2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009-2013 Michael Stapelberg and contributors (see also: LICENSE)
16 #include <cairo/cairo-xcb.h>
17 #include <pango/pangocairo.h>
22 extern xcb_connection_t *conn;
23 extern xcb_screen_t *root_screen;
25 static const i3Font *savedFont = NULL;
28 static xcb_visualtype_t *root_visual_type;
29 static double pango_font_red;
30 static double pango_font_green;
31 static double pango_font_blue;
33 /* Necessary to track whether the dpi changes and trigger a LOG() message,
34 * which is more easily visible to users. */
35 static double logged_dpi = 0.0;
37 static PangoLayout *create_layout_with_dpi(cairo_t *cr) {
39 PangoContext *context;
41 context = pango_cairo_create_context(cr);
42 const double dpi = (double)root_screen->height_in_pixels * 25.4 /
43 (double)root_screen->height_in_millimeters;
44 if (logged_dpi != dpi) {
46 LOG("X11 root window dictates %f DPI\n", dpi);
48 DLOG("X11 root window dictates %f DPI\n", dpi);
50 pango_cairo_context_set_resolution(context, dpi);
51 layout = pango_layout_new(context);
52 g_object_unref(context);
58 * Loads a Pango font description into an i3Font structure. Returns true
59 * on success, false otherwise.
62 static bool load_pango_font(i3Font *font, const char *desc) {
63 /* Load the font description */
64 font->specific.pango_desc = pango_font_description_from_string(desc);
65 if (!font->specific.pango_desc) {
66 ELOG("Could not open font %s with Pango, fallback to X font.\n", desc);
70 LOG("Using Pango font %s, size %d\n",
71 pango_font_description_get_family(font->specific.pango_desc),
72 pango_font_description_get_size(font->specific.pango_desc) / PANGO_SCALE);
74 /* We cache root_visual_type here, since you must call
75 * load_pango_font before any other pango function
76 * that would need root_visual_type */
77 root_visual_type = get_visualtype(root_screen);
79 /* Create a dummy Pango layout to compute the font height */
80 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
81 cairo_t *cr = cairo_create(surface);
82 PangoLayout *layout = create_layout_with_dpi(cr);
83 pango_layout_set_font_description(layout, font->specific.pango_desc);
85 /* Get the font height */
87 pango_layout_get_pixel_size(layout, NULL, &height);
88 font->height = height;
91 g_object_unref(layout);
93 cairo_surface_destroy(surface);
95 /* Set the font type and return successfully */
96 font->type = FONT_TYPE_PANGO;
101 * Draws text using Pango rendering.
104 static void draw_text_pango(const char *text, size_t text_len,
105 xcb_drawable_t drawable, int x, int y, int max_width) {
106 /* Create the Pango layout */
107 /* root_visual_type is cached in load_pango_font */
108 cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
109 root_visual_type, x + max_width, y + savedFont->height);
110 cairo_t *cr = cairo_create(surface);
111 PangoLayout *layout = create_layout_with_dpi(cr);
114 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
115 pango_layout_set_width(layout, max_width * PANGO_SCALE);
116 pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);
117 pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
119 pango_layout_set_text(layout, text, text_len);
122 cairo_set_source_rgb(cr, pango_font_red, pango_font_green, pango_font_blue);
123 pango_cairo_update_layout(cr, layout);
124 pango_layout_get_pixel_size(layout, NULL, &height);
125 cairo_move_to(cr, x, y - (height - savedFont->height));
126 pango_cairo_show_layout(cr, layout);
129 g_object_unref(layout);
131 cairo_surface_destroy(surface);
135 * Calculate the text width using Pango rendering.
138 static int predict_text_width_pango(const char *text, size_t text_len) {
139 /* Create a dummy Pango layout */
140 /* root_visual_type is cached in load_pango_font */
141 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
142 cairo_t *cr = cairo_create(surface);
143 PangoLayout *layout = create_layout_with_dpi(cr);
145 /* Get the font width */
147 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
148 pango_layout_set_text(layout, text, text_len);
149 pango_cairo_update_layout(cr, layout);
150 pango_layout_get_pixel_size(layout, &width, NULL);
153 g_object_unref(layout);
155 cairo_surface_destroy(surface);
162 * Loads a font for usage, also getting its metrics. If fallback is true,
163 * the fonts 'fixed' or '-misc-*' will be loaded instead of exiting.
166 i3Font load_font(const char *pattern, const bool fallback) {
168 font.type = FONT_TYPE_NONE;
170 /* No XCB connction, return early because we're just validating the
171 * configuration file. */
177 /* Try to load a pango font if specified */
178 if (strlen(pattern) > strlen("pango:") && !strncmp(pattern, "pango:", strlen("pango:"))) {
179 const char *font_pattern = pattern + strlen("pango:");
180 if (load_pango_font(&font, font_pattern)) {
181 font.pattern = sstrdup(pattern);
184 } else if (strlen(pattern) > strlen("xft:") && !strncmp(pattern, "xft:", strlen("xft:"))) {
185 const char *font_pattern = pattern + strlen("xft:");
186 if (load_pango_font(&font, font_pattern)) {
187 font.pattern = sstrdup(pattern);
193 /* Send all our requests first */
194 font.specific.xcb.id = xcb_generate_id(conn);
195 xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
196 strlen(pattern), pattern);
197 xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.specific.xcb.id);
199 /* Check for errors. If errors, fall back to default font. */
200 xcb_generic_error_t *error;
201 error = xcb_request_check(conn, font_cookie);
203 /* If we fail to open font, fall back to 'fixed' */
204 if (fallback && error != NULL) {
205 ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
206 pattern, error->error_code);
208 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
209 strlen(pattern), pattern);
210 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
212 /* Check if we managed to open 'fixed' */
213 error = xcb_request_check(conn, font_cookie);
215 /* Fall back to '-misc-*' if opening 'fixed' fails. */
217 ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
219 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
220 strlen(pattern), pattern);
221 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
223 if ((error = xcb_request_check(conn, font_cookie)) != NULL)
224 errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
225 "(fixed or -misc-*): X11 error %d",
230 font.pattern = sstrdup(pattern);
231 LOG("Using X font %s\n", pattern);
233 /* Get information (height/name) for this font */
234 if (!(font.specific.xcb.info = xcb_query_font_reply(conn, info_cookie, NULL)))
235 errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
237 /* Get the font table, if possible */
238 if (xcb_query_font_char_infos_length(font.specific.xcb.info) == 0)
239 font.specific.xcb.table = NULL;
241 font.specific.xcb.table = xcb_query_font_char_infos(font.specific.xcb.info);
243 /* Calculate the font height */
244 font.height = font.specific.xcb.info->font_ascent + font.specific.xcb.info->font_descent;
246 /* Set the font type and return successfully */
247 font.type = FONT_TYPE_XCB;
252 * Defines the font to be used for the forthcoming calls.
255 void set_font(i3Font *font) {
260 * Frees the resources taken by the current font.
263 void free_font(void) {
264 free(savedFont->pattern);
265 switch (savedFont->type) {
269 case FONT_TYPE_XCB: {
270 /* Close the font and free the info */
271 xcb_close_font(conn, savedFont->specific.xcb.id);
272 if (savedFont->specific.xcb.info)
273 free(savedFont->specific.xcb.info);
277 case FONT_TYPE_PANGO:
278 /* Free the font description */
279 pango_font_description_free(savedFont->specific.pango_desc);
289 * Defines the colors to be used for the forthcoming draw_text calls.
292 void set_font_colors(xcb_gcontext_t gc, uint32_t foreground, uint32_t background) {
293 assert(savedFont != NULL);
295 switch (savedFont->type) {
299 case FONT_TYPE_XCB: {
300 /* Change the font and colors in the GC */
301 uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
302 uint32_t values[] = {foreground, background, savedFont->specific.xcb.id};
303 xcb_change_gc(conn, gc, mask, values);
307 case FONT_TYPE_PANGO:
308 /* Save the foreground font */
309 pango_font_red = ((foreground >> 16) & 0xff) / 255.0;
310 pango_font_green = ((foreground >> 8) & 0xff) / 255.0;
311 pango_font_blue = (foreground & 0xff) / 255.0;
320 static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
322 static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,
323 xcb_gcontext_t gc, int x, int y, int max_width) {
324 /* X11 coordinates for fonts start at the baseline */
325 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
327 /* The X11 protocol limits text drawing to 255 chars, so we may need
331 /* Calculate the size of this chunk */
332 int chunk_size = (text_len > 255 ? 255 : text_len);
333 const xcb_char2b_t *chunk = text + offset;
336 xcb_image_text_16(conn, chunk_size, drawable, gc, x, pos_y, chunk);
338 /* Advance the offset and length of the text to draw */
339 offset += chunk_size;
340 text_len -= chunk_size;
342 /* Check if we're done */
346 /* Advance pos_x based on the predicted text width */
347 x += predict_text_width_xcb(chunk, chunk_size);
352 * Draws text onto the specified X drawable (normally a pixmap) at the
353 * specified coordinates (from the top left corner of the leftmost, uppermost
354 * glyph) and using the provided gc.
356 * Text must be specified as an i3String.
359 void draw_text(i3String *text, xcb_drawable_t drawable,
360 xcb_gcontext_t gc, int x, int y, int max_width) {
361 assert(savedFont != NULL);
363 switch (savedFont->type) {
368 draw_text_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text),
369 drawable, gc, x, y, max_width);
372 case FONT_TYPE_PANGO:
373 /* Render the text using Pango */
374 draw_text_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
375 drawable, x, y, max_width);
384 * ASCII version of draw_text to print static strings.
387 void draw_text_ascii(const char *text, xcb_drawable_t drawable,
388 xcb_gcontext_t gc, int x, int y, int max_width) {
389 assert(savedFont != NULL);
391 switch (savedFont->type) {
395 case FONT_TYPE_XCB: {
396 size_t text_len = strlen(text);
397 if (text_len > 255) {
398 /* The text is too long to draw it directly to X */
399 i3String *str = i3string_from_utf8(text);
400 draw_text(str, drawable, gc, x, y, max_width);
403 /* X11 coordinates for fonts start at the baseline */
404 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
406 xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
411 case FONT_TYPE_PANGO:
412 /* Render the text using Pango */
413 draw_text_pango(text, strlen(text),
414 drawable, x, y, max_width);
422 static int xcb_query_text_width(const xcb_char2b_t *text, size_t text_len) {
423 /* Make the user know we’re using the slow path, but only once. */
424 static bool first_invocation = true;
425 if (first_invocation) {
426 fprintf(stderr, "Using slow code path for text extents\n");
427 first_invocation = false;
430 /* Query the text width */
431 xcb_generic_error_t *error;
432 xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
433 savedFont->specific.xcb.id, text_len, (xcb_char2b_t *)text);
434 xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
437 /* We return a safe estimate because a rendering error is better than
438 * a crash. Plus, the user will see the error in his log. */
439 fprintf(stderr, "Could not get text extents (X error code %d)\n",
441 return savedFont->specific.xcb.info->max_bounds.character_width * text_len;
444 int width = reply->overall_width;
449 static int predict_text_width_xcb(const xcb_char2b_t *input, size_t text_len) {
454 if (savedFont->specific.xcb.table == NULL) {
455 /* If we don't have a font table, fall back to querying the server */
456 width = xcb_query_text_width(input, text_len);
458 /* Save some pointers for convenience */
459 xcb_query_font_reply_t *font_info = savedFont->specific.xcb.info;
460 xcb_charinfo_t *font_table = savedFont->specific.xcb.table;
462 /* Calculate the width using the font table */
464 for (size_t i = 0; i < text_len; i++) {
465 xcb_charinfo_t *info;
466 int row = input[i].byte1;
467 int col = input[i].byte2;
469 if (row < font_info->min_byte1 ||
470 row > font_info->max_byte1 ||
471 col < font_info->min_char_or_byte2 ||
472 col > font_info->max_char_or_byte2)
475 /* Don't you ask me, how this one works… (Merovius) */
476 info = &font_table[((row - font_info->min_byte1) *
477 (font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
478 (col - font_info->min_char_or_byte2)];
480 if (info->character_width != 0 ||
481 (info->right_side_bearing |
482 info->left_side_bearing |
484 info->descent) != 0) {
485 width += info->character_width;
494 * Predict the text width in pixels for the given text. Text must be
495 * specified as an i3String.
498 int predict_text_width(i3String *text) {
499 assert(savedFont != NULL);
501 switch (savedFont->type) {
506 return predict_text_width_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text));
508 case FONT_TYPE_PANGO:
509 /* Calculate extents using Pango */
510 return predict_text_width_pango(i3string_as_utf8(text), i3string_get_num_bytes(text));