/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
*
*/
#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <err.h>
#include <cairo/cairo-xcb.h>
#if PANGO_SUPPORT
#include <pango/pangocairo.h>
#endif
#include "libi3.h"
static const i3Font *savedFont = NULL;
#if PANGO_SUPPORT
static xcb_visualtype_t *root_visual_type;
static double pango_font_red;
static double pango_font_green;
static double pango_font_blue;
/* Necessary to track whether the dpi changes and trigger a LOG() message,
* which is more easily visible to users. */
static double logged_dpi = 0.0;
static PangoLayout *create_layout_with_dpi(cairo_t *cr) {
PangoLayout *layout;
PangoContext *context;
context = pango_cairo_create_context(cr);
const double dpi = (double)root_screen->height_in_pixels * 25.4 /
(double)root_screen->height_in_millimeters;
if (logged_dpi != dpi) {
logged_dpi = dpi;
LOG("X11 root window dictates %f DPI\n", dpi);
} else {
DLOG("X11 root window dictates %f DPI\n", dpi);
}
pango_cairo_context_set_resolution(context, dpi);
layout = pango_layout_new(context);
g_object_unref(context);
return layout;
}
/*
* Loads a Pango font description into an i3Font structure. Returns true
* on success, false otherwise.
*
*/
static bool load_pango_font(i3Font *font, const char *desc) {
/* Load the font description */
font->specific.pango_desc = pango_font_description_from_string(desc);
if (!font->specific.pango_desc) {
ELOG("Could not open font %s with Pango, fallback to X font.\n", desc);
return false;
}
LOG("Using Pango font %s, size %d\n",
pango_font_description_get_family(font->specific.pango_desc),
pango_font_description_get_size(font->specific.pango_desc) / PANGO_SCALE);
/* We cache root_visual_type here, since you must call
* load_pango_font before any other pango function
* that would need root_visual_type */
root_visual_type = get_visualtype(root_screen);
/* Create a dummy Pango layout to compute the font height */
cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
cairo_t *cr = cairo_create(surface);
PangoLayout *layout = create_layout_with_dpi(cr);
pango_layout_set_font_description(layout, font->specific.pango_desc);
/* Get the font height */
gint height;
pango_layout_get_pixel_size(layout, NULL, &height);
font->height = height;
/* Free resources */
g_object_unref(layout);
cairo_destroy(cr);
cairo_surface_destroy(surface);
/* Set the font type and return successfully */
font->type = FONT_TYPE_PANGO;
return true;
}
/*
* Draws text using Pango rendering.
*
*/
static void draw_text_pango(const char *text, size_t text_len,
xcb_drawable_t drawable, xcb_visualtype_t *visual, int x, int y,
int max_width, bool pango_markup) {
/* Create the Pango layout */
/* root_visual_type is cached in load_pango_font */
cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
visual, x + max_width, y + savedFont->height);
cairo_t *cr = cairo_create(surface);
PangoLayout *layout = create_layout_with_dpi(cr);
gint height;
pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
pango_layout_set_width(layout, max_width * PANGO_SCALE);
pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);
pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
if (pango_markup)
pango_layout_set_markup(layout, text, text_len);
else
pango_layout_set_text(layout, text, text_len);
/* Do the drawing */
cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
cairo_set_source_rgb(cr, pango_font_red, pango_font_green, pango_font_blue);
pango_cairo_update_layout(cr, layout);
pango_layout_get_pixel_size(layout, NULL, &height);
/* Center the piece of text vertically if its height is smaller than the
* cached font height, and just let "high" symbols fall out otherwise. */
int yoffset = (height < savedFont->height ? 0.5 : 1) * (height - savedFont->height);
cairo_move_to(cr, x, y - yoffset);
pango_cairo_show_layout(cr, layout);
/* Free resources */
g_object_unref(layout);
cairo_destroy(cr);
cairo_surface_destroy(surface);
}
/*
* Calculate the text width using Pango rendering.
*
*/
static int predict_text_width_pango(const char *text, size_t text_len, bool pango_markup) {
/* Create a dummy Pango layout */
/* root_visual_type is cached in load_pango_font */
cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
cairo_t *cr = cairo_create(surface);
PangoLayout *layout = create_layout_with_dpi(cr);
/* Get the font width */
gint width;
pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
if (pango_markup)
pango_layout_set_markup(layout, text, text_len);
else
pango_layout_set_text(layout, text, text_len);
pango_cairo_update_layout(cr, layout);
pango_layout_get_pixel_size(layout, &width, NULL);
/* Free resources */
g_object_unref(layout);
cairo_destroy(cr);
cairo_surface_destroy(surface);
return width;
}
#endif
/*
* Loads a font for usage, also getting its metrics. If fallback is true,
* the fonts 'fixed' or '-misc-*' will be loaded instead of exiting. If any
* font was previously loaded, it will be freed.
*
*/
i3Font load_font(const char *pattern, const bool fallback) {
/* if any font was previously loaded, free it now */
free_font();
i3Font font;
font.type = FONT_TYPE_NONE;
/* No XCB connction, return early because we're just validating the
* configuration file. */
if (conn == NULL) {
return font;
}
#if PANGO_SUPPORT
/* Try to load a pango font if specified */
if (strlen(pattern) > strlen("pango:") && !strncmp(pattern, "pango:", strlen("pango:"))) {
const char *font_pattern = pattern + strlen("pango:");
if (load_pango_font(&font, font_pattern)) {
font.pattern = sstrdup(pattern);
return font;
}
} else if (strlen(pattern) > strlen("xft:") && !strncmp(pattern, "xft:", strlen("xft:"))) {
const char *font_pattern = pattern + strlen("xft:");
if (load_pango_font(&font, font_pattern)) {
font.pattern = sstrdup(pattern);
return font;
}
}
#endif
/* Send all our requests first */
font.specific.xcb.id = xcb_generate_id(conn);
xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
strlen(pattern), pattern);
xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.specific.xcb.id);
/* Check for errors. If errors, fall back to default font. */
xcb_generic_error_t *error;
error = xcb_request_check(conn, font_cookie);
/* If we fail to open font, fall back to 'fixed' */
if (fallback && error != NULL) {
ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
pattern, error->error_code);
pattern = "fixed";
font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
strlen(pattern), pattern);
info_cookie = xcb_query_font(conn, font.specific.xcb.id);
/* Check if we managed to open 'fixed' */
free(error);
error = xcb_request_check(conn, font_cookie);
/* Fall back to '-misc-*' if opening 'fixed' fails. */
if (error != NULL) {
ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
pattern = "-misc-*";
font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
strlen(pattern), pattern);
info_cookie = xcb_query_font(conn, font.specific.xcb.id);
free(error);
if ((error = xcb_request_check(conn, font_cookie)) != NULL)
errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
"(fixed or -misc-*): X11 error %d",
error->error_code);
}
}
if (error != NULL) {
free(error);
}
font.pattern = sstrdup(pattern);
LOG("Using X font %s\n", pattern);
/* Get information (height/name) for this font */
if (!(font.specific.xcb.info = xcb_query_font_reply(conn, info_cookie, NULL)))
errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
/* Get the font table, if possible */
if (xcb_query_font_char_infos_length(font.specific.xcb.info) == 0)
font.specific.xcb.table = NULL;
else
font.specific.xcb.table = xcb_query_font_char_infos(font.specific.xcb.info);
/* Calculate the font height */
font.height = font.specific.xcb.info->font_ascent + font.specific.xcb.info->font_descent;
/* Set the font type and return successfully */
font.type = FONT_TYPE_XCB;
return font;
}
/*
* Defines the font to be used for the forthcoming calls.
*
*/
void set_font(i3Font *font) {
savedFont = font;
}
/*
* Frees the resources taken by the current font. If no font was previously
* loaded, it simply returns.
*
*/
void free_font(void) {
/* if there is no saved font, simply return */
if (savedFont == NULL)
return;
free(savedFont->pattern);
switch (savedFont->type) {
case FONT_TYPE_NONE:
/* Nothing to do */
break;
case FONT_TYPE_XCB: {
/* Close the font and free the info */
xcb_close_font(conn, savedFont->specific.xcb.id);
if (savedFont->specific.xcb.info)
free(savedFont->specific.xcb.info);
break;
}
#if PANGO_SUPPORT
case FONT_TYPE_PANGO:
/* Free the font description */
pango_font_description_free(savedFont->specific.pango_desc);
break;
#endif
default:
assert(false);
break;
}
savedFont = NULL;
}
/*
* Defines the colors to be used for the forthcoming draw_text calls.
*
*/
void set_font_colors(xcb_gcontext_t gc, color_t foreground, color_t background) {
assert(savedFont != NULL);
switch (savedFont->type) {
case FONT_TYPE_NONE:
/* Nothing to do */
break;
case FONT_TYPE_XCB: {
/* Change the font and colors in the GC */
uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
uint32_t values[] = {foreground.colorpixel, background.colorpixel, savedFont->specific.xcb.id};
xcb_change_gc(conn, gc, mask, values);
break;
}
#if PANGO_SUPPORT
case FONT_TYPE_PANGO:
/* Save the foreground font */
pango_font_red = foreground.red;
pango_font_green = foreground.green;
pango_font_blue = foreground.blue;
break;
#endif
default:
assert(false);
break;
}
}
/*
* Returns true if and only if the current font is a pango font.
*
*/
bool font_is_pango(void) {
#if PANGO_SUPPORT
return savedFont->type == FONT_TYPE_PANGO;
#else
return false;
#endif
}
static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,
xcb_gcontext_t gc, int x, int y, int max_width) {
/* X11 coordinates for fonts start at the baseline */
int pos_y = y + savedFont->specific.xcb.info->font_ascent;
/* The X11 protocol limits text drawing to 255 chars, so we may need
* multiple calls */
int offset = 0;
for (;;) {
/* Calculate the size of this chunk */
int chunk_size = (text_len > 255 ? 255 : text_len);
const xcb_char2b_t *chunk = text + offset;
/* Draw it */
xcb_image_text_16(conn, chunk_size, drawable, gc, x, pos_y, chunk);
/* Advance the offset and length of the text to draw */
offset += chunk_size;
text_len -= chunk_size;
/* Check if we're done */
if (text_len == 0)
break;
/* Advance pos_x based on the predicted text width */
x += predict_text_width_xcb(chunk, chunk_size);
}
}
/*
* Draws text onto the specified X drawable (normally a pixmap) at the
* specified coordinates (from the top left corner of the leftmost, uppermost
* glyph) and using the provided gc.
*
* Text must be specified as an i3String.
*
*/
void draw_text(i3String *text, xcb_drawable_t drawable, xcb_gcontext_t gc,
xcb_visualtype_t *visual, int x, int y, int max_width) {
assert(savedFont != NULL);
if (visual == NULL) {
visual = root_visual_type;
}
switch (savedFont->type) {
case FONT_TYPE_NONE:
/* Nothing to do */
return;
case FONT_TYPE_XCB:
draw_text_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text),
drawable, gc, x, y, max_width);
break;
#if PANGO_SUPPORT
case FONT_TYPE_PANGO:
/* Render the text using Pango */
draw_text_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
drawable, visual, x, y, max_width, i3string_is_markup(text));
return;
#endif
default:
assert(false);
}
}
/*
* ASCII version of draw_text to print static strings.
*
*/
void draw_text_ascii(const char *text, xcb_drawable_t drawable,
xcb_gcontext_t gc, int x, int y, int max_width) {
assert(savedFont != NULL);
switch (savedFont->type) {
case FONT_TYPE_NONE:
/* Nothing to do */
return;
case FONT_TYPE_XCB: {
size_t text_len = strlen(text);
if (text_len > 255) {
/* The text is too long to draw it directly to X */
i3String *str = i3string_from_utf8(text);
draw_text(str, drawable, gc, NULL, x, y, max_width);
i3string_free(str);
} else {
/* X11 coordinates for fonts start at the baseline */
int pos_y = y + savedFont->specific.xcb.info->font_ascent;
xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
}
break;
}
#if PANGO_SUPPORT
case FONT_TYPE_PANGO:
/* Render the text using Pango */
draw_text_pango(text, strlen(text),
drawable, root_visual_type, x, y, max_width, false);
return;
#endif
default:
assert(false);
}
}
static int xcb_query_text_width(const xcb_char2b_t *text, size_t text_len) {
/* Make the user know we’re using the slow path, but only once. */
static bool first_invocation = true;
if (first_invocation) {
fprintf(stderr, "Using slow code path for text extents\n");
first_invocation = false;
}
/* Query the text width */
xcb_generic_error_t *error;
xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
savedFont->specific.xcb.id, text_len, (xcb_char2b_t *)text);
xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
cookie, &error);
if (reply == NULL) {
/* We return a safe estimate because a rendering error is better than
* a crash. Plus, the user will see the error in their log. */
fprintf(stderr, "Could not get text extents (X error code %d)\n",
error->error_code);
return savedFont->specific.xcb.info->max_bounds.character_width * text_len;
}
int width = reply->overall_width;
free(reply);
return width;
}
static int predict_text_width_xcb(const xcb_char2b_t *input, size_t text_len) {
if (text_len == 0)
return 0;
int width;
if (savedFont->specific.xcb.table == NULL) {
/* If we don't have a font table, fall back to querying the server */
width = xcb_query_text_width(input, text_len);
} else {
/* Save some pointers for convenience */
xcb_query_font_reply_t *font_info = savedFont->specific.xcb.info;
xcb_charinfo_t *font_table = savedFont->specific.xcb.table;
/* Calculate the width using the font table */
width = 0;
for (size_t i = 0; i < text_len; i++) {
xcb_charinfo_t *info;
int row = input[i].byte1;
int col = input[i].byte2;
if (row < font_info->min_byte1 ||
row > font_info->max_byte1 ||
col < font_info->min_char_or_byte2 ||
col > font_info->max_char_or_byte2)
continue;
/* Don't you ask me, how this one works… (Merovius) */
info = &font_table[((row - font_info->min_byte1) *
(font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
(col - font_info->min_char_or_byte2)];
if (info->character_width != 0 ||
(info->right_side_bearing |
info->left_side_bearing |
info->ascent |
info->descent) != 0) {
width += info->character_width;
}
}
}
return width;
}
/*
* Predict the text width in pixels for the given text. Text must be
* specified as an i3String.
*
*/
int predict_text_width(i3String *text) {
assert(savedFont != NULL);
switch (savedFont->type) {
case FONT_TYPE_NONE:
/* Nothing to do */
return 0;
case FONT_TYPE_XCB:
return predict_text_width_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text));
#if PANGO_SUPPORT
case FONT_TYPE_PANGO:
/* Calculate extents using Pango */
return predict_text_width_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
i3string_is_markup(text));
#endif
default:
assert(false);
return 0;
}
}