API: Implement window/tabpage switching functions

Also moved `find_buffer` to 'api/helpers.c' and removed unnecessary declaration
in 'window.h'

1 files changed, 27 insertions, 0 deletions

diff --git a/src/api/helpers.c b/src/api/helpers.c
index 40888f351d..9b7ff5fc7c 100644
--- a/src/api/helpers.c
+++ b/src/api/helpers.c
@@ -5,6 +5,7 @@
 #include "api/helpers.h"
 #include "api/defs.h"
 #include "../vim.h"
+#include "../buffer.h"
 #include "../window.h"
 #include "memory.h"
 #include "eval.h"
@@ -266,6 +267,32 @@ Object vim_to_object(typval_T *obj)
   return rv;
 }
 
+buf_T *find_buffer(Buffer buffer, Error *err)
+{
+  buf_T *buf = buflist_findnr(buffer);
+
+  if (buf == NULL) {
+    set_api_error("Invalid buffer id", err);
+  }
+
+  return buf;
+}
+
+win_T * find_window(Window window, Error *err)
+{
+  tabpage_T *tp;
+  win_T *wp;
+
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (!--window) {
+      return wp;
+    }
+  }
+
+  set_api_error("Invalid window id", err);
+  return NULL;
+}
+
 static bool object_to_vim(Object obj, typval_T *tv, Error *err)
 {
   tv->v_type = VAR_UNKNOWN;