2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
17 #include <cairo/cairo-xcb.h>
18 #include <pango/pangocairo.h>
20 static const i3Font *savedFont = NULL;
22 static xcb_visualtype_t *root_visual_type;
23 static double pango_font_red;
24 static double pango_font_green;
25 static double pango_font_blue;
27 static PangoLayout *create_layout_with_dpi(cairo_t *cr) {
29 PangoContext *context;
31 context = pango_cairo_create_context(cr);
32 pango_cairo_context_set_resolution(context, get_dpi_value());
33 layout = pango_layout_new(context);
34 g_object_unref(context);
40 * Loads a Pango font description into an i3Font structure. Returns true
41 * on success, false otherwise.
44 static bool load_pango_font(i3Font *font, const char *desc) {
45 /* Load the font description */
46 font->specific.pango_desc = pango_font_description_from_string(desc);
47 if (!font->specific.pango_desc) {
48 ELOG("Could not open font %s with Pango, fallback to X font.\n", desc);
52 LOG("Using Pango font %s, size %d\n",
53 pango_font_description_get_family(font->specific.pango_desc),
54 pango_font_description_get_size(font->specific.pango_desc) / PANGO_SCALE);
56 /* We cache root_visual_type here, since you must call
57 * load_pango_font before any other pango function
58 * that would need root_visual_type */
59 root_visual_type = get_visualtype(root_screen);
61 /* Create a dummy Pango layout to compute the font height */
62 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
63 cairo_t *cr = cairo_create(surface);
64 PangoLayout *layout = create_layout_with_dpi(cr);
65 pango_layout_set_font_description(layout, font->specific.pango_desc);
67 /* Get the font height */
69 pango_layout_get_pixel_size(layout, NULL, &height);
70 font->height = height;
73 g_object_unref(layout);
75 cairo_surface_destroy(surface);
77 /* Set the font type and return successfully */
78 font->type = FONT_TYPE_PANGO;
83 * Draws text using Pango rendering.
86 static void draw_text_pango(const char *text, size_t text_len,
87 xcb_drawable_t drawable, xcb_visualtype_t *visual, int x, int y,
88 int max_width, bool pango_markup) {
89 /* Create the Pango layout */
90 /* root_visual_type is cached in load_pango_font */
91 cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
92 visual, x + max_width, y + savedFont->height);
93 cairo_t *cr = cairo_create(surface);
94 PangoLayout *layout = create_layout_with_dpi(cr);
97 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
98 pango_layout_set_width(layout, max_width * PANGO_SCALE);
99 pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);
100 pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
103 pango_layout_set_markup(layout, text, text_len);
105 pango_layout_set_text(layout, text, text_len);
108 cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
109 cairo_set_source_rgb(cr, pango_font_red, pango_font_green, pango_font_blue);
110 pango_cairo_update_layout(cr, layout);
111 pango_layout_get_pixel_size(layout, NULL, &height);
112 /* Center the piece of text vertically if its height is smaller than the
113 * cached font height, and just let "high" symbols fall out otherwise. */
114 int yoffset = abs(height - savedFont->height) / 2;
115 cairo_move_to(cr, x, y - yoffset);
116 pango_cairo_show_layout(cr, layout);
119 g_object_unref(layout);
121 cairo_surface_destroy(surface);
125 * Calculate the text width using Pango rendering.
128 static int predict_text_width_pango(const char *text, size_t text_len, bool pango_markup) {
129 /* Create a dummy Pango layout */
130 /* root_visual_type is cached in load_pango_font */
131 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
132 cairo_t *cr = cairo_create(surface);
133 PangoLayout *layout = create_layout_with_dpi(cr);
135 /* Get the font width */
137 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
140 pango_layout_set_markup(layout, text, text_len);
142 pango_layout_set_text(layout, text, text_len);
144 pango_cairo_update_layout(cr, layout);
145 pango_layout_get_pixel_size(layout, &width, NULL);
148 g_object_unref(layout);
150 cairo_surface_destroy(surface);
156 * Loads a font for usage, also getting its metrics. If fallback is true,
157 * the fonts 'fixed' or '-misc-*' will be loaded instead of exiting. If any
158 * font was previously loaded, it will be freed.
161 i3Font load_font(const char *pattern, const bool fallback) {
162 /* if any font was previously loaded, free it now */
166 font.type = FONT_TYPE_NONE;
168 /* No XCB connction, return early because we're just validating the
169 * configuration file. */
174 /* Try to load a pango font if specified */
175 if (strlen(pattern) > strlen("pango:") && !strncmp(pattern, "pango:", strlen("pango:"))) {
176 const char *font_pattern = pattern + strlen("pango:");
177 if (load_pango_font(&font, font_pattern)) {
178 font.pattern = sstrdup(pattern);
181 } else if (strlen(pattern) > strlen("xft:") && !strncmp(pattern, "xft:", strlen("xft:"))) {
182 const char *font_pattern = pattern + strlen("xft:");
183 if (load_pango_font(&font, font_pattern)) {
184 font.pattern = sstrdup(pattern);
189 /* Send all our requests first */
190 font.specific.xcb.id = xcb_generate_id(conn);
191 xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
192 strlen(pattern), pattern);
193 xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.specific.xcb.id);
195 /* Check for errors. If errors, fall back to default font. */
196 xcb_generic_error_t *error;
197 error = xcb_request_check(conn, font_cookie);
199 /* If we fail to open font, fall back to 'fixed' */
200 if (fallback && error != NULL) {
201 ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
202 pattern, error->error_code);
204 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
205 strlen(pattern), pattern);
206 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
208 /* Check if we managed to open 'fixed' */
210 error = xcb_request_check(conn, font_cookie);
212 /* Fall back to '-misc-*' if opening 'fixed' fails. */
214 ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
216 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
217 strlen(pattern), pattern);
218 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
221 if ((error = xcb_request_check(conn, font_cookie)) != NULL)
222 errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
223 "(fixed or -misc-*): X11 error %d",
231 font.pattern = sstrdup(pattern);
232 LOG("Using X font %s\n", pattern);
234 /* Get information (height/name) for this font */
235 if (!(font.specific.xcb.info = xcb_query_font_reply(conn, info_cookie, NULL)))
236 errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
238 /* Get the font table, if possible */
239 if (xcb_query_font_char_infos_length(font.specific.xcb.info) == 0)
240 font.specific.xcb.table = NULL;
242 font.specific.xcb.table = xcb_query_font_char_infos(font.specific.xcb.info);
244 /* Calculate the font height */
245 font.height = font.specific.xcb.info->font_ascent + font.specific.xcb.info->font_descent;
247 /* Set the font type and return successfully */
248 font.type = FONT_TYPE_XCB;
253 * Defines the font to be used for the forthcoming calls.
256 void set_font(i3Font *font) {
261 * Frees the resources taken by the current font. If no font was previously
262 * loaded, it simply returns.
265 void free_font(void) {
266 /* if there is no saved font, simply return */
267 if (savedFont == NULL)
270 free(savedFont->pattern);
271 switch (savedFont->type) {
275 case FONT_TYPE_XCB: {
276 /* Close the font and free the info */
277 xcb_close_font(conn, savedFont->specific.xcb.id);
278 if (savedFont->specific.xcb.info)
279 free(savedFont->specific.xcb.info);
282 case FONT_TYPE_PANGO:
283 /* Free the font description */
284 pango_font_description_free(savedFont->specific.pango_desc);
292 * Defines the colors to be used for the forthcoming draw_text calls.
295 void set_font_colors(xcb_gcontext_t gc, color_t foreground, color_t background) {
296 assert(savedFont != NULL);
298 switch (savedFont->type) {
302 case FONT_TYPE_XCB: {
303 /* Change the font and colors in the GC */
304 uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
305 uint32_t values[] = {foreground.colorpixel, background.colorpixel, savedFont->specific.xcb.id};
306 xcb_change_gc(conn, gc, mask, values);
309 case FONT_TYPE_PANGO:
310 /* Save the foreground font */
311 pango_font_red = foreground.red;
312 pango_font_green = foreground.green;
313 pango_font_blue = foreground.blue;
319 * Returns true if and only if the current font is a pango font.
322 bool font_is_pango(void) {
323 return savedFont->type == FONT_TYPE_PANGO;
326 static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
328 static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,
329 xcb_gcontext_t gc, int x, int y, int max_width) {
330 /* X11 coordinates for fonts start at the baseline */
331 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
333 /* The X11 protocol limits text drawing to 255 chars, so we may need
337 /* Calculate the size of this chunk */
338 int chunk_size = (text_len > 255 ? 255 : text_len);
339 const xcb_char2b_t *chunk = text + offset;
342 xcb_image_text_16(conn, chunk_size, drawable, gc, x, pos_y, chunk);
344 /* Advance the offset and length of the text to draw */
345 offset += chunk_size;
346 text_len -= chunk_size;
348 /* Check if we're done */
352 /* Advance pos_x based on the predicted text width */
353 x += predict_text_width_xcb(chunk, chunk_size);
358 * Draws text onto the specified X drawable (normally a pixmap) at the
359 * specified coordinates (from the top left corner of the leftmost, uppermost
360 * glyph) and using the provided gc.
362 * Text must be specified as an i3String.
365 void draw_text(i3String *text, xcb_drawable_t drawable, xcb_gcontext_t gc,
366 xcb_visualtype_t *visual, int x, int y, int max_width) {
367 assert(savedFont != NULL);
368 if (visual == NULL) {
369 visual = root_visual_type;
372 switch (savedFont->type) {
377 draw_text_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text),
378 drawable, gc, x, y, max_width);
380 case FONT_TYPE_PANGO:
381 /* Render the text using Pango */
382 draw_text_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
383 drawable, visual, x, y, max_width, i3string_is_markup(text));
389 * ASCII version of draw_text to print static strings.
392 void draw_text_ascii(const char *text, xcb_drawable_t drawable,
393 xcb_gcontext_t gc, int x, int y, int max_width) {
394 assert(savedFont != NULL);
396 switch (savedFont->type) {
400 case FONT_TYPE_XCB: {
401 size_t text_len = strlen(text);
402 if (text_len > 255) {
403 /* The text is too long to draw it directly to X */
404 i3String *str = i3string_from_utf8(text);
405 draw_text(str, drawable, gc, NULL, x, y, max_width);
408 /* X11 coordinates for fonts start at the baseline */
409 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
411 xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
415 case FONT_TYPE_PANGO:
416 /* Render the text using Pango */
417 draw_text_pango(text, strlen(text),
418 drawable, root_visual_type, x, y, max_width, false);
423 static int xcb_query_text_width(const xcb_char2b_t *text, size_t text_len) {
424 /* Make the user know we’re using the slow path, but only once. */
425 static bool first_invocation = true;
426 if (first_invocation) {
427 fprintf(stderr, "Using slow code path for text extents\n");
428 first_invocation = false;
431 /* Query the text width */
432 xcb_generic_error_t *error;
433 xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
434 savedFont->specific.xcb.id, text_len, (xcb_char2b_t *)text);
435 xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
438 /* We return a safe estimate because a rendering error is better than
439 * a crash. Plus, the user will see the error in their log. */
440 fprintf(stderr, "Could not get text extents (X error code %d)\n",
442 return savedFont->specific.xcb.info->max_bounds.character_width * text_len;
445 int width = reply->overall_width;
450 static int predict_text_width_xcb(const xcb_char2b_t *input, size_t text_len) {
455 if (savedFont->specific.xcb.table == NULL) {
456 /* If we don't have a font table, fall back to querying the server */
457 width = xcb_query_text_width(input, text_len);
459 /* Save some pointers for convenience */
460 xcb_query_font_reply_t *font_info = savedFont->specific.xcb.info;
461 xcb_charinfo_t *font_table = savedFont->specific.xcb.table;
463 /* Calculate the width using the font table */
465 for (size_t i = 0; i < text_len; i++) {
466 xcb_charinfo_t *info;
467 int row = input[i].byte1;
468 int col = input[i].byte2;
470 if (row < font_info->min_byte1 ||
471 row > font_info->max_byte1 ||
472 col < font_info->min_char_or_byte2 ||
473 col > font_info->max_char_or_byte2)
476 /* Don't you ask me, how this one works… (Merovius) */
477 info = &font_table[((row - font_info->min_byte1) *
478 (font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
479 (col - font_info->min_char_or_byte2)];
481 if (info->character_width != 0 ||
482 (info->right_side_bearing |
483 info->left_side_bearing |
485 info->descent) != 0) {
486 width += info->character_width;
495 * Predict the text width in pixels for the given text. Text must be
496 * specified as an i3String.
499 int predict_text_width(i3String *text) {
500 assert(savedFont != NULL);
502 switch (savedFont->type) {
507 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),
511 i3string_is_markup(text));