Add primary_selection config option

See: https://github.com/swaywm/sway/issues/4511

Adds a config option 'primary_selection', which explicitly
enables/disables the primary selection clipboard.

This is implemented as a config-option check in 'handle_request_set_primary_selection', which clears
the primary selection if the option is set to 'disabled'.

include/sway/commands.h

@@ -164,6 +164,7 @@ sway_cmd cmd_no_focus;
 sway_cmd cmd_output;
 sway_cmd cmd_permit;
 sway_cmd cmd_popup_during_fullscreen;
+sway_cmd cmd_primary_selection;
 sway_cmd cmd_reject;
 sway_cmd cmd_reload;
 sway_cmd cmd_rename;

include/sway/config.h

@@ -130,6 +130,7 @@ struct input_config_tool {
 	enum sway_tablet_tool_mode mode;
 };
 
+
 /**
  * options for input devices
  */
@@ -468,6 +469,12 @@ enum xwayland_mode {
 	XWAYLAND_MODE_IMMEDIATE,
 };
 
+enum config_primary_selection {
+	PRIMARY_SELECTION_DEFAULT,
+	PRIMARY_SELECTION_DISABLED,
+	PRIMARY_SELECTION_ENABLED,
+};
+
 /**
  * The configuration struct. The result of loading a config file.
  */
@@ -527,6 +534,7 @@ struct sway_config {
 	bool auto_back_and_forth;
 	bool show_marks;
 	enum alignment title_align;
+	enum config_primary_selection primary_selection;
 
 	bool tiling_drag;
 	int tiling_drag_threshold;

sway/commands.c

@@ -81,6 +81,7 @@ static const struct cmd_handler handlers[] = {
 	{ "no_focus", cmd_no_focus },
 	{ "output", cmd_output },
 	{ "popup_during_fullscreen", cmd_popup_during_fullscreen },
+	{ "primary_selection", cmd_primary_selection },
 	{ "seat", cmd_seat },
 	{ "set", cmd_set },
 	{ "show_marks", cmd_show_marks },

sway/commands/primary_selection.c

@@ -0,0 +1,19 @@
+#include <string.h>
+#include <strings.h>
+#include "sway/config.h"
+#include "sway/commands.h"
+#include "util.h"
+
+struct cmd_results *cmd_primary_selection(int argc, char **argv) {
+	struct cmd_results *error = NULL;
+	if ((error = checkarg(argc, "primary_selection", EXPECTED_AT_LEAST, 1))) {
+		return error;
+	}
+
+	if (parse_boolean(argv[0], true)) {
+		config->primary_selection = PRIMARY_SELECTION_ENABLED;
+	} else {
+		config->primary_selection = PRIMARY_SELECTION_DISABLED;
+	}
+	return cmd_results_new(CMD_SUCCESS, NULL);
+}

sway/config.c

@@ -265,6 +265,7 @@ static void config_defaults(struct sway_config *config) {
 	config->title_align = ALIGN_LEFT;
 	config->tiling_drag = true;
 	config->tiling_drag_threshold = 9;
+	config->primary_selection = PRIMARY_SELECTION_DEFAULT;
 
 	config->smart_gaps = SMART_GAPS_OFF;
 	config->gaps_inner = 0;

sway/input/seat.c

@@ -531,7 +531,14 @@ static void handle_request_set_primary_selection(struct wl_listener *listener,
 	struct sway_seat *seat =
 		wl_container_of(listener, seat, request_set_primary_selection);
 	struct wlr_seat_request_set_primary_selection_event *event = data;
-	wlr_seat_set_primary_selection(seat->wlr_seat, event->source, event->serial);
+	struct wlr_primary_selection_source *source;
+
+	if (config->primary_selection == PRIMARY_SELECTION_DISABLED) {
+		source = NULL;
+	} else {
+		source = event->source;
+	}
+	wlr_seat_set_primary_selection(seat->wlr_seat, source, event->serial);
 }
 
 static void collect_focus_iter(struct sway_node *node, void *data) {

sway/meson.build

@@ -83,6 +83,7 @@ sway_sources = files(
 	'commands/nop.c',
 	'commands/output.c',
 	'commands/popup_during_fullscreen.c',
+  'commands/primary_selection.c',
 	'commands/reload.c',
 	'commands/rename.c',
 	'commands/resize.c',

sway/sway.5.scd

@@ -746,6 +746,9 @@ The default colors are:
 	dialog will not be rendered. If _leave_fullscreen_, the view will exit
 	fullscreen mode and the dialog will be rendered.
 
+*primary_selection* enabled|disabled
+	Enable or disable the primary selection clipboard.
+
 *set* $<name> <value>
 	Sets variable $_name_ to _value_. You can use the new variable in the
 	arguments of future commands. When the variable is used, it can be escaped