Added Extra1 & Extra2 pointer buttons (#1603)

Extra1 is usually extra back button on most mice & Extra2 is usually extra forward button.

eframe/src/web/input.rs

@@ -14,6 +14,8 @@ pub fn button_from_mouse_event(event: &web_sys::MouseEvent) -> Option<egui::Poin
         0 => Some(egui::PointerButton::Primary),
         1 => Some(egui::PointerButton::Middle),
         2 => Some(egui::PointerButton::Secondary),
+        3 => Some(egui::PointerButton::Extra1),
+        4 => Some(egui::PointerButton::Extra2),
         _ => None,
     }
 }

egui-winit/src/lib.rs

@@ -542,6 +542,8 @@ fn translate_mouse_button(button: winit::event::MouseButton) -> Option<egui::Poi
         winit::event::MouseButton::Left => Some(egui::PointerButton::Primary),
         winit::event::MouseButton::Right => Some(egui::PointerButton::Secondary),
         winit::event::MouseButton::Middle => Some(egui::PointerButton::Middle),
+        winit::event::MouseButton::Other(1) => Some(egui::PointerButton::Extra1),
+        winit::event::MouseButton::Other(2) => Some(egui::PointerButton::Extra2),
         winit::event::MouseButton::Other(_) => None,
     }
 }

egui/src/data/input.rs

@@ -254,10 +254,14 @@ pub enum PointerButton {
     Secondary = 1,
     /// The tertiary mouse button is usually the middle mouse button (e.g. clicking the scroll wheel).
     Middle = 2,
+    /// The first extra mouse button on some mice. In web typically corresponds to the Browser back button.
+    Extra1 = 3,
+    /// The second extra mouse button on some mice. In web typically corresponds to the Browser forward button.
+    Extra2 = 4,
 }
 
 /// Number of pointer buttons supported by egui, i.e. the number of possible states of [`PointerButton`].
-pub const NUM_POINTER_BUTTONS: usize = 3;
+pub const NUM_POINTER_BUTTONS: usize = 5;
 
 /// State of the modifier keys. These must be fed to egui.
 ///

egui/src/response.rs

@@ -557,16 +557,22 @@ impl Response {
                 self.clicked[0] || other.clicked[0],
                 self.clicked[1] || other.clicked[1],
                 self.clicked[2] || other.clicked[2],
+                self.clicked[3] || other.clicked[3],
+                self.clicked[4] || other.clicked[4],
             ],
             double_clicked: [
                 self.double_clicked[0] || other.double_clicked[0],
                 self.double_clicked[1] || other.double_clicked[1],
                 self.double_clicked[2] || other.double_clicked[2],
+                self.double_clicked[3] || other.double_clicked[3],
+                self.double_clicked[4] || other.double_clicked[4],
             ],
             triple_clicked: [
                 self.triple_clicked[0] || other.triple_clicked[0],
                 self.triple_clicked[1] || other.triple_clicked[1],
                 self.triple_clicked[2] || other.triple_clicked[2],
+                self.triple_clicked[3] || other.triple_clicked[3],
+                self.triple_clicked[4] || other.triple_clicked[4],
             ],
             dragged: self.dragged || other.dragged,
             drag_released: self.drag_released || other.drag_released,

egui_demo_lib/src/demo/tests.rs

@@ -341,6 +341,8 @@ impl super::View for InputTest {
             egui::PointerButton::Primary,
             egui::PointerButton::Secondary,
             egui::PointerButton::Middle,
+            egui::PointerButton::Extra1,
+            egui::PointerButton::Extra2,
         ] {
             if response.clicked_by(button) {
                 new_info += &format!("Clicked by {:?} button\n", button);