+
+    // Intersects X locations and Y locations
+    // Assumes that the x_location will only be Left, Right or Default
+    // Assumes that the y_location will only be Top, Caption, Bottom or Default
+    fn intersect(x_location: Self, y_location: Self) -> Self {
+        match (x_location, y_location) {
+            (CursorLocation::Default, _) => y_location,
+            (_, CursorLocation::Default) => x_location,
+            (CursorLocation::Left, CursorLocation::Top) => CursorLocation::TopLeft,
+            (CursorLocation::Left, CursorLocation::Bottom) => CursorLocation::BottomLeft,
+            (CursorLocation::Right, CursorLocation::Top) => CursorLocation::TopRight,
+            (CursorLocation::Right, CursorLocation::Bottom) => CursorLocation::BottomRight,
+            _ => CursorLocation::Default,
+        }
+    }
+}
+
+const BORDER: f64 = 5.;
+const CAPTIONHEIGHT: f64 = 20.; // Titlebar
+const INIT_WIDTH: f64 = 400.;
+const INIT_HEIGHT: f64 = 200.;
+
+fn main() {
+    SimpleLogger::new().init().unwrap();
+    let event_loop = EventLoop::new();
+
+    let window = WindowBuilder::new().build(&event_loop).unwrap();
+    window.set_min_inner_size(Some(LogicalSize::new(INIT_WIDTH, INIT_HEIGHT)));
+
+    let mut border = false;
+    window.set_decorations(border);
+
+    let mut cursor_location = CursorLocation::Caption;
+    let mut x_border = INIT_WIDTH - BORDER;
+    let mut y_border = INIT_HEIGHT - BORDER;
+
+    event_loop.run(move |event, _, control_flow| match event {
+        Event::NewEvents(StartCause::Init) => {
+            eprintln!(
+                "Press 'B' to toggle borderless \nThe top of the screen functions as a titlebar"
+            )
+        }
+        Event::WindowEvent { event, .. } => match event {
+            WindowEvent::CloseRequested => *control_flow = ControlFlow::Exit,
+            WindowEvent::CursorMoved { position, .. } => {
+                // Test for X
+                let x_location = if position.x < BORDER {
+                    CursorLocation::Left
+                } else if position.x > x_border {
+                    CursorLocation::Right
+                } else {
+                    CursorLocation::Default
+                };
+
+                // Test for Y
+                let y_location = if position.y < BORDER {
+                    CursorLocation::Top
+                } else if position.y < CAPTIONHEIGHT {
+                    CursorLocation::Caption
+                } else if position.y > y_border {
+                    CursorLocation::Bottom
+                } else {
+                    CursorLocation::Default
+                };
+
+                let new_location = CursorLocation::intersect(x_location, y_location);
+
+                if new_location != cursor_location {
+                    cursor_location = new_location;
+                    window.set_cursor_icon(cursor_location.get_cursor_icon())
+                }
+            }
+
+            WindowEvent::Resized(new_size) => {
+                x_border = new_size.width as f64 - BORDER;
+                y_border = new_size.height as f64 - BORDER;
+            }
+
+            WindowEvent::MouseInput {
+                state: ElementState::Pressed,
+                button: MouseButton::Left,
+                ..
+            } => {
+                if let Some(dir) = cursor_location.to_resize_direction() {
+                    window.drag_resize_window(dir).unwrap()
+                } else if cursor_location == CursorLocation::Caption {
+                    window.drag_window().unwrap()
+                }
+            }
+            WindowEvent::KeyboardInput {
+                input:
+                    KeyboardInput {
+                        state: ElementState::Released,
+                        virtual_keycode: Some(VirtualKeyCode::B),
+                        ..
+                    },
+                ..
+            } => {
+                border = !border;
+                window.set_decorations(border);
+            }
+            _ => (),
+        },
+        _ => (),
+    });
+}

src/platform_impl/android/mod.rs

@@ -587,6 +587,15 @@ impl Window {
         ))
     }
 
+    pub fn drag_resize_window(
+        &self,
+        _direction: window::ResizeDirection,
+    ) -> Result<(), error::ExternalError> {
+        Err(error::ExternalError::NotSupported(
+            error::NotSupportedError::new(),
+        ))
+    }
+
     pub fn raw_window_handle(&self) -> raw_window_handle::RawWindowHandle {
         let a_native_window = if let Some(native_window) = ndk_glue::native_window().as_ref() {
             unsafe { native_window.ptr().as_mut() as *mut _ as *mut _ }

src/platform_impl/ios/window.rs

@@ -23,7 +23,8 @@ use crate::{
         monitor, view, EventLoopWindowTarget, MonitorHandle,
     },
     window::{
-        CursorIcon, Fullscreen, UserAttentionType, WindowAttributes, WindowId as RootWindowId,
+        CursorIcon, Fullscreen, ResizeDirection, UserAttentionType, WindowAttributes,
+        WindowId as RootWindowId,
     },
 };
 
@@ -186,6 +187,10 @@ impl Inner {
         Err(ExternalError::NotSupported(NotSupportedError::new()))
     }
 
+    pub fn drag_resize_window(&self, _direction: ResizeDirection) -> Result<(), ExternalError> {
+        Err(ExternalError::NotSupported(NotSupportedError::new()))
+    }
+
     pub fn set_minimized(&self, _minimized: bool) {
         warn!("`Window::set_minimized` is ignored on iOS")
     }

src/platform_impl/linux/mod.rs

@@ -30,7 +30,7 @@ use crate::{
     event_loop::{ControlFlow, EventLoopClosed, EventLoopWindowTarget as RootELW},
     icon::Icon,
     monitor::{MonitorHandle as RootMonitorHandle, VideoMode as RootVideoMode},
-    window::{CursorIcon, Fullscreen, UserAttentionType, WindowAttributes},
+    window::{CursorIcon, Fullscreen, ResizeDirection, UserAttentionType, WindowAttributes},
 };
 
 pub(crate) use crate::icon::RgbaIcon as PlatformIcon;
@@ -363,6 +363,11 @@ impl Window {
         x11_or_wayland!(match self; Window(window) => window.drag_window())
     }
 
+    #[inline]
+    pub fn drag_resize_window(&self, direction: ResizeDirection) -> Result<(), ExternalError> {
+        x11_or_wayland!(match self; Window(window) => window.drag_resize_window(direction))
+    }
+
     #[inline]
     pub fn scale_factor(&self) -> f64 {
         x11_or_wayland!(match self; Window(w) => w.scale_factor() as f64)

src/platform_impl/linux/wayland/window/mod.rs

@@ -17,7 +17,7 @@ use crate::platform_impl::{
     MonitorHandle as PlatformMonitorHandle, OsError,
     PlatformSpecificWindowBuilderAttributes as PlatformAttributes,
 };
-use crate::window::{CursorIcon, Fullscreen, UserAttentionType, WindowAttributes};
+use crate::window::{CursorIcon, Fullscreen, ResizeDirection, UserAttentionType, WindowAttributes};
 
 use super::env::WindowingFeatures;
 use super::event_loop::WinitState;
@@ -447,6 +447,11 @@ impl Window {
         Ok(())
     }
 
+    #[inline]
+    pub fn drag_resize_window(&self, _direction: ResizeDirection) -> Result<(), ExternalError> {
+        Err(ExternalError::NotSupported(NotSupportedError::new()))
+    }
+
     #[inline]
     pub fn set_ime_position(&self, position: Position) {
         let scale_factor = self.scale_factor() as f64;

src/platform_impl/linux/x11/window.rs

@@ -22,7 +22,7 @@ use crate::{
         MonitorHandle as PlatformMonitorHandle, OsError, PlatformSpecificWindowBuilderAttributes,
         VideoMode as PlatformVideoMode,
     },
-    window::{CursorIcon, Fullscreen, Icon, UserAttentionType, WindowAttributes},
+    window::{CursorIcon, Fullscreen, Icon, ResizeDirection, UserAttentionType, WindowAttributes},
 };
 
 use super::{
@@ -1377,6 +1377,11 @@ impl UnownedWindow {
             .map_err(|err| ExternalError::Os(os_error!(OsError::XError(err))))
     }
 
+    #[inline]
+    pub fn drag_resize_window(&self, _direction: ResizeDirection) -> Result<(), ExternalError> {
+        Err(ExternalError::NotSupported(NotSupportedError::new()))
+    }
+
     pub(crate) fn set_ime_position_physical(&self, x: i32, y: i32) {
         let _ = self
             .ime_sender

src/platform_impl/macos/window.rs

@@ -29,7 +29,8 @@ use crate::{
         OsError,
     },
     window::{
-        CursorIcon, Fullscreen, UserAttentionType, WindowAttributes, WindowId as RootWindowId,
+        CursorIcon, Fullscreen, ResizeDirection, UserAttentionType, WindowAttributes,
+        WindowId as RootWindowId,
     },
 };
 use cocoa::{
@@ -613,6 +614,11 @@ impl UnownedWindow {
         Ok(())
     }
 
+    #[inline]
+    pub fn drag_resize_window(&self, _direction: ResizeDirection) -> Result<(), ExternalError> {
+        Err(ExternalError::NotSupported(NotSupportedError::new()))
+    }
+
     pub(crate) fn is_zoomed(&self) -> bool {
         // because `isZoomed` doesn't work if the window's borderless,
         // we make it resizable temporalily.

src/platform_impl/web/window.rs

@@ -4,7 +4,8 @@ use crate::event;
 use crate::icon::Icon;
 use crate::monitor::MonitorHandle as RootMH;
 use crate::window::{
-    CursorIcon, Fullscreen, UserAttentionType, WindowAttributes, WindowId as RootWI,
+    CursorIcon, Fullscreen, ResizeDirection, UserAttentionType, WindowAttributes,
+    WindowId as RootWI,
 };
 
 use raw_window_handle::web::WebHandle;
@@ -227,6 +228,11 @@ impl Window {
         Err(ExternalError::NotSupported(NotSupportedError::new()))
     }
 
+    #[inline]
+    pub fn drag_resize_window(&self, _direction: ResizeDirection) -> Result<(), ExternalError> {
+        Err(ExternalError::NotSupported(NotSupportedError::new()))
+    }
+
     #[inline]
     pub fn set_minimized(&self, _minimized: bool) {
         // Intentionally a no-op, as canvases cannot be 'minimized'