230 lines
7.6 KiB
C
230 lines
7.6 KiB
C
/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3 - an improved dynamic tiling window manager
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* © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
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*
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*/
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#include <assert.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdbool.h>
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#include <err.h>
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#include "libi3.h"
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extern xcb_connection_t *conn;
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static const i3Font *savedFont = NULL;
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/*
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* Loads a font for usage, also getting its metrics. If fallback is true,
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* the fonts 'fixed' or '-misc-*' will be loaded instead of exiting.
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*
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*/
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i3Font load_font(const char *pattern, const bool fallback) {
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i3Font font;
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/* Send all our requests first */
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font.id = xcb_generate_id(conn);
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xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.id,
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strlen(pattern), pattern);
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xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.id);
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/* Check for errors. If errors, fall back to default font. */
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xcb_generic_error_t *error;
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error = xcb_request_check(conn, font_cookie);
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/* If we fail to open font, fall back to 'fixed' */
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if (fallback && error != NULL) {
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ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
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pattern, error->error_code);
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pattern = "fixed";
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font_cookie = xcb_open_font_checked(conn, font.id, strlen(pattern), pattern);
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info_cookie = xcb_query_font(conn, font.id);
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/* Check if we managed to open 'fixed' */
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error = xcb_request_check(conn, font_cookie);
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/* Fall back to '-misc-*' if opening 'fixed' fails. */
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if (error != NULL) {
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ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
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pattern = "-misc-*";
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font_cookie = xcb_open_font_checked(conn, font.id, strlen(pattern), pattern);
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info_cookie = xcb_query_font(conn, font.id);
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if ((error = xcb_request_check(conn, font_cookie)) != NULL)
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errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
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"(fixed or -misc-*): X11 error %d", error->error_code);
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}
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}
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/* Get information (height/name) for this font */
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if (!(font.info = xcb_query_font_reply(conn, info_cookie, NULL)))
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errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
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/* Get the font table, if possible */
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font.table = xcb_query_font_char_infos(font.info);
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/* Calculate the font height */
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font.height = font.info->font_ascent + font.info->font_descent;
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return font;
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}
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/*
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* Defines the font to be used for the forthcoming draw_text and
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* predict_text_width calls.
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*
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*/
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void set_font(i3Font *font) {
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savedFont = font;
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}
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/*
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* Defines the colors to be used for the forthcoming draw_text calls.
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*
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*/
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void set_font_colors(xcb_gcontext_t gc, uint32_t foreground, uint32_t background) {
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assert(savedFont != NULL);
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uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
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uint32_t values[] = { foreground, background, savedFont->id };
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xcb_change_gc(conn, gc, mask, values);
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}
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/*
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* Draws text onto the specified X drawable (normally a pixmap) at the
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* specified coordinates (from the top left corner of the leftmost, uppermost
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* glyph) and using the provided gc. Text can be specified as UCS-2 or UTF-8.
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*
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*/
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void draw_text(char *text, size_t text_len, bool is_ucs2, xcb_drawable_t drawable,
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xcb_gcontext_t gc, int x, int y, int max_width) {
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assert(savedFont != NULL);
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assert(text_len != 0);
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/* X11 coordinates for fonts start at the baseline */
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int pos_y = y + savedFont->info->font_ascent;
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/* As an optimization, check if we can bypass conversion */
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if (!is_ucs2 && text_len <= 255) {
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xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
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return;
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}
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/* Convert the text into UCS-2 so we can do basic pointer math */
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char *input = (is_ucs2 ? text : (char*)convert_utf8_to_ucs2(text, &text_len));
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/* The X11 protocol limits text drawing to 255 chars, so we may need
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* multiple calls */
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int pos_x = x;
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int offset = 0;
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for (;;) {
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/* Calculate the size of this chunk */
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int chunk_size = (text_len > 255 ? 255 : text_len);
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xcb_char2b_t *chunk = (xcb_char2b_t*)input + offset;
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/* Draw it */
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xcb_image_text_16(conn, chunk_size, drawable, gc, pos_x, pos_y, chunk);
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/* Advance the offset and length of the text to draw */
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offset += chunk_size;
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text_len -= chunk_size;
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/* Check if we're done */
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if (text_len == 0)
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break;
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/* Advance pos_x based on the predicted text width */
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pos_x += predict_text_width((char*)chunk, chunk_size, true);
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}
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/* If we had to convert, free the converted string */
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if (!is_ucs2)
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free(input);
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}
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static int xcb_query_text_width(xcb_char2b_t *text, size_t text_len) {
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/* Make the user know we’re using the slow path, but only once. */
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static bool first_invocation = true;
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if (first_invocation) {
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fprintf(stderr, "Using slow code path for text extents\n");
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first_invocation = false;
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}
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/* Query the text width */
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xcb_generic_error_t *error;
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xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
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savedFont->id, text_len, (xcb_char2b_t*)text);
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xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
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cookie, &error);
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if (reply == NULL) {
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/* We return a safe estimate because a rendering error is better than
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* a crash. Plus, the user will see the error in his log. */
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fprintf(stderr, "Could not get text extents (X error code %d)\n",
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error->error_code);
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return savedFont->info->max_bounds.character_width * text_len;
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}
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int width = reply->overall_width;
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free(reply);
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return width;
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}
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/*
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* Predict the text width in pixels for the given text. Text can be specified
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* as UCS-2 or UTF-8.
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*
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*/
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int predict_text_width(char *text, size_t text_len, bool is_ucs2) {
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/* Convert the text into UTF-16 so we can do basic pointer math */
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xcb_char2b_t *input;
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if (is_ucs2)
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input = (xcb_char2b_t*)text;
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else
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input = convert_utf8_to_ucs2(text, &text_len);
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int width;
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if (savedFont->table == NULL) {
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/* If we don't have a font table, fall back to querying the server */
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width = xcb_query_text_width(input, text_len);
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} else {
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/* Save some pointers for convenience */
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xcb_query_font_reply_t *font_info = savedFont->info;
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xcb_charinfo_t *font_table = savedFont->table;
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/* Calculate the width using the font table */
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width = 0;
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for (size_t i = 0; i < text_len; i++) {
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xcb_charinfo_t *info;
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int row = input[i].byte1;
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int col = input[i].byte2;
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if (row < font_info->min_byte1 ||
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row > font_info->max_byte1 ||
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col < font_info->min_char_or_byte2 ||
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col > font_info->max_char_or_byte2)
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continue;
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/* Don't you ask me, how this one works… (Merovius) */
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info = &font_table[((row - font_info->min_byte1) *
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(font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
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(col - font_info->min_char_or_byte2)];
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if (info->character_width != 0 ||
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(info->right_side_bearing |
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info->left_side_bearing |
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info->ascent |
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info->descent) != 0) {
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width += info->character_width;
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}
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}
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}
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/* If we had to convert, free the converted string */
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if (!is_ucs2)
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free(input);
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return width;
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}
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