don't show rectangle when it's too small

src/gui.rs

@@ -158,7 +158,11 @@ impl Gui {
         }
 
         impl State {
-            pub fn rect(&self) -> Rectangle {
+            pub fn rect(&self) -> Option<Rectangle> {
+                if self.dx < 0 || self.dy < 0 {
+                    return None;
+                }
+
                 let tlx = self.dx.min(self.mx);
                 let tly = self.dy.min(self.my);
 
@@ -168,18 +172,25 @@ impl Gui {
                 let rw = (brx - tlx) as u16;
                 let rh = (bry - tly) as u16;
 
-                Rectangle::new(tlx, tly, rw, rh)
+                if rw <= 2 || rh <= 2 {
+                    return None;
+                }
+
+                Some(Rectangle::new(tlx, tly, rw, rh))
             }
         }
 
         let mut state = State::default();
+        state.dx = -1;
+        state.dy = -1;
+
         let mut cancelled = false;
 
         let redraw = |state: &State| -> Result<()> {
             xcb_image::put(&self.conn, window_id, window_gc, &image.image, 0, 0);
 
+            if let Some(rect) = state.rect() {
                 if state.dragging {
-                let rect = state.rect();
                     xproto::change_gc(
                         &self.conn,
                         window_gc,
@@ -200,9 +211,9 @@ impl Gui {
                     );
                     xproto::poly_rectangle(&self.conn, window_id, window_gc, &[rect2]);
                 }
+            }
 
             self.conn.flush();
-
             Ok(())
         };
 
@@ -227,6 +238,8 @@ impl Gui {
                 xcb::BUTTON_PRESS => {
                     let button_evt = unsafe { xcb::cast_event::<xcb::ButtonPressEvent>(&evt) };
                     info!("pressed mouse button {:?}", button_evt.detail());
+                    state.mx = button_evt.root_x();
+                    state.my = button_evt.root_y();
                     state.dx = button_evt.root_x();
                     state.dy = button_evt.root_y();
 
@@ -241,16 +254,19 @@ impl Gui {
 
                     // left mouse button
                     if state.dragging && button_evt.detail() == 1 {
+                            state.dragging = false;
+                        if let Some(_) = state.rect() {
                             break;
                         }
                     }
+                }
                 xcb::MOTION_NOTIFY => {
                     let motion_evt = unsafe { xcb::cast_event::<xcb::MotionNotifyEvent>(&evt) };
                     state.mx = motion_evt.root_x();
                     state.my = motion_evt.root_y();
                 }
                 v => {
-                    println!("event type: {:?}", v);
+                    info!("event type: {:?}", v);
                 }
             }
 
@@ -261,7 +277,7 @@ impl Gui {
         xproto::ungrab_keyboard(&self.conn, xcb::CURRENT_TIME).request_check()?;
         xproto::ungrab_pointer(&self.conn, xcb::CURRENT_TIME).request_check()?;
 
-        Ok(if cancelled { None } else { Some(state.rect()) })
+        Ok(if cancelled { None } else { state.rect() })
     }
 }