From 8d863206b3c041a4e358a88566edf1adea6a757a Mon Sep 17 00:00:00 2001
From: Michael Zhang <mail@mzhang.io>
Date: Wed, 6 Jan 2021 13:30:23 -0600
Subject: [PATCH] don't show rectangle when it's too small

---
 src/gui.rs | 68 +++++++++++++++++++++++++++++++++---------------------
 1 file changed, 42 insertions(+), 26 deletions(-)

diff --git a/src/gui.rs b/src/gui.rs
index ba93410..ccd76e5 100644
--- a/src/gui.rs
+++ b/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);
 
@@ -168,41 +172,48 @@ 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 state.dragging {
-                let rect = state.rect();
-                xproto::change_gc(
-                    &self.conn,
-                    window_gc,
-                    &[(xcb::GC_FOREGROUND, screen.black_pixel())],
-                );
-                xproto::poly_rectangle(&self.conn, window_id, window_gc, &[rect]);
+            if let Some(rect) = state.rect() {
+                if state.dragging {
+                    xproto::change_gc(
+                        &self.conn,
+                        window_gc,
+                        &[(xcb::GC_FOREGROUND, screen.black_pixel())],
+                    );
+                    xproto::poly_rectangle(&self.conn, window_id, window_gc, &[rect]);
 
-                let rect2 = Rectangle::new(
-                    rect.x() + 1,
-                    rect.y() + 1,
-                    rect.width() - 2,
-                    rect.height() - 2,
-                );
-                xproto::change_gc(
-                    &self.conn,
-                    window_gc,
-                    &[(xcb::GC_FOREGROUND, screen.white_pixel())],
-                );
-                xproto::poly_rectangle(&self.conn, window_id, window_gc, &[rect2]);
+                    let rect2 = Rectangle::new(
+                        rect.x() + 1,
+                        rect.y() + 1,
+                        rect.width() - 2,
+                        rect.height() - 2,
+                    );
+                    xproto::change_gc(
+                        &self.conn,
+                        window_gc,
+                        &[(xcb::GC_FOREGROUND, screen.white_pixel())],
+                    );
+                    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();
 
@@ -241,7 +254,10 @@ impl Gui {
 
                     // left mouse button
                     if state.dragging && button_evt.detail() == 1 {
-                        break;
+                            state.dragging = false;
+                        if let Some(_) = state.rect() {
+                            break;
+                        }
                     }
                 }
                 xcb::MOTION_NOTIFY => {
@@ -250,7 +266,7 @@ impl Gui {
                     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() })
     }
 }