udev: input_id - refactor device detection

This change switches to bools and separates bit flag evaluation from
decision making and application of udev properties, while hopefully
keeping the same semantics. Apart from using BTN_LEFT instead of BTN_MOUSE
for mouse detection.

1 files changed, 72 insertions, 62 deletions

diff --git a/src/udev/udev-builtin-input_id.c b/src/udev/udev-builtin-input_id.c
index 6d06cef07c..91a6141e26 100644
--- a/src/udev/udev-builtin-input_id.c
+++ b/src/udev/udev-builtin-input_id.c
@@ -133,79 +133,89 @@ static bool test_pointers(struct udev_device *dev,
                           const unsigned long* bitmask_rel,
                           const unsigned long* bitmask_props,
                           bool test) {
-        int is_mouse = 0;
-        int is_touchpad = 0;
-        bool ret = false;
-
-        if (test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props)) {
+        bool has_abs_coordinates = false;
+        bool has_rel_coordinates = false;
+        bool has_joystick_axes_or_buttons = false;
+        bool has_touch = false;
+        bool has_3d_coordinates = false;
+        bool has_keys = false;
+        bool stylus_or_pen = false;
+        bool finger_but_no_pen = false;
+        bool has_mouse_button = false;
+        bool is_mouse = false;
+        bool is_touchpad = false;
+        bool is_touchscreen = false;
+        bool is_tablet = false;
+        bool is_joystick = false;
+        bool is_accelerometer = false;
+        bool is_pointing_stick= false;
+
+        has_keys = test_bit(EV_KEY, bitmask_ev);
+        has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
+        has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
+        is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
+
+        if (!has_keys && has_3d_coordinates)
+                is_accelerometer = true;
+
+        if (is_accelerometer) {
                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
                 return true;
         }
 
-        if (!test_bit(EV_KEY, bitmask_ev)) {
-                if (test_bit(EV_ABS, bitmask_ev) &&
-                    test_bit(ABS_X, bitmask_abs) &&
-                    test_bit(ABS_Y, bitmask_abs) &&
-                    test_bit(ABS_Z, bitmask_abs)) {
-                        udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
-                        ret = true;
-                }
-                return ret;
-        }
-
-        if (test_bit(EV_ABS, bitmask_ev) &&
-            test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs)) {
-                if (test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key)) {
-                        udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
-                        ret = true;
-                } else if (test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key)) {
-                        is_touchpad = 1;
-                } else if (test_bit(BTN_MOUSE, bitmask_key)) {
+        is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
+        stylus_or_pen = test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key);
+        finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
+        has_mouse_button = test_bit(BTN_LEFT, bitmask_key);
+        has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
+        has_touch = test_bit(BTN_TOUCH, bitmask_key);
+        /* joysticks don't necessarily have buttons; e. g.
+         * rudders/pedals are joystick-like, but buttonless; they have
+         * other fancy axes */
+        has_joystick_axes_or_buttons = test_bit(BTN_TRIGGER, bitmask_key) ||
+                                       test_bit(BTN_A, bitmask_key) ||
+                                       test_bit(BTN_1, bitmask_key) ||
+                                       test_bit(ABS_RX, bitmask_abs) ||
+                                       test_bit(ABS_RY, bitmask_abs) ||
+                                       test_bit(ABS_RZ, bitmask_abs) ||
+                                       test_bit(ABS_THROTTLE, bitmask_abs) ||
+                                       test_bit(ABS_RUDDER, bitmask_abs) ||
+                                       test_bit(ABS_WHEEL, bitmask_abs) ||
+                                       test_bit(ABS_GAS, bitmask_abs) ||
+                                       test_bit(ABS_BRAKE, bitmask_abs);
+
+        if (has_abs_coordinates) {
+                if (stylus_or_pen)
+                        is_tablet = true;
+                else if (finger_but_no_pen)
+                        is_touchpad = true;
+                else if (has_mouse_button)
                         /* This path is taken by VMware's USB mouse, which has
                          * absolute axes, but no touch/pressure button. */
-                        is_mouse = 1;
-                } else if (test_bit(BTN_TOUCH, bitmask_key)) {
-                        udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
-                        ret = true;
-                /* joysticks don't necessarily have to have buttons; e. g.
-                 * rudders/pedals are joystick-like, but buttonless; they have
-                 * other fancy axes */
-                } else if (test_bit(BTN_TRIGGER, bitmask_key) ||
-                           test_bit(BTN_A, bitmask_key) ||
-                           test_bit(BTN_1, bitmask_key) ||
-                           test_bit(ABS_RX, bitmask_abs) ||
-                           test_bit(ABS_RY, bitmask_abs) ||
-                           test_bit(ABS_RZ, bitmask_abs) ||
-                           test_bit(ABS_THROTTLE, bitmask_abs) ||
-                           test_bit(ABS_RUDDER, bitmask_abs) ||
-                           test_bit(ABS_WHEEL, bitmask_abs) ||
-                           test_bit(ABS_GAS, bitmask_abs) ||
-                           test_bit(ABS_BRAKE, bitmask_abs)) {
-                        udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
-                        ret = true;
-                }
-        }
-
-        if (test_bit(INPUT_PROP_POINTING_STICK, bitmask_props)) {
-                udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
-                ret = true;
+                        is_mouse = true;
+                else if (has_touch)
+                        is_touchscreen = true;
+                else if (has_joystick_axes_or_buttons)
+                        is_joystick = true;
         }
 
-        if (test_bit(EV_REL, bitmask_ev) &&
-            test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel) &&
-            test_bit(BTN_MOUSE, bitmask_key))
-                is_mouse = 1;
+        if (has_rel_coordinates && has_mouse_button)
+                is_mouse = true;
 
-        if (is_mouse) {
+        if (is_pointing_stick)
+                udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
+        if (is_mouse)
                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
-                ret = true;
-        }
-        if (is_touchpad) {
+        if (is_touchpad)
                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
-                ret = true;
-        }
-
-        return ret;
+        if (is_touchscreen)
+                udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
+        if (is_joystick)
+                udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
+        if (is_tablet)
+                udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
+
+        return is_tablet || is_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 }
 
 /* key like devices */