ui::testing::TestNativeHost¶

Header: winui/testing/TestNativeHost.hpp.

Derives from ui::NativeHost.

NativeHost test double: tracks one Entry per native child instead of creating native windows.

A NativeControl's lifecycle (create once, move on every changed arrange, hide/show, clip, destroy with the control) is plain state, and this host records it so a test can check it without a window. Hand it to Element::sync_native() or install it with Window::set_native_host(). The host must outlive every control synced against it, since a NativeControl calls destroy() from its destructor.

Example:

ui::NativeControlDesc desc;
desc.class_name = "EDIT";

ui::testing::TestNativeHost host;
{
    ui::NativeControl control{desc, ui::Size{120.0f, 24.0f}};
    control.arrange({10, 10, 120, 24});
    control.sync_native(host);

    const ui::testing::TestNativeHost::Entry* entry = host.find(control.visual_id());
    REQUIRE(entry != nullptr);
    REQUIRE(entry->create_count == 1);
    REQUIRE(entry->bounds == ui::Rect{10, 10, 120, 24});
    REQUIRE(entry->owner == &control);
}
REQUIRE(host.count() == 0); // destroyed along with the control

ensure_created¶

void ensure_created(VisualId id, const NativeControlDesc& desc) override

Creates the entry on the first call for id and stores desc; later calls are no-ops.

set_bounds¶

void set_bounds(VisualId id, const Rect& bounds) override

Records bounds and bumps Entry::move_count.

set_visible¶

void set_visible(VisualId id, bool visible) override

Records visible and bumps Entry::visible_count; ignored for an id with no entry.

set_clip¶

void set_clip(VisualId id, const std::optional<Rect>& visible) override

Records the visible region (nullopt: unclipped) and bumps Entry::clip_count.

destroy¶

void destroy(VisualId id) override

Erases the entry, so find() returns null and count() drops.

~TestNativeHost¶

~TestNativeHost() override

Tells every control still registered that its host is gone, as the real host does when its window is closed under a tree that lives on.

set_owner¶

void set_owner(VisualId id, NativeControl* owner) override

Records owner on the entry for id.

native_handle¶

NativeHandle native_handle(VisualId) const override

Always null: no real handle exists headlessly.

find¶

const Entry* find(VisualId id) const

The entry for id, or null if it was never touched or has been destroyed. The pointer is invalidated by the next call that adds or erases an entry.

count¶

std::size_t count() const

Number of live entries (native children created or touched and not yet destroyed).

struct Entry¶

Everything recorded about one native child, keyed by its VisualId.