text_input_v3: Note features supported by the text field

With this information, consumers can realize they will never retrieve some state, and adjust their strategy.

include/wlr/types/wlr_text_input_v3.h

@@ -13,6 +13,12 @@
 #include <wlr/types/wlr_seat.h>
 #include <wlr/types/wlr_surface.h>
 
+enum wlr_text_input_v3_features {
+	WLR_TEXT_INPUT_V3_FEATURE_SURROUNDING_TEXT = 1 << 0,
+	WLR_TEXT_INPUT_v3_FEATURE_CONTENT_TYPE = 1 << 1,
+	WLR_TEXT_INPUT_V3_FEATURE_CURSOR_RECTANGLE = 1 << 2,
+};
+
 struct wlr_text_input_v3_state {
 	struct {
 		char *text; // NULL is allowed and equivalent to empty string
@@ -33,6 +39,10 @@ struct wlr_text_input_v3_state {
 		int32_t width;
 		int32_t height;
 	} cursor_rectangle;
+
+	// Tracks which features were used in the current commit.
+	// Useful in the enabling commit, where usage means support.
+	uint32_t features; // OR'ed wlr_text_input_v3_features
 };
 
 struct wlr_text_input_v3 {
@@ -44,6 +54,8 @@ struct wlr_text_input_v3 {
 	uint32_t current_serial; // next in line to send
 	bool pending_enabled;
 	bool current_enabled;
+	// supported in the current text input, more granular than surface
+	uint32_t active_features; // OR'ed wlr_text_input_v3_features
 
 	struct wl_list link;
 

types/wlr_text_input_v3.c

@@ -121,7 +121,7 @@ static void text_input_set_surrounding_text(struct wl_client *client,
 	if (!text_input->pending.surrounding.text) {
 		wl_client_post_no_memory(client);
 	}
-
+	text_input->pending.features |= WLR_TEXT_INPUT_V3_FEATURE_SURROUNDING_TEXT;
 	text_input->pending.surrounding.cursor = cursor;
 	text_input->pending.surrounding.anchor = anchor;
 }
@@ -141,6 +141,7 @@ static void text_input_set_content_type(struct wl_client *client,
 	if (!text_input) {
 		return;
 	}
+	text_input->pending.features |= WLR_TEXT_INPUT_v3_FEATURE_CONTENT_TYPE;
 	text_input->pending.content_type.hint = hint;
 	text_input->pending.content_type.purpose = purpose;
 }
@@ -152,6 +153,7 @@ static void text_input_set_cursor_rectangle(struct wl_client *client,
 	if (!text_input) {
 		return;
 	}
+	text_input->pending.features |= WLR_TEXT_INPUT_V3_FEATURE_CURSOR_RECTANGLE;
 	text_input->pending.cursor_rectangle.x = x;
 	text_input->pending.cursor_rectangle.y = y;
 	text_input->pending.cursor_rectangle.width = width;
@@ -180,8 +182,10 @@ static void text_input_commit(struct wl_client *client,
 	}
 
 	if (!old_enabled && text_input->current_enabled) {
+		text_input->active_features	= text_input->current.features;
 		wlr_signal_emit_safe(&text_input->events.enable, text_input);
 	} else if (old_enabled && !text_input->current_enabled) {
+		text_input->active_features	= 0;
 		wlr_signal_emit_safe(&text_input->events.disable, text_input);
 	} else { // including never enabled
 		wlr_signal_emit_safe(&text_input->events.commit, text_input);