it: test toplevel drag

src/it/tests/t0020_surface_offset.rs

@@ -42,7 +42,8 @@ async fn test(run: Rc<TestRun>) -> Result<(), TestError> {
 
     client.sync().await;
     let enter = enter.next()?;
-    seat.pointer.set_cursor(enter.serial, &surface, 0, 0)?;
+    seat.pointer
+        .set_cursor(enter.serial, Some(&surface), 0, 0)?;
 
     client.compare_screenshot("1", true).await?;
 

src/it/tests/t0037_toplevel_drag.rs

@@ -0,0 +1,44 @@
+use {
+    crate::{
+        ifs::wl_seat::BTN_LEFT,
+        it::{
+            test_error::{TestErrorExt, TestResult},
+            testrun::TestRun,
+        },
+    },
+    std::rc::Rc,
+};
+
+testcase!();
+
+async fn test(run: Rc<TestRun>) -> TestResult {
+    let ds = run.create_default_setup().await?;
+
+    let client = run.create_client().await?;
+    let drag_manager = client.registry.get_drag_manager().await?;
+    let seat = client.get_default_seat().await?;
+    let source = client.data_device_manager.create_data_source()?;
+    let dev = client.data_device_manager.get_data_device(&seat.seat)?;
+    let drag = drag_manager.get_xdg_toplevel_drag(&source)?;
+    let win = client.create_window().await?;
+    win.set_color(255, 255, 0, 255);
+    win.map2().await?;
+
+    let button = seat.pointer.button.expect()?;
+    let click = ds.mouse.click(BTN_LEFT);
+
+    client.sync().await;
+    let serial = button.next().with_context(|| "button")?.serial;
+    seat.pointer.set_cursor(serial, None, 0, 0)?;
+    drag.attach(&win.tl, 100, 100)?;
+    source.set_actions(1)?;
+    dev.start_drag(&source, &win.surface, None, serial)?;
+
+    client.sync().await;
+    client.compare_screenshot("1", true).await?;
+    drop(click);
+    client.sync().await;
+    client.compare_screenshot("2", true).await?;
+
+    Ok(())
+}