From fe6e1ce28fb6fd9b0d6bd6b6bc1b81cae95994ad Mon Sep 17 00:00:00 2001
From: Alejandro Perea <alexpro820@gmail.com>
Date: Thu, 5 May 2022 23:26:15 +0200
Subject: [PATCH] Add *_released & *_clicked PointerState methods (#1582)

---
 CHANGELOG.md            |  2 +-
 egui/src/context.rs     |  2 +-
 egui/src/input_state.rs | 46 ++++++++++++++++++++++++++++++++++++++---
 3 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 873e337e3d7..440fa8fc630 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@ NOTE: [`epaint`](epaint/CHANGELOG.md), [`eframe`](eframe/CHANGELOG.md), [`egui-w
 
 
 ## Unreleased
-
+* Add `*_released` & `*_clicked` methods for `PointerState`.
 
 ## 0.18.1 - 2022-05-01
 * Change `Shape::Callback` from `&dyn Any` to `&mut dyn Any` to support more backends.
diff --git a/egui/src/context.rs b/egui/src/context.rs
index e2609b4a86b..63e1a2407e6 100644
--- a/egui/src/context.rs
+++ b/egui/src/context.rs
@@ -375,7 +375,7 @@ impl Context {
             for pointer_event in &input.pointer.pointer_events {
                 match pointer_event {
                     PointerEvent::Moved(_) => {}
-                    PointerEvent::Pressed(_) => {
+                    PointerEvent::Pressed { .. } => {
                         if hovered {
                             if sense.click && memory.interaction.click_id.is_none() {
                                 // potential start of a click
diff --git a/egui/src/input_state.rs b/egui/src/input_state.rs
index 5d043fb0f4f..2ca5d38a17f 100644
--- a/egui/src/input_state.rs
+++ b/egui/src/input_state.rs
@@ -367,13 +367,16 @@ impl Click {
 #[derive(Clone, Debug, PartialEq)]
 pub(crate) enum PointerEvent {
     Moved(Pos2),
-    Pressed(Pos2),
+    Pressed {
+        position: Pos2,
+        button: PointerButton,
+    },
     Released(Option<Click>),
 }
 
 impl PointerEvent {
     pub fn is_press(&self) -> bool {
-        matches!(self, PointerEvent::Pressed(_))
+        matches!(self, PointerEvent::Pressed { .. })
     }
     pub fn is_release(&self) -> bool {
         matches!(self, PointerEvent::Released(_))
@@ -509,7 +512,10 @@ impl PointerState {
                         self.press_origin = Some(pos);
                         self.press_start_time = Some(time);
                         self.has_moved_too_much_for_a_click = false;
-                        self.pointer_events.push(PointerEvent::Pressed(pos));
+                        self.pointer_events.push(PointerEvent::Pressed {
+                            position: pos,
+                            button,
+                        });
                     } else {
                         let clicked = self.could_any_button_be_click();
 
@@ -667,6 +673,23 @@ impl PointerState {
         self.pointer_events.iter().any(|event| event.is_release())
     }
 
+    /// Was the button given released this frame?
+    pub fn button_released(&self, button: PointerButton) -> bool {
+        self.pointer_events
+            .iter()
+            .any(|event| matches!(event, &PointerEvent::Released(Some(Click{button: b, ..})) if button == b))
+    }
+
+    /// Was the primary button released this frame?
+    pub fn primary_released(&self) -> bool {
+        self.button_released(PointerButton::Primary)
+    }
+
+    /// Was the secondary button released this frame?
+    pub fn secondary_released(&self) -> bool {
+        self.button_released(PointerButton::Secondary)
+    }
+
     /// Is any pointer button currently down?
     pub fn any_down(&self) -> bool {
         self.down.iter().any(|&down| down)
@@ -677,6 +700,23 @@ impl PointerState {
         self.pointer_events.iter().any(|event| event.is_click())
     }
 
+    /// Was the button given clicked this frame?
+    pub fn button_clicked(&self, button: PointerButton) -> bool {
+        self.pointer_events
+            .iter()
+            .any(|event| matches!(event, &PointerEvent::Pressed { button: b, .. } if button == b))
+    }
+
+    /// Was the primary button clicked this frame?
+    pub fn primary_clicked(&self) -> bool {
+        self.button_clicked(PointerButton::Primary)
+    }
+
+    /// Was the secondary button clicked this frame?
+    pub fn secondary_clicked(&self) -> bool {
+        self.button_clicked(PointerButton::Secondary)
+    }
+
     // /// Was this button pressed (`!down -> down`) this frame?
     // /// This can sometimes return `true` even if `any_down() == false`
     // /// because a press can be shorted than one frame.