input/tablet: add tool_mode option to set tablet tools as relative input

Closes #4139.

7 files changed, 133 insertions, 6 deletions

diff --git a/sway/commands/input.c b/sway/commands/input.c
index 53db9a16..c9bb8e06 100644
--- a/sway/commands/input.c
+++ b/sway/commands/input.c
@@ -29,6 +29,7 @@ static struct cmd_handler input_handlers[] = {
         { "scroll_method", input_cmd_scroll_method },
         { "tap", input_cmd_tap },
         { "tap_button_map", input_cmd_tap_button_map },
+        { "tool_mode", input_cmd_tool_mode },
         { "xkb_file", input_cmd_xkb_file },
         { "xkb_layout", input_cmd_xkb_layout },
         { "xkb_model", input_cmd_xkb_model },
diff --git a/sway/commands/input/tool_mode.c b/sway/commands/input/tool_mode.c
new file mode 100644
index 00000000..04316857
--- /dev/null
+++ b/sway/commands/input/tool_mode.c
@@ -0,0 +1,73 @@
+#include <strings.h>
+#include "sway/commands.h"
+#include "sway/config.h"
+
+static void set_tool_mode(struct input_config *ic,
+                enum wlr_tablet_tool_type type, enum sway_tablet_tool_mode mode) {
+        for (int i = 0; i < ic->tools->length; i++) {
+                struct input_config_tool *tool = ic->tools->items[i];
+                if (tool->type == type) {
+                        tool->mode = mode;
+                        return;
+                }
+        }
+
+        struct input_config_tool *tool = calloc(1, sizeof(*tool));
+        if (tool) {
+                tool->type = type;
+                tool->mode = mode;
+                list_add(ic->tools, tool);
+        }
+}
+
+struct cmd_results *input_cmd_tool_mode(int argc, char **argv) {
+        struct cmd_results *error;
+        if ((error = checkarg(argc, "tool_mode", EXPECTED_AT_LEAST, 2))) {
+                return error;
+        }
+
+        struct input_config *ic = config->handler_context.input_config;
+        if (!ic) {
+                return cmd_results_new(CMD_FAILURE, "No input device defined.");
+        }
+
+        enum sway_tablet_tool_mode tool_mode;
+        if (!strcasecmp(argv[1], "absolute")) {
+                tool_mode = SWAY_TABLET_TOOL_MODE_ABSOLUTE;
+        } else if (!strcasecmp(argv[1], "relative")) {
+                tool_mode = SWAY_TABLET_TOOL_MODE_RELATIVE;
+        } else {
+                goto invalid_command;
+        }
+
+        if (!strcasecmp(argv[0], "*")) {
+                set_tool_mode(ic, WLR_TABLET_TOOL_TYPE_PEN, tool_mode);
+                set_tool_mode(ic, WLR_TABLET_TOOL_TYPE_ERASER, tool_mode);
+                set_tool_mode(ic, WLR_TABLET_TOOL_TYPE_BRUSH, tool_mode);
+                set_tool_mode(ic, WLR_TABLET_TOOL_TYPE_PENCIL, tool_mode);
+                set_tool_mode(ic, WLR_TABLET_TOOL_TYPE_AIRBRUSH, tool_mode);
+        } else {
+                enum wlr_tablet_tool_type tool_type;
+                if (!strcasecmp(argv[0], "pen")) {
+                        tool_type = WLR_TABLET_TOOL_TYPE_PEN;
+                } else if (!strcasecmp(argv[0], "eraser")) {
+                        tool_type = WLR_TABLET_TOOL_TYPE_ERASER;
+                } else if (!strcasecmp(argv[0], "brush")) {
+                        tool_type = WLR_TABLET_TOOL_TYPE_BRUSH;
+                } else if (!strcasecmp(argv[0], "pencil")) {
+                        tool_type = WLR_TABLET_TOOL_TYPE_PENCIL;
+                } else if (!strcasecmp(argv[0], "airbrush")) {
+                        tool_type = WLR_TABLET_TOOL_TYPE_AIRBRUSH;
+                } else {
+                        goto invalid_command;
+                }
+
+                set_tool_mode(ic, tool_type, tool_mode);
+        }
+
+        return cmd_results_new(CMD_SUCCESS, NULL);
+
+invalid_command:
+        return cmd_results_new(CMD_INVALID,
+                "Expected 'tool_mode <tool> <absolute|relative>'");
+}
diff --git a/sway/config/input.c b/sway/config/input.c
index 2ed9c016..a998e170 100644
--- a/sway/config/input.c
+++ b/sway/config/input.c
@@ -40,6 +40,7 @@ struct input_config *new_input_config(const char* identifier) {
         input->xkb_numlock = INT_MIN;
         input->xkb_capslock = INT_MIN;
         input->xkb_file_is_set = false;
+        input->tools = create_list();
 
         return input;
 }
@@ -153,6 +154,22 @@ void merge_input_config(struct input_config *dst, struct input_config *src) {
                 memcpy(dst->calibration_matrix.matrix, src->calibration_matrix.matrix,
                         sizeof(src->calibration_matrix.matrix));
         }
+        for (int i = 0; i < src->tools->length; i++) {
+                struct input_config_tool *src_tool = src->tools->items[i];
+                for (int j = 0; j < dst->tools->length; j++) {
+                        struct input_config_tool *dst_tool = dst->tools->items[j];
+                        if (src_tool->type == dst_tool->type) {
+                                dst_tool->mode = src_tool->mode;
+                                goto tool_merge_outer;
+                        }
+                }
+
+                struct input_config_tool *dst_tool = malloc(sizeof(*dst_tool));
+                memcpy(dst_tool, src_tool, sizeof(*dst_tool));
+                list_add(dst->tools, dst_tool);
+
+                tool_merge_outer:;
+        }
 }
 
 static bool validate_xkb_merge(struct input_config *dest,
@@ -358,6 +375,7 @@ void free_input_config(struct input_config *ic) {
         free(ic->mapped_from_region);
         free(ic->mapped_to_output);
         free(ic->mapped_to_region);
+        list_free_items_and_destroy(ic->tools);
         free(ic);
 }
 
diff --git a/sway/input/cursor.c b/sway/input/cursor.c
index 61d75b8a..e47410a5 100644
--- a/sway/input/cursor.c
+++ b/sway/input/cursor.c
@@ -567,14 +567,14 @@ static void handle_tablet_tool_position(struct sway_cursor *cursor,
                         ic->mapped_from_region, &x, &y);
         }
 
-        switch (tool->tablet_v2_tool->wlr_tool->type) {
-        case WLR_TABLET_TOOL_TYPE_LENS:
-        case WLR_TABLET_TOOL_TYPE_MOUSE:
-                wlr_cursor_move(cursor->cursor, input_device->wlr_device, dx, dy);
-                break;
-        default:
+        switch (tool->mode) {
+        case SWAY_TABLET_TOOL_MODE_ABSOLUTE:
                 wlr_cursor_warp_absolute(cursor->cursor, input_device->wlr_device,
                         change_x ? x : NAN, change_y ? y : NAN);
+                break;
+        case SWAY_TABLET_TOOL_MODE_RELATIVE:
+                wlr_cursor_move(cursor->cursor, input_device->wlr_device, dx, dy);
+                break;
         }
 
         double sx, sy;
diff --git a/sway/input/tablet.c b/sway/input/tablet.c
index b74347aa..5f81f772 100644
--- a/sway/input/tablet.c
+++ b/sway/input/tablet.c
@@ -140,6 +140,29 @@ void sway_tablet_tool_configure(struct sway_tablet *tablet,
                 return;
         }
 
+        switch (wlr_tool->type) {
+        case WLR_TABLET_TOOL_TYPE_LENS:
+        case WLR_TABLET_TOOL_TYPE_MOUSE:
+                tool->mode = SWAY_TABLET_TOOL_MODE_RELATIVE;
+                break;
+        default:
+                tool->mode = SWAY_TABLET_TOOL_MODE_ABSOLUTE;
+
+                struct input_config *ic = input_device_get_config(
+                        tablet->seat_device->input_device);
+                if (!ic) {
+                        break;
+                }
+
+                for (int i = 0; i < ic->tools->length; i++) {
+                        struct input_config_tool *tool_config = ic->tools->items[i];
+                        if (tool_config->type == wlr_tool->type) {
+                                tool->mode = tool_config->mode;
+                                break;
+                        }
+                }
+        }
+
         tool->seat = tablet->seat_device->sway_seat;
         tool->tablet = tablet;
         tool->tablet_v2_tool =
diff --git a/sway/meson.build b/sway/meson.build
index b65a5211..6e138101 100644
--- a/sway/meson.build
+++ b/sway/meson.build
@@ -168,6 +168,7 @@ sway_sources = files(
         'commands/input/scroll_method.c',
         'commands/input/tap.c',
         'commands/input/tap_button_map.c',
+        'commands/input/tool_mode.c',
         'commands/input/xkb_capslock.c',
         'commands/input/xkb_file.c',
         'commands/input/xkb_layout.c',
diff --git a/sway/sway-input.5.scd b/sway/sway-input.5.scd
index 9ec5eeae..d8180c1c 100644
--- a/sway/sway-input.5.scd
+++ b/sway/sway-input.5.scd
@@ -94,6 +94,17 @@ The following commands may only be used in the configuration file.
 *input* <identifier> xkb_numlock enabled|disabled
         Initially enables or disables NumLock on startup, the default is disabled.
 
+## TABLET CONFIGURATION
+
+*input* <identifier> tool_mode <tool> <absolute|relative>
+        Sets whether movement of a tablet tool should be treated as absolute or
+        relative; the default is absolute.
+
+        Valid values for _\<tool\>_ are currently "pen", "eraser", "brush",
+        "pencil", "airbrush", and the wildcard _\*_, which matches all tools.
+
+        Mouse and lens tools ignore this setting and are always treated as relative.
+
 ## MAPPING CONFIGURATION
 
 *input* <identifier> map_to_output <identifier>