it: add frame callback test

src/it/tests/t0048_frame_callback.rs

@@ -0,0 +1,91 @@
+use {
+    crate::it::{test_error::TestResult, testrun::TestRun},
+    std::rc::Rc,
+};
+
+testcase!();
+
+/// Test wl_surface.frame callbacks
+/// This test verifies that the compositor sends wl_callback.done events after the vblank event.
+/// According to the Wayland protocol, frame callbacks should be fired to indicate when
+/// it's a good time to start drawing the next frame, and they should be posted after
+/// the compositor has finished presenting the previous frame (i.e., after vblank).
+async fn test(run: Rc<TestRun>) -> TestResult {
+    run.backend.install_default()?;
+    let client = run.create_client().await?;
+
+    // Create a visible window so frame callbacks can be triggered
+    let window = client.create_window().await?;
+    window.map().await?;
+    client.sync().await;
+
+    // Test 1: Basic frame callback functionality
+    let surface = &window.surface.surface;
+    let callback1 = surface.frame()?;
+    surface.commit()?;
+    client.sync().await;
+
+    // Manually trigger vblank event to simulate frame completion
+    let connector_id = run.backend.default_connector.id;
+
+    // Trigger vblank manually - this processes frame callbacks
+    run.state.vblank(connector_id);
+    client.sync().await;
+
+    // The frame callback should have been fired after vblank
+    tassert!(callback1.done.get());
+
+    // Test 2: Multiple frame callbacks
+    let callback2 = surface.frame()?;
+    let callback3 = surface.frame()?;
+    surface.commit()?;
+    client.sync().await;
+
+    // Before triggering vblank, callbacks should not be done yet
+    tassert!(!callback2.done.get());
+    tassert!(!callback3.done.get());
+
+    // Trigger vblank manually - this processes frame callbacks
+    run.state.vblank(connector_id);
+    client.sync().await;
+
+    // Both callbacks should be done after vblank
+    tassert!(callback2.done.get());
+    tassert!(callback3.done.get());
+
+    // Test 3: Frame callbacks on invisible surface should not be processed
+    // Create a new surface but don't make it visible
+    let invisible_surface = client.comp.create_surface().await?;
+    let buffer = client
+        .spbm
+        .create_buffer(crate::theme::Color::from_srgb(255, 0, 0))?;
+    invisible_surface.attach(buffer.id)?;
+
+    let callback_invisible = invisible_surface.frame()?;
+    invisible_surface.commit()?;
+    client.sync().await;
+
+    // Trigger vblank manually - this processes frame callbacks
+    run.state.vblank(connector_id);
+    client.sync().await;
+
+    // Frame callback on invisible surface should not be processed
+    tassert!(!callback_invisible.done.get());
+
+    // Test 4: Frame callback timing - verify they happen after vblank
+    let callback_timing = surface.frame()?;
+    surface.commit()?;
+    client.sync().await;
+
+    // The callback should not be done immediately after commit
+    tassert!(!callback_timing.done.get());
+
+    // Trigger vblank manually - this processes frame callbacks
+    run.state.vblank(connector_id);
+    client.sync().await;
+
+    // Now it should be done
+    tassert!(callback_timing.done.get());
+
+    Ok(())
+}