core: Add clipboard_content getter

core/src/backend/ui.rs

@@ -15,6 +15,9 @@ pub trait UiBackend {
     /// Changes the mouse cursor image.
     fn set_mouse_cursor(&mut self, cursor: MouseCursor);
 
+    /// Get the clipboard content
+    fn clipboard_content(&mut self) -> String;
+
     /// Sets the clipboard to the given content.
     fn set_clipboard_content(&mut self, content: String);
 
@@ -145,6 +148,10 @@ impl UiBackend for NullUiBackend {
 
     fn set_mouse_cursor(&mut self, _cursor: MouseCursor) {}
 
+    fn clipboard_content(&mut self) -> String {
+        "".to_string()
+    }
+
     fn set_clipboard_content(&mut self, _content: String) {}
 
     fn set_fullscreen(&mut self, _is_full: bool) -> Result<(), FullscreenError> {

desktop/src/ui.rs

@@ -62,6 +62,12 @@ impl UiBackend for DesktopUiBackend {
         self.window.set_cursor_icon(icon);
     }
 
+    fn clipboard_content(&mut self) -> String {
+        self.clipboard
+            .get_text()
+            .unwrap_or_else(|_| "".to_string())
+    }
+
     fn set_clipboard_content(&mut self, content: String) {
         if let Err(e) = self.clipboard.set_text(content) {
             error!("Couldn't set clipboard contents: {:?}", e);

web/src/ui.rs

@@ -65,6 +65,11 @@ impl UiBackend for WebUiBackend {
         self.update_mouse_cursor();
     }
 
+    fn clipboard_content(&mut self) -> String {
+        tracing::warn!("get clipboard not implemented");
+        "".to_string()
+    }
+
     fn set_clipboard_content(&mut self, content: String) {
         // We use `document.execCommand("copy")` as `navigator.clipboard.writeText("string")`
         // is available only in secure contexts (HTTPS).