Add click method libinput option (#1416)

<libinput>
  <device>
    <clickMethod>none|buttonAreas|clickfinger</clickMethod>
  </device>
</libinput>

docs/labwc-config.5.scd

@@ -592,6 +592,7 @@ extending outward from the snapped edge.
     <dragLock></dragLock>
     <middleEmulation></middleEmulation>
     <disableWhileTyping></disableWhileTyping>
+    <clickMethod></clickMethod>
   </device>
 </libinput>
 ```
@@ -667,6 +668,22 @@ extending outward from the snapped edge.
 	any motion events while a keyboard is typing, and for a short while
 	after as well.
 
+*<libinput><device><clickMethod>* [none|buttonAreas|clickfinger]
+	Configure the method by which physical clicks on a touchpad are mapped to
+	mouse-button events.
+
+	The click methods available are:
+	- *buttonAreas* - The bottom of the touchpad is divided into distinct
+	  regions corresponding to left, middle and right buttons; clicking within
+	  the region will trigger the corresponding event. Clicking the main area
+	  further up produces a left button event.
+	- *clickfinger* - Clicking with one, two or three finger(s) will produce
+	  left, right or middle button event without regard to the location of a
+	  click.
+	- *none* - Physical clicks will not produce button events.
+
+	The default method depends on the touchpad hardware.
+
 ## WINDOW RULES
 
 Two types of window rules are supported, actions and properties. They are

docs/rc.xml.all

@@ -465,13 +465,14 @@
     non-touch, default or the name of a device. You can obtain device names by
     running *libinput list-devices* as root or member of the input group.
 
-    Tap is set to *yes* be default. All others are left blank in order to use
+    Tap is set to *yes* by default. All others are left blank in order to use
     device defaults.
 
     All values are [yes|no] except for:
       - pointerSpeed [-1.0 to 1.0]
       - accelProfile [flat|adaptive]
       - tapButtonMap [lrm|lmr]
+      - clickMethod [none|buttonAreas|clickfinger]
   -->
   <libinput>
     <device category="default">
@@ -485,6 +486,7 @@
       <dragLock></dragLock>
       <middleEmulation></middleEmulation>
       <disableWhileTyping></disableWhileTyping>
+      <clickMethod></clickMethod>
     </device>
   </libinput>
 

include/config/libinput.h

@@ -28,6 +28,7 @@ struct libinput_category {
 	int accel_profile; /* -1 or libinput_config_accel_profile */
 	int middle_emu; /* -1 or libinput_config_middle_emulation_state */
 	int dwt; /* -1 or libinput_config_dwt_state */
+	int click_method; /* -1 or libinput_config_click_method */
 };
 
 enum lab_libinput_device_type get_device_type(const char *s);

src/config/libinput.c

@@ -23,6 +23,7 @@ libinput_category_init(struct libinput_category *l)
 	l->accel_profile = -1;
 	l->middle_emu = -1;
 	l->dwt = -1;
+	l->click_method = -1;
 }
 
 enum lab_libinput_device_type

src/config/rcxml.c

@@ -563,6 +563,19 @@ fill_libinput_category(char *nodename, char *content)
 		current_libinput_category->dwt = ret
 			? LIBINPUT_CONFIG_DWT_ENABLED
 			: LIBINPUT_CONFIG_DWT_DISABLED;
+	} else if (!strcasecmp(nodename, "clickMethod")) {
+		if (!strcasecmp(content, "none")) {
+			current_libinput_category->click_method =
+				LIBINPUT_CONFIG_CLICK_METHOD_NONE;
+		} else if (!strcasecmp(content, "clickfinger")) {
+			current_libinput_category->click_method =
+				LIBINPUT_CONFIG_CLICK_METHOD_CLICKFINGER;
+		} else if (!strcasecmp(content, "buttonAreas")) {
+			current_libinput_category->click_method =
+				LIBINPUT_CONFIG_CLICK_METHOD_BUTTON_AREAS;
+		} else {
+			wlr_log(WLR_ERROR, "invalid clickMethod");
+		}
 	}
 }
 

src/seat.c

@@ -189,6 +189,24 @@ configure_libinput(struct wlr_input_device *wlr_input_device)
 		wlr_log(WLR_INFO, "dwt configured");
 		libinput_device_config_dwt_set_enabled(libinput_dev, dc->dwt);
 	}
+	if ((libinput_device_config_click_get_methods(libinput_dev)
+				& dc->click_method) == 0
+			|| dc->click_method < 0) {
+		wlr_log(WLR_INFO, "click method not configured");
+	} else {
+		wlr_log(WLR_INFO, "click method configured");
+
+		/*
+		 * Note, the documentation claims that:
+		 * > [...] The device may require changing to a neutral state
+		 * > first before activating the new method.
+		 *
+		 * However, just setting the method seems to work without
+		 * issues.
+		 */
+
+		libinput_device_config_click_set_method(libinput_dev, dc->click_method);
+	}
 }
 
 static struct wlr_output *