Merge pull request #1203 from dcz-purism/input

Support input method and text input

1 files changed, 394 insertions, 0 deletions

diff --git a/examples/text-input.c b/examples/text-input.c
new file mode 100644
index 00000000..3ccd99a0
--- /dev/null
+++ b/examples/text-input.c
@@ -0,0 +1,394 @@
+#define _POSIX_C_SOURCE 200809L
+#include <GLES2/gl2.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <wayland-client.h>
+#include <wayland-egl.h>
+#include <wlr/render/egl.h>
+#include "text-input-unstable-v3-client-protocol.h"
+#include "xdg-shell-client-protocol.h"
+
+const char usage[] = "Usage: text-input [seconds [width height]]\n\
+\n\
+Creates a xdg-toplevel using the text-input protocol.\n\
+It will be solid black when it has no text input focus, yellow when it\n\
+has focus, and red when it was notified that the focus moved away\n\
+but still didn't give up the text input ability.\n\
+\n\
+The \"seconds\" argument is optional and defines the delay between getting\n\
+notified of lost focus and releasing text input.\n\
+\n\
+The \"width\" and \"height\" arguments define the window shape.\n\
+\n\
+The console will print the internal state of the text field:\n\
+- the text in the 1st line\n\
+- \".\" under each preedit character\n\
+- \"_\" under each selected preedit character\n\
+- \"|\" at the cursor position if there are no selected characters in the\n\
+preedit.\n\
+\n\
+The cursor positions may be inaccurate, especially in presence of zero-width\n\
+characters or non-monospaced fonts.\n";
+
+struct text_input_state {
+	char *commit;
+	struct {
+		char *text;
+		int32_t cursor_begin;
+		int32_t cursor_end;
+	} preedit;
+	struct {
+		uint32_t after_length;
+		uint32_t before_length;
+	} delete_surrounding;
+};
+
+static struct text_input_state pending = {0};
+static struct text_input_state current = {0};
+static bool entered = false;
+static uint32_t serial;
+static char *buffer; // text buffer
+// cursor is not present, there's no way to move it outside of preedit
+
+static int sleeptime = 0;
+static int width = 100, height = 200;
+static int enabled = 0;
+
+static struct wl_display *display = NULL;
+static struct wl_compositor *compositor = NULL;
+static struct wl_seat *seat = NULL;
+static struct xdg_wm_base *wm_base = NULL;
+static struct zwp_text_input_manager_v3 *text_input_manager = NULL;
+static struct zwp_text_input_v3 *text_input	= NULL;
+
+struct wlr_egl egl;
+struct wl_egl_window *egl_window;
+struct wlr_egl_surface *egl_surface;
+
+static void draw(void) {
+	eglMakeCurrent(egl.display, egl_surface, egl_surface, egl.context);
+
+	float color[] = {1.0, 1.0, 0.0, 1.0};
+	color[0] = enabled * 1.0;
+	color[1] = entered * 1.0;
+
+	glViewport(0, 0, width, height);
+	glClearColor(color[0], color[1], color[2], 1.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	eglSwapBuffers(egl.display, egl_surface);
+}
+
+static size_t utf8_strlen(char *str) {
+	size_t cp_count = 0;
+	for (; *str != '\0'; str++) {
+		if ((*str & 0xc0) != 0x80) {
+			cp_count++;
+		}
+	}
+	return cp_count;
+}
+
+static size_t utf8_offset(char *utf8_str, size_t byte_offset) {
+	size_t cp_count = 0;
+	for (char *c = utf8_str; c < utf8_str + byte_offset; c++) {
+		if ((*c & 0xc0) != 0x80) {
+			cp_count++;
+		}
+	}
+	return cp_count;
+}
+
+// TODO: would be nicer to have this text display inside the window
+static void show_status() {
+	printf("State %d:", serial);
+	if (!enabled) {
+		printf(" disabled");
+	}
+
+	char *preedit_text = current.preedit.text;
+	if (!preedit_text) {
+		preedit_text = "";
+	}
+
+	printf("\n");
+	printf("%s", buffer);
+	printf("%s\n", preedit_text);
+
+	// Positioning of the cursor requires UTF8 offsets to match monospaced
+	// glyphs
+	for (unsigned i = 0; i < utf8_strlen(buffer); i++) {
+		printf(" ");
+	}
+	char *cursor_mark = calloc(utf8_strlen(preedit_text) + 2, sizeof(char));
+	for (unsigned i = 0; i < utf8_strlen(preedit_text); i++) {
+		cursor_mark[i] = '.';
+	}
+	if (current.preedit.cursor_begin == -1
+			&& current.preedit.cursor_end == -1) {
+		goto end;
+	}
+	if (current.preedit.cursor_begin == -1
+			|| current.preedit.cursor_end == -1) {
+		printf("Only one cursor side is defined: %d to %d\n",
+			current.preedit.cursor_begin, current.preedit.cursor_end);
+		goto end;
+	}
+
+	if ((unsigned)current.preedit.cursor_begin > strlen(preedit_text)
+			|| (unsigned)current.preedit.cursor_begin > strlen(preedit_text)) {
+		printf("Cursor out of bounds\n");
+		goto end;
+	}
+
+	if (current.preedit.cursor_begin == current.preedit.cursor_end) {
+		cursor_mark[utf8_offset(preedit_text, current.preedit.cursor_begin)]
+			= '|';
+		goto print;
+	}
+
+	if (current.preedit.cursor_begin > current.preedit.cursor_end) {
+		printf("End cursor is before start cursor\n");
+		goto end;
+	}
+
+	// negative offsets already checked before
+	for (unsigned i = utf8_offset(preedit_text, current.preedit.cursor_begin);
+			i < utf8_offset(preedit_text, current.preedit.cursor_end); i++) {
+		cursor_mark[i] = '_';
+	}
+print:
+	printf("%s\n", cursor_mark);
+end:
+	free(cursor_mark);
+}
+
+static void commit(struct zwp_text_input_v3 *text_input) {
+	zwp_text_input_v3_commit(text_input);
+	serial++;
+}
+
+static void send_status_update(struct zwp_text_input_v3 *text_input) {
+	zwp_text_input_v3_set_surrounding_text(text_input, buffer, strlen(buffer), strlen(buffer));
+	zwp_text_input_v3_set_text_change_cause(text_input, ZWP_TEXT_INPUT_V3_CHANGE_CAUSE_INPUT_METHOD);
+	commit(text_input);
+}
+
+static void text_input_handle_enter(void *data,
+		struct zwp_text_input_v3 *zwp_text_input_v3,
+		struct wl_surface *surface) {
+	entered = true;
+	zwp_text_input_v3_enable(zwp_text_input_v3);
+	commit(zwp_text_input_v3);
+	enabled = true;
+	draw();
+	show_status();
+}
+
+static void text_input_handle_leave(void *data,
+		struct zwp_text_input_v3 *zwp_text_input_v3,
+		struct wl_surface *surface) {
+	entered = false;
+	draw();
+	wl_display_roundtrip(display);
+	sleep(sleeptime);
+	zwp_text_input_v3_disable(zwp_text_input_v3);
+	commit(zwp_text_input_v3);
+	enabled = false;
+	draw();
+	show_status();
+}
+
+static void text_input_commit_string(void *data,
+		struct zwp_text_input_v3 *zwp_text_input_v3,
+		const char *text) {
+	free(pending.commit);
+	pending.commit = strdup(text);
+}
+
+static void text_input_delete_surrounding_text(void *data,
+		struct zwp_text_input_v3 *zwp_text_input_v3,
+		uint32_t before_length, uint32_t after_length) {
+	pending.delete_surrounding.before_length = before_length;
+	pending.delete_surrounding.after_length = after_length;
+}
+
+static void text_input_preedit_string(void *data,
+		struct zwp_text_input_v3 *zwp_text_input_v3,
+		const char *text, int32_t cursor_begin, int32_t cursor_end) {
+	free(pending.preedit.text);
+	pending.preedit.text = strdup(text);
+	pending.preedit.cursor_begin = cursor_begin;
+	pending.preedit.cursor_end = cursor_end;
+}
+
+static void text_input_handle_done(void *data,
+		 struct zwp_text_input_v3 *zwp_text_input_v3,
+		 uint32_t incoming_serial) {
+	if (serial != incoming_serial) {
+		fprintf(stderr, "Received serial %d while expecting %d\n", incoming_serial, serial);
+		return;
+	}
+	free(current.preedit.text);
+	free(current.commit);
+	current = pending;
+	struct text_input_state empty = {0};
+	pending = empty;
+
+	if (current.delete_surrounding.after_length + current.delete_surrounding.before_length > 0) {
+		// cursor is always after committed text, after_length != 0 will never happen
+		unsigned delete_before = current.delete_surrounding.before_length;
+		if (delete_before > strlen(buffer)) {
+			delete_before = strlen(buffer);
+		}
+		buffer[strlen(buffer) - delete_before] = '\0';
+	}
+
+	char *commit_string = current.commit;
+	if (!commit_string) {
+		commit_string = "";
+	}
+	char *old_buffer = buffer;
+	buffer = calloc(strlen(buffer) + strlen(commit_string) + 1, sizeof(char)); // realloc may fail anyway
+	strcpy(buffer, old_buffer);
+	free(old_buffer);
+	strcat(buffer, commit_string);
+
+	send_status_update(zwp_text_input_v3);
+	show_status();
+}
+
+static const struct zwp_text_input_v3_listener text_input_listener = {
+	.enter = text_input_handle_enter,
+	.leave = text_input_handle_leave,
+	.commit_string = text_input_commit_string,
+	.delete_surrounding_text = text_input_delete_surrounding_text,
+	.preedit_string = text_input_preedit_string,
+	.done = text_input_handle_done,
+};
+
+static void xdg_surface_handle_configure(void *data,
+		struct xdg_surface *xdg_surface, uint32_t serial) {
+	xdg_surface_ack_configure(xdg_surface, serial);
+	wl_egl_window_resize(egl_window, width, height, 0, 0);
+	draw();
+}
+
+static const struct xdg_surface_listener xdg_surface_listener = {
+	.configure = xdg_surface_handle_configure,
+};
+
+static void xdg_toplevel_handle_configure(void *data,
+		struct xdg_toplevel *xdg_toplevel, int32_t w, int32_t h,
+		struct wl_array *states) {
+	width = w;
+	height = h;
+}
+
+static void xdg_toplevel_handle_close(void *data,
+		struct xdg_toplevel *xdg_toplevel) {
+	exit(EXIT_SUCCESS);
+}
+
+static const struct xdg_toplevel_listener xdg_toplevel_listener = {
+	.configure = xdg_toplevel_handle_configure,
+	.close = xdg_toplevel_handle_close,
+};
+
+static void handle_global(void *data, struct wl_registry *registry,
+		uint32_t name, const char *interface, uint32_t version) {
+	if (strcmp(interface, "wl_compositor") == 0) {
+		compositor = wl_registry_bind(registry, name,
+			&wl_compositor_interface, 1);
+	} else if (strcmp(interface, xdg_wm_base_interface.name) == 0) {
+		wm_base = wl_registry_bind(registry, name, &xdg_wm_base_interface, 1);
+	} else if (strcmp(interface, zwp_text_input_manager_v3_interface.name) == 0) {
+		text_input_manager = wl_registry_bind(registry, name,
+			&zwp_text_input_manager_v3_interface, 1);
+	} else if (strcmp(interface, wl_seat_interface.name) == 0) {
+		seat = wl_registry_bind(registry, name, &wl_seat_interface, version);
+	}
+}
+
+static void handle_global_remove(void *data, struct wl_registry *registry,
+		uint32_t name) {
+	// who cares
+}
+
+static const struct wl_registry_listener registry_listener = {
+	.global = handle_global,
+	.global_remove = handle_global_remove,
+};
+
+int main(int argc, char **argv) {
+	if (argc > 1) {
+		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-h") == 0) {
+			printf(usage);
+			return 0;
+		}
+		sleeptime = atoi(argv[1]);
+		if (argc > 3) {
+			width = atoi(argv[2]);
+			height = atoi(argv[3]);
+		}
+	}
+
+	buffer = calloc(1, sizeof(char));
+
+	display = wl_display_connect(NULL);
+	if (display == NULL) {
+		fprintf(stderr, "Failed to create display\n");
+		return EXIT_FAILURE;
+	}
+
+	struct wl_registry *registry = wl_display_get_registry(display);
+	wl_registry_add_listener(registry, &registry_listener, NULL);
+	wl_display_dispatch(display);
+	wl_display_roundtrip(display);
+
+	if (compositor == NULL) {
+		fprintf(stderr, "wl-compositor not available\n");
+		return EXIT_FAILURE;
+	}
+	if (wm_base == NULL) {
+		fprintf(stderr, "xdg-shell not available\n");
+		return EXIT_FAILURE;
+	}
+	if (text_input_manager == NULL) {
+		fprintf(stderr, "text-input not available\n");
+		return EXIT_FAILURE;
+	}
+
+	text_input = zwp_text_input_manager_v3_get_text_input(text_input_manager, seat);
+
+	zwp_text_input_v3_add_listener(text_input, &text_input_listener, NULL);
+
+
+	wlr_egl_init(&egl, EGL_PLATFORM_WAYLAND_EXT, display, NULL,
+		WL_SHM_FORMAT_ARGB8888);
+
+	struct wl_surface *surface = wl_compositor_create_surface(compositor);
+	struct xdg_surface *xdg_surface =
+		xdg_wm_base_get_xdg_surface(wm_base, surface);
+	struct xdg_toplevel *xdg_toplevel = xdg_surface_get_toplevel(xdg_surface);
+
+	xdg_surface_add_listener(xdg_surface, &xdg_surface_listener, NULL);
+	xdg_toplevel_add_listener(xdg_toplevel, &xdg_toplevel_listener, NULL);
+
+	wl_surface_commit(surface);
+
+	egl_window = wl_egl_window_create(surface, width, height);
+	egl_surface = wlr_egl_create_surface(&egl, egl_window);
+
+	wl_display_roundtrip(display);
+
+	draw();
+
+	while (wl_display_dispatch(display) != -1) {
+		// This space intentionally left blank
+	}
+
+	return EXIT_SUCCESS;
+}