ui: add helpers for virtio-multitouch events

Add helpers for generating Multi-touch events from the UI backends that
can be sent to the guest through a virtio-multitouch device.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230526112925.38794-6-slp@redhat.com>

include/ui/input.h

@@ -64,6 +64,11 @@ int qemu_input_scale_axis(int value,
 void qemu_input_queue_rel(QemuConsole *src, InputAxis axis, int value);
 void qemu_input_queue_abs(QemuConsole *src, InputAxis axis, int value,
                           int min_in, int max_in);
+void qemu_input_queue_mtt(QemuConsole *src, InputMultiTouchType type, int slot,
+                          int tracking_id);
+void qemu_input_queue_mtt_abs(QemuConsole *src, InputAxis axis, int value,
+                              int min_in, int max_in,
+                              int slot, int tracking_id);
 
 void qemu_input_check_mode_change(void);
 void qemu_add_mouse_mode_change_notifier(Notifier *notify);

ui/input.c

@@ -547,6 +547,42 @@ void qemu_input_queue_abs(QemuConsole *src, InputAxis axis, int value,
     qemu_input_event_send(src, &evt);
 }
 
+void qemu_input_queue_mtt(QemuConsole *src, InputMultiTouchType type,
+                          int slot, int tracking_id)
+{
+    InputMultiTouchEvent mtt = {
+        .type = type,
+        .slot = slot,
+        .tracking_id = tracking_id,
+    };
+    InputEvent evt = {
+        .type = INPUT_EVENT_KIND_MTT,
+        .u.mtt.data = &mtt,
+    };
+
+    qemu_input_event_send(src, &evt);
+}
+
+void qemu_input_queue_mtt_abs(QemuConsole *src, InputAxis axis, int value,
+                              int min_in, int max_in, int slot, int tracking_id)
+{
+    InputMultiTouchEvent mtt = {
+        .type = INPUT_MULTI_TOUCH_TYPE_DATA,
+        .slot = slot,
+        .tracking_id = tracking_id,
+        .axis = axis,
+        .value = qemu_input_scale_axis(value, min_in, max_in,
+                                       INPUT_EVENT_ABS_MIN,
+                                       INPUT_EVENT_ABS_MAX),
+    };
+    InputEvent evt = {
+        .type = INPUT_EVENT_KIND_MTT,
+        .u.mtt.data = &mtt,
+    };
+
+    qemu_input_event_send(src, &evt);
+}
+
 void qemu_input_check_mode_change(void)
 {
     static int current_is_absolute;