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Diffstat (limited to 'src/libsystemd-terminal/term-page.c')
| -rw-r--r-- | src/libsystemd-terminal/term-page.c | 2091 |
1 files changed, 0 insertions, 2091 deletions
diff --git a/src/libsystemd-terminal/term-page.c b/src/libsystemd-terminal/term-page.c deleted file mode 100644 index bac85200f1..0000000000 --- a/src/libsystemd-terminal/term-page.c +++ /dev/null @@ -1,2091 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com> - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -/* - * Terminal Page/Line/Cell/Char Handling - * This file implements page handling of a terminal. It is split into pages, - * lines, cells and characters. Each object is independent of the next upper - * object. - * - * The Terminal layer keeps each line of a terminal separate and dynamically - * allocated. This allows us to move lines from main-screen to history-buffers - * very fast. Same is true for scrolling, top/bottom borders and other buffer - * operations. - * - * While lines are dynamically allocated, cells are not. This would be a waste - * of memory and causes heavy fragmentation. Furthermore, cells are moved much - * less frequently than lines so the performance-penalty is pretty small. - * However, to support combining-characters, we have to initialize and cleanup - * cells properly and cannot just release the underlying memory. Therefore, - * cells are treated as proper objects despite being allocated in arrays. - * - * Each cell has a set of attributes and a stored character. This is usually a - * single Unicode character stored as 32bit UCS-4 char. However, we need to - * support Unicode combining-characters, therefore this gets more complicated. - * Characters themselves are represented by a "term_char_t" object. It - * should be treated as a normal integer and passed by value. The - * surrounding struct is just to hide the internals. A term-char can contain a - * base character together with up to 2 combining-chars in a single integer. - * Only if you need more combining-chars (very unlikely!) a term-char is a - * pointer to an allocated storage. This requires you to always free term-char - * objects once no longer used (even though this is a no-op most of the time). - * Furthermore, term-char objects are not ref-counted so you must duplicate them - * in case you want to store it somewhere and retain a copy yourself. By - * convention, all functions that take a term-char object will not duplicate - * it but implicitly take ownership of the passed value. It's up to the caller - * to duplicate it beforehand, in case it wants to retain a copy. - * - * If it turns out, that more than 2 comb-chars become common in specific - * languages, we can try to optimize this. One idea is to ref-count allocated - * characters and store them in a hash-table (like gnome's libvte3 does). This - * way we will never have two allocated chars for the same content. Or we can - * simply put two uint64_t into a "term_char_t". This will slow down operations - * on systems that don't need that many comb-chars, but avoid the dynamic - * allocations on others. - * Anyhow, until we have proper benchmarks, we will keep the current code. It - * seems to compete very well with other solutions so far. - * - * The page-layer is a one-dimensional array of lines. Considering that each - * line is a one-dimensional array of cells, the page layer provides the - * two-dimensional cell-page required for terminals. The page itself only - * operates on lines. All cell-related operations are forwarded to the correct - * line. - * A page does not contain any cursor tracking. It only provides the raw - * operations to shuffle lines and modify the page. - */ - -#include <stdbool.h> -#include <stdint.h> -#include <stdlib.h> -#include "macro.h" -#include "term-internal.h" -#include "util.h" - -/* maximum UCS-4 character */ -#define CHAR_UCS4_MAX (0x10ffff) -/* mask for valid UCS-4 characters (21bit) */ -#define CHAR_UCS4_MASK (0x1fffff) -/* UCS-4 replacement character */ -#define CHAR_UCS4_REPLACEMENT (0xfffd) - -/* real storage behind "term_char_t" in case it's not packed */ -typedef struct term_character { - uint8_t n; - uint32_t codepoints[]; -} term_character; - -/* - * char_pack() takes 3 UCS-4 values and packs them into a term_char_t object. - * Note that UCS-4 chars only take 21 bits, so we still have the LSB as marker. - * We set it to 1 so others can distinguish it from pointers. - */ -static inline term_char_t char_pack(uint32_t v1, uint32_t v2, uint32_t v3) { - uint64_t packed, u1, u2, u3; - - u1 = v1; - u2 = v2; - u3 = v3; - - packed = 0x01; - packed |= (u1 & (uint64_t)CHAR_UCS4_MASK) << 43; - packed |= (u2 & (uint64_t)CHAR_UCS4_MASK) << 22; - packed |= (u3 & (uint64_t)CHAR_UCS4_MASK) << 1; - - return TERM_CHAR_INIT(packed); -} - -#define char_pack1(_v1) char_pack2((_v1), CHAR_UCS4_MAX + 1) -#define char_pack2(_v1, _v2) char_pack3((_v1), (_v2), CHAR_UCS4_MAX + 1) -#define char_pack3(_v1, _v2, _v3) char_pack((_v1), (_v2), (_v3)) - -/* - * char_unpack() is the inverse of char_pack(). It extracts the 3 stored UCS-4 - * characters and returns them. Note that this does not validate the passed - * term_char_t. That's the responsibility of the caller. - * This returns the number of characters actually packed. This obviously is a - * number between 0 and 3 (inclusive). - */ -static inline uint8_t char_unpack(term_char_t packed, uint32_t *out_v1, uint32_t *out_v2, uint32_t *out_v3) { - uint32_t v1, v2, v3; - - v1 = (packed._value >> 43) & (uint64_t)CHAR_UCS4_MASK; - v2 = (packed._value >> 22) & (uint64_t)CHAR_UCS4_MASK; - v3 = (packed._value >> 1) & (uint64_t)CHAR_UCS4_MASK; - - if (out_v1) - *out_v1 = v1; - if (out_v2) - *out_v2 = v2; - if (out_v3) - *out_v3 = v3; - - return (v1 > CHAR_UCS4_MAX) ? 0 : - ((v2 > CHAR_UCS4_MAX) ? 1 : - ((v3 > CHAR_UCS4_MAX) ? 2 : - 3)); -} - -/* cast a term_char_t to a term_character* */ -static inline term_character *char_to_ptr(term_char_t ch) { - return (term_character*)(unsigned long)ch._value; -} - -/* cast a term_character* to a term_char_t */ -static inline term_char_t char_from_ptr(term_character *c) { - return TERM_CHAR_INIT((unsigned long)c); -} - -/* - * char_alloc() allocates a properly aligned term_character object and returns - * a pointer to it. NULL is returned on allocation errors. The object will have - * enough room for @n following UCS-4 chars. - * Note that we allocate (n+1) characters and set the last one to 0 in case - * anyone prints this string for debugging. - */ -static term_character *char_alloc(uint8_t n) { - term_character *c; - int r; - - r = posix_memalign((void**)&c, - MAX(sizeof(void*), (size_t)2), - sizeof(*c) + sizeof(*c->codepoints) * (n + 1)); - if (r) - return NULL; - - c->n = n; - c->codepoints[n] = 0; - - return c; -} - -/* - * char_free() frees the memory allocated via char_alloc(). It is safe to call - * this on any term_char_t, only allocated characters are freed. - */ -static inline void char_free(term_char_t ch) { - if (term_char_is_allocated(ch)) - free(char_to_ptr(ch)); -} - -/* - * This appends @append_ucs4 to the existing character @base and returns - * it as a new character. In case that's not possible, @base is returned. The - * caller can use term_char_same() to test whether the returned character was - * freshly allocated or not. - */ -static term_char_t char_build(term_char_t base, uint32_t append_ucs4) { - /* soft-limit for combining-chars; hard-limit is currently 255 */ - const size_t climit = 64; - term_character *c; - uint32_t buf[3], *t; - uint8_t n; - - /* ignore invalid UCS-4 */ - if (append_ucs4 > CHAR_UCS4_MAX) - return base; - - if (term_char_is_null(base)) { - return char_pack1(append_ucs4); - } else if (!term_char_is_allocated(base)) { - /* unpack and try extending the packed character */ - n = char_unpack(base, &buf[0], &buf[1], &buf[2]); - - switch (n) { - case 0: - return char_pack1(append_ucs4); - case 1: - if (climit < 2) - return base; - - return char_pack2(buf[0], append_ucs4); - case 2: - if (climit < 3) - return base; - - return char_pack3(buf[0], buf[1], append_ucs4); - default: - /* fallthrough */ - break; - } - - /* already fully packed, we need to allocate a new one */ - t = buf; - } else { - /* already an allocated type, we need to allocate a new one */ - c = char_to_ptr(base); - t = c->codepoints; - n = c->n; - } - - /* bail out if soft-limit is reached */ - if (n >= climit) - return base; - - /* allocate new char */ - c = char_alloc(n + 1); - if (!c) - return base; - - memcpy(c->codepoints, t, sizeof(*t) * n); - c->codepoints[n] = append_ucs4; - - return char_from_ptr(c); -} - -/** - * term_char_set() - Reset character to a single UCS-4 character - * @previous: term-char to reset - * @append_ucs4: UCS-4 char to set - * - * This frees all resources in @previous and re-initializes it to @append_ucs4. - * The new char is returned. - * - * Usually, this is used like this: - * obj->ch = term_char_set(obj->ch, ucs4); - * - * Returns: The previous character reset to @append_ucs4. - */ -term_char_t term_char_set(term_char_t previous, uint32_t append_ucs4) { - char_free(previous); - return char_build(TERM_CHAR_NULL, append_ucs4); -} - -/** - * term_char_merge() - Merge UCS-4 char at the end of an existing char - * @base: existing term-char - * @append_ucs4: UCS-4 character to append - * - * This appends @append_ucs4 to @base and returns the result. @base is - * invalidated by this function and must no longer be used. The returned value - * replaces the old one. - * - * Usually, this is used like this: - * obj->ch = term_char_merge(obj->ch, ucs4); - * - * Returns: The new merged character. - */ -term_char_t term_char_merge(term_char_t base, uint32_t append_ucs4) { - term_char_t ch; - - ch = char_build(base, append_ucs4); - if (!term_char_same(ch, base)) - term_char_free(base); - - return ch; -} - -/** - * term_char_dup() - Duplicate character - * @ch: character to duplicate - * - * This duplicates a term-character. In case the character is not allocated, - * nothing is done. Otherwise, the underlying memory is copied and returned. You - * need to call term_char_free() on the returned character to release it again. - * On allocation errors, a replacement character is returned. Therefore, the - * caller can safely assume that this function always succeeds. - * - * Returns: The duplicated term-character. - */ -term_char_t term_char_dup(term_char_t ch) { - term_character *c, *newc; - - if (!term_char_is_allocated(ch)) - return ch; - - c = char_to_ptr(ch); - newc = char_alloc(c->n); - if (!newc) - return char_pack1(CHAR_UCS4_REPLACEMENT); - - memcpy(newc->codepoints, c->codepoints, sizeof(*c->codepoints) * c->n); - return char_from_ptr(newc); -} - -/** - * term_char_dup_append() - Duplicate tsm-char with UCS-4 character appended - * @base: existing term-char - * @append_ucs4: UCS-4 character to append - * - * This is similar to term_char_merge(), but it returns a separately allocated - * character. That is, @base will stay valid after this returns and is not - * touched. In case the append-operation fails, @base is duplicated and - * returned. That is, the returned char is always independent of @base. - * - * Returns: Newly allocated character with @append_ucs4 appended to @base. - */ -term_char_t term_char_dup_append(term_char_t base, uint32_t append_ucs4) { - term_char_t ch; - - ch = char_build(base, append_ucs4); - if (term_char_same(ch, base)) - ch = term_char_dup(base); - - return ch; -} - -/** - * term_char_resolve() - Retrieve the UCS-4 string for a term-char - * @ch: character to resolve - * @s: storage for size of string or NULL - * @b: storage for string or NULL - * - * This takes a term-character and returns the UCS-4 string associated with it. - * In case @ch is not allocated, the string is stored in @b (in case @b is NULL - * static storage is used). Otherwise, a pointer to the allocated storage is - * returned. - * - * The returned string is only valid as long as @ch and @b are valid. The string - * is zero-terminated and can safely be printed via long-character printf(). - * The length of the string excluding the zero-character is returned in @s. - * - * This never returns NULL. Even if the size is 0, this points to a buffer of at - * least a zero-terminator. - * - * Returns: The UCS-4 string-representation of @ch, and its size in @s. - */ -const uint32_t *term_char_resolve(term_char_t ch, size_t *s, term_charbuf_t *b) { - static term_charbuf_t static_b; - term_character *c; - uint32_t *cache; - size_t len; - - if (b) - cache = b->buf; - else - cache = static_b.buf; - - if (term_char_is_null(ch)) { - len = 0; - cache[0] = 0; - } else if (term_char_is_allocated(ch)) { - c = char_to_ptr(ch); - len = c->n; - cache = c->codepoints; - } else { - len = char_unpack(ch, &cache[0], &cache[1], &cache[2]); - cache[len] = 0; - } - - if (s) - *s = len; - - return cache; -} - -/** - * term_char_lookup_width() - Lookup cell-width of a character - * @ch: character to return cell-width for - * - * This is an equivalent of wcwidth() for term_char_t. It can deal directly - * with UCS-4 and combining-characters and avoids the mess that is wchar_t and - * locale handling. - * - * Returns: 0 for unprintable characters, >0 for everything else. - */ -unsigned int term_char_lookup_width(term_char_t ch) { - term_charbuf_t b; - const uint32_t *str; - unsigned int max; - size_t i, len; - int r; - - max = 0; - str = term_char_resolve(ch, &len, &b); - - for (i = 0; i < len; ++i) { - /* - * Oh god, C99 locale handling strikes again: wcwidth() expects - * wchar_t, but there is no way for us to know the - * internal encoding of wchar_t. Moreover, it is nearly - * impossible to convert UCS-4 into wchar_t (except for iconv, - * which is way too much overhead). - * Therefore, we use our own copy of wcwidth(). Lets just hope - * that glibc will one day export it's internal UCS-4 and UTF-8 - * helpers for direct use. - */ - assert_cc(sizeof(wchar_t) >= 4); - r = mk_wcwidth((wchar_t)str[i]); - if (r > 0 && (unsigned int)r > max) - max = r; - } - - return max; -} - -/** - * term_cell_init() - Initialize a new cell - * @cell: cell to initialize - * @ch: character to set on the cell or TERM_CHAR_NULL - * @cwidth: character width of @ch - * @attr: attributes to set on the cell or NULL - * @age: age to set on the cell or TERM_AGE_NULL - * - * This initializes a new cell. The backing-memory of the cell must be allocated - * by the caller beforehand. The caller is responsible to destroy the cell via - * term_cell_destroy() before freeing the backing-memory. - * - * It is safe (and supported!) to use: - * zero(*c); - * instead of: - * term_cell_init(c, TERM_CHAR_NULL, NULL, TERM_AGE_NULL); - * - * Note that this call takes ownership of @ch. If you want to use it yourself - * after this call, you need to duplicate it before calling this. - */ -static void term_cell_init(term_cell *cell, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age) { - assert(cell); - - cell->ch = ch; - cell->cwidth = cwidth; - cell->age = age; - - if (attr) - memcpy(&cell->attr, attr, sizeof(*attr)); - else - zero(cell->attr); -} - -/** - * term_cell_destroy() - Destroy previously initialized cell - * @cell: cell to destroy or NULL - * - * This releases all resources associated with a cell. The backing memory is - * kept as-is. It's the responsibility of the caller to manage it. - * - * You must not call any other cell operations on this cell after this call - * returns. You must re-initialize the cell via term_cell_init() before you can - * use it again. - * - * If @cell is NULL, this is a no-op. - */ -static void term_cell_destroy(term_cell *cell) { - if (!cell) - return; - - term_char_free(cell->ch); -} - -/** - * term_cell_set() - Change contents of a cell - * @cell: cell to modify - * @ch: character to set on the cell or cell->ch - * @cwidth: character width of @ch or cell->cwidth - * @attr: attributes to set on the cell or NULL - * @age: age to set on the cell or cell->age - * - * This changes the contents of a cell. It can be used to change the character, - * attributes and age. To keep the current character, pass cell->ch as @ch. To - * reset the current attributes, pass NULL. To keep the current age, pass - * cell->age. - * - * This call takes ownership of @ch. You need to duplicate it first, in case you - * want to use it for your own purposes after this call. - * - * The cell must have been initialized properly before calling this. See - * term_cell_init(). - */ -static void term_cell_set(term_cell *cell, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age) { - assert(cell); - - if (!term_char_same(ch, cell->ch)) { - term_char_free(cell->ch); - cell->ch = ch; - } - - cell->cwidth = cwidth; - cell->age = age; - - if (attr) - memcpy(&cell->attr, attr, sizeof(*attr)); - else - zero(cell->attr); -} - -/** - * term_cell_append() - Append a combining-char to a cell - * @cell: cell to modify - * @ucs4: UCS-4 character to append to the cell - * @age: new age to set on the cell or cell->age - * - * This appends a combining-character to a cell. No validation of the UCS-4 - * character is done, so this can be used to append any character. Additionally, - * this can update the age of the cell. - * - * The cell must have been initialized properly before calling this. See - * term_cell_init(). - */ -static void term_cell_append(term_cell *cell, uint32_t ucs4, term_age_t age) { - assert(cell); - - cell->ch = term_char_merge(cell->ch, ucs4); - cell->age = age; -} - -/** - * term_cell_init_n() - Initialize an array of cells - * @cells: pointer to an array of cells to initialize - * @n: number of cells - * @attr: attributes to set on all cells or NULL - * @age: age to set on all cells - * - * This is the same as term_cell_init() but initializes an array of cells. - * Furthermore, this always sets the character to TERM_CHAR_NULL. - * If you want to set a specific characters on all cells, you need to hard-code - * this loop and duplicate the character for each cell. - */ -static void term_cell_init_n(term_cell *cells, unsigned int n, const term_attr *attr, term_age_t age) { - for ( ; n > 0; --n, ++cells) - term_cell_init(cells, TERM_CHAR_NULL, 0, attr, age); -} - -/** - * term_cell_destroy_n() - Destroy an array of cells - * @cells: pointer to an array of cells to destroy - * @n: number of cells - * - * This is the same as term_cell_destroy() but destroys an array of cells. - */ -static void term_cell_destroy_n(term_cell *cells, unsigned int n) { - for ( ; n > 0; --n, ++cells) - term_cell_destroy(cells); -} - -/** - * term_cell_clear_n() - Clear contents of an array of cells - * @cells: pointer to an array of cells to modify - * @n: number of cells - * @attr: attributes to set on all cells or NULL - * @age: age to set on all cells - * - * This is the same as term_cell_set() but operates on an array of cells. Note - * that all characters are always set to TERM_CHAR_NULL, unlike term_cell_set() - * which takes the character as argument. - * If you want to set a specific characters on all cells, you need to hard-code - * this loop and duplicate the character for each cell. - */ -static void term_cell_clear_n(term_cell *cells, unsigned int n, const term_attr *attr, term_age_t age) { - for ( ; n > 0; --n, ++cells) - term_cell_set(cells, TERM_CHAR_NULL, 0, attr, age); -} - -/** - * term_line_new() - Allocate a new line - * @out: place to store pointer to new line - * - * This allocates and initialized a new line. The line is unlinked and - * independent of any page. It can be used for any purpose. The initial - * cell-count is set to 0. - * - * The line has to be freed via term_line_free() once it's no longer needed. - * - * Returns: 0 on success, negative error code on failure. - */ -int term_line_new(term_line **out) { - _term_line_free_ term_line *line = NULL; - - assert_return(out, -EINVAL); - - line = new0(term_line, 1); - if (!line) - return -ENOMEM; - - *out = line; - line = NULL; - return 0; -} - -/** - * term_line_free() - Free a line - * @line: line to free or NULL - * - * This frees a line that was previously allocated via term_line_free(). All its - * cells are released, too. - * - * If @line is NULL, this is a no-op. - */ -term_line *term_line_free(term_line *line) { - if (!line) - return NULL; - - term_cell_destroy_n(line->cells, line->n_cells); - free(line->cells); - free(line); - - return NULL; -} - -/** - * term_line_reserve() - Pre-allocate cells for a line - * @line: line to pre-allocate cells for - * @width: numbers of cells the line shall have pre-allocated - * @attr: attribute for all allocated cells or NULL - * @age: current age for all modifications - * @protect_width: width to protect from erasure - * - * This pre-allocates cells for this line. Please note that @width is the number - * of cells the line is guaranteed to have allocated after this call returns. - * It's not the number of cells that are added, neither is it the new width of - * the line. - * - * This function never frees memory. That is, reducing the line-width will - * always succeed, same is true for increasing the width to a previously set - * width. - * - * @attr and @age are used to initialize new cells. Additionally, any - * existing cell outside of the protected area specified by @protect_width are - * cleared and reset with @attr and @age. - * - * Returns: 0 on success, negative error code on failure. - */ -int term_line_reserve(term_line *line, unsigned int width, const term_attr *attr, term_age_t age, unsigned int protect_width) { - unsigned int min_width; - term_cell *t; - - assert_return(line, -EINVAL); - - /* reset existing cells if required */ - min_width = MIN(line->n_cells, width); - if (min_width > protect_width) - term_cell_clear_n(line->cells + protect_width, - min_width - protect_width, - attr, - age); - - /* allocate new cells if required */ - - if (width > line->n_cells) { - t = realloc_multiply(line->cells, sizeof(*t), width); - if (!t) - return -ENOMEM; - - if (!attr && !age) - memzero(t + line->n_cells, - sizeof(*t) * (width - line->n_cells)); - else - term_cell_init_n(t + line->n_cells, - width - line->n_cells, - attr, - age); - - line->cells = t; - line->n_cells = width; - } - - line->fill = MIN(line->fill, protect_width); - - return 0; -} - -/** - * term_line_set_width() - Change width of a line - * @line: line to modify - * @width: new width - * - * This changes the actual width of a line. It is the caller's responsibility - * to use term_line_reserve() to make sure enough space is allocated. If @width - * is greater than the allocated size, it is cropped. - * - * This does not modify any cells. Use term_line_reserve() or term_line_erase() - * to clear any newly added cells. - * - * NOTE: The fill state is cropped at line->width. Therefore, if you increase - * the line-width afterwards, but there is a multi-cell character at the - * end of the line that got cropped, then the fill-state will _not_ be - * adjusted. - * This means, the fill-state always includes the cells up to the start - * of the right-most character, but it might or might not cover it until - * its end. This should be totally fine, though. You should never access - * multi-cell tails directly, anyway. - */ -void term_line_set_width(term_line *line, unsigned int width) { - assert(line); - - if (width > line->n_cells) - width = line->n_cells; - - line->width = width; - line->fill = MIN(line->fill, width); -} - -/** - * line_insert() - Insert characters and move existing cells to the right - * @from: position to insert cells at - * @num: number of cells to insert - * @head_char: character that is set on the first cell - * @head_cwidth: character-length of @head_char - * @attr: attribute for all inserted cells or NULL - * @age: current age for all modifications - * - * The INSERT operation (or writes with INSERT_MODE) writes data at a specific - * position on a line and shifts the existing cells to the right. Cells that are - * moved beyond the right hand border are discarded. - * - * This helper contains the actual INSERT implementation which is independent of - * the data written. It works on cells, not on characters. The first cell is set - * to @head_char, all others are reset to TERM_CHAR_NULL. See each caller for a - * more detailed description. - */ -static inline void line_insert(term_line *line, unsigned int from, unsigned int num, term_char_t head_char, unsigned int head_cwidth, const term_attr *attr, term_age_t age) { - unsigned int i, rem, move; - - if (from >= line->width) - return; - if (from + num < from || from + num > line->width) - num = line->width - from; - if (!num) - return; - - move = line->width - from - num; - rem = MIN(num, move); - - if (rem > 0) { - /* - * Make room for @num cells; shift cells to the right if - * required. @rem is the number of remaining cells that we will - * knock off on the right and overwrite during the right shift. - * - * For INSERT_MODE, @num/@rem are usually 1 or 2, @move is 50% - * of the line on average. Therefore, the actual move is quite - * heavy and we can safely invalidate cells manually instead of - * the whole line. - * However, for INSERT operations, any parameters are - * possible. But we cannot place any assumption on its usage - * across applications, so we just handle it the same as - * INSERT_MODE and do per-cell invalidation. - */ - - /* destroy cells that are knocked off on the right */ - term_cell_destroy_n(line->cells + line->width - rem, rem); - - /* move remaining bulk of cells */ - memmove(line->cells + from + num, - line->cells + from, - sizeof(*line->cells) * move); - - /* invalidate cells */ - for (i = 0; i < move; ++i) - line->cells[from + num + i].age = age; - - /* initialize fresh head-cell */ - term_cell_init(line->cells + from, - head_char, - head_cwidth, - attr, - age); - - /* initialize fresh tail-cells */ - term_cell_init_n(line->cells + from + 1, - num - 1, - attr, - age); - - /* adjust fill-state */ - line->fill = MIN(line->width, - MAX(line->fill + num, - from + num)); - } else { - /* modify head-cell */ - term_cell_set(line->cells + from, - head_char, - head_cwidth, - attr, - age); - - /* reset tail-cells */ - term_cell_clear_n(line->cells + from + 1, - num - 1, - attr, - age); - - /* adjust fill-state */ - line->fill = line->width; - } -} - -/** - * term_line_write() - Write to a single, specific cell - * @line: line to write to - * @pos_x: x-position of cell in @line to write to - * @ch: character to write to the cell - * @cwidth: character width of @ch - * @attr: attributes to set on the cell or NULL - * @age: current age for all modifications - * @insert_mode: true if INSERT-MODE is enabled - * - * This writes to a specific cell in a line. The cell is addressed by its - * X-position @pos_x. If that cell does not exist, this is a no-op. - * - * @ch and @attr are set on this cell. - * - * If @insert_mode is true, this inserts the character instead of overwriting - * existing data (existing data is now moved to the right before writing). - * - * This function is the low-level handler of normal writes to a terminal. - */ -void term_line_write(term_line *line, unsigned int pos_x, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age, bool insert_mode) { - unsigned int len; - - assert(line); - - if (pos_x >= line->width) - return; - - len = MAX(1U, cwidth); - if (pos_x + len < pos_x || pos_x + len > line->width) - len = line->width - pos_x; - if (!len) - return; - - if (insert_mode) { - /* Use line_insert() to insert the character-head and fill - * the remains with NULLs. */ - line_insert(line, pos_x, len, ch, cwidth, attr, age); - } else { - /* modify head-cell */ - term_cell_set(line->cells + pos_x, ch, cwidth, attr, age); - - /* reset tail-cells */ - term_cell_clear_n(line->cells + pos_x + 1, - len - 1, - attr, - age); - - /* adjust fill-state */ - line->fill = MIN(line->width, - MAX(line->fill, - pos_x + len)); - } -} - -/** - * term_line_insert() - Insert empty cells - * @line: line to insert empty cells into - * @from: x-position where to insert cells - * @num: number of cells to insert - * @attr: attributes to set on the cells or NULL - * @age: current age for all modifications - * - * This inserts @num empty cells at position @from in line @line. All existing - * cells to the right are shifted to make room for the new cells. Cells that get - * pushed beyond the right hand border are discarded. - */ -void term_line_insert(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age) { - /* use line_insert() to insert @num empty cells */ - return line_insert(line, from, num, TERM_CHAR_NULL, 0, attr, age); -} - -/** - * term_line_delete() - Delete cells from line - * @line: line to delete cells from - * @from: position to delete cells at - * @num: number of cells to delete - * @attr: attributes to set on any new cells - * @age: current age for all modifications - * - * Delete cells from a line. All cells to the right of the deleted cells are - * shifted to the left to fill the empty space. New cells appearing on the right - * hand border are cleared and initialized with @attr. - */ -void term_line_delete(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age) { - unsigned int rem, move, i; - - assert(line); - - if (from >= line->width) - return; - if (from + num < from || from + num > line->width) - num = line->width - from; - if (!num) - return; - - /* destroy and move as many upfront as possible */ - move = line->width - from - num; - rem = MIN(num, move); - if (rem > 0) { - /* destroy to be removed cells */ - term_cell_destroy_n(line->cells + from, rem); - - /* move tail upfront */ - memmove(line->cells + from, - line->cells + from + num, - sizeof(*line->cells) * move); - - /* invalidate copied cells */ - for (i = 0; i < move; ++i) - line->cells[from + i].age = age; - - /* initialize tail that was moved away */ - term_cell_init_n(line->cells + line->width - rem, - rem, - attr, - age); - - /* reset remaining cells in case the move was too small */ - if (num > move) - term_cell_clear_n(line->cells + from + move, - num - move, - attr, - age); - } else { - /* reset cells */ - term_cell_clear_n(line->cells + from, - num, - attr, - age); - } - - /* adjust fill-state */ - if (from + num < line->fill) - line->fill -= num; - else if (from < line->fill) - line->fill = from; -} - -/** - * term_line_append_combchar() - Append combining char to existing cell - * @line: line to modify - * @pos_x: position of cell to append combining char to - * @ucs4: combining character to append - * @age: current age for all modifications - * - * Unicode allows trailing combining characters, which belong to the - * char in front of them. The caller is responsible of detecting - * combining characters and calling term_line_append_combchar() instead of - * term_line_write(). This simply appends the char to the correct cell then. - * If the cell is not in the visible area, this call is skipped. - * - * Note that control-sequences are not 100% compatible with combining - * characters as they require delayed parsing. However, we must handle - * control-sequences immediately. Therefore, there might be trailing - * combining chars that should be discarded by the parser. - * However, to prevent programming errors, we're also being pedantic - * here and discard weirdly placed combining chars. This prevents - * situations were invalid content is parsed into the terminal and you - * might end up with cells containing only combining chars. - * - * Long story short: To get combining-characters working with old-fashioned - * terminal-emulation, we parse them exclusively for direct cell-writes. Other - * combining-characters are usually simply discarded and ignored. - */ -void term_line_append_combchar(term_line *line, unsigned int pos_x, uint32_t ucs4, term_age_t age) { - assert(line); - - if (pos_x >= line->width) - return; - - /* Unused cell? Skip appending any combining chars then. */ - if (term_char_is_null(line->cells[pos_x].ch)) - return; - - term_cell_append(line->cells + pos_x, ucs4, age); -} - -/** - * term_line_erase() - Erase parts of a line - * @line: line to modify - * @from: position to start the erase - * @num: number of cells to erase - * @attr: attributes to initialize erased cells with - * @age: current age for all modifications - * @keep_protected: true if protected cells should be kept - * - * This is the standard erase operation. It clears all cells in the targeted - * area and re-initializes them. Cells to the right are not shifted left, you - * must use DELETE to achieve that. Cells outside the visible area are skipped. - * - * If @keep_protected is true, protected cells will not be erased. - */ -void term_line_erase(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age, bool keep_protected) { - term_cell *cell; - unsigned int i, last_protected; - - assert(line); - - if (from >= line->width) - return; - if (from + num < from || from + num > line->width) - num = line->width - from; - if (!num) - return; - - last_protected = 0; - for (i = 0; i < num; ++i) { - cell = line->cells + from + i; - if (keep_protected && cell->attr.protect) { - /* only count protected-cells inside the fill-region */ - if (from + i < line->fill) - last_protected = from + i; - - continue; - } - - term_cell_set(cell, TERM_CHAR_NULL, 0, attr, age); - } - - /* Adjust fill-state. This is a bit tricks, we can only adjust it in - * case the erase-region starts inside the fill-region and ends at the - * tail or beyond the fill-region. Otherwise, the current fill-state - * stays as it was. - * Furthermore, we must account for protected cells. The loop above - * ensures that protected-cells are only accounted for if they're - * inside the fill-region. */ - if (from < line->fill && from + num >= line->fill) - line->fill = MAX(from, last_protected); -} - -/** - * term_line_reset() - Reset a line - * @line: line to reset - * @attr: attributes to initialize all cells with - * @age: current age for all modifications - * - * This resets all visible cells of a line and sets their attributes and ages - * to @attr and @age. This is equivalent to erasing a whole line via - * term_line_erase(). - */ -void term_line_reset(term_line *line, const term_attr *attr, term_age_t age) { - assert(line); - - return term_line_erase(line, 0, line->width, attr, age, 0); -} - -/** - * term_line_link() - Link line in front of a list - * @line: line to link - * @first: member pointing to first entry - * @last: member pointing to last entry - * - * This links a line into a list of lines. The line is inserted at the front and - * must not be linked, yet. See the TERM_LINE_LINK() macro for an easier usage of - * this. - */ -void term_line_link(term_line *line, term_line **first, term_line **last) { - assert(line); - assert(first); - assert(last); - assert(!line->lines_prev); - assert(!line->lines_next); - - line->lines_prev = NULL; - line->lines_next = *first; - if (*first) - (*first)->lines_prev = line; - else - *last = line; - *first = line; -} - -/** - * term_line_link_tail() - Link line at tail of a list - * @line: line to link - * @first: member pointing to first entry - * @last: member pointing to last entry - * - * Same as term_line_link() but links the line at the tail. - */ -void term_line_link_tail(term_line *line, term_line **first, term_line **last) { - assert(line); - assert(first); - assert(last); - assert(!line->lines_prev); - assert(!line->lines_next); - - line->lines_next = NULL; - line->lines_prev = *last; - if (*last) - (*last)->lines_next = line; - else - *first = line; - *last = line; -} - -/** - * term_line_unlink() - Unlink line from a list - * @line: line to unlink - * @first: member pointing to first entry - * @last: member pointing to last entry - * - * This unlinks a previously linked line. See TERM_LINE_UNLINK() for an easier to - * use macro. - */ -void term_line_unlink(term_line *line, term_line **first, term_line **last) { - assert(line); - assert(first); - assert(last); - - if (line->lines_prev) - line->lines_prev->lines_next = line->lines_next; - else - *first = line->lines_next; - if (line->lines_next) - line->lines_next->lines_prev = line->lines_prev; - else - *last = line->lines_prev; - - line->lines_prev = NULL; - line->lines_next = NULL; -} - -/** - * term_page_new() - Allocate new page - * @out: storage for pointer to new page - * - * Allocate a new page. The initial dimensions are 0/0. - * - * Returns: 0 on success, negative error code on failure. - */ -int term_page_new(term_page **out) { - _term_page_free_ term_page *page = NULL; - - assert_return(out, -EINVAL); - - page = new0(term_page, 1); - if (!page) - return -ENOMEM; - - *out = page; - page = NULL; - return 0; -} - -/** - * term_page_free() - Free page - * @page: page to free or NULL - * - * Free a previously allocated page and all associated data. If @page is NULL, - * this is a no-op. - * - * Returns: NULL - */ -term_page *term_page_free(term_page *page) { - unsigned int i; - - if (!page) - return NULL; - - for (i = 0; i < page->n_lines; ++i) - term_line_free(page->lines[i]); - - free(page->line_cache); - free(page->lines); - free(page); - - return NULL; -} - -/** - * term_page_get_cell() - Return pointer to requested cell - * @page: page to operate on - * @x: x-position of cell - * @y: y-position of cell - * - * This returns a pointer to the cell at position @x/@y. You're free to modify - * this cell as much as you like. However, once you call any other function on - * the page, you must drop the pointer to the cell. - * - * Returns: Pointer to the cell or NULL if out of the visible area. - */ -term_cell *term_page_get_cell(term_page *page, unsigned int x, unsigned int y) { - assert_return(page, NULL); - - if (x >= page->width) - return NULL; - if (y >= page->height) - return NULL; - - return &page->lines[y]->cells[x]; -} - -/** - * page_scroll_up() - Scroll up - * @page: page to operate on - * @new_width: width to use for any new line moved into the visible area - * @num: number of lines to scroll up - * @attr: attributes to set on new lines - * @age: age to use for all modifications - * @history: history to use for old lines or NULL - * - * This scrolls the scroll-region by @num lines. New lines are cleared and reset - * with the given attributes. Old lines are moved into the history if non-NULL. - * If a new line is allocated, moved from the history buffer or moved from - * outside the visible region into the visible region, this call makes sure it - * has at least @width cells allocated. If a possible memory-allocation fails, - * the previous line is reused. This has the side effect, that it will not be - * linked into the history buffer. - * - * If the scroll-region is empty, this is a no-op. - */ -static void page_scroll_up(term_page *page, unsigned int new_width, unsigned int num, const term_attr *attr, term_age_t age, term_history *history) { - term_line *line, **cache; - unsigned int i; - int r; - - assert(page); - - if (num > page->scroll_num) - num = page->scroll_num; - if (num < 1) - return; - - /* Better safe than sorry: avoid under-allocating lines, even when - * resizing. */ - new_width = MAX(new_width, page->width); - - cache = page->line_cache; - - /* Try moving lines into history and allocate new lines for each moved - * line. In case allocation fails, or if we have no history, reuse the - * line. - * We keep the lines in the line-cache so we can safely move the - * remaining lines around. */ - for (i = 0; i < num; ++i) { - line = page->lines[page->scroll_idx + i]; - - r = -EAGAIN; - if (history) { - r = term_line_new(&cache[i]); - if (r >= 0) { - r = term_line_reserve(cache[i], - new_width, - attr, - age, - 0); - if (r < 0) - term_line_free(cache[i]); - else - term_line_set_width(cache[i], page->width); - } - } - - if (r >= 0) { - term_history_push(history, line); - } else { - cache[i] = line; - term_line_reset(line, attr, age); - } - } - - if (num < page->scroll_num) { - memmove(page->lines + page->scroll_idx, - page->lines + page->scroll_idx + num, - sizeof(*page->lines) * (page->scroll_num - num)); - - /* update age of moved lines */ - for (i = 0; i < page->scroll_num - num; ++i) - page->lines[page->scroll_idx + i]->age = age; - } - - /* copy remaining lines from cache; age is already updated */ - memcpy(page->lines + page->scroll_idx + page->scroll_num - num, - cache, - sizeof(*cache) * num); - - /* update fill */ - page->scroll_fill -= MIN(page->scroll_fill, num); -} - -/** - * page_scroll_down() - Scroll down - * @page: page to operate on - * @new_width: width to use for any new line moved into the visible area - * @num: number of lines to scroll down - * @attr: attributes to set on new lines - * @age: age to use for all modifications - * @history: history to use for new lines or NULL - * - * This scrolls the scroll-region by @num lines. New lines are retrieved from - * the history or cleared if the history is empty or NULL. - * - * Usually, scroll-down implies that new lines are cleared. Therefore, you're - * highly encouraged to set @history to NULL. However, if you resize a terminal, - * you might want to include history-lines in the new area. In that case, you - * should set @history to non-NULL. - * - * If a new line is allocated, moved from the history buffer or moved from - * outside the visible region into the visible region, this call makes sure it - * has at least @width cells allocated. If a possible memory-allocation fails, - * the previous line is reused. This will have the side-effect that lines from - * the history will not get visible on-screen but kept in history. - * - * If the scroll-region is empty, this is a no-op. - */ -static void page_scroll_down(term_page *page, unsigned int new_width, unsigned int num, const term_attr *attr, term_age_t age, term_history *history) { - term_line *line, **cache, *t; - unsigned int i, last_idx; - - assert(page); - - if (num > page->scroll_num) - num = page->scroll_num; - if (num < 1) - return; - - /* Better safe than sorry: avoid under-allocating lines, even when - * resizing. */ - new_width = MAX(new_width, page->width); - - cache = page->line_cache; - last_idx = page->scroll_idx + page->scroll_num - 1; - - /* Try pulling out lines from history; if history is empty or if no - * history is given, we reuse the to-be-removed lines. Otherwise, those - * lines are released. */ - for (i = 0; i < num; ++i) { - line = page->lines[last_idx - i]; - - t = NULL; - if (history) - t = term_history_pop(history, new_width, attr, age); - - if (t) { - cache[num - 1 - i] = t; - term_line_free(line); - } else { - cache[num - 1 - i] = line; - term_line_reset(line, attr, age); - } - } - - if (num < page->scroll_num) { - memmove(page->lines + page->scroll_idx + num, - page->lines + page->scroll_idx, - sizeof(*page->lines) * (page->scroll_num - num)); - - /* update age of moved lines */ - for (i = 0; i < page->scroll_num - num; ++i) - page->lines[page->scroll_idx + num + i]->age = age; - } - - /* copy remaining lines from cache; age is already updated */ - memcpy(page->lines + page->scroll_idx, - cache, - sizeof(*cache) * num); - - /* update fill; but only if there's already content in it */ - if (page->scroll_fill > 0) - page->scroll_fill = MIN(page->scroll_num, - page->scroll_fill + num); -} - -/** - * page_reserve() - Reserve page area - * @page: page to modify - * @cols: required columns (width) - * @rows: required rows (height) - * @attr: attributes for newly allocated cells - * @age: age to set on any modified cells - * - * This allocates the required amount of lines and cells to guarantee that the - * page has at least the demanded dimensions of @cols x @rows. Note that this - * never shrinks the page-memory. We keep cells allocated for performance - * reasons. - * - * Additionally to allocating lines, this also clears any newly added cells so - * you can safely change the size afterwards without clearing new cells. - * - * Note that you must be careful what operations you call on the page between - * page_reserve() and updating page->width/height. Any newly allocated line (or - * shifted line) might not meet your new width/height expectations. - * - * Returns: 0 on success, negative error code on failure. - */ -int term_page_reserve(term_page *page, unsigned int cols, unsigned int rows, const term_attr *attr, term_age_t age) { - _term_line_free_ term_line *line = NULL; - unsigned int i, min_lines; - term_line **t; - int r; - - assert_return(page, -EINVAL); - - /* - * First make sure the first MIN(page->n_lines, rows) lines have at - * least the required width of @cols. This does not modify any visible - * cells in the existing @page->width x @page->height area, therefore, - * we can safely bail out afterwards in case anything else fails. - * Note that lines in between page->height and page->n_lines might be - * shorter than page->width. Hence, we need to resize them all, but we - * can skip some of them for better performance. - */ - min_lines = MIN(page->n_lines, rows); - for (i = 0; i < min_lines; ++i) { - /* lines below page->height have at least page->width cells */ - if (cols < page->width && i < page->height) - continue; - - r = term_line_reserve(page->lines[i], - cols, - attr, - age, - (i < page->height) ? page->width : 0); - if (r < 0) - return r; - } - - /* - * We now know the first @min_lines lines have at least width @cols and - * are prepared for resizing. We now only have to allocate any - * additional lines below @min_lines in case @rows is greater than - * page->n_lines. - */ - if (rows > page->n_lines) { - t = realloc_multiply(page->lines, sizeof(*t), rows); - if (!t) - return -ENOMEM; - page->lines = t; - - t = realloc_multiply(page->line_cache, sizeof(*t), rows); - if (!t) - return -ENOMEM; - page->line_cache = t; - - while (page->n_lines < rows) { - r = term_line_new(&line); - if (r < 0) - return r; - - r = term_line_reserve(line, cols, attr, age, 0); - if (r < 0) - return r; - - page->lines[page->n_lines++] = line; - line = NULL; - } - } - - return 0; -} - -/** - * term_page_resize() - Resize page - * @page: page to modify - * @cols: number of columns (width) - * @rows: number of rows (height) - * @attr: attributes for newly allocated cells - * @age: age to set on any modified cells - * @history: history buffer to use for new/old lines or NULL - * - * This changes the visible dimensions of a page. You must have called - * term_page_reserve() beforehand, otherwise, this will fail. - * - * Returns: 0 on success, negative error code on failure. - */ -void term_page_resize(term_page *page, unsigned int cols, unsigned int rows, const term_attr *attr, term_age_t age, term_history *history) { - unsigned int i, num, empty, max, old_height; - term_line *line; - - assert(page); - assert(page->n_lines >= rows); - - old_height = page->height; - - if (rows < old_height) { - /* - * If we decrease the terminal-height, we emulate a scroll-up. - * This way, existing data from the scroll-area is moved into - * the history, making space at the bottom to reduce the screen - * height. In case the scroll-fill indicates empty lines, we - * reduce the amount of scrolled lines. - * Once scrolled, we have to move the lower margin from below - * the scroll area up so it is preserved. - */ - - /* move lines to history if scroll region is filled */ - num = old_height - rows; - empty = page->scroll_num - page->scroll_fill; - if (num > empty) - page_scroll_up(page, - cols, - num - empty, - attr, - age, - history); - - /* move lower margin up; drop its lines if not enough space */ - num = LESS_BY(old_height, page->scroll_idx + page->scroll_num); - max = LESS_BY(rows, page->scroll_idx); - num = MIN(num, max); - if (num > 0) { - unsigned int top, bottom; - - top = rows - num; - bottom = page->scroll_idx + page->scroll_num; - - /* might overlap; must run topdown, not bottomup */ - for (i = 0; i < num; ++i) { - line = page->lines[top + i]; - page->lines[top + i] = page->lines[bottom + i]; - page->lines[bottom + i] = line; - } - } - - /* update vertical extents */ - page->height = rows; - page->scroll_idx = MIN(page->scroll_idx, rows); - page->scroll_num -= MIN(page->scroll_num, old_height - rows); - /* fill is already up-to-date or 0 due to scroll-up */ - } else if (rows > old_height) { - /* - * If we increase the terminal-height, we emulate a scroll-down - * and fetch new lines from the history. - * New lines are always accounted to the scroll-region. Thus we - * have to preserve the lower margin first, by moving it down. - */ - - /* move lower margin down */ - num = LESS_BY(old_height, page->scroll_idx + page->scroll_num); - if (num > 0) { - unsigned int top, bottom; - - top = page->scroll_idx + page->scroll_num; - bottom = top + (rows - old_height); - - /* might overlap; must run bottomup, not topdown */ - for (i = num; i-- > 0; ) { - line = page->lines[top + i]; - page->lines[top + i] = page->lines[bottom + i]; - page->lines[bottom + i] = line; - } - } - - /* update vertical extents */ - page->height = rows; - page->scroll_num = MIN(LESS_BY(rows, page->scroll_idx), - page->scroll_num + (rows - old_height)); - - /* check how many lines can be received from history */ - if (history) - num = term_history_peek(history, - rows - old_height, - cols, - attr, - age); - else - num = 0; - - /* retrieve new lines from history if available */ - if (num > 0) - page_scroll_down(page, - cols, - num, - attr, - age, - history); - } - - /* set horizontal extents */ - page->width = cols; - for (i = 0; i < page->height; ++i) - term_line_set_width(page->lines[i], cols); -} - -/** - * term_page_write() - Write to a single cell - * @page: page to operate on - * @pos_x: x-position of cell to write to - * @pos_y: y-position of cell to write to - * @ch: character to write - * @cwidth: character-width of @ch - * @attr: attributes to set on the cell or NULL - * @age: age to use for all modifications - * @insert_mode: true if INSERT-MODE is enabled - * - * This writes a character to a specific cell. If the cell is beyond bounds, - * this is a no-op. @attr and @age are used to update the cell. @flags can be - * used to alter the behavior of this function. - * - * This is a wrapper around term_line_write(). - * - * This call does not wrap around lines. That is, this only operates on a single - * line. - */ -void term_page_write(term_page *page, unsigned int pos_x, unsigned int pos_y, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age, bool insert_mode) { - assert(page); - - if (pos_y >= page->height) - return; - - term_line_write(page->lines[pos_y], pos_x, ch, cwidth, attr, age, insert_mode); -} - -/** - * term_page_insert_cells() - Insert cells into a line - * @page: page to operate on - * @from_x: x-position where to insert new cells - * @from_y: y-position where to insert new cells - * @num: number of cells to insert - * @attr: attributes to set on new cells or NULL - * @age: age to use for all modifications - * - * This inserts new cells into a given line. This is a wrapper around - * term_line_insert(). - * - * This call does not wrap around lines. That is, this only operates on a single - * line. - */ -void term_page_insert_cells(term_page *page, unsigned int from_x, unsigned int from_y, unsigned int num, const term_attr *attr, term_age_t age) { - assert(page); - - if (from_y >= page->height) - return; - - term_line_insert(page->lines[from_y], from_x, num, attr, age); -} - -/** - * term_page_delete_cells() - Delete cells from a line - * @page: page to operate on - * @from_x: x-position where to delete cells - * @from_y: y-position where to delete cells - * @num: number of cells to delete - * @attr: attributes to set on new cells or NULL - * @age: age to use for all modifications - * - * This deletes cells from a given line. This is a wrapper around - * term_line_delete(). - * - * This call does not wrap around lines. That is, this only operates on a single - * line. - */ -void term_page_delete_cells(term_page *page, unsigned int from_x, unsigned int from_y, unsigned int num, const term_attr *attr, term_age_t age) { - assert(page); - - if (from_y >= page->height) - return; - - term_line_delete(page->lines[from_y], from_x, num, attr, age); -} - -/** - * term_page_append_combchar() - Append combining-character to a cell - * @page: page to operate on - * @pos_x: x-position of target cell - * @pos_y: y-position of target cell - * @ucs4: combining character to append - * @age: age to use for all modifications - * - * This appends a combining-character to a specific cell. This is a wrapper - * around term_line_append_combchar(). - */ -void term_page_append_combchar(term_page *page, unsigned int pos_x, unsigned int pos_y, uint32_t ucs4, term_age_t age) { - assert(page); - - if (pos_y >= page->height) - return; - - term_line_append_combchar(page->lines[pos_y], pos_x, ucs4, age); -} - -/** - * term_page_erase() - Erase parts of a page - * @page: page to operate on - * @from_x: x-position where to start erasure (inclusive) - * @from_y: y-position where to start erasure (inclusive) - * @to_x: x-position where to stop erasure (inclusive) - * @to_y: y-position where to stop erasure (inclusive) - * @attr: attributes to set on cells - * @age: age to use for all modifications - * @keep_protected: true if protected cells should be kept - * - * This erases all cells starting at @from_x/@from_y up to @to_x/@to_y. Note - * that this wraps around line-boundaries so lines between @from_y and @to_y - * are cleared entirely. - * - * Lines outside the visible area are left untouched. - */ -void term_page_erase(term_page *page, unsigned int from_x, unsigned int from_y, unsigned int to_x, unsigned int to_y, const term_attr *attr, term_age_t age, bool keep_protected) { - unsigned int i, from, to; - - assert(page); - - for (i = from_y; i <= to_y && i < page->height; ++i) { - from = 0; - to = page->width; - - if (i == from_y) - from = from_x; - if (i == to_y) - to = to_x; - - term_line_erase(page->lines[i], - from, - LESS_BY(to, from), - attr, - age, - keep_protected); - } -} - -/** - * term_page_reset() - Reset page - * @page: page to modify - * @attr: attributes to set on cells - * @age: age to use for all modifications - * - * This erases the whole visible page. See term_page_erase(). - */ -void term_page_reset(term_page *page, const term_attr *attr, term_age_t age) { - assert(page); - - return term_page_erase(page, - 0, 0, - page->width - 1, page->height - 1, - attr, - age, - 0); -} - -/** - * term_page_set_scroll_region() - Set scroll region - * @page: page to operate on - * @idx: start-index of scroll region - * @num: number of lines in scroll region - * - * This sets the scroll region of a page. Whenever an operation needs to scroll - * lines, it scrolls them inside of that region. Lines outside the region are - * left untouched. In case a scroll-operation is targeted outside of this - * region, it will implicitly get a scroll-region of only one line (i.e., no - * scroll region at all). - * - * Note that the scroll-region is clipped to the current page-extents. Growing - * or shrinking the page always accounts new/old lines to the scroll region and - * moves top/bottom margins accordingly so they're preserved. - */ -void term_page_set_scroll_region(term_page *page, unsigned int idx, unsigned int num) { - assert(page); - - if (page->height < 1) { - page->scroll_idx = 0; - page->scroll_num = 0; - } else { - page->scroll_idx = MIN(idx, page->height - 1); - page->scroll_num = MIN(num, page->height - page->scroll_idx); - } -} - -/** - * term_page_scroll_up() - Scroll up - * @page: page to operate on - * @num: number of lines to scroll up - * @attr: attributes to set on new lines - * @age: age to use for all modifications - * @history: history to use for old lines or NULL - * - * This scrolls the scroll-region by @num lines. New lines are cleared and reset - * with the given attributes. Old lines are moved into the history if non-NULL. - * - * If the scroll-region is empty, this is a no-op. - */ -void term_page_scroll_up(term_page *page, unsigned int num, const term_attr *attr, term_age_t age, term_history *history) { - page_scroll_up(page, page->width, num, attr, age, history); -} - -/** - * term_page_scroll_down() - Scroll down - * @page: page to operate on - * @num: number of lines to scroll down - * @attr: attributes to set on new lines - * @age: age to use for all modifications - * @history: history to use for new lines or NULL - * - * This scrolls the scroll-region by @num lines. New lines are retrieved from - * the history or cleared if the history is empty or NULL. - * - * Usually, scroll-down implies that new lines are cleared. Therefore, you're - * highly encouraged to set @history to NULL. However, if you resize a terminal, - * you might want to include history-lines in the new area. In that case, you - * should set @history to non-NULL. - * - * If the scroll-region is empty, this is a no-op. - */ -void term_page_scroll_down(term_page *page, unsigned int num, const term_attr *attr, term_age_t age, term_history *history) { - page_scroll_down(page, page->width, num, attr, age, history); -} - -/** - * term_page_insert_lines() - Insert new lines - * @page: page to operate on - * @pos_y: y-position where to insert new lines - * @num: number of lines to insert - * @attr: attributes to set on new lines - * @age: age to use for all modifications - * - * This inserts @num new lines at position @pos_y. If @pos_y is beyond - * boundaries or @num is 0, this is a no-op. - * All lines below @pos_y are moved down to make space for the new lines. Lines - * on the bottom are dropped. Note that this only moves lines above or inside - * the scroll-region. If @pos_y is below the scroll-region, a scroll-region of - * one line is implied (which means the line is simply cleared). - */ -void term_page_insert_lines(term_page *page, unsigned int pos_y, unsigned int num, const term_attr *attr, term_age_t age) { - unsigned int scroll_idx, scroll_num; - - assert(page); - - if (pos_y >= page->height) - return; - if (num >= page->height) - num = page->height; - - /* remember scroll-region */ - scroll_idx = page->scroll_idx; - scroll_num = page->scroll_num; - - /* set scroll-region temporarily so we can reuse scroll_down() */ - { - page->scroll_idx = pos_y; - if (pos_y >= scroll_idx + scroll_num) - page->scroll_num = 1; - else if (pos_y >= scroll_idx) - page->scroll_num -= pos_y - scroll_idx; - else - page->scroll_num += scroll_idx - pos_y; - - term_page_scroll_down(page, num, attr, age, NULL); - } - - /* reset scroll-region */ - page->scroll_idx = scroll_idx; - page->scroll_num = scroll_num; -} - -/** - * term_page_delete_lines() - Delete lines - * @page: page to operate on - * @pos_y: y-position where to delete lines - * @num: number of lines to delete - * @attr: attributes to set on new lines - * @age: age to use for all modifications - * - * This deletes @num lines at position @pos_y. If @pos_y is beyond boundaries or - * @num is 0, this is a no-op. - * All lines below @pos_y are moved up into the newly made space. New lines - * on the bottom are clear. Note that this only moves lines above or inside - * the scroll-region. If @pos_y is below the scroll-region, a scroll-region of - * one line is implied (which means the line is simply cleared). - */ -void term_page_delete_lines(term_page *page, unsigned int pos_y, unsigned int num, const term_attr *attr, term_age_t age) { - unsigned int scroll_idx, scroll_num; - - assert(page); - - if (pos_y >= page->height) - return; - if (num >= page->height) - num = page->height; - - /* remember scroll-region */ - scroll_idx = page->scroll_idx; - scroll_num = page->scroll_num; - - /* set scroll-region temporarily so we can reuse scroll_up() */ - { - page->scroll_idx = pos_y; - if (pos_y >= scroll_idx + scroll_num) - page->scroll_num = 1; - else if (pos_y > scroll_idx) - page->scroll_num -= pos_y - scroll_idx; - else - page->scroll_num += scroll_idx - pos_y; - - term_page_scroll_up(page, num, attr, age, NULL); - } - - /* reset scroll-region */ - page->scroll_idx = scroll_idx; - page->scroll_num = scroll_num; -} - -/** - * term_history_new() - Create new history object - * @out: storage for pointer to new history - * - * Create a new history object. Histories are used to store scrollback-lines - * from VTE pages. You're highly recommended to set a history-limit on - * history->max_lines and trim it via term_history_trim(), otherwise history - * allocations are unlimited. - * - * Returns: 0 on success, negative error code on failure. - */ -int term_history_new(term_history **out) { - _term_history_free_ term_history *history = NULL; - - assert_return(out, -EINVAL); - - history = new0(term_history, 1); - if (!history) - return -ENOMEM; - - history->max_lines = 4096; - - *out = history; - history = NULL; - return 0; -} - -/** - * term_history_free() - Free history - * @history: history to free - * - * Clear and free history. You must not access the object afterwards. - * - * Returns: NULL - */ -term_history *term_history_free(term_history *history) { - if (!history) - return NULL; - - term_history_clear(history); - free(history); - return NULL; -} - -/** - * term_history_clear() - Clear history - * @history: history to clear - * - * Remove all linked lines from a history and reset it to its initial state. - */ -void term_history_clear(term_history *history) { - return term_history_trim(history, 0); -} - -/** - * term_history_trim() - Trim history - * @history: history to trim - * @max: maximum number of lines to be left in history - * - * This removes lines from the history until it is smaller than @max. Lines are - * removed from the top. - */ -void term_history_trim(term_history *history, unsigned int max) { - term_line *line; - - if (!history) - return; - - while (history->n_lines > max && (line = history->lines_first)) { - TERM_LINE_UNLINK(line, history); - term_line_free(line); - --history->n_lines; - } -} - -/** - * term_history_push() - Push line into history - * @history: history to work on - * @line: line to push into history - * - * This pushes a line into the given history. It is linked at the tail. In case - * the history is limited, the top-most line might be freed. - */ -void term_history_push(term_history *history, term_line *line) { - assert(history); - assert(line); - - TERM_LINE_LINK_TAIL(line, history); - if (history->max_lines > 0 && history->n_lines >= history->max_lines) { - line = history->lines_first; - TERM_LINE_UNLINK(line, history); - term_line_free(line); - } else { - ++history->n_lines; - } -} - -/** - * term_history_pop() - Retrieve last line from history - * @history: history to work on - * @new_width: width to reserve and set on the line - * @attr: attributes to use for cell reservation - * @age: age to use for cell reservation - * - * This unlinks the last linked line of the history and returns it. This also - * makes sure the line has the given width pre-allocated (see - * term_line_reserve()). If the pre-allocation fails, this returns NULL, so it - * is treated like there's no line in history left. This simplifies - * history-handling on the caller's side in case of allocation errors. No need - * to throw lines away just because the reservation failed. We can keep them in - * history safely, and make them available as scrollback. - * - * Returns: Line from history or NULL - */ -term_line *term_history_pop(term_history *history, unsigned int new_width, const term_attr *attr, term_age_t age) { - term_line *line; - int r; - - assert_return(history, NULL); - - line = history->lines_last; - if (!line) - return NULL; - - r = term_line_reserve(line, new_width, attr, age, line->width); - if (r < 0) - return NULL; - - term_line_set_width(line, new_width); - TERM_LINE_UNLINK(line, history); - --history->n_lines; - - return line; -} - -/** - * term_history_peek() - Return number of available history-lines - * @history: history to work on - * @max: maximum number of lines to look at - * @reserve_width: width to reserve on the line - * @attr: attributes to use for cell reservation - * @age: age to use for cell reservation - * - * This returns the number of available lines in the history given as @history. - * It returns at most @max. For each line that is looked at, the line is - * verified to have at least @reserve_width cells. Valid cells are preserved, - * new cells are initialized with @attr and @age. In case an allocation fails, - * we bail out and return the number of lines that are valid so far. - * - * Usually, this function should be used before running a loop on - * term_history_pop(). This function guarantees that term_history_pop() (with - * the same arguments) will succeed at least the returned number of times. - * - * Returns: Number of valid lines that can be received via term_history_pop(). - */ -unsigned int term_history_peek(term_history *history, unsigned int max, unsigned int reserve_width, const term_attr *attr, term_age_t age) { - unsigned int num; - term_line *line; - int r; - - assert(history); - - num = 0; - line = history->lines_last; - - while (num < max && line) { - r = term_line_reserve(line, reserve_width, attr, age, line->width); - if (r < 0) - break; - - ++num; - line = line->lines_prev; - } - - return num; -} |