gri3-wm/libi3/font.c

538 lines
18 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009-2013 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>
#if PANGO_SUPPORT
#include <cairo/cairo-xcb.h>
#include <pango/pangocairo.h>
#endif
#include "libi3.h"
extern xcb_connection_t *conn;
extern xcb_screen_t *root_screen;
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, int x, int y,
int max_width, bool is_markup) {
/* Create the Pango layout */
/* root_visual_type is cached in load_pango_font */
cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
root_visual_type, 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 (is_markup)
pango_layout_set_markup(layout, text, text_len);
else
pango_layout_set_text(layout, text, text_len);
/* Do the drawing */
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);
cairo_move_to(cr, x, y - (height - savedFont->height));
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 is_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 (is_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' */
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);
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);
}
}
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, uint32_t foreground, uint32_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, background, 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 >> 16) & 0xff) / 255.0;
pango_font_green = ((foreground >> 8) & 0xff) / 255.0;
pango_font_blue = (foreground & 0xff) / 255.0;
break;
#endif
default:
assert(false);
break;
}
}
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, 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:
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, 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, 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, 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 were 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 his 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;
}
}