2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
15 #include <cairo/cairo-xcb.h>
17 #include <pango/pangocairo.h>
22 static const i3Font *savedFont = NULL;
25 static xcb_visualtype_t *root_visual_type;
26 static double pango_font_red;
27 static double pango_font_green;
28 static double pango_font_blue;
30 /* Necessary to track whether the dpi changes and trigger a LOG() message,
31 * which is more easily visible to users. */
32 static double logged_dpi = 0.0;
34 static PangoLayout *create_layout_with_dpi(cairo_t *cr) {
36 PangoContext *context;
38 context = pango_cairo_create_context(cr);
39 const double dpi = (double)root_screen->height_in_pixels * 25.4 /
40 (double)root_screen->height_in_millimeters;
41 if (logged_dpi != dpi) {
43 LOG("X11 root window dictates %f DPI\n", dpi);
45 DLOG("X11 root window dictates %f DPI\n", dpi);
47 pango_cairo_context_set_resolution(context, dpi);
48 layout = pango_layout_new(context);
49 g_object_unref(context);
55 * Loads a Pango font description into an i3Font structure. Returns true
56 * on success, false otherwise.
59 static bool load_pango_font(i3Font *font, const char *desc) {
60 /* Load the font description */
61 font->specific.pango_desc = pango_font_description_from_string(desc);
62 if (!font->specific.pango_desc) {
63 ELOG("Could not open font %s with Pango, fallback to X font.\n", desc);
67 LOG("Using Pango font %s, size %d\n",
68 pango_font_description_get_family(font->specific.pango_desc),
69 pango_font_description_get_size(font->specific.pango_desc) / PANGO_SCALE);
71 /* We cache root_visual_type here, since you must call
72 * load_pango_font before any other pango function
73 * that would need root_visual_type */
74 root_visual_type = get_visualtype(root_screen);
76 /* Create a dummy Pango layout to compute the font height */
77 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
78 cairo_t *cr = cairo_create(surface);
79 PangoLayout *layout = create_layout_with_dpi(cr);
80 pango_layout_set_font_description(layout, font->specific.pango_desc);
82 /* Get the font height */
84 pango_layout_get_pixel_size(layout, NULL, &height);
85 font->height = height;
88 g_object_unref(layout);
90 cairo_surface_destroy(surface);
92 /* Set the font type and return successfully */
93 font->type = FONT_TYPE_PANGO;
98 * Draws text using Pango rendering.
101 static void draw_text_pango(const char *text, size_t text_len,
102 xcb_drawable_t drawable, xcb_visualtype_t *visual, int x, int y,
103 int max_width, bool pango_markup) {
104 /* Create the Pango layout */
105 /* root_visual_type is cached in load_pango_font */
106 cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
107 visual, x + max_width, y + savedFont->height);
108 cairo_t *cr = cairo_create(surface);
109 PangoLayout *layout = create_layout_with_dpi(cr);
112 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
113 pango_layout_set_width(layout, max_width * PANGO_SCALE);
114 pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);
115 pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
118 pango_layout_set_markup(layout, text, text_len);
120 pango_layout_set_text(layout, text, text_len);
123 cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
124 cairo_set_source_rgb(cr, pango_font_red, pango_font_green, pango_font_blue);
125 pango_cairo_update_layout(cr, layout);
126 pango_layout_get_pixel_size(layout, NULL, &height);
127 /* Center the piece of text vertically if its height is smaller than the
128 * cached font height, and just let "high" symbols fall out otherwise. */
129 int yoffset = (height < savedFont->height ? 0.5 : 1) * (height - savedFont->height);
130 cairo_move_to(cr, x, y - yoffset);
131 pango_cairo_show_layout(cr, layout);
134 g_object_unref(layout);
136 cairo_surface_destroy(surface);
140 * Calculate the text width using Pango rendering.
143 static int predict_text_width_pango(const char *text, size_t text_len, bool pango_markup) {
144 /* Create a dummy Pango layout */
145 /* root_visual_type is cached in load_pango_font */
146 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
147 cairo_t *cr = cairo_create(surface);
148 PangoLayout *layout = create_layout_with_dpi(cr);
150 /* Get the font width */
152 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
155 pango_layout_set_markup(layout, text, text_len);
157 pango_layout_set_text(layout, text, text_len);
159 pango_cairo_update_layout(cr, layout);
160 pango_layout_get_pixel_size(layout, &width, NULL);
163 g_object_unref(layout);
165 cairo_surface_destroy(surface);
172 * Loads a font for usage, also getting its metrics. If fallback is true,
173 * the fonts 'fixed' or '-misc-*' will be loaded instead of exiting. If any
174 * font was previously loaded, it will be freed.
177 i3Font load_font(const char *pattern, const bool fallback) {
178 /* if any font was previously loaded, free it now */
182 font.type = FONT_TYPE_NONE;
184 /* No XCB connction, return early because we're just validating the
185 * configuration file. */
191 /* Try to load a pango font if specified */
192 if (strlen(pattern) > strlen("pango:") && !strncmp(pattern, "pango:", strlen("pango:"))) {
193 const char *font_pattern = pattern + strlen("pango:");
194 if (load_pango_font(&font, font_pattern)) {
195 font.pattern = sstrdup(pattern);
198 } else if (strlen(pattern) > strlen("xft:") && !strncmp(pattern, "xft:", strlen("xft:"))) {
199 const char *font_pattern = pattern + strlen("xft:");
200 if (load_pango_font(&font, font_pattern)) {
201 font.pattern = sstrdup(pattern);
207 /* Send all our requests first */
208 font.specific.xcb.id = xcb_generate_id(conn);
209 xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
210 strlen(pattern), pattern);
211 xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.specific.xcb.id);
213 /* Check for errors. If errors, fall back to default font. */
214 xcb_generic_error_t *error;
215 error = xcb_request_check(conn, font_cookie);
217 /* If we fail to open font, fall back to 'fixed' */
218 if (fallback && error != NULL) {
219 ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
220 pattern, error->error_code);
222 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
223 strlen(pattern), pattern);
224 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
226 /* Check if we managed to open 'fixed' */
228 error = xcb_request_check(conn, font_cookie);
230 /* Fall back to '-misc-*' if opening 'fixed' fails. */
232 ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
234 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
235 strlen(pattern), pattern);
236 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
239 if ((error = xcb_request_check(conn, font_cookie)) != NULL)
240 errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
241 "(fixed or -misc-*): X11 error %d",
249 font.pattern = sstrdup(pattern);
250 LOG("Using X font %s\n", pattern);
252 /* Get information (height/name) for this font */
253 if (!(font.specific.xcb.info = xcb_query_font_reply(conn, info_cookie, NULL)))
254 errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
256 /* Get the font table, if possible */
257 if (xcb_query_font_char_infos_length(font.specific.xcb.info) == 0)
258 font.specific.xcb.table = NULL;
260 font.specific.xcb.table = xcb_query_font_char_infos(font.specific.xcb.info);
262 /* Calculate the font height */
263 font.height = font.specific.xcb.info->font_ascent + font.specific.xcb.info->font_descent;
265 /* Set the font type and return successfully */
266 font.type = FONT_TYPE_XCB;
271 * Defines the font to be used for the forthcoming calls.
274 void set_font(i3Font *font) {
279 * Frees the resources taken by the current font. If no font was previously
280 * loaded, it simply returns.
283 void free_font(void) {
284 /* if there is no saved font, simply return */
285 if (savedFont == NULL)
288 free(savedFont->pattern);
289 switch (savedFont->type) {
293 case FONT_TYPE_XCB: {
294 /* Close the font and free the info */
295 xcb_close_font(conn, savedFont->specific.xcb.id);
296 if (savedFont->specific.xcb.info)
297 free(savedFont->specific.xcb.info);
301 case FONT_TYPE_PANGO:
302 /* Free the font description */
303 pango_font_description_free(savedFont->specific.pango_desc);
315 * Defines the colors to be used for the forthcoming draw_text calls.
318 void set_font_colors(xcb_gcontext_t gc, color_t foreground, color_t background) {
319 assert(savedFont != NULL);
321 switch (savedFont->type) {
325 case FONT_TYPE_XCB: {
326 /* Change the font and colors in the GC */
327 uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
328 uint32_t values[] = {foreground.colorpixel, background.colorpixel, savedFont->specific.xcb.id};
329 xcb_change_gc(conn, gc, mask, values);
333 case FONT_TYPE_PANGO:
334 /* Save the foreground font */
335 pango_font_red = foreground.red;
336 pango_font_green = foreground.green;
337 pango_font_blue = foreground.blue;
347 * Returns true if and only if the current font is a pango font.
350 bool font_is_pango(void) {
352 return savedFont->type == FONT_TYPE_PANGO;
358 static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
360 static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,
361 xcb_gcontext_t gc, int x, int y, int max_width) {
362 /* X11 coordinates for fonts start at the baseline */
363 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
365 /* The X11 protocol limits text drawing to 255 chars, so we may need
369 /* Calculate the size of this chunk */
370 int chunk_size = (text_len > 255 ? 255 : text_len);
371 const xcb_char2b_t *chunk = text + offset;
374 xcb_image_text_16(conn, chunk_size, drawable, gc, x, pos_y, chunk);
376 /* Advance the offset and length of the text to draw */
377 offset += chunk_size;
378 text_len -= chunk_size;
380 /* Check if we're done */
384 /* Advance pos_x based on the predicted text width */
385 x += predict_text_width_xcb(chunk, chunk_size);
390 * Draws text onto the specified X drawable (normally a pixmap) at the
391 * specified coordinates (from the top left corner of the leftmost, uppermost
392 * glyph) and using the provided gc.
394 * Text must be specified as an i3String.
397 void draw_text(i3String *text, xcb_drawable_t drawable, xcb_gcontext_t gc,
398 xcb_visualtype_t *visual, int x, int y, int max_width) {
399 assert(savedFont != NULL);
401 if (visual == NULL) {
402 visual = root_visual_type;
406 switch (savedFont->type) {
411 draw_text_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text),
412 drawable, gc, x, y, max_width);
415 case FONT_TYPE_PANGO:
416 /* Render the text using Pango */
417 draw_text_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
418 drawable, visual, x, y, max_width, i3string_is_markup(text));
427 * ASCII version of draw_text to print static strings.
430 void draw_text_ascii(const char *text, xcb_drawable_t drawable,
431 xcb_gcontext_t gc, int x, int y, int max_width) {
432 assert(savedFont != NULL);
434 switch (savedFont->type) {
438 case FONT_TYPE_XCB: {
439 size_t text_len = strlen(text);
440 if (text_len > 255) {
441 /* The text is too long to draw it directly to X */
442 i3String *str = i3string_from_utf8(text);
443 draw_text(str, drawable, gc, NULL, x, y, max_width);
446 /* X11 coordinates for fonts start at the baseline */
447 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
449 xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
454 case FONT_TYPE_PANGO:
455 /* Render the text using Pango */
456 draw_text_pango(text, strlen(text),
457 drawable, root_visual_type, x, y, max_width, false);
465 static int xcb_query_text_width(const xcb_char2b_t *text, size_t text_len) {
466 /* Make the user know we’re using the slow path, but only once. */
467 static bool first_invocation = true;
468 if (first_invocation) {
469 fprintf(stderr, "Using slow code path for text extents\n");
470 first_invocation = false;
473 /* Query the text width */
474 xcb_generic_error_t *error;
475 xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
476 savedFont->specific.xcb.id, text_len, (xcb_char2b_t *)text);
477 xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
480 /* We return a safe estimate because a rendering error is better than
481 * a crash. Plus, the user will see the error in their log. */
482 fprintf(stderr, "Could not get text extents (X error code %d)\n",
484 return savedFont->specific.xcb.info->max_bounds.character_width * text_len;
487 int width = reply->overall_width;
492 static int predict_text_width_xcb(const xcb_char2b_t *input, size_t text_len) {
497 if (savedFont->specific.xcb.table == NULL) {
498 /* If we don't have a font table, fall back to querying the server */
499 width = xcb_query_text_width(input, text_len);
501 /* Save some pointers for convenience */
502 xcb_query_font_reply_t *font_info = savedFont->specific.xcb.info;
503 xcb_charinfo_t *font_table = savedFont->specific.xcb.table;
505 /* Calculate the width using the font table */
507 for (size_t i = 0; i < text_len; i++) {
508 xcb_charinfo_t *info;
509 int row = input[i].byte1;
510 int col = input[i].byte2;
512 if (row < font_info->min_byte1 ||
513 row > font_info->max_byte1 ||
514 col < font_info->min_char_or_byte2 ||
515 col > font_info->max_char_or_byte2)
518 /* Don't you ask me, how this one works… (Merovius) */
519 info = &font_table[((row - font_info->min_byte1) *
520 (font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
521 (col - font_info->min_char_or_byte2)];
523 if (info->character_width != 0 ||
524 (info->right_side_bearing |
525 info->left_side_bearing |
527 info->descent) != 0) {
528 width += info->character_width;
537 * Predict the text width in pixels for the given text. Text must be
538 * specified as an i3String.
541 int predict_text_width(i3String *text) {
542 assert(savedFont != NULL);
544 switch (savedFont->type) {
549 return predict_text_width_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text));
551 case FONT_TYPE_PANGO:
552 /* Calculate extents using Pango */
553 return predict_text_width_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
554 i3string_is_markup(text));