Implement dragging and resizing of borderless window

CHANGELOG.md

@@ -10,6 +10,10 @@ Notable changes to the `alacritty_terminal` crate are documented in its
 
 ## 0.14.0-dev
 
+### Added
+
+- Moving and resizing of windows without decorations by dragging the padding at the top or bottom-right
+
 ### Changed
 
 - Pressing `Alt` with unicode input will now add `ESC` like for ASCII input

alacritty/src/display/window.rs

@@ -16,6 +16,7 @@ use {
     png::Decoder,
 };
 
+use log::debug;
 use std::fmt::{self, Display, Formatter};
 
 #[cfg(target_os = "macos")]
@@ -33,8 +34,8 @@ use winit::monitor::MonitorHandle;
 #[cfg(windows)]
 use winit::platform::windows::IconExtWindows;
 use winit::window::{
-    CursorIcon, Fullscreen, ImePurpose, Theme, UserAttentionType, Window as WinitWindow,
-    WindowAttributes, WindowId,
+    CursorIcon, Fullscreen, ImePurpose, ResizeDirection, Theme, UserAttentionType,
+    Window as WinitWindow, WindowAttributes, WindowId,
 };
 
 use alacritty_terminal::index::Point;
@@ -363,6 +364,18 @@ impl Window {
         self.window.set_resize_increments(Some(increments));
     }
 
+    pub fn drag_window(&self) {
+        if let Err(err) = self.window.drag_window() {
+            debug!("Unable to initiate dragging the window: {}", err);
+        }
+    }
+
+    pub fn drag_resize_window(&self, direction: ResizeDirection) {
+        if let Err(err) = self.window.drag_resize_window(direction) {
+            debug!("Unable to initiate resizing the window: {}", err);
+        }
+    }
+
     /// Toggle the window's fullscreen state.
     pub fn toggle_fullscreen(&self) {
         self.set_fullscreen(self.window.fullscreen().is_none());

alacritty/src/event.rs

@@ -1582,6 +1582,7 @@ pub struct Mouse {
     pub block_hint_launcher: bool,
     pub hint_highlight_dirty: bool,
     pub inside_text_area: bool,
+    pub padding_interaction: bool,
     pub x: usize,
     pub y: usize,
 }
@@ -1599,6 +1600,7 @@ impl Default for Mouse {
             hint_highlight_dirty: Default::default(),
             block_hint_launcher: Default::default(),
             inside_text_area: Default::default(),
+            padding_interaction: Default::default(),
             accumulated_scroll: Default::default(),
             x: Default::default(),
             y: Default::default(),

alacritty/src/input/mod.rs

@@ -24,7 +24,7 @@ use winit::event_loop::ActiveEventLoop;
 use winit::keyboard::ModifiersState;
 #[cfg(target_os = "macos")]
 use winit::platform::macos::ActiveEventLoopExtMacOS;
-use winit::window::CursorIcon;
+use winit::window::{CursorIcon, ResizeDirection};
 
 use alacritty_terminal::event::EventListener;
 use alacritty_terminal::grid::{Dimensions, Scroll};
@@ -36,7 +36,6 @@ use alacritty_terminal::vi_mode::ViMotion;
 use alacritty_terminal::vte::ansi::{ClearMode, Handler};
 
 use crate::clipboard::Clipboard;
-#[cfg(target_os = "macos")]
 use crate::config::window::Decorations;
 use crate::config::{Action, BindingMode, MouseAction, SearchAction, UiConfig, ViAction};
 use crate::display::hint::HintMatch;
@@ -77,6 +76,13 @@ pub struct Processor<T: EventListener, A: ActionContext<T>> {
     _phantom: PhantomData<T>,
 }
 
+struct PaddingHoverinfo {
+    pub north: bool,
+    pub east: bool,
+    pub south: bool,
+    pub west: bool,
+}
+
 pub trait ActionContext<T: EventListener> {
     fn write_to_pty<B: Into<Cow<'static, [u8]>>>(&self, _data: B) {}
     fn mark_dirty(&mut self) {}
@@ -449,6 +455,19 @@ impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
 
         let inside_text_area = size_info.contains_point(x, y);
         let cell_side = self.cell_side(x);
+        let padding_hover = self.padding_hoverinfo(self.ctx.mouse(), &size_info);
+
+        let mut padding_interaction = false;
+        if !inside_text_area
+            && !lmb_pressed
+            && !rmb_pressed
+            && self.ctx.config().window.decorations == Decorations::None
+        {
+            // North padding of borderless window allows to move the window, south-east and
+            // south-west corner allow resize.
+            padding_interaction = padding_hover.north
+                || (padding_hover.south && (padding_hover.east || padding_hover.west));
+        }
 
         let point = self.ctx.mouse().point(&size_info, display_offset);
         let cell_changed = old_point != point;
@@ -457,12 +476,14 @@ impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
         if !cell_changed
             && self.ctx.mouse().cell_side == cell_side
             && self.ctx.mouse().inside_text_area == inside_text_area
+            && self.ctx.mouse().padding_interaction == padding_interaction
         {
             return;
         }
 
         self.ctx.mouse_mut().inside_text_area = inside_text_area;
         self.ctx.mouse_mut().cell_side = cell_side;
+        self.ctx.mouse_mut().padding_interaction = padding_interaction;
 
         // Update mouse state and check for URL change.
         let mouse_state = self.cursor_state();
@@ -625,7 +646,27 @@ impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
 
             // Load mouse point, treating message bar and padding as the closest cell.
             let display_offset = self.ctx.terminal().grid().display_offset();
-            let point = self.ctx.mouse().point(&self.ctx.size_info(), display_offset);
+            let size_info = self.ctx.size_info();
+            let point = self.ctx.mouse().point(&size_info, display_offset);
+
+            if self.ctx.config().window.decorations == Decorations::None {
+                let padding_hover = self.padding_hoverinfo(self.ctx.mouse(), &size_info);
+                // When clicking the north padding, drag window.
+                if padding_hover.north {
+                    self.ctx.window().drag_window();
+                    return;
+                }
+                // When clicking the south-east padding corner, resize window.
+                if padding_hover.south && padding_hover.east {
+                    self.ctx.window().drag_resize_window(ResizeDirection::SouthEast);
+                    return;
+                }
+                // When clicking the south-west padding corner, resize window.
+                if padding_hover.south && padding_hover.west {
+                    self.ctx.window().drag_resize_window(ResizeDirection::SouthWest);
+                    return;
+                }
+            }
 
             if let MouseButton::Left = button {
                 self.on_left_click(point)
@@ -1054,11 +1095,21 @@ impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
         let display_offset = self.ctx.terminal().grid().display_offset();
         let point = self.ctx.mouse().point(&self.ctx.size_info(), display_offset);
         let hyperlink = self.ctx.terminal().grid()[point].hyperlink();
+        let padding_hover = self.padding_hoverinfo(self.ctx.mouse(), &self.ctx.size_info());
+        let padding_interaction_active = self.ctx.config().window.decorations == Decorations::None
+            && self.ctx.mouse().left_button_state == ElementState::Released
+            && self.ctx.mouse().right_button_state == ElementState::Released;
 
         // Function to check if mouse is on top of a hint.
         let hint_highlighted = |hint: &HintMatch| hint.should_highlight(point, hyperlink.as_ref());
 
-        if let Some(mouse_state) = self.message_bar_cursor_state() {
+        if padding_interaction_active && padding_hover.north {
+            CursorIcon::Move
+        } else if padding_interaction_active && padding_hover.south && padding_hover.east {
+            CursorIcon::SeResize
+        } else if padding_interaction_active && padding_hover.south && padding_hover.west {
+            CursorIcon::SwResize
+        } else if let Some(mouse_state) = self.message_bar_cursor_state() {
             mouse_state
         } else if self.ctx.display().highlighted_hint.as_ref().map_or(false, hint_highlighted) {
             CursorIcon::Pointer
@@ -1103,6 +1154,23 @@ impl<T: EventListener, A: ActionContext<T>> Processor<T, A> {
         scheduler.unschedule(timer_id);
         scheduler.schedule(event, SELECTION_SCROLLING_INTERVAL, true, timer_id);
     }
+
+    /// Whether the padding is hovered in the north, east, south and west direction, respectively.
+    fn padding_hoverinfo(&self, mouse: &Mouse, size_info: &SizeInfo) -> PaddingHoverinfo {
+        let x = mouse.x;
+        let y = mouse.y;
+        let padding_x = size_info.padding_x() as usize;
+        let padding_y = size_info.padding_y() as usize;
+        let width = size_info.width() as usize;
+        let height = size_info.height() as usize;
+
+        PaddingHoverinfo {
+            north: y < padding_y,
+            east: x > width - padding_x,
+            south: y > height - padding_y,
+            west: x < padding_x,
+        }
+    }
 }
 
 #[cfg(test)]