Enable shift+select in mouse mode

When an application takes control over the mouse, it usually disables
selection completely. However the common way to still make selection
possible is by allowing selection while the shift key is held down.

This feature is implemented here by making use of the new `modifiers`
field on mouse events with glutin/winit.

This fixes jwilm/alacritty#146.

2 files changed, 36 insertions, 17 deletions

diff --git a/src/event.rs b/src/event.rs
index 894777fa..3dce4d66 100644
--- a/src/event.rs
+++ b/src/event.rs
@@ -298,19 +298,19 @@ impl<N: Notify> Processor<N> {
                     ReceivedCharacter(c) => {
                         processor.received_char(c);
                     },
-                    MouseInput { state, button, .. } => {
+                    MouseInput { state, button, modifiers, .. } => {
                         *hide_cursor = false;
-                        processor.mouse_input(state, button);
+                        processor.mouse_input(state, button, modifiers);
                         processor.ctx.terminal.dirty = true;
                     },
-                    CursorMoved { position: (x, y), .. } => {
+                    CursorMoved { position: (x, y), modifiers, .. } => {
                         let x = x as i32;
                         let y = y as i32;
                         let x = limit(x, 0, processor.ctx.size_info.width as i32);
                         let y = limit(y, 0, processor.ctx.size_info.height as i32);
 
                         *hide_cursor = false;
-                        processor.mouse_moved(x as u32, y as u32);
+                        processor.mouse_moved(x as u32, y as u32, modifiers);
 
                         if !processor.ctx.selection.is_none() {
                             processor.ctx.terminal.dirty = true;
diff --git a/src/input.rs b/src/input.rs
index fa1ce385..586a664c 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -25,8 +25,7 @@ use std::time::Instant;
 use std::os::unix::process::CommandExt;
 
 use copypasta::{Clipboard, Load, Buffer};
-use glutin::{ElementState, VirtualKeyCode, MouseButton, TouchPhase, MouseScrollDelta};
-use glutin::ModifiersState;
+use glutin::{ElementState, VirtualKeyCode, MouseButton, TouchPhase, MouseScrollDelta, ModifiersState};
 
 use config;
 use event::{ClickState, Mouse};
@@ -254,7 +253,7 @@ impl From<&'static str> for Action {
 
 impl<'a, A: ActionContext + 'a> Processor<'a, A> {
     #[inline]
-    pub fn mouse_moved(&mut self, x: u32, y: u32) {
+    pub fn mouse_moved(&mut self, x: u32, y: u32, modifiers: ModifiersState) {
         self.ctx.mouse_mut().x = x;
         self.ctx.mouse_mut().y = y;
 
@@ -275,7 +274,7 @@ impl<'a, A: ActionContext + 'a> Processor<'a, A> {
 
             if self.ctx.mouse_mut().left_button_state == ElementState::Pressed {
                 let report_mode = mode::TermMode::MOUSE_REPORT_CLICK | mode::TermMode::MOUSE_MOTION;
-                if !self.ctx.terminal_mode().intersects(report_mode) {
+                if modifiers.shift || !self.ctx.terminal_mode().intersects(report_mode) {
                     self.ctx.update_selection(Point {
                         line: point.line,
                         col: point.col
@@ -338,7 +337,7 @@ impl<'a, A: ActionContext + 'a> Processor<'a, A> {
         }
     }
 
-    pub fn on_mouse_press(&mut self) {
+    pub fn on_mouse_press(&mut self, modifiers: ModifiersState) {
         let now = Instant::now();
         let elapsed = self.ctx.mouse_mut().last_click_timestamp.elapsed();
         self.ctx.mouse_mut().last_click_timestamp = now;
@@ -354,7 +353,7 @@ impl<'a, A: ActionContext + 'a> Processor<'a, A> {
             },
             _ => {
                 let report_modes = mode::TermMode::MOUSE_REPORT_CLICK | mode::TermMode::MOUSE_MOTION;
-                if self.ctx.terminal_mode().intersects(report_modes) {
+                if !modifiers.shift && self.ctx.terminal_mode().intersects(report_modes) {
                     self.mouse_report(0);
                     return;
                 }
@@ -365,8 +364,10 @@ impl<'a, A: ActionContext + 'a> Processor<'a, A> {
         };
     }
 
-    pub fn on_mouse_release(&mut self) {
-        if self.ctx.terminal_mode().intersects(mode::TermMode::MOUSE_REPORT_CLICK | mode::TermMode::MOUSE_MOTION) {
+    pub fn on_mouse_release(&mut self, modifiers: ModifiersState) {
+        let report_modes = mode::TermMode::MOUSE_REPORT_CLICK | mode::TermMode::MOUSE_MOTION;
+        if !modifiers.shift && self.ctx.terminal_mode().intersects(report_modes)
+        {
             self.mouse_report(3);
             return;
         }
@@ -455,16 +456,16 @@ impl<'a, A: ActionContext + 'a> Processor<'a, A> {
         }
     }
 
-    pub fn mouse_input(&mut self, state: ElementState, button: MouseButton) {
+    pub fn mouse_input(&mut self, state: ElementState, button: MouseButton, modifiers: ModifiersState) {
         if let MouseButton::Left = button {
             let state = mem::replace(&mut self.ctx.mouse_mut().left_button_state, state);
             if self.ctx.mouse_mut().left_button_state != state {
                 match self.ctx.mouse_mut().left_button_state {
                     ElementState::Pressed => {
-                        self.on_mouse_press();
+                        self.on_mouse_press(modifiers);
                     },
                     ElementState::Released => {
-                        self.on_mouse_release();
+                        self.on_mouse_release(modifiers);
                     }
                 }
             }
@@ -701,8 +702,8 @@ mod tests {
                     mouse_bindings: &config.mouse_bindings()[..],
                 };
 
-                if let Event::WindowEvent { event: WindowEvent::MouseInput { state, button, .. }, .. } = $input {
-                    processor.mouse_input(state, button);
+                if let Event::WindowEvent { event: WindowEvent::MouseInput { state, button, modifiers, .. }, .. } = $input {
+                    processor.mouse_input(state, button, modifiers);
                 };
 
                 assert!(match mouse.click_state {
@@ -740,6 +741,12 @@ mod tests {
                 state: ElementState::Pressed,
                 button: MouseButton::Left,
                 device_id: unsafe { ::std::mem::transmute_copy(&0) },
+                modifiers: ModifiersState {
+                    shift: false,
+                    ctrl: false,
+                    alt: false,
+                    logo: false,
+                },
             },
             window_id: unsafe { ::std::mem::transmute_copy(&0) },
         },
@@ -755,6 +762,12 @@ mod tests {
                 state: ElementState::Pressed,
                 button: MouseButton::Left,
                 device_id: unsafe { ::std::mem::transmute_copy(&0) },
+                modifiers: ModifiersState {
+                    shift: false,
+                    ctrl: false,
+                    alt: false,
+                    logo: false,
+                },
             },
             window_id: unsafe { ::std::mem::transmute_copy(&0) },
         },
@@ -770,6 +783,12 @@ mod tests {
                 state: ElementState::Pressed,
                 button: MouseButton::Left,
                 device_id: unsafe { ::std::mem::transmute_copy(&0) },
+                modifiers: ModifiersState {
+                    shift: false,
+                    ctrl: false,
+                    alt: false,
+                    logo: false,
+                },
             },
             window_id: unsafe { ::std::mem::transmute_copy(&0) },
         },