1 files changed, 95 insertions, 0 deletions
diff --git a/src/minibuffer.c b/src/minibuffer.c
new file mode 100644
index 0000000..4e6e3b7
--- /dev/null
+++ b/src/minibuffer.c
@@ -0,0 +1,95 @@
+#include "minibuffer.h"
+#include "display.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static struct minibuffer g_minibuffer = {0};
+
+void minibuffer_init(uint32_t row) {
+  g_minibuffer.buffer = malloc(4096);
+  g_minibuffer.capacity = 4096;
+  g_minibuffer.nbytes = 0;
+  g_minibuffer.row = row;
+  g_minibuffer.dirty = false;
+}
+
+void minibuffer_destroy() {
+  free(g_minibuffer.buffer);
+  g_minibuffer.capacity = 0;
+  g_minibuffer.dirty = false;
+}
+
+struct minibuffer_update minibuffer_update(alloc_fn frame_alloc) {
+  // TODO: multiline
+  if (g_minibuffer.nbytes == 0 && !g_minibuffer.dirty) {
+    return (struct minibuffer_update){.cmds = NULL, .ncmds = 0};
+  }
+
+  struct timespec current;
+  clock_gettime(CLOCK_MONOTONIC, &current);
+  if (current.tv_sec < g_minibuffer.expires.tv_sec) {
+    struct render_cmd *cmds =
+        (struct render_cmd *)frame_alloc(sizeof(struct render_cmd));
+
+    cmds[0].col = 0;
+    cmds[0].row = g_minibuffer.row;
+    cmds[0].data = g_minibuffer.buffer;
+    cmds[0].len = g_minibuffer.nbytes;
+
+    g_minibuffer.dirty = false;
+
+    return (struct minibuffer_update){
+        .cmds = cmds,
+        .ncmds = 1,
+    };
+  } else {
+    g_minibuffer.nbytes = 0;
+    g_minibuffer.dirty = false;
+    // send a clear draw command
+    struct render_cmd *cmds =
+        (struct render_cmd *)frame_alloc(sizeof(struct render_cmd));
+
+    cmds[0].col = 0;
+    cmds[0].row = g_minibuffer.row;
+    cmds[0].data = NULL;
+    cmds[0].len = 0;
+
+    return (struct minibuffer_update){
+        .cmds = cmds,
+        .ncmds = 1,
+    };
+  }
+}
+
+void echo(uint32_t timeout, const char *fmt, va_list args) {
+  size_t nbytes =
+      vsnprintf((char *)g_minibuffer.buffer, g_minibuffer.capacity, fmt, args);
+
+  // vsnprintf returns how many characters it would have wanted to write in case
+  // of overflow
+  g_minibuffer.nbytes =
+      nbytes > g_minibuffer.capacity ? g_minibuffer.capacity : nbytes;
+  g_minibuffer.dirty = true;
+
+  clock_gettime(CLOCK_MONOTONIC, &g_minibuffer.expires);
+  g_minibuffer.expires.tv_sec += timeout;
+}
+
+void minibuffer_echo(const char *fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  echo(1000, fmt, args);
+  va_end(args);
+}
+
+void minibuffer_echo_timeout(uint32_t timeout, const char *fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  echo(timeout, fmt, args);
+  va_end(args);
+}
+
+bool minibuffer_displaying() { return g_minibuffer.nbytes > 0; }
+void minibuffer_clear() { g_minibuffer.expires.tv_nsec = 0; }