Add custom touch handling code for buttons

native/src/widget/button.rs

@@ -6,10 +6,12 @@ use crate::layout;
 use crate::mouse;
 use crate::overlay;
 use crate::touch;
+use crate::touch::Finger;
 use crate::{
     Clipboard, Element, Hasher, Layout, Length, Padding, Point, Rectangle,
     Widget,
 };
+use std::collections::HashSet;
 use std::hash::Hash;
 
 /// A generic widget that produces a message when pressed.
@@ -63,6 +65,7 @@ pub struct Button<'a, Message, Renderer: self::Renderer> {
     min_height: u32,
     padding: Padding,
     style: Renderer::Style,
+    fingers_mid_press: HashSet<Finger>,
 }
 
 impl<'a, Message, Renderer> Button<'a, Message, Renderer>
@@ -86,6 +89,8 @@ where
             min_height: 0,
             padding: Renderer::DEFAULT_PADDING,
             style: Renderer::Style::default(),
+
+            fingers_mid_press: HashSet::with_capacity(2),
         }
     }
 
@@ -204,8 +209,7 @@ where
         }
 
         match event {
-            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
-            | Event::Touch(touch::Event::FingerPressed { .. }) => {
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => {
                 if self.on_press.is_some() {
                     let bounds = layout.bounds();
 
@@ -216,8 +220,7 @@ where
                     }
                 }
             }
-            Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
-            | Event::Touch(touch::Event::FingerLifted { .. }) => {
+            Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left)) => {
                 if let Some(on_press) = self.on_press.clone() {
                     let bounds = layout.bounds();
 
@@ -232,8 +235,38 @@ where
                     }
                 }
             }
-            Event::Touch(touch::Event::FingerLost { .. }) => {
-                self.state.is_pressed = false;
+            Event::Touch(x) => {
+                match x {
+                    touch::Event::FingerPressed { id, position } => {
+                        if layout.bounds().contains(position) {
+                            let _ = self.fingers_mid_press.insert(id);
+
+                            return event::Status::Captured;
+                        }
+                    }
+                    touch::Event::FingerMoved { id, position } => {
+                        if !layout.bounds().contains(position) {
+                            let _ = self.fingers_mid_press.remove(&id);
+
+                            return event::Status::Captured;
+                        }
+                    }
+                    touch::Event::FingerLifted { id, position } => {
+                        if self.fingers_mid_press.remove(&id)
+                            && layout.bounds().contains(position)
+                        {
+                            // this should be treated as a click
+                            if let Some(on_press) = self.on_press.clone() {
+                                messages.push(on_press);
+                            }
+
+                            return event::Status::Captured;
+                        }
+                    }
+                    touch::Event::FingerLost { id, .. } => {
+                        let _ = self.fingers_mid_press.remove(&id);
+                    }
+                }
             }
             _ => {}
         }

native/src/widget/toggler.rs

@@ -181,8 +181,6 @@ where
                 }
             }
             Event::Touch(x) => {
-                eprintln!("{:?}", x);
-
                 match x {
                     touch::Event::FingerPressed { id, position } => {
                         if layout.bounds().contains(position) {