From be5022138495d2e509735dec7486a040d3e2eb2d Mon Sep 17 00:00:00 2001

From: David Herrmann <dh.herrmann@gmail.com>

Date: Thu, 2 Oct 2014 19:31:43 +0200

Subject: [PATCH] terminal: add screen renderer

We don't want to expose the term_screen internals for rendering.

Therefore, provide an iterator that allows external renderers to draw

terminals.

---

 src/libsystemd-terminal/term-screen.c | 66 +++++++++++++++++++++++++++++++++++

 src/libsystemd-terminal/term.h        | 12 +++++++

 2 files changed, 78 insertions(+)

diff --git a/src/libsystemd-terminal/term-screen.c b/src/libsystemd-terminal/term-screen.c

index 2f3f6f91cb..b442b96050 100644

--- a/src/libsystemd-terminal/term-screen.c

+++ b/src/libsystemd-terminal/term-screen.c

@@ -3892,3 +3892,69 @@ int term_screen_set_answerback(term_screen *screen, const char *answerback) {

         return 0;

 }

+

+int term_screen_draw(term_screen *screen,

+                     int (*draw_fn) (term_screen *screen,

+                                     void *userdata,

+                                     unsigned int x,

+                                     unsigned int y,

+                                     const term_attr *attr,

+                                     const uint32_t *ch,

+                                     size_t n_ch,

+                                     unsigned int ch_width),

+                     void *userdata,

+                     uint64_t *fb_age) {

+        uint64_t cell_age, line_age, age = 0;

+        term_charbuf_t ch_buf;

+        const uint32_t *ch_str;

+        unsigned int i, j, cw;

+        term_page *page;

+        term_line *line;

+        term_cell *cell;

+        size_t ch_n;

+        int r;

+

+        assert(screen);

+        assert(draw_fn);

+

+        if (fb_age)

+                age = *fb_age;

+

+        page = screen->page;

+

+        for (j = 0; j < page->height; ++j) {

+                line = page->lines[j];

+                line_age = MAX(line->age, page->age);

+

+                for (i = 0; i < page->width; ++i) {

+                        cell = &line->cells[i];

+                        cell_age = MAX(cell->age, line_age);

+

+                        if (age != 0 && cell_age <= age)

+                                continue;

+

+                        ch_str = term_char_resolve(cell->ch, &ch_n, &ch_buf);

+

+                        /* Character-width of 0 is used for cleared cells.

+                         * Always treat this as single-cell character, so

+                         * renderers can assume ch_width is set properpy. */

+                        cw = MAX(cell->cwidth, 1U);

+

+                        r = draw_fn(screen,

+                                    userdata,

+                                    i,

+                                    j,

+                                    &cell->attr,

+                                    ch_str,

+                                    ch_n,

+                                    cw);

+                        if (r != 0)

+                                return r;

+                }

+        }

+

+        if (fb_age)

+                *fb_age = screen->age++;

+

+        return 0;

+}

diff --git a/src/libsystemd-terminal/term.h b/src/libsystemd-terminal/term.h

index d5b934fc59..a3ca252e31 100644

--- a/src/libsystemd-terminal/term.h

+++ b/src/libsystemd-terminal/term.h

@@ -147,3 +147,15 @@ 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);

+

+int term_screen_draw(term_screen *screen,

+                     int (*draw_fn) (term_screen *screen,

+                                     void *userdata,

+                                     unsigned int x,

+                                     unsigned int y,

+                                     const term_attr *attr,

+                                     const uint32_t *ch,

+                                     size_t n_ch,

+                                     unsigned int ch_width),

+                     void *userdata,

+                     uint64_t *fb_age);