terminal: add screen-handling

The screen-layer represents the terminal-side (compared to the host-side).
It connects term_parser with term_page and implements all the required
control sequences.

We do not implement all available control sequences. Even though our
parser recognizes them, there is no need to handle them. Most of them are
legacy or unused. We try to be as compatible to xterm, so if we missed
something, we can implement it later. However, all the VT510 / VT440 stuff
can safely be skipped (who needs terminal macros? WTF?).

The keyboard-handling is still missing. It will be added once
systemd-console is available and we pulled in the key-definitions.

1 files changed, 227 insertions, 131 deletions

diff --git a/src/libsystemd-terminal/term-internal.h b/src/libsystemd-terminal/term-internal.h
index a3d1f5458b..345996b943 100644
--- a/src/libsystemd-terminal/term-internal.h
+++ b/src/libsystemd-terminal/term-internal.h
@@ -42,6 +42,8 @@ typedef struct term_seq term_seq;
 typedef struct term_parser term_parser;
 typedef uint32_t term_charset[96];
 
+typedef struct term_screen term_screen;
+
 /*
  * Miscellaneous
  * Sundry things and external helpers.
@@ -433,8 +435,8 @@ enum {
         TERM_CMD_DA1,                           /* primary-device-attributes */
         TERM_CMD_DA2,                           /* secondary-device-attributes */
         TERM_CMD_DA3,                           /* tertiary-device-attributes */
-        TERM_CMD_DC1,                           /* device-control-1 */
-        TERM_CMD_DC3,                           /* device-control-3 */
+        TERM_CMD_DC1,                           /* device-control-1 or XON */
+        TERM_CMD_DC3,                           /* device-control-3 or XOFF */
         TERM_CMD_DCH,                           /* delete-character */
         TERM_CMD_DECALN,                        /* screen-alignment-pattern */
         TERM_CMD_DECANM,                        /* ansi-mode */
@@ -445,135 +447,135 @@ enum {
         TERM_CMD_DECDHL_BH,                     /* double-width-double-height-line: bottom half */
         TERM_CMD_DECDHL_TH,                     /* double-width-double-height-line: top half */
         TERM_CMD_DECDWL,                        /* double-width-single-height-line */
-        TERM_CMD_DECEFR,
-        TERM_CMD_DECELF,
-        TERM_CMD_DECELR,
-        TERM_CMD_DECERA,
-        TERM_CMD_DECFI,
-        TERM_CMD_DECFRA,
-        TERM_CMD_DECIC,
-        TERM_CMD_DECID,
-        TERM_CMD_DECINVM,
-        TERM_CMD_DECKBD,
-        TERM_CMD_DECKPAM,
-        TERM_CMD_DECKPNM,
-        TERM_CMD_DECLFKC,
-        TERM_CMD_DECLL,
-        TERM_CMD_DECLTOD,
-        TERM_CMD_DECPCTERM,
-        TERM_CMD_DECPKA,
-        TERM_CMD_DECPKFMR,
-        TERM_CMD_DECRARA,
-        TERM_CMD_DECRC,
-        TERM_CMD_DECREQTPARM,
-        TERM_CMD_DECRPKT,
-        TERM_CMD_DECRQCRA,
-        TERM_CMD_DECRQDE,
-        TERM_CMD_DECRQKT,
-        TERM_CMD_DECRQLP,
-        TERM_CMD_DECRQM_ANSI,
-        TERM_CMD_DECRQM_DEC,
-        TERM_CMD_DECRQPKFM,
-        TERM_CMD_DECRQPSR,
-        TERM_CMD_DECRQTSR,
-        TERM_CMD_DECRQUPSS,
-        TERM_CMD_DECSACE,
-        TERM_CMD_DECSASD,
-        TERM_CMD_DECSC,
-        TERM_CMD_DECSCA,
-        TERM_CMD_DECSCL,
-        TERM_CMD_DECSCP,
-        TERM_CMD_DECSCPP,
-        TERM_CMD_DECSCS,
-        TERM_CMD_DECSCUSR,
-        TERM_CMD_DECSDDT,
-        TERM_CMD_DECSDPT,
-        TERM_CMD_DECSED,
-        TERM_CMD_DECSEL,
-        TERM_CMD_DECSERA,
-        TERM_CMD_DECSFC,
-        TERM_CMD_DECSKCV,
-        TERM_CMD_DECSLCK,
-        TERM_CMD_DECSLE,
-        TERM_CMD_DECSLPP,
-        TERM_CMD_DECSLRM_OR_SC,
-        TERM_CMD_DECSMBV,
-        TERM_CMD_DECSMKR,
-        TERM_CMD_DECSNLS,
-        TERM_CMD_DECSPP,
-        TERM_CMD_DECSPPCS,
-        TERM_CMD_DECSPRTT,
-        TERM_CMD_DECSR,
-        TERM_CMD_DECSRFR,
-        TERM_CMD_DECSSCLS,
-        TERM_CMD_DECSSDT,
-        TERM_CMD_DECSSL,
-        TERM_CMD_DECST8C,
-        TERM_CMD_DECSTBM,
-        TERM_CMD_DECSTR,
-        TERM_CMD_DECSTRL,
-        TERM_CMD_DECSWBV,
-        TERM_CMD_DECSWL,
-        TERM_CMD_DECTID,
-        TERM_CMD_DECTME,
-        TERM_CMD_DECTST,
-        TERM_CMD_DL,
-        TERM_CMD_DSR_ANSI,
-        TERM_CMD_DSR_DEC,
-        TERM_CMD_ECH,
-        TERM_CMD_ED,
-        TERM_CMD_EL,
-        TERM_CMD_ENQ,
-        TERM_CMD_EPA,
-        TERM_CMD_FF,
-        TERM_CMD_HPA,
-        TERM_CMD_HPR,
-        TERM_CMD_HT,
-        TERM_CMD_HTS,
-        TERM_CMD_HVP,
-        TERM_CMD_ICH,
-        TERM_CMD_IL,
-        TERM_CMD_IND,
-        TERM_CMD_LF,
-        TERM_CMD_LS1R,
-        TERM_CMD_LS2,
-        TERM_CMD_LS2R,
-        TERM_CMD_LS3,
-        TERM_CMD_LS3R,
-        TERM_CMD_MC_ANSI,
-        TERM_CMD_MC_DEC,
-        TERM_CMD_NEL,
-        TERM_CMD_NP,
-        TERM_CMD_NULL,
-        TERM_CMD_PP,
-        TERM_CMD_PPA,
-        TERM_CMD_PPB,
-        TERM_CMD_PPR,
-        TERM_CMD_RC,
-        TERM_CMD_REP,
-        TERM_CMD_RI,
-        TERM_CMD_RIS,
-        TERM_CMD_RM_ANSI,
-        TERM_CMD_RM_DEC,
-        TERM_CMD_S7C1T,
-        TERM_CMD_S8C1T,
-        TERM_CMD_SCS,
-        TERM_CMD_SD,
-        TERM_CMD_SGR,
-        TERM_CMD_SI,
-        TERM_CMD_SM_ANSI,
-        TERM_CMD_SM_DEC,
-        TERM_CMD_SO,
-        TERM_CMD_SPA,
-        TERM_CMD_SS2,
-        TERM_CMD_SS3,
-        TERM_CMD_ST,
-        TERM_CMD_SU,
-        TERM_CMD_SUB,
-        TERM_CMD_TBC,
-        TERM_CMD_VPA,
-        TERM_CMD_VPR,
-        TERM_CMD_VT,
+        TERM_CMD_DECEFR,                        /* enable-filter-rectangle */
+        TERM_CMD_DECELF,                        /* enable-local-functions */
+        TERM_CMD_DECELR,                        /* enable-locator-reporting */
+        TERM_CMD_DECERA,                        /* erase-rectangular-area */
+        TERM_CMD_DECFI,                         /* forward-index */
+        TERM_CMD_DECFRA,                        /* fill-rectangular-area */
+        TERM_CMD_DECIC,                         /* insert-column */
+        TERM_CMD_DECID,                         /* return-terminal-id */
+        TERM_CMD_DECINVM,                       /* invoke-macro */
+        TERM_CMD_DECKBD,                        /* keyboard-language-selection */
+        TERM_CMD_DECKPAM,                       /* keypad-application-mode */
+        TERM_CMD_DECKPNM,                       /* keypad-numeric-mode */
+        TERM_CMD_DECLFKC,                       /* local-function-key-control */
+        TERM_CMD_DECLL,                         /* load-leds */
+        TERM_CMD_DECLTOD,                       /* load-time-of-day */
+        TERM_CMD_DECPCTERM,                     /* pcterm-mode */
+        TERM_CMD_DECPKA,                        /* program-key-action */
+        TERM_CMD_DECPKFMR,                      /* program-key-free-memory-report */
+        TERM_CMD_DECRARA,                       /* reverse-attributes-in-rectangular-area */
+        TERM_CMD_DECRC,                         /* restore-cursor */
+        TERM_CMD_DECREQTPARM,                   /* request-terminal-parameters */
+        TERM_CMD_DECRPKT,                       /* report-key-type */
+        TERM_CMD_DECRQCRA,                      /* request-checksum-of-rectangular-area */
+        TERM_CMD_DECRQDE,                       /* request-display-extent */
+        TERM_CMD_DECRQKT,                       /* request-key-type */
+        TERM_CMD_DECRQLP,                       /* request-locator-position */
+        TERM_CMD_DECRQM_ANSI,                   /* request-mode-ansi */
+        TERM_CMD_DECRQM_DEC,                    /* request-mode-dec */
+        TERM_CMD_DECRQPKFM,                     /* request-program-key-free-memory */
+        TERM_CMD_DECRQPSR,                      /* request-presentation-state-report */
+        TERM_CMD_DECRQTSR,                      /* request-terminal-state-report */
+        TERM_CMD_DECRQUPSS,                     /* request-user-preferred-supplemental-set */
+        TERM_CMD_DECSACE,                       /* select-attribute-change-extent */
+        TERM_CMD_DECSASD,                       /* select-active-status-display */
+        TERM_CMD_DECSC,                         /* save-cursor */
+        TERM_CMD_DECSCA,                        /* select-character-protection-attribute */
+        TERM_CMD_DECSCL,                        /* select-conformance-level */
+        TERM_CMD_DECSCP,                        /* select-communication-port */
+        TERM_CMD_DECSCPP,                       /* select-columns-per-page */
+        TERM_CMD_DECSCS,                        /* select-communication-speed */
+        TERM_CMD_DECSCUSR,                      /* set-cursor-style */
+        TERM_CMD_DECSDDT,                       /* select-disconnect-delay-time */
+        TERM_CMD_DECSDPT,                       /* select-digital-printed-data-type */
+        TERM_CMD_DECSED,                        /* selective-erase-in-display */
+        TERM_CMD_DECSEL,                        /* selective-erase-in-line */
+        TERM_CMD_DECSERA,                       /* selective-erase-rectangular-area */
+        TERM_CMD_DECSFC,                        /* select-flow-control */
+        TERM_CMD_DECSKCV,                       /* set-key-click-volume */
+        TERM_CMD_DECSLCK,                       /* set-lock-key-style */
+        TERM_CMD_DECSLE,                        /* select-locator-events */
+        TERM_CMD_DECSLPP,                       /* set-lines-per-page */
+        TERM_CMD_DECSLRM_OR_SC,                 /* set-left-and-right-margins or save-cursor */
+        TERM_CMD_DECSMBV,                       /* set-margin-bell-volume */
+        TERM_CMD_DECSMKR,                       /* select-modifier-key-reporting */
+        TERM_CMD_DECSNLS,                       /* set-lines-per-screen */
+        TERM_CMD_DECSPP,                        /* set-port-parameter */
+        TERM_CMD_DECSPPCS,                      /* select-pro-printer-character-set */
+        TERM_CMD_DECSPRTT,                      /* select-printer-type */
+        TERM_CMD_DECSR,                         /* secure-reset */
+        TERM_CMD_DECSRFR,                       /* select-refresh-rate */
+        TERM_CMD_DECSSCLS,                      /* set-scroll-speed */
+        TERM_CMD_DECSSDT,                       /* select-status-display-line-type */
+        TERM_CMD_DECSSL,                        /* select-setup-language */
+        TERM_CMD_DECST8C,                       /* set-tab-at-every-8-columns */
+        TERM_CMD_DECSTBM,                       /* set-top-and-bottom-margins */
+        TERM_CMD_DECSTR,                        /* soft-terminal-reset */
+        TERM_CMD_DECSTRL,                       /* set-transmit-rate-limit */
+        TERM_CMD_DECSWBV,                       /* set-warning-bell-volume */
+        TERM_CMD_DECSWL,                        /* single-width-single-height-line */
+        TERM_CMD_DECTID,                        /* select-terminal-id */
+        TERM_CMD_DECTME,                        /* terminal-mode-emulation */
+        TERM_CMD_DECTST,                        /* invoke-confidence-test */
+        TERM_CMD_DL,                            /* delete-line */
+        TERM_CMD_DSR_ANSI,                      /* device-status-report-ansi */
+        TERM_CMD_DSR_DEC,                       /* device-status-report-dec */
+        TERM_CMD_ECH,                           /* erase-character */
+        TERM_CMD_ED,                            /* erase-in-display */
+        TERM_CMD_EL,                            /* erase-in-line */
+        TERM_CMD_ENQ,                           /* enquiry */
+        TERM_CMD_EPA,                           /* end-of-guarded-area */
+        TERM_CMD_FF,                            /* form-feed */
+        TERM_CMD_HPA,                           /* horizontal-position-absolute */
+        TERM_CMD_HPR,                           /* horizontal-position-relative */
+        TERM_CMD_HT,                            /* horizontal-tab */
+        TERM_CMD_HTS,                           /* horizontal-tab-set */
+        TERM_CMD_HVP,                           /* horizontal-and-vertical-position */
+        TERM_CMD_ICH,                           /* insert-character */
+        TERM_CMD_IL,                            /* insert-line */
+        TERM_CMD_IND,                           /* index */
+        TERM_CMD_LF,                            /* line-feed */
+        TERM_CMD_LS1R,                          /* locking-shift-1-right */
+        TERM_CMD_LS2,                           /* locking-shift-2 */
+        TERM_CMD_LS2R,                          /* locking-shift-2-right */
+        TERM_CMD_LS3,                           /* locking-shift-3 */
+        TERM_CMD_LS3R,                          /* locking-shift-3-right */
+        TERM_CMD_MC_ANSI,                       /* media-copy-ansi */
+        TERM_CMD_MC_DEC,                        /* media-copy-dec */
+        TERM_CMD_NEL,                           /* next-line */
+        TERM_CMD_NP,                            /* next-page */
+        TERM_CMD_NULL,                          /* null */
+        TERM_CMD_PP,                            /* preceding-page */
+        TERM_CMD_PPA,                           /* page-position-absolute */
+        TERM_CMD_PPB,                           /* page-position-backward */
+        TERM_CMD_PPR,                           /* page-position-relative */
+        TERM_CMD_RC,                            /* restore-cursor */
+        TERM_CMD_REP,                           /* repeat */
+        TERM_CMD_RI,                            /* reverse-index */
+        TERM_CMD_RIS,                           /* reset-to-initial-state */
+        TERM_CMD_RM_ANSI,                       /* reset-mode-ansi */
+        TERM_CMD_RM_DEC,                        /* reset-mode-dec */
+        TERM_CMD_S7C1T,                         /* set-7bit-c1-terminal */
+        TERM_CMD_S8C1T,                         /* set-8bit-c1-terminal */
+        TERM_CMD_SCS,                           /* select-character-set */
+        TERM_CMD_SD,                            /* scroll-down */
+        TERM_CMD_SGR,                           /* select-graphics-rendition */
+        TERM_CMD_SI,                            /* shift-in */
+        TERM_CMD_SM_ANSI,                       /* set-mode-ansi */
+        TERM_CMD_SM_DEC,                        /* set-mode-dec */
+        TERM_CMD_SO,                            /* shift-out */
+        TERM_CMD_SPA,                           /* start-of-protected-area */
+        TERM_CMD_SS2,                           /* single-shift-2 */
+        TERM_CMD_SS3,                           /* single-shift-3 */
+        TERM_CMD_ST,                            /* string-terminator */
+        TERM_CMD_SU,                            /* scroll-up */
+        TERM_CMD_SUB,                           /* substitute */
+        TERM_CMD_TBC,                           /* tab-clear */
+        TERM_CMD_VPA,                           /* vertical-line-position-absolute */
+        TERM_CMD_VPR,                           /* vertical-line-position-relative */
+        TERM_CMD_VT,                            /* vertical-tab */
         TERM_CMD_XTERM_CLLHP,                   /* xterm-cursor-lower-left-hp-bugfix */
         TERM_CMD_XTERM_IHMT,                    /* xterm-initiate-highlight-mouse-tracking*/
         TERM_CMD_XTERM_MLHP,                    /* xterm-memory-lock-hp-bugfix */
@@ -684,3 +686,97 @@ int term_parser_feed(term_parser *parser, const term_seq **seq_out, uint32_t raw
 
 #define _term_parser_free_ _cleanup_(term_parser_freep)
 DEFINE_TRIVIAL_CLEANUP_FUNC(term_parser*, term_parser_free);
+
+/*
+ * Screens
+ * A term_screen object represents the terminal-side of the communication. It
+ * connects the term-parser and term-pages and handles all required commands.
+ * All state is managed by it.
+ */
+
+enum {
+        TERM_FLAG_7BIT_MODE                     = (1U << 0),    /* 7bit mode (default: off) */
+        TERM_FLAG_HIDE_CURSOR                   = (1U << 1),    /* hide cursor caret (default: off) */
+        TERM_FLAG_INHIBIT_TPARM                 = (1U << 2),    /* do not send TPARM unrequested (default: off) */
+        TERM_FLAG_NEWLINE_MODE                  = (1U << 3),    /* perform carriage-return on line-feeds (default: off) */
+        TERM_FLAG_ORIGIN_MODE                   = (1U << 4),    /* in origin mode, the cursor is bound by the margins (default: off) */
+        TERM_FLAG_PENDING_WRAP                  = (1U << 5),    /* wrap-around is pending */
+        TERM_FLAG_AUTO_WRAP                     = (1U << 6),    /* auto-wrap mode causes line-wraps at line-ends (default: off) */
+        TERM_FLAG_KEYPAD_MODE                   = (1U << 7),    /* application-keypad mode (default: off) */
+        TERM_FLAG_CURSOR_KEYS                   = (1U << 8),    /* enable application cursor-keys (default: off) */
+};
+
+enum {
+        TERM_CONFORMANCE_LEVEL_VT52,
+        TERM_CONFORMANCE_LEVEL_VT100,
+        TERM_CONFORMANCE_LEVEL_VT400,
+        TERM_CONFORMANCE_LEVEL_CNT,
+};
+
+typedef int (*term_screen_write_fn) (term_screen *screen, void *userdata, const void *buf, size_t size);
+typedef int (*term_screen_cmd_fn) (term_screen *screen, void *userdata, unsigned int cmd, const term_seq *seq);
+
+struct term_screen {
+        unsigned long ref;
+        term_age_t age;
+
+        term_page *page;
+        term_page *page_main;
+        term_page *page_alt;
+        term_history *history;
+        term_history *history_main;
+
+        unsigned int n_tabs;
+        uint8_t *tabs;
+
+        term_utf8 utf8;
+        term_parser *parser;
+
+        term_screen_write_fn write_fn;
+        void *write_fn_data;
+        term_screen_cmd_fn cmd_fn;
+        void *cmd_fn_data;
+
+        unsigned int flags;
+        unsigned int conformance_level;
+        unsigned int cursor_x;
+        unsigned int cursor_y;
+        term_attr attr;
+        term_attr default_attr;
+
+        term_charset **gl;
+        term_charset **gr;
+        term_charset **glt;
+        term_charset **grt;
+        term_charset *g0;
+        term_charset *g1;
+        term_charset *g2;
+        term_charset *g3;
+
+        char *answerback;
+
+        struct {
+                unsigned int cursor_x;
+                unsigned int cursor_y;
+                term_attr attr;
+                term_charset **gl;
+                term_charset **gr;
+                term_charset **glt;
+                term_charset **grt;
+                unsigned int flags;
+        } saved;
+};
+
+int term_screen_new(term_screen **out, term_screen_write_fn write_fn, void *write_fn_data, term_screen_cmd_fn cmd_fn, void *cmd_fn_data);
+term_screen *term_screen_ref(term_screen *screen);
+term_screen *term_screen_unref(term_screen *screen);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(term_screen*, term_screen_unref);
+
+int term_screen_feed_text(term_screen *screen, const uint8_t *in, size_t size);
+int term_screen_feed_keyboard(term_screen *screen, uint32_t keysym, uint32_t ascii, uint32_t ucs4, unsigned int mods);
+int term_screen_resize(term_screen *screen, unsigned int width, unsigned int height);
+void term_screen_soft_reset(term_screen *screen);
+void term_screen_hard_reset(term_screen *screen);
+
+int term_screen_set_answerback(term_screen *screen, const char *answerback);