7 files changed, 45 insertions, 0 deletions

diff --git a/include/sway/commands.h b/include/sway/commands.h
index dda0606a..32d6cefd 100644
--- a/include/sway/commands.h
+++ b/include/sway/commands.h
@@ -207,6 +207,7 @@ sway_cmd input_cmd_natural_scroll;
 sway_cmd input_cmd_pointer_accel;
 sway_cmd input_cmd_repeat_delay;
 sway_cmd input_cmd_repeat_rate;
+sway_cmd input_cmd_scroll_button;
 sway_cmd input_cmd_scroll_method;
 sway_cmd input_cmd_tap;
 sway_cmd input_cmd_xkb_layout;
diff --git a/include/sway/config.h b/include/sway/config.h
index 99575274..75acd4f2 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -75,6 +75,7 @@ struct input_config {
         float pointer_accel;
         int repeat_delay;
         int repeat_rate;
+        int scroll_button;
         int scroll_method;
         int send_events;
         int tap;
diff --git a/sway/commands/input.c b/sway/commands/input.c
index 574e1f8c..e7906b0e 100644
--- a/sway/commands/input.c
+++ b/sway/commands/input.c
@@ -20,6 +20,7 @@ static struct cmd_handler input_handlers[] = {
         { "pointer_accel", input_cmd_pointer_accel },
         { "repeat_delay", input_cmd_repeat_delay },
         { "repeat_rate", input_cmd_repeat_rate },
+        { "scroll_button", input_cmd_scroll_button },
         { "scroll_method", input_cmd_scroll_method },
         { "tap", input_cmd_tap },
         { "xkb_layout", input_cmd_xkb_layout },
diff --git a/sway/commands/input/scroll_button.c b/sway/commands/input/scroll_button.c
new file mode 100644
index 00000000..a9d697cf
--- /dev/null
+++ b/sway/commands/input/scroll_button.c
@@ -0,0 +1,31 @@
+#include <string.h>
+#include <strings.h>
+#include "sway/config.h"
+#include "sway/commands.h"
+#include "sway/input/input-manager.h"
+
+struct cmd_results *input_cmd_scroll_button(int argc, char **argv) {
+        struct cmd_results *error = NULL;
+        if ((error = checkarg(argc, "scroll_button", EXPECTED_AT_LEAST, 1))) {
+                return error;
+        }
+        struct input_config *current_input_config =
+                config->handler_context.input_config;
+        if (!current_input_config) {
+                return cmd_results_new(CMD_FAILURE, "scroll_button",
+                        "No input device defined.");
+        }
+        struct input_config *new_config =
+                new_input_config(current_input_config->identifier);
+
+        int scroll_button = atoi(argv[0]);
+        if (scroll_button < 1 || scroll_button > 10) {
+                free_input_config(new_config);
+                return cmd_results_new(CMD_INVALID, "scroll_button",
+                                "Input out of range [1, 10]");
+        }
+        new_config->scroll_button = scroll_button;
+
+        apply_input_config(new_config);
+        return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}
diff --git a/sway/config/input.c b/sway/config/input.c
index 9840df18..62d77cf7 100644
--- a/sway/config/input.c
+++ b/sway/config/input.c
@@ -28,6 +28,7 @@ struct input_config *new_input_config(const char* identifier) {
         input->accel_profile = INT_MIN;
         input->pointer_accel = FLT_MIN;
         input->scroll_method = INT_MIN;
+        input->scroll_button = INT_MIN;
         input->left_handed = INT_MIN;
         input->repeat_delay = INT_MIN;
         input->repeat_rate = INT_MIN;
@@ -70,6 +71,9 @@ void merge_input_config(struct input_config *dst, struct input_config *src) {
         if (src->scroll_method != INT_MIN) {
                 dst->scroll_method = src->scroll_method;
         }
+        if (src->scroll_button != INT_MIN) {
+                dst->scroll_button= src->scroll_button;
+        }
         if (src->send_events != INT_MIN) {
                 dst->send_events = src->send_events;
         }
diff --git a/sway/input/input-manager.c b/sway/input/input-manager.c
index daaf1fb6..b18989d0 100644
--- a/sway/input/input-manager.c
+++ b/sway/input/input-manager.c
@@ -158,6 +158,12 @@ static void input_manager_libinput_config_pointer(
                 libinput_device_config_accel_set_speed(libinput_device,
                         ic->pointer_accel);
         }
+        if (ic->scroll_button != INT_MIN) {
+                wlr_log(WLR_DEBUG, "libinput_config_pointer(%s) scroll_set_button(%d)",
+                        ic->identifier, ic->scroll_button);
+                libinput_device_config_scroll_set_button(libinput_device,
+                        ic->scroll_button);
+        }
         if (ic->scroll_method != INT_MIN) {
                 wlr_log(WLR_DEBUG, "libinput_config_pointer(%s) scroll_set_method(%d)",
                         ic->identifier, ic->scroll_method);
diff --git a/sway/meson.build b/sway/meson.build
index 72192917..6fc78db3 100644
--- a/sway/meson.build
+++ b/sway/meson.build
@@ -118,6 +118,7 @@ sway_sources = files(
         'commands/input/pointer_accel.c',
         'commands/input/repeat_delay.c',
         'commands/input/repeat_rate.c',
+        'commands/input/scroll_button.c',
         'commands/input/scroll_method.c',
         'commands/input/tap.c',
         'commands/input/xkb_layout.c',