X11: Implement putting things into the clipboard

CHANGELOG.md

@@ -46,7 +46,7 @@ You can find its changes [documented below](#070---2021-01-01).
 - X11: Added support for `get_monitors` ([#1804] by [@psychon])
 - x11: Remove some unnecessary casts ([#1851] by [@psychon])
 - `has_focus` method on `WidgetPod` ([#1825] by [@ForLoveOfCats])
-- x11: Add support for getting clipboard contents ([#1805] by [@psychon])
+- x11: Add support for getting and setting clipboard contents ([#1805] and [#1851] by [@psychon])
 - Linux extension: primary_clipboard ([#1843] by [@Maan2003])
 
 ### Changed

druid-shell/src/backend/x11/application.rs

@@ -66,6 +66,8 @@ pub(crate) struct Application {
     /// The X11 resource database used to query dpi.
     pub(crate) rdb: Rc<ResourceDb>,
     pub(crate) cursors: Cursors,
+    /// The clipboard implementation
+    clipboard: Clipboard,
     /// The default screen of the connected display.
     ///
     /// The connected display may also have additional screens.
@@ -211,6 +213,15 @@ impl Application {
             .ok_or_else(|| anyhow!("Couldn't get visual from screen"))?;
         let argb_visual_type = util::get_argb_visual_type(&*connection, &screen)?;
 
+        let timestamp = Rc::new(Cell::new(x11rb::CURRENT_TIME));
+        let pending_events = Default::default();
+        let clipboard = Clipboard::new(
+            Rc::clone(&connection),
+            screen_num,
+            Rc::clone(&pending_events),
+            Rc::clone(&timestamp),
+        )?;
+
         Ok(Application {
             connection,
             rdb,
@@ -219,14 +230,15 @@ impl Application {
             state,
             idle_read,
             cursors,
+            clipboard,
             idle_write,
             present_opcode,
             root_visual_type,
             argb_visual_type,
             pending_events: Default::default(),
             marker: std::marker::PhantomData,
             render_argb32_pictformat_cursor,
-            timestamp: Rc::new(Cell::new(x11rb::CURRENT_TIME)),
+            timestamp,
         })
     }
 
@@ -497,6 +509,21 @@ impl Application {
                 w.handle_idle_notify(ev)
                     .context("IDLE_NOTIFY - failed to handle")?;
             }
+            Event::SelectionClear(ev) => {
+                self.clipboard
+                    .handle_clear(*ev)
+                    .context("SELECTION_CLEAR event handling")?;
+            }
+            Event::SelectionRequest(ev) => {
+                self.clipboard
+                    .handle_request(ev)
+                    .context("SELECTION_REQUEST event handling")?;
+            }
+            Event::PropertyNotify(ev) => {
+                self.clipboard
+                    .handle_property_notify(*ev)
+                    .context("PROPERTY_NOTIFY event handling")?;
+            }
             Event::Error(e) => {
                 // TODO: if an error is caused by the present extension, disable it and fall back
                 // to copying pixels. This is blocked on
@@ -633,12 +660,7 @@ impl Application {
     }
 
     pub fn clipboard(&self) -> Clipboard {
-        Clipboard::new(
-            Rc::clone(&self.connection),
-            self.screen_num,
-            Rc::clone(&self.pending_events),
-            Rc::clone(&self.timestamp),
-        )
+        self.clipboard.clone()
     }
 
     pub fn get_locale() -> String {