vim-patch:partial:9.0.0917: the WinScrolled autocommand event is not enough (#21161)

Problem:    The WinScrolled autocommand event is not enough.
Solution:   Add WinResized and provide information about what changed.
            (closes vim/vim#11576)

https://github.com/vim/vim/commit/35fc61cb5b5eba8bbb9d8f0700332fbab38f40ca

Omit "func_name" comment in tv_dict_extend(): Vim9 script only.
Skip layout locking and E1312.
Skip list_alloc_with_items() and list_set_item().

Since this overrides remaining changes in patch 9.0.0913, that patch can
now be marked as fully ported:

vim-patch:9.0.0913: only change in current window triggers the WinScrolled event

N/A patches for version.c:

vim-patch:9.0.0919: build failure with tiny features

Problem:    Build failure with tiny features.
Solution:   Adjust #ifdef's.

https://github.com/vim/vim/commit/9c5b7cb4cf67c64648a324e9dfd1e17d793335a4

Co-authored-by: Bram Moolenaar <Bram@vim.org>

1 files changed, 222 insertions, 20 deletions

diff --git a/src/nvim/window.c b/src/nvim/window.c
index f25e25e905..beb96aaa03 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -5301,39 +5301,241 @@ void may_make_initial_scroll_size_snapshot(void)
   }
 }
 
-/// Trigger WinScrolled if any window scrolled or changed size.
-void may_trigger_winscrolled(void)
+/// Create a dictionary with information about size and scroll changes in a
+/// window.
+/// Returns the dictionary with refcount set to one.
+/// Returns NULL on internal error.
+static dict_T *make_win_info_dict(int width, int height, int topline, int leftcol, int skipcol)
+{
+  dict_T *const d = tv_dict_alloc();
+  d->dv_refcount = 1;
+
+  // not actually looping, for breaking out on error
+  while (1) {
+    typval_T tv = {
+      .v_lock = VAR_UNLOCKED,
+      .v_type = VAR_NUMBER,
+    };
+
+    tv.vval.v_number = width;
+    if (tv_dict_add_tv(d, S_LEN("width"), &tv) == FAIL) {
+      break;
+    }
+    tv.vval.v_number = height;
+    if (tv_dict_add_tv(d, S_LEN("height"), &tv) == FAIL) {
+      break;
+    }
+    tv.vval.v_number = topline;
+    if (tv_dict_add_tv(d, S_LEN("topline"), &tv) == FAIL) {
+      break;
+    }
+    tv.vval.v_number = leftcol;
+    if (tv_dict_add_tv(d, S_LEN("leftcol"), &tv) == FAIL) {
+      break;
+    }
+    tv.vval.v_number = skipcol;
+    if (tv_dict_add_tv(d, S_LEN("skipcol"), &tv) == FAIL) {
+      break;
+    }
+    return d;
+  }
+  tv_dict_unref(d);
+  return NULL;
+}
+
+/// Return values of check_window_scroll_resize():
+enum {
+  CWSR_SCROLLED = 1,  ///< at least one window scrolled
+  CWSR_RESIZED  = 2,  ///< at least one window size changed
+};
+
+/// This function is used for three purposes:
+/// 1. Goes over all windows in the current tab page and returns:
+///      0                               no scrolling and no size changes found
+///      CWSR_SCROLLED                   at least one window scrolled
+///      CWSR_RESIZED                    at least one window changed size
+///      CWSR_SCROLLED + CWSR_RESIZED    both
+///    "size_count" is set to the nr of windows with size changes.
+///    "first_scroll_win" is set to the first window with any relevant changes.
+///    "first_size_win" is set to the first window with size changes.
+///
+/// 2. When the first three arguments are NULL and "winlist" is not NULL,
+///    "winlist" is set to the list of window IDs with size changes.
+///
+/// 3. When the first three arguments are NULL and "v_event" is not NULL,
+///    information about changed windows is added to "v_event".
+static int check_window_scroll_resize(int *size_count, win_T **first_scroll_win,
+                                      win_T **first_size_win, list_T *winlist, dict_T *v_event)
+{
+  int result = 0;
+  // int listidx = 0;
+  int tot_width = 0;
+  int tot_height = 0;
+  int tot_topline = 0;
+  int tot_leftcol = 0;
+  int tot_skipcol = 0;
+
+  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+    const bool size_changed = wp->w_last_width != wp->w_width
+                              || wp->w_last_height != wp->w_height;
+    if (size_changed) {
+      result |= CWSR_RESIZED;
+      if (winlist != NULL) {
+        // Add this window to the list of changed windows.
+        typval_T tv = {
+          .v_lock = VAR_UNLOCKED,
+          .v_type = VAR_NUMBER,
+          .vval.v_number = wp->handle,
+        };
+        // tv_list_set_item(winlist, listidx++, &tv);
+        tv_list_append_owned_tv(winlist, tv);
+      } else if (size_count != NULL) {
+        (*size_count)++;
+        if (*first_size_win == NULL) {
+          *first_size_win = wp;
+        }
+        // For WinScrolled the first window with a size change is used
+        // even when it didn't scroll.
+        if (*first_scroll_win == NULL) {
+          *first_scroll_win = wp;
+        }
+      }
+    }
+
+    const bool scroll_changed = wp->w_last_topline != wp->w_topline
+                                || wp->w_last_leftcol != wp->w_leftcol
+                                || wp->w_last_skipcol != wp->w_skipcol;
+    if (scroll_changed) {
+      result |= CWSR_SCROLLED;
+      if (first_scroll_win != NULL && *first_scroll_win == NULL) {
+        *first_scroll_win = wp;
+      }
+    }
+
+    if ((size_changed || scroll_changed) && v_event != NULL) {
+      // Add info about this window to the v:event dictionary.
+      int width = wp->w_width - wp->w_last_width;
+      int height = wp->w_height - wp->w_last_height;
+      int topline = wp->w_topline - wp->w_last_topline;
+      int leftcol = wp->w_leftcol - wp->w_last_leftcol;
+      int skipcol = wp->w_skipcol - wp->w_last_skipcol;
+      dict_T *d = make_win_info_dict(width, height,
+                                     topline, leftcol, skipcol);
+      if (d == NULL) {
+        break;
+      }
+      char winid[NUMBUFLEN];
+      int key_len = vim_snprintf(winid, sizeof(winid), "%d", wp->handle);
+      if (tv_dict_add_dict(v_event, winid, (size_t)key_len, d) == FAIL) {
+        tv_dict_unref(d);
+        break;
+      }
+      d->dv_refcount--;
+
+      tot_width += abs(width);
+      tot_height += abs(height);
+      tot_topline += abs(topline);
+      tot_leftcol += abs(leftcol);
+      tot_skipcol += abs(skipcol);
+    }
+  }
+
+  if (v_event != NULL) {
+    dict_T *alldict = make_win_info_dict(tot_width, tot_height,
+                                         tot_topline, tot_leftcol, tot_skipcol);
+    if (alldict != NULL) {
+      if (tv_dict_add_dict(v_event, S_LEN("all"), alldict) == FAIL) {
+        tv_dict_unref(alldict);
+      } else {
+        alldict->dv_refcount--;
+      }
+    }
+  }
+
+  return result;
+}
+
+/// Trigger WinScrolled and/or WinResized if any window in the current tab page
+/// scrolled or changed size.
+void may_trigger_win_scrolled_resized(void)
 {
   static bool recursive = false;
+  const bool do_resize = has_event(EVENT_WINRESIZED);
+  const bool do_scroll = has_event(EVENT_WINSCROLLED);
 
   if (recursive
-      || !has_event(EVENT_WINSCROLLED)
+      || !(do_scroll || do_resize)
       || !did_initial_scroll_size_snapshot) {
     return;
   }
 
-  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-    if (wp->w_last_topline != wp->w_topline
-        || wp->w_last_leftcol != wp->w_leftcol
-        || wp->w_last_skipcol != wp->w_skipcol
-        || wp->w_last_width != wp->w_width
-        || wp->w_last_height != wp->w_height) {
-      // WinScrolled is triggered only once, even when multiple windows
-      // scrolled or changed size.  Store the current values before
-      // triggering the event, if a scroll or resize happens as a side
-      // effect then WinScrolled is triggered again later.
-      snapshot_windows_scroll_size();
+  int size_count = 0;
+  win_T *first_scroll_win = NULL, *first_size_win = NULL;
+  int cwsr = check_window_scroll_resize(&size_count,
+                                        &first_scroll_win, &first_size_win,
+                                        NULL, NULL);
+  int trigger_resize = do_resize && size_count > 0;
+  int trigger_scroll = do_scroll && cwsr != 0;
+  if (!trigger_resize && !trigger_scroll) {
+    return;  // no relevant changes
+  }
 
-      char winid[NUMBUFLEN];
-      vim_snprintf(winid, sizeof(winid), "%d", wp->handle);
+  list_T *windows_list = NULL;
+  if (trigger_resize) {
+    // Create the list for v:event.windows before making the snapshot.
+    // windows_list = tv_list_alloc_with_items(size_count);
+    windows_list = tv_list_alloc(size_count);
+    (void)check_window_scroll_resize(NULL, NULL, NULL, windows_list, NULL);
+  }
 
-      recursive = true;
-      apply_autocmds(EVENT_WINSCROLLED, winid, winid, false, wp->w_buffer);
-      recursive = false;
+  dict_T *scroll_dict = NULL;
+  if (trigger_scroll) {
+    // Create the dict with entries for v:event before making the snapshot.
+    scroll_dict = tv_dict_alloc();
+    scroll_dict->dv_refcount = 1;
+    (void)check_window_scroll_resize(NULL, NULL, NULL, NULL, scroll_dict);
+  }
 
-      break;
+  // WinScrolled/WinResized are triggered only once, even when multiple
+  // windows scrolled or changed size.  Store the current values before
+  // triggering the event, if a scroll or resize happens as a side effect
+  // then WinScrolled/WinResized is triggered for that later.
+  snapshot_windows_scroll_size();
+
+  recursive = true;
+
+  // If both are to be triggered do WinResized first.
+  if (trigger_resize) {
+    save_v_event_T save_v_event;
+    dict_T *v_event = get_v_event(&save_v_event);
+
+    if (tv_dict_add_list(v_event, S_LEN("windows"), windows_list) == OK) {
+      tv_dict_set_keys_readonly(v_event);
+
+      char winid[NUMBUFLEN];
+      vim_snprintf(winid, sizeof(winid), "%d", first_size_win->handle);
+      apply_autocmds(EVENT_WINRESIZED, winid, winid, false, first_size_win->w_buffer);
     }
+    restore_v_event(v_event, &save_v_event);
   }
+
+  if (trigger_scroll) {
+    save_v_event_T save_v_event;
+    dict_T *v_event = get_v_event(&save_v_event);
+
+    // Move the entries from scroll_dict to v_event.
+    tv_dict_extend(v_event, scroll_dict, "move");
+    tv_dict_set_keys_readonly(v_event);
+    tv_dict_unref(scroll_dict);
+
+    char winid[NUMBUFLEN];
+    vim_snprintf(winid, sizeof(winid), "%d", first_scroll_win->handle);
+    apply_autocmds(EVENT_WINSCROLLED, winid, winid, false, first_scroll_win->w_buffer);
+
+    restore_v_event(v_event, &save_v_event);
+  }
+
+  recursive = false;
 }
 
 // Save the size of all windows in "gap".