9 files changed, 211 insertions, 0 deletions
diff --git a/include/block.h b/include/block.h
new file mode 100644
index 0000000..c4f8d54
--- /dev/null
+++ b/include/block.h
@@ -0,0 +1,29 @@
+#ifndef BLOCK_H
+#define BLOCK_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "config.h"
+#include "util.h"
+
+typedef struct {
+    const char *const icon;
+    const char *const command;
+    const unsigned int interval;
+    const int signal;
+
+    int pipe[PIPE_FD_COUNT];
+    char output[MAX_BLOCK_OUTPUT_LENGTH * UTF8_MAX_BYTE_COUNT + 1];
+    pid_t fork_pid;
+} block;
+
+block block_new(const char *const icon, const char *const command,
+                const unsigned int interval, const int signal);
+int block_init(block *const block);
+int block_deinit(block *const block);
+int block_execute(block *const block, const uint8_t button);
+int block_update(block *const block);
+
+#endif  // BLOCK_H
diff --git a/include/cli.h b/include/cli.h
new file mode 100644
index 0000000..2f93f62
--- /dev/null
+++ b/include/cli.h
@@ -0,0 +1,12 @@
+#ifndef CLI_H
+#define CLI_H
+
+#include <stdbool.h>
+
+typedef struct {
+    bool is_debug_mode;
+} cli_arguments;
+
+cli_arguments cli_parse_arguments(const char* const argv[], const int argc);
+
+#endif  // CLI_H
diff --git a/include/main.h b/include/main.h
new file mode 100644
index 0000000..b37a6b1
--- /dev/null
+++ b/include/main.h
@@ -0,0 +1,16 @@
+#ifndef MAIN_H
+#define MAIN_H
+
+#include <signal.h>
+
+#include "config.h"
+#include "util.h"
+
+#define REFRESH_SIGNAL SIGUSR1
+
+// Utilise C's adjacent string concatenation to count the number of blocks.
+#define X(...) "."
+enum { BLOCK_COUNT = LEN(BLOCKS(X)) - 1 };
+#undef X
+
+#endif  // MAIN_H
diff --git a/include/signal-handler.h b/include/signal-handler.h
new file mode 100644
index 0000000..da2d471
--- /dev/null
+++ b/include/signal-handler.h
@@ -0,0 +1,33 @@
+#ifndef SIGNAL_HANDLER_H
+#define SIGNAL_HANDLER_H
+
+#include <signal.h>
+
+#include "block.h"
+#include "timer.h"
+
+typedef sigset_t signal_set;
+typedef int (*signal_refresh_callback)(block* const blocks,
+                                       const unsigned short block_count);
+typedef int (*signal_timer_callback)(block* const blocks,
+                                     const unsigned short block_code,
+                                     timer* const timer);
+
+typedef struct {
+    int fd;
+    const signal_refresh_callback refresh_callback;
+    const signal_timer_callback timer_callback;
+
+    block* const blocks;
+    const unsigned short block_count;
+} signal_handler;
+
+signal_handler signal_handler_new(
+    block* const blocks, const unsigned short block_count,
+    const signal_refresh_callback refresh_callback,
+    const signal_timer_callback timer_callback);
+int signal_handler_init(signal_handler* const handler);
+int signal_handler_deinit(signal_handler* const handler);
+int signal_handler_process(signal_handler* const handler, timer* const timer);
+
+#endif  // SIGNAL_HANDLER_H
diff --git a/include/status.h b/include/status.h
new file mode 100644
index 0000000..48fb3d8
--- /dev/null
+++ b/include/status.h
@@ -0,0 +1,31 @@
+#ifndef STATUS_H
+#define STATUS_H
+
+#include <stdbool.h>
+
+#include "block.h"
+#include "config.h"
+#include "main.h"
+#include "util.h"
+#include "x11.h"
+
+typedef struct {
+#define STATUS_LENGTH                                                        \
+    ((BLOCK_COUNT * (MEMBER_LENGTH(block, output) - 1) + CLICKABLE_BLOCKS) + \
+     (BLOCK_COUNT - 1 + LEADING_DELIMITER + TRAILING_DELIMITER) *            \
+         (LEN(DELIMITER) - 1) +                                              \
+     1)
+    char current[STATUS_LENGTH];
+    char previous[STATUS_LENGTH];
+#undef STATUS_LENGTH
+
+    const block* const blocks;
+    const unsigned short block_count;
+} status;
+
+status status_new(const block* const blocks, const unsigned short block_count);
+bool status_update(status* const status);
+int status_write(const status* const status, const bool is_debug_mode,
+                 x11_connection* const connection);
+
+#endif  // STATUS_H
diff --git a/include/timer.h b/include/timer.h
new file mode 100644
index 0000000..1ec7f75
--- /dev/null
+++ b/include/timer.h
@@ -0,0 +1,21 @@
+#ifndef TIMER_H
+#define TIMER_H
+
+#include <signal.h>
+#include <stdbool.h>
+
+#include "block.h"
+
+#define TIMER_SIGNAL SIGALRM
+
+typedef struct {
+    unsigned int time;
+    const unsigned int tick;
+    const unsigned int reset_value;
+} timer;
+
+timer timer_new(const block *const blocks, const unsigned short block_count);
+int timer_arm(timer *const timer);
+bool timer_must_run_block(const timer *const timer, const block *const block);
+
+#endif  // TIMER_H
diff --git a/include/util.h b/include/util.h
new file mode 100644
index 0000000..a3bdcce
--- /dev/null
+++ b/include/util.h
@@ -0,0 +1,28 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <stddef.h>
+
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define LEN(arr)  (sizeof(arr) / sizeof((arr)[0]))
+#define BIT(n)    (1 << (n))
+
+// NOLINTBEGIN(bugprone-macro-parentheses)
+#define MEMBER_SIZE(type, member) sizeof(((type*)NULL)->member)
+#define MEMBER_LENGTH(type, member) \
+    (MEMBER_SIZE(type, member) / MEMBER_SIZE(type, member[0]))
+// NOLINTEND(bugprone-macro-parentheses)
+
+#define UTF8_MAX_BYTE_COUNT 4
+
+enum pipe_fd_index {
+    READ_END,
+    WRITE_END,
+    PIPE_FD_COUNT,
+};
+
+unsigned int gcd(unsigned int a, unsigned int b);
+size_t truncate_utf8_string(char* const buffer, const size_t size,
+                            const size_t char_limit);
+
+#endif  // UTIL_H
diff --git a/include/watcher.h b/include/watcher.h
new file mode 100644
index 0000000..ff31809
--- /dev/null
+++ b/include/watcher.h
@@ -0,0 +1,28 @@
+#ifndef WATCHER_H
+#define WATCHER_H
+
+#include <poll.h>
+#include <stdbool.h>
+
+#include "block.h"
+#include "main.h"
+
+enum watcher_fd_index {
+    SIGNAL_FD = BLOCK_COUNT,
+    WATCHER_FD_COUNT,
+};
+
+typedef struct pollfd watcher_fd;
+
+typedef struct {
+    watcher_fd fds[WATCHER_FD_COUNT];
+    unsigned short active_blocks[BLOCK_COUNT];
+    unsigned short active_block_count;
+    bool got_signal;
+} watcher;
+
+int watcher_init(watcher *const watcher, const block *const blocks,
+                 const unsigned short block_count, const int signal_fd);
+int watcher_poll(watcher *const watcher, const int timeout_ms);
+
+#endif  // WATCHER_H
diff --git a/include/x11.h b/include/x11.h
new file mode 100644
index 0000000..6faaced
--- /dev/null
+++ b/include/x11.h
@@ -0,0 +1,13 @@
+#ifndef X11_H
+#define X11_H
+
+#include <xcb/xcb.h>
+
+typedef xcb_connection_t x11_connection;
+
+x11_connection* x11_connection_open(void);
+void x11_connection_close(x11_connection* const connection);
+int x11_set_root_name(x11_connection* const connection,
+                      const char* const name);
+
+#endif  // X11_H