patch 9.0.0917: the WinScrolled autocommand event is not enough

brammool · brammool · commit 35fc61cb5b5e · 2022-11-22T12:40:50.000Z
Problem: The WinScrolled autocommand event is not enough. Solution: Add WinResized and provide information about what changed. (closes #11576)
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
@@ -1371,33 +1371,42 @@ WinNew				When a new window was created.  Not done for
 				Before a WinEnter event.
 
 							*WinScrolled*
-WinScrolled			After scrolling the content of a window or
-				resizing a window in the current tab page.
-
-				When more than one window scrolled or resized
-				only one WinScrolled event is triggered.  You
-				can use the `winlayout()` and `getwininfo()`
-				functions to see what changed.
+WinScrolled			After any window in the current tab page
+				scrolled the text (horizontally or vertically)
+				or changed width or height.  See
+				|win-scrolled-resized|.
 
 				The pattern is matched against the |window-ID|
 				of the first window that scrolled or resized.
 				Both <amatch> and <afile> are set to the
 				|window-ID|.
 
+				|v:event| is set with information about size
+				and scroll changes. |WinScrolled-event|
+
 				Only starts triggering after startup finished
 				and the first screen redraw was done.
+				Does not trigger when defining the first
+				WinScrolled or WinResized event, but may
+				trigger when adding more.
 
 				Non-recursive: the event will not trigger
 				while executing commands for the WinScrolled
 				event.  However, if the command causes a
 				window to scroll or change size, then another
 				WinScrolled event will be triggered later.
 
-				Does not trigger when the command is added,
-				only after the first scroll or resize.
-							*E1312*
-				It is not allowed to change the window layout
-				here (split, close or move windows).
+
+							*WinResized*
+WinResized			After a window in the current tab page changed
+				width or height.
+				See |win-scrolled-resized|.
+
+				|v:event| is set with information about size
+				changes. |WinResized-event|
+
+				Same behavior as |WinScrolled| for the
+				pattern, triggering and recursiveness.
 
 ==============================================================================
 6. Patterns					*autocmd-patterns* *{aupat}*
diff --git a/runtime/doc/windows.txt b/runtime/doc/windows.txt
@@ -631,6 +631,54 @@ it).
 The minimal height and width of a window is set with 'winminheight' and
 'winminwidth'.  These are hard values, a window will never become smaller.
 
+
+WinScrolled and WinResized autocommands ~
+						*win-scrolled-resized*
+If you want to get notified of changes in window sizes, the |WinResized|
+autocommand event can be used.
+If you want to get notified of text in windows scrolling vertically or
+horizontally, the |WinScrolled| autocommand event can be used.  This will also
+trigger in window size changes.
+							*WinResized-event*
+The |WinResized| event is triggered after updating the display, several
+windows may have changed size then.  A list of the IDs of windows that changed
+since last time is provided in the v:event.windows variable, for example:
+	[1003, 1006]
+							*WinScrolled-event*
+The |WinScrolled| event is triggered after |WinResized|, and also if a window
+was scrolled.  That can be vertically (the text at the top of the window
+changed) or horizontally (when 'wrap' is off or when the first displayed part
+of the first line changes).  Note that |WinScrolled| will trigger many more
+times than |WinResized|, it may slow down editing a bit.
+
+The information provided by |WinScrolled| is a dictionary for each window that
+has changes, using the window ID as the key, and a total count of the changes
+with the key "all".  Example value for |v:event| (|Vim9| syntax):
+	{
+	   all: {width: 0, height: 2, leftcol: 0, topline: 1, skipcol: 0},
+	   1003: {width: 0, height: -1, leftcol: 0, topline: 0, skipcol: 0},
+	   1006: {width: 0, height: 1, leftcol: 0, topline: 1, skipcol: 0},
+	}
+
+Note that the "all" entry has the absolute values of the individual windows
+accumulated.
+
+If you need more information about what changed, or you want to "debounce" the
+events (not handle every event to avoid doing too much work), you may want to
+use the `winlayout()` and `getwininfo()` functions.
+
+|WinScrolled| and |WinResized| do not trigger when the first autocommand is
+added, only after the first scroll or resize.  They may trigger when switching
+to another tab page.
+
+The commands executed are expected to not cause window size or scroll changes.
+If this happens anyway, the event will trigger again very soon.  In other
+words: Just before triggering the event, the current sizes and scroll
+positions are stored and used to decide whether there was a change.
+								*E1312*
+It is not allowed to change the window layout here (split, close or move
+windows).
+
 ==============================================================================
 7. Argument and buffer list commands			*buffer-list*
 
diff --git a/src/autocmd.c b/src/autocmd.c
@@ -191,6 +191,7 @@ static struct event_name
     {"WinClosed",	EVENT_WINCLOSED},
     {"WinEnter",	EVENT_WINENTER},
     {"WinLeave",	EVENT_WINLEAVE},
+    {"WinResized",	EVENT_WINRESIZED},
     {"WinScrolled",	EVENT_WINSCROLLED},
     {"VimResized",	EVENT_VIMRESIZED},
     {"TextYankPost",	EVENT_TEXTYANKPOST},
@@ -1263,10 +1264,11 @@ do_autocmd_event(
 		if (event == EVENT_MODECHANGED && !has_modechanged())
 		    get_mode(last_mode);
 #endif
-		// Initialize the fields checked by the WinScrolled trigger to
-		// prevent it from firing right after the first autocmd is
-		// defined.
-		if (event == EVENT_WINSCROLLED && !has_winscrolled())
+		// Initialize the fields checked by the WinScrolled and
+		// WinResized trigger to prevent them from firing right after
+		// the first autocmd is defined.
+		if ((event == EVENT_WINSCROLLED || event == EVENT_WINRESIZED)
+			&& !(has_winscrolled() || has_winresized()))
 		{
 		    tabpage_T *save_curtab = curtab;
 		    tabpage_T *tp;
@@ -1810,6 +1812,15 @@ trigger_cursorhold(void)
     return FALSE;
 }
 
+/*
+ * Return TRUE when there is a WinResized autocommand defined.
+ */
+    int
+has_winresized(void)
+{
+    return (first_autopat[(int)EVENT_WINRESIZED] != NULL);
+}
+
 /*
  * Return TRUE when there is a WinScrolled autocommand defined.
  */
@@ -2117,6 +2128,7 @@ apply_autocmds_group(
 		|| event == EVENT_MENUPOPUP
 		|| event == EVENT_USER
 		|| event == EVENT_WINCLOSED
+		|| event == EVENT_WINRESIZED
 		|| event == EVENT_WINSCROLLED)
 	{
 	    fname = vim_strsave(fname);
diff --git a/src/dict.c b/src/dict.c
@@ -1082,13 +1082,14 @@ eval_dict(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int literal)
  * Go over all entries in "d2" and add them to "d1".
  * When "action" is "error" then a duplicate key is an error.
  * When "action" is "force" then a duplicate key is overwritten.
+ * When "action" is "move" then move items instead of copying.
  * Otherwise duplicate keys are ignored ("action" is "keep").
+ * "func_name" is used for reporting where an error occurred.
  */
     void
 dict_extend(dict_T *d1, dict_T *d2, char_u *action, char *func_name)
 {
     dictitem_T	*di1;
-    hashitem_T	*hi2;
     int		todo;
     char_u	*arg_errmsg = (char_u *)N_("extend() argument");
     type_T	*type;
@@ -1098,8 +1099,11 @@ dict_extend(dict_T *d1, dict_T *d2, char_u *action, char *func_name)
     else
 	type = NULL;
 
+    if (*action == 'm')
+	hash_lock(&d2->dv_hashtab);  // don't rehash on hash_remove()
+
     todo = (int)d2->dv_hashtab.ht_used;
-    for (hi2 = d2->dv_hashtab.ht_array; todo > 0; ++hi2)
+    for (hashitem_T *hi2 = d2->dv_hashtab.ht_array; todo > 0; ++hi2)
     {
 	if (!HASHITEM_EMPTY(hi2))
 	{
@@ -1116,9 +1120,19 @@ dict_extend(dict_T *d1, dict_T *d2, char_u *action, char *func_name)
 
 	    if (di1 == NULL)
 	    {
-		di1 = dictitem_copy(HI2DI(hi2));
-		if (di1 != NULL && dict_add(d1, di1) == FAIL)
-		    dictitem_free(di1);
+		if (*action == 'm')
+		{
+		    // cheap way to move a dict item from "d2" to "d1"
+		    di1 = HI2DI(hi2);
+		    dict_add(d1, di1);
+		    hash_remove(&d2->dv_hashtab, hi2);
+		}
+		else
+		{
+		    di1 = dictitem_copy(HI2DI(hi2));
+		    if (di1 != NULL && dict_add(d1, di1) == FAIL)
+			dictitem_free(di1);
+		}
 	    }
 	    else if (*action == 'e')
 	    {
@@ -1138,6 +1152,9 @@ dict_extend(dict_T *d1, dict_T *d2, char_u *action, char *func_name)
 	    }
 	}
     }
+
+    if (*action == 'm')
+	hash_unlock(&d2->dv_hashtab);
 }
 
 /*
@@ -1272,7 +1289,7 @@ dict_extend_func(
 	    action = (char_u *)"force";
 
 	if (type != NULL && check_typval_arg_type(type, &argvars[1],
-		    func_name, 2) == FAIL)
+							 func_name, 2) == FAIL)
 	    return;
 	dict_extend(d1, d2, action, func_name);
 
diff --git a/src/edit.c b/src/edit.c
@@ -1510,7 +1510,7 @@ ins_redraw(int ready)	    // not busy with something
     }
 
     if (ready)
-	may_trigger_winscrolled();
+	may_trigger_win_scrolled_resized();
 
     // Trigger SafeState if nothing is pending.
     may_trigger_safestate(ready
diff --git a/src/gui.c b/src/gui.c
@@ -5097,7 +5097,7 @@ gui_update_screen(void)
     }
 
     if (!finish_op)
-	may_trigger_winscrolled();
+	may_trigger_win_scrolled_resized();
 
 # ifdef FEAT_CONCEAL
     if (conceal_update_lines
diff --git a/src/main.c b/src/main.c
@@ -1358,7 +1358,7 @@ main_loop(
 	    validate_cursor();
 
 	    if (!finish_op)
-		may_trigger_winscrolled();
+		may_trigger_win_scrolled_resized();
 
 	    // If nothing is pending and we are going to wait for the user to
 	    // type a character, trigger SafeState.
diff --git a/src/mouse.c b/src/mouse.c
@@ -1171,7 +1171,7 @@ do_mousescroll(cmdarg_T *cap)
 	    leftcol = 0;
 	do_mousescroll_horiz((long_u)leftcol);
     }
-    may_trigger_winscrolled();
+    may_trigger_win_scrolled_resized();
 }
 
 /*
diff --git a/src/proto/autocmd.pro b/src/proto/autocmd.pro
@@ -16,6 +16,7 @@ int apply_autocmds(event_T event, char_u *fname, char_u *fname_io, int force, bu
 int apply_autocmds_exarg(event_T event, char_u *fname, char_u *fname_io, int force, buf_T *buf, exarg_T *eap);
 int apply_autocmds_retval(event_T event, char_u *fname, char_u *fname_io, int force, buf_T *buf, int *retval);
 int trigger_cursorhold(void);
+int has_winresized(void);
 int has_winscrolled(void);
 int has_cursormoved(void);
 int has_cursormovedI(void);
diff --git a/src/proto/window.pro b/src/proto/window.pro
@@ -20,7 +20,7 @@ int one_window(void);
 int win_close(win_T *win, int free_buf);
 void snapshot_windows_scroll_size(void);
 void may_make_initial_scroll_size_snapshot(void);
-void may_trigger_winscrolled(void);
+void may_trigger_win_scrolled_resized(void);
 void win_close_othertab(win_T *win, int free_buf, tabpage_T *tp);
 void win_free_all(void);
 win_T *winframe_remove(win_T *win, int *dirp, tabpage_T *tp);
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
diff --git a/src/version.c b/src/version.c
diff --git a/src/vim.h b/src/vim.h
diff --git a/src/window.c b/src/window.c

Original file line number	Diff line number	Diff line change
`@@ -1510,7 +1510,7 @@ ins_redraw(int ready) // not busy with something`
`1510`	`1510`	`}`
`1511`	`1511`
`1512`	`1512`	`if (ready)`
`1513`		`- may_trigger_winscrolled();`
	`1513`	`+ may_trigger_win_scrolled_resized();`
`1514`	`1514`
`1515`	`1515`	`// Trigger SafeState if nothing is pending.`
`1516`	`1516`	`may_trigger_safestate(ready`
Original file line number	Diff line number	Diff line change
`@@ -5097,7 +5097,7 @@ gui_update_screen(void)`
`5097`	`5097`	`}`
`5098`	`5098`
`5099`	`5099`	`if (!finish_op)`
`5100`		`- may_trigger_winscrolled();`
	`5100`	`+ may_trigger_win_scrolled_resized();`
`5101`	`5101`
`5102`	`5102`	`# ifdef FEAT_CONCEAL`
`5103`	`5103`	`if (conceal_update_lines`
Original file line number	Diff line number	Diff line change
`@@ -1171,7 +1171,7 @@ do_mousescroll(cmdarg_T *cap)`
`1171`	`1171`	`leftcol = 0;`
`1172`	`1172`	`do_mousescroll_horiz((long_u)leftcol);`
`1173`	`1173`	`}`
`1174`		`- may_trigger_winscrolled();`
	`1174`	`+ may_trigger_win_scrolled_resized();`
`1175`	`1175`	`}`
`1176`	`1176`
`1177`	`1177`	`/*`