2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009-2011 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;
34 * Loads a Pango font description into an i3Font structure. Returns true
35 * on success, false otherwise.
38 static bool load_pango_font(i3Font *font, const char *desc) {
39 /* Load the font description */
40 font->specific.pango_desc = pango_font_description_from_string(desc);
41 if (!font->specific.pango_desc) {
42 ELOG("Could not open font %s with Pango, fallback to X font.\n", desc);
46 LOG("Using Pango font %s, size %d\n",
47 pango_font_description_get_family(font->specific.pango_desc),
48 pango_font_description_get_size(font->specific.pango_desc) / PANGO_SCALE
51 /* We cache root_visual_type here, since you must call
52 * load_pango_font before any other pango function
53 * that would need root_visual_type */
54 root_visual_type = get_visualtype(root_screen);
56 /* Create a dummy Pango layout to compute the font height */
57 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
58 cairo_t *cr = cairo_create(surface);
59 PangoLayout *layout = pango_cairo_create_layout(cr);
60 pango_layout_set_font_description(layout, font->specific.pango_desc);
62 /* Get the font height */
64 pango_layout_get_pixel_size(layout, NULL, &height);
65 font->height = height;
68 g_object_unref(layout);
70 cairo_surface_destroy(surface);
72 /* Set the font type and return successfully */
73 font->type = FONT_TYPE_PANGO;
78 * Draws text using Pango rendering.
81 static void draw_text_pango(const char *text, size_t text_len,
82 xcb_drawable_t drawable, int x, int y, int max_width) {
83 /* Create the Pango layout */
84 /* root_visual_type is cached in load_pango_font */
85 cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
86 root_visual_type, x + max_width, y + savedFont->height);
87 cairo_t *cr = cairo_create(surface);
88 PangoLayout *layout = pango_cairo_create_layout(cr);
89 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
90 pango_layout_set_width(layout, max_width * PANGO_SCALE);
91 pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);
92 pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
95 cairo_set_source_rgb(cr, pango_font_red, pango_font_green, pango_font_blue);
96 cairo_move_to(cr, x, y);
97 pango_layout_set_text(layout, text, text_len);
98 pango_cairo_update_layout(cr, layout);
99 pango_cairo_show_layout(cr, layout);
102 g_object_unref(layout);
104 cairo_surface_destroy(surface);
108 * Calculate the text width using Pango rendering.
111 static int predict_text_width_pango(const char *text, size_t text_len) {
112 /* Create a dummy Pango layout */
113 /* root_visual_type is cached in load_pango_font */
114 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
115 cairo_t *cr = cairo_create(surface);
116 PangoLayout *layout = pango_cairo_create_layout(cr);
118 /* Get the font width */
120 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
121 pango_layout_set_text(layout, text, text_len);
122 pango_cairo_update_layout(cr, layout);
123 pango_layout_get_pixel_size(layout, &width, NULL);
126 g_object_unref(layout);
128 cairo_surface_destroy(surface);
135 * Loads a font for usage, also getting its metrics. If fallback is true,
136 * the fonts 'fixed' or '-misc-*' will be loaded instead of exiting.
139 i3Font load_font(const char *pattern, const bool fallback) {
141 font.type = FONT_TYPE_NONE;
144 /* Try to load a pango font if specified */
145 if (strlen(pattern) > strlen("xft:") && !strncmp(pattern, "xft:", strlen("xft:"))) {
146 pattern += strlen("xft:");
147 if (load_pango_font(&font, pattern))
152 /* Send all our requests first */
153 font.specific.xcb.id = xcb_generate_id(conn);
154 xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
155 strlen(pattern), pattern);
156 xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.specific.xcb.id);
158 /* Check for errors. If errors, fall back to default font. */
159 xcb_generic_error_t *error;
160 error = xcb_request_check(conn, font_cookie);
162 /* If we fail to open font, fall back to 'fixed' */
163 if (fallback && error != NULL) {
164 ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
165 pattern, error->error_code);
167 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
168 strlen(pattern), pattern);
169 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
171 /* Check if we managed to open 'fixed' */
172 error = xcb_request_check(conn, font_cookie);
174 /* Fall back to '-misc-*' if opening 'fixed' fails. */
176 ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
178 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
179 strlen(pattern), pattern);
180 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
182 if ((error = xcb_request_check(conn, font_cookie)) != NULL)
183 errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
184 "(fixed or -misc-*): X11 error %d", error->error_code);
188 LOG("Using X font %s\n", pattern);
190 /* Get information (height/name) for this font */
191 if (!(font.specific.xcb.info = xcb_query_font_reply(conn, info_cookie, NULL)))
192 errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
194 /* Get the font table, if possible */
195 if (xcb_query_font_char_infos_length(font.specific.xcb.info) == 0)
196 font.specific.xcb.table = NULL;
198 font.specific.xcb.table = xcb_query_font_char_infos(font.specific.xcb.info);
200 /* Calculate the font height */
201 font.height = font.specific.xcb.info->font_ascent + font.specific.xcb.info->font_descent;
203 /* Set the font type and return successfully */
204 font.type = FONT_TYPE_XCB;
209 * Defines the font to be used for the forthcoming calls.
212 void set_font(i3Font *font) {
217 * Frees the resources taken by the current font.
220 void free_font(void) {
221 switch (savedFont->type) {
225 case FONT_TYPE_XCB: {
226 /* Close the font and free the info */
227 xcb_close_font(conn, savedFont->specific.xcb.id);
228 if (savedFont->specific.xcb.info)
229 free(savedFont->specific.xcb.info);
233 case FONT_TYPE_PANGO:
234 /* Free the font description */
235 pango_font_description_free(savedFont->specific.pango_desc);
245 * Defines the colors to be used for the forthcoming draw_text calls.
248 void set_font_colors(xcb_gcontext_t gc, uint32_t foreground, uint32_t background) {
249 assert(savedFont != NULL);
251 switch (savedFont->type) {
255 case FONT_TYPE_XCB: {
256 /* Change the font and colors in the GC */
257 uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
258 uint32_t values[] = { foreground, background, savedFont->specific.xcb.id };
259 xcb_change_gc(conn, gc, mask, values);
263 case FONT_TYPE_PANGO:
264 /* Save the foreground font */
265 pango_font_red = ((foreground >> 16) & 0xff) / 255.0;
266 pango_font_green = ((foreground >> 8) & 0xff) / 255.0;
267 pango_font_blue = (foreground & 0xff) / 255.0;
276 static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
278 static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,
279 xcb_gcontext_t gc, int x, int y, int max_width) {
280 /* X11 coordinates for fonts start at the baseline */
281 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
283 /* The X11 protocol limits text drawing to 255 chars, so we may need
287 /* Calculate the size of this chunk */
288 int chunk_size = (text_len > 255 ? 255 : text_len);
289 const xcb_char2b_t *chunk = text + offset;
292 xcb_image_text_16(conn, chunk_size, drawable, gc, x, pos_y, chunk);
294 /* Advance the offset and length of the text to draw */
295 offset += chunk_size;
296 text_len -= chunk_size;
298 /* Check if we're done */
302 /* Advance pos_x based on the predicted text width */
303 x += predict_text_width_xcb(chunk, chunk_size);
308 * Draws text onto the specified X drawable (normally a pixmap) at the
309 * specified coordinates (from the top left corner of the leftmost, uppermost
310 * glyph) and using the provided gc.
312 * Text must be specified as an i3String.
315 void draw_text(i3String *text, xcb_drawable_t drawable,
316 xcb_gcontext_t gc, int x, int y, int max_width) {
317 assert(savedFont != NULL);
319 switch (savedFont->type) {
324 draw_text_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text),
325 drawable, gc, x, y, max_width);
328 case FONT_TYPE_PANGO:
329 /* Render the text using Pango */
330 draw_text_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
331 drawable, x, y, max_width);
340 * ASCII version of draw_text to print static strings.
343 void draw_text_ascii(const char *text, xcb_drawable_t drawable,
344 xcb_gcontext_t gc, int x, int y, int max_width) {
345 assert(savedFont != NULL);
347 switch (savedFont->type) {
353 size_t text_len = strlen(text);
354 if (text_len > 255) {
355 /* The text is too long to draw it directly to X */
356 i3String *str = i3string_from_utf8(text);
357 draw_text(str, drawable, gc, x, y, max_width);
360 /* X11 coordinates for fonts start at the baseline */
361 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
363 xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
368 case FONT_TYPE_PANGO:
369 /* Render the text using Pango */
370 draw_text_pango(text, strlen(text),
371 drawable, x, y, max_width);
379 static int xcb_query_text_width(const xcb_char2b_t *text, size_t text_len) {
380 /* Make the user know we’re using the slow path, but only once. */
381 static bool first_invocation = true;
382 if (first_invocation) {
383 fprintf(stderr, "Using slow code path for text extents\n");
384 first_invocation = false;
387 /* Query the text width */
388 xcb_generic_error_t *error;
389 xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
390 savedFont->specific.xcb.id, text_len, (xcb_char2b_t*)text);
391 xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
394 /* We return a safe estimate because a rendering error is better than
395 * a crash. Plus, the user will see the error in his log. */
396 fprintf(stderr, "Could not get text extents (X error code %d)\n",
398 return savedFont->specific.xcb.info->max_bounds.character_width * text_len;
401 int width = reply->overall_width;
406 static int predict_text_width_xcb(const xcb_char2b_t *input, size_t text_len) {
411 if (savedFont->specific.xcb.table == NULL) {
412 /* If we don't have a font table, fall back to querying the server */
413 width = xcb_query_text_width(input, text_len);
415 /* Save some pointers for convenience */
416 xcb_query_font_reply_t *font_info = savedFont->specific.xcb.info;
417 xcb_charinfo_t *font_table = savedFont->specific.xcb.table;
419 /* Calculate the width using the font table */
421 for (size_t i = 0; i < text_len; i++) {
422 xcb_charinfo_t *info;
423 int row = input[i].byte1;
424 int col = input[i].byte2;
426 if (row < font_info->min_byte1 ||
427 row > font_info->max_byte1 ||
428 col < font_info->min_char_or_byte2 ||
429 col > font_info->max_char_or_byte2)
432 /* Don't you ask me, how this one works… (Merovius) */
433 info = &font_table[((row - font_info->min_byte1) *
434 (font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
435 (col - font_info->min_char_or_byte2)];
437 if (info->character_width != 0 ||
438 (info->right_side_bearing |
439 info->left_side_bearing |
441 info->descent) != 0) {
442 width += info->character_width;
451 * Predict the text width in pixels for the given text. Text must be
452 * specified as an i3String.
455 int predict_text_width(i3String *text) {
456 assert(savedFont != NULL);
458 switch (savedFont->type) {
463 return predict_text_width_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text));
465 case FONT_TYPE_PANGO:
466 /* Calculate extents using Pango */
467 return predict_text_width_pango(i3string_as_utf8(text), i3string_get_num_bytes(text));