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authorPřemysl Janouch <p.janouch@gmail.com>2014-10-18 20:34:53 +0200
committerPřemysl Janouch <p.janouch@gmail.com>2014-10-22 22:22:26 +0200
commit70bcfde0212b4009467f8551c197743b70355b99 (patch)
tree7fae97c86695ab8ad13cd818f09c57bc67b9b5f8 /demo-draw.c
parent86025fcf6fd8b58de0dee23c4fd2c33daad38e17 (diff)
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Add a demo for drawing in curses
Diffstat (limited to 'demo-draw.c')
-rw-r--r--demo-draw.c230
1 files changed, 230 insertions, 0 deletions
diff --git a/demo-draw.c b/demo-draw.c
new file mode 100644
index 0000000..85d81fc
--- /dev/null
+++ b/demo-draw.c
@@ -0,0 +1,230 @@
+// <poll.h> might need this for sigset_t
+#define _XOPEN_SOURCE 600
+
+#include <stdio.h>
+#include <unistd.h>
+#include <locale.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <poll.h>
+#include <signal.h>
+
+#include <curses.h>
+#include "termo.h"
+
+typedef struct app_data app_data_t;
+struct app_data
+{
+ termo_t *tk;
+
+ // Current attributes for the left mouse button
+ int current_attrs_left;
+ // Current attributes for the right mouse button
+ int current_attrs_right;
+};
+
+static int g_winch_pipe[2];
+
+static void
+display (const char *format, ...)
+{
+ va_list ap;
+
+ mvwhline (stdscr, 0, 0, A_REVERSE, COLS);
+ attron (A_REVERSE);
+
+ va_start (ap, format);
+ vw_printw (stdscr, format, ap);
+ va_end (ap);
+
+ attroff (A_REVERSE);
+ refresh ();
+}
+
+static void
+init_palette (app_data_t *app)
+{
+ start_color ();
+
+ // Also does init_pair (0, -1, -1);
+ use_default_colors ();
+ // Duplicate it for convenience.
+ init_pair (9, -1, -1);
+
+ // Add the basic 8 colors to the default pair. Once normally, once
+ // inverted to workaround VTE's inability to set a bright background.
+ for (int i = 0; i < 8; i++)
+ {
+ init_pair (1 + i, COLOR_WHITE, COLOR_BLACK + i);
+ init_pair (10 + i, COLOR_BLACK + i, COLOR_WHITE);
+ }
+
+ // This usually creates a solid black or white.
+ app->current_attrs_left =
+ app->current_attrs_right = COLOR_PAIR (9) | A_REVERSE | A_BOLD;
+}
+
+static void
+redraw (void)
+{
+ int i;
+
+ mvwhline (stdscr, 1, 0, A_REVERSE, COLS);
+ mvwhline (stdscr, 2, 0, A_REVERSE, COLS);
+
+ for (i = 0; i < COLS; i++)
+ {
+ int pair = (float) i / COLS * 9;
+ mvaddch (1, i, ' ' | COLOR_PAIR (pair));
+ mvaddch (2, i, ' ' | COLOR_PAIR (pair + 9) | A_REVERSE | A_BOLD);
+ }
+
+ display ("Choose a color from the palette and draw. "
+ "Press Escape or ^C to quit.");
+ refresh ();
+}
+
+static bool
+on_key (app_data_t *app, termo_key_t *key)
+{
+ if (key->type == TERMO_TYPE_KEYSYM
+ && key->code.sym == TERMO_SYM_ESCAPE)
+ return false;
+
+ if (key->type == TERMO_TYPE_KEY
+ && (key->modifiers & TERMO_KEYMOD_CTRL)
+ && (key->code.codepoint == 'C' || key->code.codepoint == 'c'))
+ return false;
+
+ if (key->type != TERMO_TYPE_MOUSE)
+ return true;
+
+ int line, col, button;
+ termo_mouse_event_t event;
+
+ termo_interpret_mouse (app->tk, key, &event, &button, &line, &col);
+ if (event != TERMO_MOUSE_PRESS && event != TERMO_MOUSE_DRAG)
+ return true;
+
+ int *attrs;
+ if (button == 1)
+ attrs = &app->current_attrs_left;
+ else if (button == 3)
+ attrs = &app->current_attrs_right;
+ else
+ return true;
+
+ chtype ch = mvwinch (stdscr, line, col);
+ if (line >= 3)
+ {
+ // Paste the attributes where the user clicked.
+ addch (' ' | *attrs);
+ refresh ();
+ }
+ else if (line > 0)
+ // Copy attributes from the pallete.
+ *attrs = ch & (A_COLOR | A_ATTRIBUTES);
+
+ return true;
+}
+
+static void
+winch_handler (int signum)
+{
+ (void) signum;
+ write (g_winch_pipe[1], "x", 1);
+}
+
+int
+main (int argc, char *argv[])
+{
+ (void) argc;
+ (void) argv;
+
+ TERMO_CHECK_VERSION;
+ setlocale (LC_CTYPE, "");
+
+ struct sigaction act;
+ act.sa_handler = winch_handler;
+ act.sa_flags = SA_RESTART;
+ sigemptyset (&act.sa_mask);
+
+ // Set up a self-pipe so that we can actually poll on SIGWINCH
+ if (sigaction (SIGWINCH, &act, NULL) || pipe (g_winch_pipe))
+ {
+ fprintf (stderr, "Cannot set up signal handler\n");
+ exit (EXIT_FAILURE);
+ }
+
+ termo_t *tk = termo_new (STDIN_FILENO, NULL, 0);
+ if (!tk)
+ {
+ fprintf (stderr, "Cannot allocate termo instance\n");
+ exit (EXIT_FAILURE);
+ }
+
+ termo_set_mouse_proto (tk, termo_guess_mouse_proto (tk));
+ termo_set_mouse_tracking_mode (tk, TERMO_MOUSE_TRACKING_DRAG);
+
+ // Set up curses for our drawing needs
+ if (!initscr () || nonl () == ERR || curs_set (0) == ERR)
+ {
+ fprintf (stderr, "Cannot initialize curses\n");
+ exit (EXIT_FAILURE);
+ }
+
+ app_data_t app;
+ memset (&app, 0, sizeof app);
+ app.tk = tk;
+
+ init_palette (&app);
+ redraw ();
+
+ termo_result_t ret;
+ termo_key_t key;
+
+ // We listen for mouse/key input and terminal resize events
+ struct pollfd fds[2] =
+ {
+ { .fd = STDIN_FILENO, .events = POLLIN },
+ { .fd = g_winch_pipe[0], .events = POLLIN },
+ };
+
+ // Run a simple event loop with poll()
+ int nextwait = -1;
+ bool running = true;
+ while (running)
+ {
+ if (!poll (fds, 2, nextwait))
+ if (termo_getkey_force (tk, &key) == TERMO_RES_KEY)
+ running &= on_key (&app, &key);
+
+ if (fds[1].revents & (POLLIN | POLLHUP | POLLERR))
+ {
+ char x;
+ read (fds[1].fd, &x, 1);
+
+ // The "official" simple and flicker-prone method of resizing
+ // the internal buffers of curses
+ endwin ();
+ refresh ();
+
+ redraw ();
+ }
+ if (fds[0].revents & (POLLIN | POLLHUP | POLLERR))
+ termo_advisereadable (tk);
+
+ while ((ret = termo_getkey (tk, &key)) == TERMO_RES_KEY)
+ running &= on_key (&app, &key);
+
+ nextwait = -1;
+ if (ret == TERMO_RES_AGAIN)
+ nextwait = termo_get_waittime (tk);
+ }
+
+ endwin ();
+ termo_destroy (tk);
+}
+