cancelled by user case

src/gui.rs

@@ -46,7 +46,7 @@ impl Gui {
         Ok(ScreenCapture { image })
     }
 
-    pub fn interactive_select(&self, image: &ScreenCapture) -> Result<Rectangle> {
+    pub fn interactive_select(&self, image: &ScreenCapture) -> Result<Option<Rectangle>> {
         let id = self.conn.generate_id();
         let screen = self.get_default_screen();
         let root_window = screen.root();
@@ -166,6 +166,7 @@ impl Gui {
         }
 
         let mut state = State::default();
+        let mut cancelled = false;
 
         let redraw = |state: &State| {
             xcb_image::put(&self.conn, id, gc, &image.image, 0, 0);
@@ -185,6 +186,7 @@ impl Gui {
                 xcb::KEY_RELEASE => {
                     let key_evt = unsafe { xcb::cast_event::<xcb::KeyReleaseEvent>(&evt) };
                     if key_evt.detail() == 9 {
+                        cancelled = true;
                         break;
                     }
                 }
@@ -226,7 +228,7 @@ impl Gui {
         xproto::ungrab_keyboard(&self.conn, xcb::CURRENT_TIME).request_check()?;
         xproto::ungrab_pointer(&self.conn, xcb::CURRENT_TIME).request_check()?;
 
-        Ok(state.rect())
+        Ok(if cancelled { None } else { Some(state.rect()) })
     }
 }
 

src/main.rs

@@ -5,6 +5,7 @@ extern crate anyhow;
 
 mod gui;
 
+use std::process;
 use std::path::PathBuf;
 
 use anyhow::Result;
@@ -29,8 +30,12 @@ fn main() -> Result<()> {
             capture.save_to(&opt.outfile)?;
         }
         Region::Selection => {
-            let rectangle = gui.interactive_select(&capture)?;
-            capture.save_cropped_to(&opt.outfile, rectangle)?;
+            if let Some(rectangle) = gui.interactive_select(&capture)? {
+                capture.save_cropped_to(&opt.outfile, rectangle)?;
+            } else {
+                info!("Cancelled by user.");
+                process::exit(1);
+            }
         }
     }