Report held pointer buttons on every pointer event

Pointer events set button only on press and release, so wsap_term tracked
held buttons itself to tell a drag from a hover.

yasl_pointer_event.buttons now holds a YASL_BUTTON_BIT() mask of the buttons
held after each event. The common input queue tracks it from the DOWN and
UP events it queues, and clears it on INPUT_RESET and on allocation
failure. Wayland also clears it on leave, since the compositor sends leave
during a press only when it takes the pointer and no release follows. X11
and Cocoa keep it, because they deliver motion and the release to the
pressed window after leave.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/tests/common/test_contracts.c b/tests/common/test_contracts.c
index 7c1ab06..654eb1e 100644
--- a/tests/common/test_contracts.c
+++ b/tests/common/test_contracts.c
@@ -143,6 +143,45 @@ static bool native_frame(struct yasl_surface *s, const struct yasl_framebuffer *
     return true;
 }
 
+static uint32_t push_buttons(struct input_queue *q, enum yasl_event_type type,
+                             enum yasl_pointer_button button)
+{
+    struct yasl_event ev = {.type = type, .pointer.button = button};
+    assert(input_queue_push(q, &ev));
+    assert(input_queue_pop(q, &ev));
+    return ev.pointer.buttons;
+}
+
+static void test_held_buttons(void)
+{
+    const uint32_t primary = YASL_BUTTON_BIT(YASL_BUTTON_PRIMARY);
+    const uint32_t secondary = YASL_BUTTON_BIT(YASL_BUTTON_SECONDARY);
+    struct input_queue q = {0};
+    assert(push_buttons(&q, YASL_EVENT_POINTER_MOTION, 0) == 0);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_DOWN, YASL_BUTTON_PRIMARY) == primary);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_MOTION, 0) == primary);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_DOWN, YASL_BUTTON_SECONDARY) == (primary | secondary));
+    assert(push_buttons(&q, YASL_EVENT_POINTER_UP, YASL_BUTTON_PRIMARY) == secondary);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_SCROLL, 0) == secondary);
+    /* X11 and Cocoa keep the press across leave; the release still follows. */
+    assert(push_buttons(&q, YASL_EVENT_POINTER_LEAVE, 0) == secondary);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_UP, YASL_BUTTON_SECONDARY) == 0);
+    /* A release without a press leaves nothing held. */
+    assert(push_buttons(&q, YASL_EVENT_POINTER_UP, YASL_BUTTON_MIDDLE) == 0);
+
+    assert(push_buttons(&q, YASL_EVENT_POINTER_DOWN, YASL_BUTTON_PRIMARY) == primary);
+    struct yasl_event reset = {.type = YASL_EVENT_INPUT_RESET};
+    assert(input_queue_push(&q, &reset));
+    assert(input_queue_pop(&q, &reset));
+    assert(push_buttons(&q, YASL_EVENT_POINTER_MOTION, 0) == 0);
+
+    q.leave_ends_press = true;
+    assert(push_buttons(&q, YASL_EVENT_POINTER_DOWN, YASL_BUTTON_PRIMARY) == primary);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_LEAVE, 0) == 0);
+    assert(push_buttons(&q, YASL_EVENT_POINTER_MOTION, 0) == 0);
+    input_queue_clear(&q);
+}
+
 static void test_native(void)
 {
     const struct yasl_backend_ops ops = {.display_caps = native_caps,
@@ -332,6 +371,7 @@ int main(void)
     test_timing_clock();
     test_surface_state();
     test_queue();
+    test_held_buttons();
     test_validation();
     test_native();
     test_scale();
diff --git a/tests/common/test_input_alloc.c b/tests/common/test_input_alloc.c
index b999a62..7aba4b2 100644
--- a/tests/common/test_input_alloc.c
+++ b/tests/common/test_input_alloc.c
@@ -46,6 +46,16 @@ int main(void)
         assert(input_queue_pop(&q, &out) && out.type == YASL_EVENT_INPUT_RESET);
         assert(input_queue_pop(&q, &out) && out.key.action == YASL_KEY_RELEASE);
         input_queue_clear(&q);
+
+        /* A lost event clears held buttons along with the stream. */
+        in = (struct yasl_event){.surface = surface, .type = YASL_EVENT_POINTER_DOWN};
+        assert(input_queue_push(&q, &in) && q.buttons);
+        for (size_t i = 1; i < q.capacity; i++) assert(input_queue_push(&q, &in));
+        allocations = 0;
+        assert(!input_queue_push(&q, &in));
+        allocations = -1;
+        assert(!q.buttons);
+        input_queue_clear(&q);
     }
     return 0;
 }