ui/term: add line/cell/char handling for terminal pages

This commit introduces libsystemd-ui, a systemd-internal helper library
that will contain all the UI related functionality. It is going to be used
by systemd-welcomed, systemd-consoled, systemd-greeter and systemd-er.
Further use-cases may follow.

For now, this commit only adds terminal-page handling based on lines only.
Follow-up commits will add more functionality.

1 files changed, 463 insertions, 0 deletions

diff --git a/src/libsystemd-terminal/test-term-page.c b/src/libsystemd-terminal/test-term-page.c
new file mode 100644
index 0000000000..bba83ee405
--- /dev/null
+++ b/src/libsystemd-terminal/test-term-page.c
@@ -0,0 +1,463 @@
+/*-*- 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 Tests
+ * This tests internals of terminal page, line, cell and char handling. It
+ * relies on some implementation details, so it might need to be updated if
+ * those internals are changed. They should be fairly obvious, though.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "macro.h"
+#include "term-internal.h"
+#include "util.h"
+
+#define MY_ASSERT_VALS __FILE__, __LINE__, __PRETTY_FUNCTION__
+#define MY_ASSERT_FORW _FILE, _LINE, _FUNC
+#define MY_ASSERT_ARGS const char *_FILE, int _LINE, const char *_FUNC
+#define MY_ASSERT(expr)                                                 \
+        do {                                                            \
+                if (_unlikely_(!(expr)))                                \
+                        log_assert_failed(#expr, _FILE, _LINE, _FUNC);  \
+        } while (false)                                                 \
+
+/*
+ * Character Tests
+ *
+ * These tests rely on some implementation details of term_char_t, including
+ * the way we pack characters and the internal layout of "term_char_t". These
+ * tests have to be updated once we change the implementation.
+ */
+
+#define PACK(v1, v2, v3) \
+                TERM_CHAR_INIT( \
+                        (((((uint64_t)v1) & 0x1fffffULL) << 43) | \
+                         ((((uint64_t)v2) & 0x1fffffULL) << 22) | \
+                         ((((uint64_t)v3) & 0x1fffffULL) <<  1) | \
+                         0x1) \
+                )
+#define PACK1(v1) PACK2((v1), 0x110000)
+#define PACK2(v1, v2) PACK3((v1), (v2), 0x110000)
+#define PACK3(v1, v2, v3) PACK((v1), (v2), (v3))
+
+static void test_term_char_misc(void) {
+        term_char_t c, t;
+
+        /* test TERM_CHAR_NULL handling */
+
+        c = TERM_CHAR_NULL;                     /* c is NULL */
+        assert_se(term_char_same(c, TERM_CHAR_NULL));
+        assert_se(term_char_equal(c, TERM_CHAR_NULL));
+        assert_se(term_char_is_null(c));
+        assert_se(term_char_is_null(TERM_CHAR_NULL));
+        assert_se(!term_char_is_allocated(c));
+
+        /* test single char handling */
+
+        t = term_char_dup_append(c, 'A');       /* t is >A< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(!term_char_equal(c, t));
+        assert_se(!term_char_is_allocated(t));
+        assert_se(!term_char_is_null(t));
+
+        /* test basic combined char handling */
+
+        t = term_char_dup_append(t, '~');
+        t = term_char_dup_append(t, '^');       /* t is >A~^< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(!term_char_is_allocated(t));
+        assert_se(!term_char_is_null(t));
+
+        c = term_char_dup_append(c, 'A');
+        c = term_char_dup_append(c, '~');
+        c = term_char_dup_append(c, '^');       /* c is >A~^< now */
+        assert_se(term_char_same(c, t));
+        assert_se(term_char_equal(c, t));
+
+        /* test more than 2 comb-chars so the chars are allocated */
+
+        t = term_char_dup_append(t, '`');       /* t is >A~^`< now */
+        c = term_char_dup_append(c, '`');       /* c is >A~^`< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(term_char_equal(c, t));
+
+        /* test dup_append() on allocated chars */
+
+        term_char_free(t);
+        t = term_char_dup_append(c, '"');       /* t is >A~^`"< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(!term_char_equal(c, t));
+        c = term_char_merge(c, '"');            /* c is >A~^`"< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(term_char_equal(c, t));
+
+        term_char_free(t);
+        term_char_free(c);
+}
+
+static void test_term_char_packing(void)  {
+        uint32_t seqs[][1024] = {
+                { -1 },
+                { 0, -1 },
+                { 'A', '~', -1 },
+                { 'A', '~', 0, -1 },
+                { 'A', '~', 'a', -1 },
+        };
+        term_char_t res[] = {
+                TERM_CHAR_NULL,
+                PACK1(0),
+                PACK2('A', '~'),
+                PACK3('A', '~', 0),
+                PACK3('A', '~', 'a'),
+        };
+        uint32_t next;
+        unsigned int i, j;
+        term_char_t c = TERM_CHAR_NULL;
+
+        /*
+         * This creates term_char_t objects based on the data in @seqs and
+         * compares the result to @res. Only basic packed types are tested, no
+         * allocations are done.
+         */
+
+        for (i = 0; i < ELEMENTSOF(seqs); ++i) {
+                for (j = 0; j < ELEMENTSOF(seqs[i]); ++j) {
+                        next = seqs[i][j];
+                        if (next == (uint32_t)-1)
+                                break;
+
+                        c = term_char_merge(c, next);
+                }
+
+                assert_se(!memcmp(&c, &res[i], sizeof(c)));
+                c = term_char_free(c);
+        }
+}
+
+static void test_term_char_allocating(void) {
+        uint32_t seqs[][1024] = {
+                { 0, -1 },
+                { 'A', '~', -1 },
+                { 'A', '~', 0, -1 },
+                { 'A', '~', 'a', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', 0, '^', -1 },
+                /* exceeding implementation-defined soft-limit of 64 */
+                { 'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd', -1 },
+        };
+        term_char_t res[] = {
+                PACK1(0),
+                PACK2('A', '~'),
+                PACK3('A', '~', 0),
+                PACK3('A', '~', 'a'),
+                TERM_CHAR_NULL,                 /* allocated */
+                TERM_CHAR_NULL,                 /* allocated */
+                TERM_CHAR_NULL,                 /* allocated */
+        };
+        uint32_t str[][1024] = {
+                { 0, -1 },
+                { 'A', '~', -1 },
+                { 'A', '~', 0, -1 },
+                { 'A', '~', 'a', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', 0, '^', -1 },
+                { 'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd', -1 },
+        };
+        size_t n;
+        uint32_t next;
+        unsigned int i, j;
+        const uint32_t *t;
+
+        /*
+         * This builds term_char_t objects based on the data in @seqs. It
+         * compares the result to @res for packed chars, otherwise it requires
+         * them to be allocated.
+         * After that, we resolve the UCS-4 string and compare it to the
+         * expected strings in @str.
+         */
+
+        for (i = 0; i < ELEMENTSOF(seqs); ++i) {
+                _term_char_free_ term_char_t c = TERM_CHAR_NULL;
+
+                for (j = 0; j < ELEMENTSOF(seqs[i]); ++j) {
+                        next = seqs[i][j];
+                        if (next == (uint32_t)-1)
+                                break;
+
+                        c = term_char_merge(c, next);
+                }
+
+                /* we use TERM_CHAR_NULL as marker for allocated chars here */
+                if (term_char_is_null(res[i]))
+                        assert_se(term_char_is_allocated(c));
+                else
+                        assert_se(!memcmp(&c, &res[i], sizeof(c)));
+
+                t = term_char_resolve(c, &n, NULL);
+                for (j = 0; j < ELEMENTSOF(str[i]); ++j) {
+                        next = str[i][j];
+                        if (next == (uint32_t)-1)
+                                break;
+
+                        assert_se(t[j] == next);
+                }
+
+                assert_se(n == j);
+        }
+}
+
+/*
+ * Line Tests
+ *
+ * The following tests work on term_line objects and verify their behavior when
+ * we modify them. To verify and set line layouts, we have two simple helpers
+ * to avoid harcoding the cell-verification all the time:
+ *   line_set(): Set a line to a given layout
+ *   line_assert(): Verify that a line has a given layout
+ *
+ * These functions take the line-layout encoded as a string and verify it
+ * against, or set it on, a term_line object. The format used to describe a
+ * line looks like this:
+ *       example: "|   | A |   |   |   |   |   | 10 *AB* |"
+ *
+ * The string describes the contents of all cells of a line, separated by
+ * pipe-symbols ('|'). Whitespace are ignored, the leading pipe-symbol is
+ * optional.
+ * The description of each cell can contain an arbitrary amount of characters
+ * in the range 'A'-'Z', 'a'-'z'. All those are combined and used as term_char_t
+ * on this cell. Any numbers in the description are combined and are used as
+ * cell-age.
+ * The occurance of a '*'-symbol marks the cell as bold, '/' marks it as italic.
+ * You can use those characters multiple times, but only the first one has an
+ * effect.
+ * For further symbols, see parse_attr().
+ *
+ * Therefore, the following descriptions are equivalent:
+ *       1) "|   | /A*   |   |   |   |   |   | 10 *AB*  |"
+ *       2) "|   | /A**  |   |   |   |   |   | 10 *AB*  |"
+ *       3) "|   | A* // |   |   |   |   |   | 10 *AB*  |"
+ *       4) "|   | A* // |   |   |   |   |   | 1 *AB* 0 |"
+ *       5) "|   | A* // |   |   |   |   |   | A1B0*    |"
+ *
+ * The parser isn't very strict about placement of alpha/numerical characters,
+ * but simply appends all found chars. Don't make use of that feature! It's
+ * just a stupid parser to simplify these tests. Make them readable!
+ */
+
+static void parse_attr(char c, term_char_t *ch, term_attr *attr, term_age_t *age) {
+        switch (c) {
+        case ' ':
+                /* ignore */
+                break;
+        case '0' ... '9':
+                /* increase age */
+                *age = *age * 10;
+                *age = *age + c - '0';
+                break;
+        case 'A' ... 'Z':
+        case 'a' ... 'z':
+                /* add to character */
+                *ch = term_char_merge(*ch, c);
+                break;
+        case '*':
+                attr->bold = true;
+                break;
+        case '/':
+                attr->italic = true;
+                break;
+        default:
+                assert_se(0);
+                break;
+        }
+}
+
+static void cell_assert(MY_ASSERT_ARGS, term_cell *c, term_char_t ch, const term_attr *attr, term_age_t age) {
+        MY_ASSERT(term_char_equal(c->ch, ch));
+        MY_ASSERT(!memcmp(&c->attr, attr, sizeof(*attr)));
+        MY_ASSERT(c->age == age);
+}
+#define CELL_ASSERT(_cell, _ch, _attr, _age) cell_assert(MY_ASSERT_VALS, (_cell), (_ch), (_attr), (_age))
+
+static void line_assert(MY_ASSERT_ARGS, term_line *l, const char *str, unsigned int fill) {
+        unsigned int cell_i;
+        term_char_t ch = TERM_CHAR_NULL;
+        term_attr attr = { };
+        term_age_t age = TERM_AGE_NULL;
+        char c;
+
+        assert_se(l->fill == fill);
+
+        /* skip leading whitespace */
+        while (*str == ' ')
+                ++str;
+
+        /* skip leading '|' */
+        if (*str == '|')
+                ++str;
+
+        cell_i = 0;
+        while ((c = *str++)) {
+                switch (c) {
+                case '|':
+                        /* end of cell-description; compare it */
+                        assert_se(cell_i < l->n_cells);
+                        cell_assert(MY_ASSERT_FORW,
+                                    &l->cells[cell_i],
+                                    ch,
+                                    &attr,
+                                    age);
+
+                        ++cell_i;
+                        ch = term_char_free(ch);
+                        zero(attr);
+                        age = TERM_AGE_NULL;
+                        break;
+                default:
+                        parse_attr(c, &ch, &attr, &age);
+                        break;
+                }
+        }
+
+        assert_se(cell_i == l->n_cells);
+}
+#define LINE_ASSERT(_line, _str, _fill) line_assert(MY_ASSERT_VALS, (_line), (_str), (_fill))
+
+static void line_set(term_line *l, unsigned int pos, const char *str, bool insert_mode) {
+        term_char_t ch = TERM_CHAR_NULL;
+        term_attr attr = { };
+        term_age_t age = TERM_AGE_NULL;
+        char c;
+
+        while ((c = *str++))
+                parse_attr(c, &ch, &attr, &age);
+
+        term_line_write(l, pos, ch, 1, &attr, age, insert_mode);
+}
+
+static void line_resize(term_line *l, unsigned int width, const term_attr *attr, term_age_t age) {
+        assert_se(term_line_reserve(l, width, attr, age, width) >= 0);
+        term_line_set_width(l, width);
+}
+
+static void test_term_line_misc(void) {
+        term_line *l;
+
+        assert_se(term_line_new(&l) >= 0);
+        assert_se(!term_line_free(l));
+
+        assert_se(term_line_new(NULL) < 0);
+        assert_se(!term_line_free(NULL));
+
+        assert_se(term_line_new(&l) >= 0);
+        assert_se(l->n_cells == 0);
+        assert_se(l->fill == 0);
+        assert_se(term_line_reserve(l, 16, NULL, 0, 0) >= 0);
+        assert_se(l->n_cells == 16);
+        assert_se(l->fill == 0);
+        assert_se(term_line_reserve(l, 512, NULL, 0, 0) >= 0);
+        assert_se(l->n_cells == 512);
+        assert_se(l->fill == 0);
+        assert_se(term_line_reserve(l, 16, NULL, 0, 0) >= 0);
+        assert_se(l->n_cells == 512);
+        assert_se(l->fill == 0);
+        assert_se(!term_line_free(l));
+}
+
+static void test_term_line_ops(void) {
+        term_line *l;
+        term_attr attr_regular = { };
+        term_attr attr_bold = { .bold = true };
+        term_attr attr_italic = { .italic = true };
+
+        assert_se(term_line_new(&l) >= 0);
+        line_resize(l, 8, NULL, 0);
+        assert_se(l->n_cells == 8);
+
+        LINE_ASSERT(l, "| | | | | | | | |", 0);
+
+        term_line_write(l, 4, TERM_CHAR_NULL, 0, NULL, TERM_AGE_NULL, 0);
+        LINE_ASSERT(l, "| | | | | | | | |", 5);
+
+        term_line_write(l, 1, PACK1('A'), 1, NULL, TERM_AGE_NULL, 0);
+        LINE_ASSERT(l, "| |A| | | | | | |", 5);
+
+        term_line_write(l, 8, PACK2('A', 'B'), 1, NULL, TERM_AGE_NULL, 0);
+        LINE_ASSERT(l, "| |A| | | | | | |", 5);
+
+        term_line_write(l, 7, PACK2('A', 'B'), 1, &attr_regular, 10, 0);
+        LINE_ASSERT(l, "| |A| | | | | | 10 AB |", 8);
+
+        term_line_write(l, 7, PACK2('A', 'B'), 1, &attr_bold, 10, 0);
+        LINE_ASSERT(l, "| |A| | | | | | 10 *AB* |", 8);
+
+        term_line_reset(l, NULL, TERM_AGE_NULL);
+
+        LINE_ASSERT(l, "|   |   |          |          |          |   |   |   |", 0);
+        line_set(l, 2, "*wxyz* 8", 0);
+        line_set(l, 3, "/wxyz/ 8", 0);
+        LINE_ASSERT(l, "|   |   | *wxyz* 8 | /wxyz/ 8 |          |   |   |   |", 4);
+        line_set(l, 2, "*abc* 9", true);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 9 | 9 |", 5);
+        line_set(l, 7, "*abc* 10", true);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 9 | *abc* 10 |", 8);
+
+        term_line_erase(l, 6, 1, NULL, 11, 0);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 11 | *abc* 10 |", 8);
+        term_line_erase(l, 6, 2, &attr_italic, 12, 0);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 12 // | 12 // |", 6);
+        term_line_erase(l, 7, 2, &attr_regular, 13, 0);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 12 // | 13 |", 6);
+        term_line_delete(l, 1, 3, &attr_bold, 14);
+        LINE_ASSERT(l, "|   | /wxyz/ 14 | 14 | 14 // | 14 | 14 ** | 14 ** | 14 ** |", 3);
+        term_line_insert(l, 2, 2, &attr_regular, 15);
+        LINE_ASSERT(l, "|   | /wxyz/ 14 | 15 | 15 | 15 | 15 // | 15 | 15 ** |", 5);
+
+        assert_se(!term_line_free(l));
+}
+
+int main(int argc, char *argv[]) {
+        test_term_char_misc();
+        test_term_char_packing();
+        test_term_char_allocating();
+
+        test_term_line_misc();
+        test_term_line_ops();
+
+        return 0;
+}