touchpad: don't allow gestures with a clickpad button down by a finger

Allowing gestures when holding a physical click enables tasks like
switching workspaces while dragging an icon, but this should only be
possible with a *thumb* holding down the clickpad, not fingers. This
commit restores the ability to hold down the clickpad with two or three
fingers to right- or middle-drag.

Fixes #339, #340

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

2 files changed, 101 insertions, 2 deletions

diff --git a/src/evdev-mt-touchpad-gestures.c b/src/evdev-mt-touchpad-gestures.c
index 4a0287c7..fed25c90 100644
--- a/src/evdev-mt-touchpad-gestures.c
+++ b/src/evdev-mt-touchpad-gestures.c
@@ -717,8 +717,13 @@ tp_gesture_post_events(struct tp_dispatch *tp, uint64_t time)
 	if (tp->gesture.finger_count == 0)
 		return;
 
-	/* When tap-and-dragging, force 1fg mode. */
-	if (tp_tap_dragging(tp)) {
+	/* When tap-and-dragging, force 1fg mode. On clickpads, if the
+	 * physical button is down, don't allow gestures unless the button
+	 * is held down by a *thumb*, specifically.
+	 */
+	if (tp_tap_dragging(tp) ||
+	    (tp->buttons.is_clickpad && tp->buttons.state &&
+	     tp->thumb.state == THUMB_STATE_FINGER)) {
 		tp_gesture_cancel(tp, time);
 		tp->gesture.finger_count = 1;
 		tp->gesture.finger_count_pending = 0;
diff --git a/test/test-touchpad-buttons.c b/test/test-touchpad-buttons.c
index 4759b896..907d12bc 100644
--- a/test/test-touchpad-buttons.c
+++ b/test/test-touchpad-buttons.c
@@ -958,6 +958,96 @@ START_TEST(touchpad_clickfinger_appletouch_3fg)
 }
 END_TEST
 
+START_TEST(touchpad_clickfinger_click_drag)
+{
+	struct litest_device *dev = litest_current_device();
+	struct libinput *li = dev->libinput;
+	int nfingers = _i; /* ranged test */
+	unsigned int button;
+	int nslots = libevdev_get_num_slots(dev->evdev);
+
+	litest_enable_clickfinger(dev);
+	litest_drain_events(li);
+
+	litest_touch_down(dev, 0, 40, 50);
+	button = BTN_LEFT;
+
+	if (nfingers > 1) {
+		if (nslots > 1) {
+			litest_touch_down(dev, 1, 50, 50);
+		} else {
+			litest_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, 1);
+		}
+		button = BTN_RIGHT;
+	}
+
+	if (nfingers > 2) {
+		if (nslots > 2) {
+			litest_touch_down(dev, 2, 60, 50);
+		} else {
+			litest_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, 0);
+			litest_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, 1);
+		}
+		button = BTN_MIDDLE;
+	}
+
+	litest_button_click(dev, BTN_LEFT, true);
+
+	libinput_dispatch(li);
+	litest_assert_button_event(li, button,
+				   LIBINPUT_BUTTON_STATE_PRESSED);
+
+	for (int i = 0; i < 20; i++) {
+		litest_push_event_frame(dev);
+		switch (nfingers) {
+		case 3:
+			if (nslots >= nfingers)
+				litest_touch_move(dev, 2, 60, 50 + i);
+			/* fallthrough */
+		case 2:
+			if (nslots >= nfingers)
+				litest_touch_move(dev, 1, 50, 50 + i);
+			/* fallthrough */
+		case 1:
+			litest_touch_move(dev, 0, 40, 50 + i);
+			break;
+		}
+		litest_pop_event_frame(dev);
+		libinput_dispatch(li);
+	}
+
+	litest_assert_only_typed_events(li, LIBINPUT_EVENT_POINTER_MOTION);
+
+	litest_button_click(dev, BTN_LEFT, false);
+	litest_assert_button_event(li, button,
+				   LIBINPUT_BUTTON_STATE_RELEASED);
+
+	if (nfingers > 3) {
+		if (nslots > 3) {
+			litest_touch_up(dev, 2);
+		} else {
+			litest_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, 1);
+			litest_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, 0);
+		}
+	}
+
+	if (nfingers > 2) {
+		if (nslots > 2) {
+			litest_touch_up(dev, 1);
+		} else {
+			litest_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, 0);
+		}
+		button = BTN_MIDDLE;
+	}
+
+	litest_touch_up(dev, 0);
+
+
+	libinput_dispatch(li);
+	litest_assert_empty_queue(li);
+}
+END_TEST
+
 START_TEST(touchpad_btn_left)
 {
 	struct litest_device *dev = litest_current_device();
@@ -2006,6 +2096,8 @@ END_TEST
 
 TEST_COLLECTION(touchpad_buttons)
 {
+	struct range finger_count = {1, 4};
+
 	litest_add("touchpad:button", touchpad_button, LITEST_TOUCHPAD, LITEST_CLICKPAD);
 
 	litest_add("touchpad:clickfinger", touchpad_1fg_clickfinger, LITEST_CLICKPAD, LITEST_ANY);
@@ -2036,6 +2128,8 @@ TEST_COLLECTION(touchpad_buttons)
 	litest_add_for_device("touchpad:clickfinger", touchpad_clickfinger_appletouch_2fg, LITEST_APPLETOUCH);
 	litest_add_for_device("touchpad:clickfinger", touchpad_clickfinger_appletouch_3fg, LITEST_APPLETOUCH);
 
+	litest_add_ranged("touchpad:clickfinger", touchpad_clickfinger_click_drag, LITEST_CLICKPAD, LITEST_ANY, &finger_count);
+
 	litest_add("touchpad:click", touchpad_click_defaults_clickfinger, LITEST_APPLE_CLICKPAD, LITEST_ANY);
 	litest_add("touchpad:click", touchpad_click_defaults_btnarea, LITEST_CLICKPAD, LITEST_APPLE_CLICKPAD);
 	litest_add("touchpad:click", touchpad_click_defaults_none, LITEST_TOUCHPAD, LITEST_CLICKPAD);