Split out new crate egui-winit from egui_glium (#735)

egui-winit/src/clipboard.rs

@@ -0,0 +1,69 @@
+/// Handles interfacing either with the OS clipboard.
+/// If the "clipboard" feature is off it will instead simulate the clipboard locally.
+pub struct Clipboard {
+    #[cfg(feature = "copypasta")]
+    copypasta: Option<copypasta::ClipboardContext>,
+
+    /// Fallback manual clipboard.
+    #[cfg(not(feature = "copypasta"))]
+    clipboard: String,
+}
+
+impl Default for Clipboard {
+    fn default() -> Self {
+        Self {
+            #[cfg(feature = "copypasta")]
+            copypasta: init_copypasta(),
+
+            #[cfg(not(feature = "copypasta"))]
+            clipboard: String::default(),
+        }
+    }
+}
+
+impl Clipboard {
+    pub fn get(&mut self) -> Option<String> {
+        #[cfg(feature = "copypasta")]
+        if let Some(clipboard) = &mut self.copypasta {
+            use copypasta::ClipboardProvider as _;
+            match clipboard.get_contents() {
+                Ok(contents) => Some(contents),
+                Err(err) => {
+                    eprintln!("Paste error: {}", err);
+                    None
+                }
+            }
+        } else {
+            None
+        }
+
+        #[cfg(not(feature = "copypasta"))]
+        Some(self.clipboard.clone())
+    }
+
+    pub fn set(&mut self, text: String) {
+        #[cfg(feature = "copypasta")]
+        if let Some(clipboard) = &mut self.copypasta {
+            use copypasta::ClipboardProvider as _;
+            if let Err(err) = clipboard.set_contents(text) {
+                eprintln!("Copy/Cut error: {}", err);
+            }
+        }
+
+        #[cfg(not(feature = "copypasta"))]
+        {
+            self.clipboard = text;
+        }
+    }
+}
+
+#[cfg(feature = "copypasta")]
+fn init_copypasta() -> Option<copypasta::ClipboardContext> {
+    match copypasta::ClipboardContext::new() {
+        Ok(clipboard) => Some(clipboard),
+        Err(err) => {
+            eprintln!("Failed to initialize clipboard: {}", err);
+            None
+        }
+    }
+}