hide_cursor: Add an option to hide when typing

Add an option for the `hide_cursor` command to hide the cursor when
typing, i.e. whenever a key is pressed.

include/sway/config.h

@@ -181,6 +181,12 @@ struct seat_attachment_config {
 	// TODO other things are configured here for some reason
 };
 
+enum seat_config_hide_cursor_when_typing {
+	HIDE_WHEN_TYPING_DEFAULT, // the default is currently disabled
+	HIDE_WHEN_TYPING_ENABLE,
+	HIDE_WHEN_TYPING_DISABLE,
+};
+
 enum seat_config_allow_constrain {
 	CONSTRAIN_DEFAULT, // the default is currently enabled
 	CONSTRAIN_ENABLE,
@@ -216,6 +222,7 @@ struct seat_config {
 	int fallback; // -1 means not set
 	list_t *attachments; // list of seat_attachment configs
 	int hide_cursor_timeout;
+	enum seat_config_hide_cursor_when_typing hide_cursor_when_typing;
 	enum seat_config_allow_constrain allow_constrain;
 	enum seat_config_shortcuts_inhibit shortcuts_inhibit;
 	enum seat_keyboard_grouping keyboard_grouping;

include/sway/input/cursor.h

@@ -6,6 +6,7 @@
 #include <wlr/types/wlr_pointer_gestures_v1.h>
 #include <wlr/types/wlr_surface.h>
 #include "sway/input/seat.h"
+#include "config.h"
 
 #define SWAY_CURSOR_PRESSED_BUTTONS_CAP 32
 
@@ -68,6 +69,10 @@ struct sway_cursor {
 
 	struct wl_event_source *hide_source;
 	bool hidden;
+	// This field is just a cache of the field in seat_config in order to avoid
+	// costly seat_config lookups on every keypress. HIDE_WHEN_TYPING_DEFAULT
+	// indicates that there is no cached value.
+	enum seat_config_hide_cursor_when_typing hide_when_typing;
 
 	size_t pressed_button_count;
 };
@@ -94,6 +99,7 @@ void cursor_handle_activity(struct sway_cursor *cursor,
 		struct wlr_input_device *device);
 void cursor_unhide(struct sway_cursor *cursor);
 int cursor_get_timeout(struct sway_cursor *cursor);
+void cursor_notify_key_press(struct sway_cursor *cursor);
 
 void dispatch_cursor_button(struct sway_cursor *cursor,
 	struct wlr_input_device *device, uint32_t time_msec, uint32_t button,

sway/commands/seat/hide_cursor.c

@@ -3,17 +3,25 @@
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/input/seat.h"
+#include "sway/input/cursor.h"
+#include "sway/server.h"
 #include "stringop.h"
+#include "util.h"
 
 struct cmd_results *seat_cmd_hide_cursor(int argc, char **argv) {
 	struct cmd_results *error = NULL;
-	if ((error = checkarg(argc, "hide_cursor", EXPECTED_EQUAL_TO, 1))) {
+	if ((error = checkarg(argc, "hide_cursor", EXPECTED_AT_LEAST, 1))) {
 		return error;
 	}
-	if (!config->handler_context.seat_config) {
+	if ((error = checkarg(argc, "hide_cursor", EXPECTED_AT_MOST, 2))) {
+		return error;
+	}
+	struct seat_config *seat_config = config->handler_context.seat_config;
+	if (!seat_config) {
 		return cmd_results_new(CMD_FAILURE, "No seat defined");
 	}
 
+	if (argc == 1) {
 		char *end;
 		int timeout = strtol(argv[0], &end, 10);
 		if (*end) {
@@ -22,7 +30,21 @@ struct cmd_results *seat_cmd_hide_cursor(int argc, char **argv) {
 		if (timeout < 100 && timeout != 0) {
 			timeout = 100;
 		}
-	config->handler_context.seat_config->hide_cursor_timeout = timeout;
+		seat_config->hide_cursor_timeout = timeout;
+	} else {
+		if (strcmp(argv[0], "when-typing") != 0) {
+			return cmd_results_new(CMD_INVALID,
+				"Expected 'hide_cursor <timeout>|when-typing [enable|disable]'");
+		}
+		seat_config->hide_cursor_when_typing = parse_boolean(argv[1], true) ?
+			HIDE_WHEN_TYPING_ENABLE : HIDE_WHEN_TYPING_DISABLE;
+
+		// Invalidate all the caches for this config
+		struct sway_seat *seat = NULL;
+		wl_list_for_each(seat, &server.input->seats, link) {
+			seat->cursor->hide_when_typing = HIDE_WHEN_TYPING_DEFAULT;
+		}
+	}
 
 	return cmd_results_new(CMD_SUCCESS, NULL);
 }

sway/config/seat.c

@@ -29,6 +29,7 @@ struct seat_config *new_seat_config(const char* name) {
 		return NULL;
 	}
 	seat->hide_cursor_timeout = -1;
+	seat->hide_cursor_when_typing = HIDE_WHEN_TYPING_DEFAULT;
 	seat->allow_constrain = CONSTRAIN_DEFAULT;
 	seat->shortcuts_inhibit = SHORTCUTS_INHIBIT_DEFAULT;
 	seat->keyboard_grouping = KEYBOARD_GROUP_DEFAULT;
@@ -151,6 +152,10 @@ void merge_seat_config(struct seat_config *dest, struct seat_config *source) {
 		dest->hide_cursor_timeout = source->hide_cursor_timeout;
 	}
 
+	if (source->hide_cursor_when_typing != HIDE_WHEN_TYPING_DEFAULT) {
+		dest->hide_cursor_when_typing = source->hide_cursor_when_typing;
+	}
+
 	if (source->allow_constrain != CONSTRAIN_DEFAULT) {
 		dest->allow_constrain = source->allow_constrain;
 	}

sway/input/cursor.c

@@ -253,6 +253,32 @@ int cursor_get_timeout(struct sway_cursor *cursor) {
 	return timeout;
 }
 
+void cursor_notify_key_press(struct sway_cursor *cursor) {
+	if (cursor->hidden) {
+		return;
+	}
+
+	if (cursor->hide_when_typing == HIDE_WHEN_TYPING_DEFAULT) {
+		// No cached value, need to lookup in the seat_config
+		const struct seat_config *seat_config = seat_get_config(cursor->seat);
+		if (!seat_config) {
+			seat_config = seat_get_config_by_name("*");
+			if (!seat_config) {
+				return;
+			}
+		}
+		cursor->hide_when_typing = seat_config->hide_cursor_when_typing;
+		// The default is currently disabled
+		if (cursor->hide_when_typing == HIDE_WHEN_TYPING_DEFAULT) {
+			cursor->hide_when_typing = HIDE_WHEN_TYPING_DISABLE;
+		}
+	}
+
+	if (cursor->hide_when_typing == HIDE_WHEN_TYPING_ENABLE) {
+		cursor_hide(cursor);
+	}
+}
+
 static enum sway_input_idle_source idle_source_from_device(
 		struct wlr_input_device *device) {
 	switch (device->type) {

sway/input/keyboard.c

@@ -13,6 +13,7 @@
 #include "sway/input/input-manager.h"
 #include "sway/input/keyboard.h"
 #include "sway/input/seat.h"
+#include "sway/input/cursor.h"
 #include "sway/ipc-server.h"
 #include "log.h"
 
@@ -392,6 +393,10 @@ static void handle_key_event(struct sway_keyboard *keyboard,
 		keyboard_shortcuts_inhibitor_get_for_focused_surface(seat);
 	bool shortcuts_inhibited = sway_inhibitor && sway_inhibitor->inhibitor->active;
 
+	if (event->state == WLR_KEY_PRESSED) {
+		cursor_notify_key_press(seat->cursor);
+	}
+
 	// Identify new keycode, raw keysym(s), and translated keysym(s)
 	struct key_info keyinfo;
 	update_keyboard_state(keyboard, event->keycode, event->state, &keyinfo);

sway/sway-input.5.scd

@@ -229,11 +229,16 @@ correct seat.
 	Set this seat as the fallback seat. A fallback seat will attach any device
 	not explicitly attached to another seat (similar to a "default" seat).
 
-*seat* <name> hide_cursor <timeout>
-	Hides the cursor image after the specified _timeout_ (in milliseconds)
-	has elapsed with no activity on that cursor. A timeout of 0 (default)
-	disables hiding the cursor. The minimal timeout is 100 and any value less
-	than that (aside from 0), will be increased to 100.
+*seat* <name> hide_cursor <timeout>|when-typing [enable|disable]
+	Hides the cursor image after the specified event occured.
+
+	If _timeout_ is specified, then the cursor will be hidden after _timeout_
+	(in milliseconds) has elapsed with no activity on the cursor. A timeout of 0
+	(default) disables hiding the cursor. The minimal timeout is 100 and any
+	value less than that (aside from 0), will be increased to 100.
+
+	If _when-typing_ is enabled, then the cursor will be hidden whenever a key
+	is pressed.
 
 *seat* <name> idle_inhibit <sources...>
 	Sets the set of input event sources which can prevent the seat from