1 files changed, 74 insertions, 0 deletions
diff --git a/stockton-input/src/button.rs b/stockton-input/src/button.rs
new file mode 100644
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--- /dev/null
+++ b/stockton-input/src/button.rs
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) Oscar Shrimpton 2020
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+use std::fmt::Debug;
+
+#[derive(Debug, Clone, PartialEq)]
+/// A boolean input, with additional tracking for if it just changed state.
+pub struct Button {
+    /// How many of the mapped inputs are currently pressed.
+    /// This is used so that holding one button, then another, then releasing the first, will keep the button down continuously as expected.
+    inputs_down: u8,
+
+    /// Whether or not the button changed state in the last batch of actions processed
+    /// Note that pushing 2 buttons bound to this action one after the other won't trigger this twice.
+    pub is_hot: bool,
+}
+
+impl Button {
+    pub fn new() -> Self {
+        Button {
+            inputs_down: 0,
+            is_hot: false,
+        }
+    }
+
+    pub fn is_down(&self) -> bool {
+        self.inputs_down > 0
+    }
+    pub fn is_up(&self) -> bool {
+        self.inputs_down == 0
+    }
+
+    pub fn is_just_down(&self) -> bool {
+        self.is_down() && self.is_hot
+    }
+    pub fn is_just_up(&self) -> bool {
+        self.is_up() && self.is_hot
+    }
+
+    pub fn modify_inputs(&mut self, add: bool) {
+        self.inputs_down = if add {
+            self.inputs_down + 1
+        } else {
+            self.inputs_down - 1
+        };
+
+        if self.inputs_down == 1 || self.inputs_down == 0 {
+            self.is_hot = true;
+        }
+    }
+
+    pub fn set_not_hot(&mut self) {
+        self.is_hot = false;
+    }
+}
+
+impl Default for Button {
+    fn default() -> Self {
+        Self::new()
+    }
+}