API: Implement window/tabpage switching functions

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

6 files changed, 105 insertions, 45 deletions

diff --git a/src/api/buffer.c b/src/api/buffer.c
index 39c69f1ce7..d5b46943da 100644
--- a/src/api/buffer.c
+++ b/src/api/buffer.c
@@ -14,8 +14,6 @@
 #include "../window.h"
 #include "undo.h"
 
-static buf_T *find_buffer(Buffer buffer, Error *err);
-
 // Find a window that contains "buf" and switch to it.
 // If there is no such window, use the current window and change "curbuf".
 // Caller must initialize save_curbuf to NULL.
@@ -198,17 +196,6 @@ Position buffer_mark(Buffer buffer, String name, Error *err)
   abort();
 }
 
-static 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;
-}
-
 static void switch_to_win_for_buf(buf_T *buf,
                                   win_T **save_curwinp,
                                   tabpage_T **save_curtabp,
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;
diff --git a/src/api/helpers.h b/src/api/helpers.h
index d98ed3b22b..f9b8a81c16 100644
--- a/src/api/helpers.h
+++ b/src/api/helpers.h
@@ -66,5 +66,19 @@ void set_option_to(void *to, int type, String name, Object value, Error *err);
 /// @return The converted value
 Object vim_to_object(typval_T *obj);
 
+/// Finds the pointer for a window number
+///
+/// @param window the window number
+/// @param[out] err Details of an error that may have occurred
+/// @return the window pointer
+buf_T *find_buffer(Buffer buffer, Error *err);
+
+/// Finds the pointer for a window number
+///
+/// @param window the window number
+/// @param[out] err Details of an error that may have occurred
+/// @return the window pointer
+win_T * find_window(Window window, Error *err);
+
 #endif /* NEOVIM_API_HELPERS_H */
 
diff --git a/src/api/vim.c b/src/api/vim.c
index 6b04c4b7a5..bf7db27110 100644
--- a/src/api/vim.c
+++ b/src/api/vim.c
@@ -9,6 +9,7 @@
 #include "api/buffer.h"
 #include "../vim.h"
 #include "../buffer.h"
+#include "../window.h"
 #include "types.h"
 #include "ascii.h"
 #include "ex_docmd.h"
@@ -209,42 +210,87 @@ void vim_set_current_buffer(Buffer buffer, Error *err)
 
 int64_t vim_get_window_count(void)
 {
-  abort();
-}
+  tabpage_T *tp;
+  win_T *wp;
+  uint64_t rv = 0;
 
-Window vim_get_window(int64_t num, Error *err)
-{
-  abort();
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    rv++;
+  }
+
+  return rv;
 }
 
 Window vim_get_current_window(void)
 {
+  tabpage_T *tp;
+  win_T *wp;
+  Window rv = 1;
+
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (wp == curwin) {
+      return rv;
+    }
+
+    rv++;
+  }
+
+  // There should always be a current window
   abort();
 }
 
-void vim_set_current_window(Window window)
+void vim_set_current_window(Window window, Error *err)
 {
-  abort();
+  win_T *win = find_window(window, err);
+
+  if (!win) {
+    return;
+  }
+
+  try_start();
+  win_goto(win);
+
+  if (win != curwin) {
+    if (try_end(err)) {
+      return;
+    }
+    set_api_error("did not switch to the specified window", err);
+    return;
+  }
+
+  try_end(err);
 }
 
 int64_t vim_get_tabpage_count(void)
 {
-  abort();
-}
+  tabpage_T *tp = first_tabpage;
+  uint64_t rv = 0;
 
-Tabpage vim_get_tabpage(int64_t num, Error *err)
-{
-  abort();
+  while (tp != NULL) {
+    tp = tp->tp_next;
+    rv++;
+  }
+
+  return rv;
 }
 
 Tabpage vim_get_current_tabpage(void)
 {
-  abort();
+  Tabpage rv = 1;
+  tabpage_T *t;
+
+  for (t = first_tabpage; t != NULL && t != curtab; t = t->tp_next) {
+    rv++;
+  }
+
+  return rv;
 }
 
-void vim_set_current_tabpage(Tabpage tabpage)
+void vim_set_current_tabpage(Tabpage tabpage, Error *err)
 {
-  abort();
+  try_start();
+  goto_tabpage(tabpage);
+  try_end(err);
 }
 
 static void write_msg(String message, bool to_err)
diff --git a/src/api/vim.h b/src/api/vim.h
index e310842e5b..19de6554a6 100644
--- a/src/api/vim.h
+++ b/src/api/vim.h
@@ -117,13 +117,6 @@ void vim_set_current_buffer(Buffer buffer, Error *err);
 /// @return The number of windows
 int64_t vim_get_window_count(void);
 
-/// Gets a window by index
-///
-/// @param num The window number
-/// @param[out] err Details of an error that may have occurred
-/// @return The window handle
-Window vim_get_window(int64_t num, Error *err);
-
 /// Return the current window
 ///
 /// @return The window handle
@@ -132,20 +125,13 @@ Window vim_get_current_window(void);
 /// Sets the current window
 ///
 /// @param handle The window handle
-void vim_set_current_window(Window window);
+void vim_set_current_window(Window window, Error *err);
 
 /// Gets the number of tab pages
 ///
 /// @return The number of tab pages
 int64_t vim_get_tabpage_count(void);
 
-/// Gets a tab page by index
-///
-/// @param num The tabpage number
-/// @param[out] err Details of an error that may have occurred
-/// @return The tab page handle
-Tabpage vim_get_tabpage(int64_t num, Error *err);
-
 /// Return the current tab page
 ///
 /// @return The tab page handle
@@ -154,7 +140,8 @@ Tabpage vim_get_current_tabpage(void);
 /// Sets the current tab page
 ///
 /// @param handle The tab page handle
-void vim_set_current_tabpage(Tabpage tabpage);
+/// @param[out] err Details of an error that may have occurred
+void vim_set_current_tabpage(Tabpage tabpage, Error *err);
 
 #endif // NEOVIM_API_VIM_H
 
diff --git a/src/window.h b/src/window.h
index f276938873..86a5bba2b4 100644
--- a/src/window.h
+++ b/src/window.h
@@ -34,7 +34,6 @@ void goto_tabpage_tp(tabpage_T *tp, int trigger_enter_autocmds,
 void goto_tabpage_win(tabpage_T *tp, win_T *wp);
 void tabpage_move(int nr);
 void win_goto(win_T *wp);
-win_T *win_find_nr(int winnr);
 tabpage_T *win_find_tabpage(win_T *win);
 void win_enter(win_T *wp, int undo_sync);
 win_T *buf_jump_open_win(buf_T *buf);