Add repaint-mode bind function

If we switch the bind mode, we add a "force-repaint" there just to
redraw the mode indicator.

That's quite wasteful and annoying, considering that sometimes the prompt can take
half a second.

So we add a "repaint-mode" function that just reexecutes the
mode-prompt and uses the cached values for the others.

Fixes #5783.

share/functions/fish_vi_key_bindings.fish

@@ -63,7 +63,7 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     # Add a way to switch from insert to normal (command) mode.
     # Note if we are paging, we want to stay in insert mode
     # See #2871
-    bind -s --preset -M insert \e "if commandline -P; commandline -f cancel; else; set fish_bind_mode default; commandline -f backward-char force-repaint; end"
+    bind -s --preset -M insert \e "if commandline -P; commandline -f cancel; else; set fish_bind_mode default; commandline -f backward-char repaint-mode; end"
 
     # Default (command) mode
     bind -s --preset :q exit
@@ -72,14 +72,14 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     bind -s --preset -M default l forward-char
     bind -s --preset -m insert \n execute
     bind -s --preset -m insert \r execute
-    bind -s --preset -m insert i force-repaint
+    bind -s --preset -m insert i repaint-mode
-    bind -s --preset -m insert I beginning-of-line force-repaint
+    bind -s --preset -m insert I beginning-of-line repaint-mode
-    bind -s --preset -m insert a forward-char force-repaint
+    bind -s --preset -m insert a forward-char repaint-mode
-    bind -s --preset -m insert A end-of-line force-repaint
+    bind -s --preset -m insert A end-of-line repaint-mode
-    bind -s --preset -m visual v begin-selection force-repaint
+    bind -s --preset -m visual v begin-selection repaint-mode
 
-    #bind -s --preset -m insert o "commandline -a \n" down-line force-repaint
+    #bind -s --preset -m insert o "commandline -a \n" down-line repaint-mode
-    #bind -s --preset -m insert O beginning-of-line "commandline -i \n" up-line force-repaint # doesn't work
+    #bind -s --preset -m insert O beginning-of-line "commandline -i \n" up-line repaint-mode # doesn't work
 
     bind -s --preset gg beginning-of-buffer
     bind -s --preset G end-of-buffer
@@ -154,24 +154,24 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     bind -s --preset dF begin-selection backward-jump kill-selection end-selection
     bind -s --preset dT begin-selection backward-jump forward-char kill-selection end-selection
 
-    bind -s --preset -m insert s delete-char force-repaint
+    bind -s --preset -m insert s delete-char repaint-mode
-    bind -s --preset -m insert S kill-whole-line force-repaint
+    bind -s --preset -m insert S kill-whole-line repaint-mode
-    bind -s --preset -m insert cc kill-whole-line force-repaint
+    bind -s --preset -m insert cc kill-whole-line repaint-mode
-    bind -s --preset -m insert C kill-line force-repaint
+    bind -s --preset -m insert C kill-line repaint-mode
-    bind -s --preset -m insert c\$ kill-line force-repaint
+    bind -s --preset -m insert c\$ kill-line repaint-mode
-    bind -s --preset -m insert c\^ backward-kill-line force-repaint
+    bind -s --preset -m insert c\^ backward-kill-line repaint-mode
-    bind -s --preset -m insert cw kill-word force-repaint
+    bind -s --preset -m insert cw kill-word repaint-mode
-    bind -s --preset -m insert cW kill-bigword force-repaint
+    bind -s --preset -m insert cW kill-bigword repaint-mode
-    bind -s --preset -m insert ciw forward-char forward-char backward-word kill-word force-repaint
+    bind -s --preset -m insert ciw forward-char forward-char backward-word kill-word repaint-mode
-    bind -s --preset -m insert ciW forward-char forward-char backward-bigword kill-bigword force-repaint
+    bind -s --preset -m insert ciW forward-char forward-char backward-bigword kill-bigword repaint-mode
-    bind -s --preset -m insert caw forward-char forward-char backward-word kill-word force-repaint
+    bind -s --preset -m insert caw forward-char forward-char backward-word kill-word repaint-mode
-    bind -s --preset -m insert caW forward-char forward-char backward-bigword kill-bigword force-repaint
+    bind -s --preset -m insert caW forward-char forward-char backward-bigword kill-bigword repaint-mode
-    bind -s --preset -m insert ce kill-word force-repaint
+    bind -s --preset -m insert ce kill-word repaint-mode
-    bind -s --preset -m insert cE kill-bigword force-repaint
+    bind -s --preset -m insert cE kill-bigword repaint-mode
-    bind -s --preset -m insert cb backward-kill-word force-repaint
+    bind -s --preset -m insert cb backward-kill-word repaint-mode
-    bind -s --preset -m insert cB backward-kill-bigword force-repaint
+    bind -s --preset -m insert cB backward-kill-bigword repaint-mode
-    bind -s --preset -m insert cge backward-kill-word force-repaint
+    bind -s --preset -m insert cge backward-kill-word repaint-mode
-    bind -s --preset -m insert cgE backward-kill-bigword force-repaint
+    bind -s --preset -m insert cgE backward-kill-bigword repaint-mode
 
     bind -s --preset '~' capitalize-word
     bind -s --preset gu downcase-word
@@ -215,9 +215,9 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     #
     # Lowercase r, enters replace_one mode
     #
-    bind -s --preset -m replace_one r force-repaint
+    bind -s --preset -m replace_one r repaint-mode
-    bind -s --preset -M replace_one -m default '' delete-char self-insert backward-char force-repaint
+    bind -s --preset -M replace_one -m default '' delete-char self-insert backward-char repaint-mode
-    bind -s --preset -M replace_one -m default \e cancel force-repaint
+    bind -s --preset -M replace_one -m default \e cancel repaint-mode
 
     #
     # visual mode
@@ -236,7 +236,7 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     bind -s --preset -M visual W forward-bigword
     bind -s --preset -M visual e forward-word
     bind -s --preset -M visual E forward-bigword
-    bind -s --preset -M visual o swap-selection-start-stop force-repaint
+    bind -s --preset -M visual o swap-selection-start-stop repaint-mode
 
     bind -s --preset -M visual f forward-jump
     bind -s --preset -M visual t forward-jump-till
@@ -250,15 +250,15 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
         bind -s --preset -M visual $key beginning-of-line
     end
 
-    bind -s --preset -M visual -m insert c kill-selection end-selection force-repaint
+    bind -s --preset -M visual -m insert c kill-selection end-selection repaint-mode
-    bind -s --preset -M visual -m default d kill-selection end-selection force-repaint
+    bind -s --preset -M visual -m default d kill-selection end-selection repaint-mode
-    bind -s --preset -M visual -m default x kill-selection end-selection force-repaint
+    bind -s --preset -M visual -m default x kill-selection end-selection repaint-mode
-    bind -s --preset -M visual -m default X kill-whole-line end-selection force-repaint
+    bind -s --preset -M visual -m default X kill-whole-line end-selection repaint-mode
-    bind -s --preset -M visual -m default y kill-selection yank end-selection force-repaint
+    bind -s --preset -M visual -m default y kill-selection yank end-selection repaint-mode
-    bind -s --preset -M visual -m default '"*y' "commandline -s | xsel -p; commandline -f end-selection force-repaint"
+    bind -s --preset -M visual -m default '"*y' "commandline -s | xsel -p; commandline -f end-selection repaint-mode"
 
-    bind -s --preset -M visual -m default \cc end-selection force-repaint
+    bind -s --preset -M visual -m default \cc end-selection repaint-mode
-    bind -s --preset -M visual -m default \e end-selection force-repaint
+    bind -s --preset -M visual -m default \e end-selection repaint-mode
 
     # Make it easy to turn an unexecuted command into a comment in the shell history. Also, remove
     # the commenting chars so the command can be further edited then executed.

sphinx_doc_src/cmds/bind.rst

@@ -136,6 +136,10 @@ The following special input functions are available:
 
 - ``pager-toggle-search``, toggles the search field if the completions pager is visible.
 
+- ``repaint`` reexecutes the prompt functions and redraws the prompt. Multiple successive repaints are coalesced.
+
+- ``repaint-mode`` reexecutes the fish_mode_prompt function and redraws the prompt. This is useful for vi-mode.
+
 - ``suppress-autosuggestion``, remove the current autosuggestion
 
 - ``swap-selection-start-stop``, go to the other end of the highlighted text without changing the selection

src/input.cpp

@@ -112,6 +112,7 @@ static const input_function_metadata_t input_function_metadata[] = {
     {readline_cmd_t::execute, L"execute"},
     {readline_cmd_t::beginning_of_buffer, L"beginning-of-buffer"},
     {readline_cmd_t::end_of_buffer, L"end-of-buffer"},
+    {readline_cmd_t::repaint_mode, L"repaint-mode"},
     {readline_cmd_t::repaint, L"repaint"},
     {readline_cmd_t::force_repaint, L"force-repaint"},
     {readline_cmd_t::up_line, L"up-line"},

src/input_common.h

@@ -50,6 +50,7 @@ enum class readline_cmd_t {
     execute,
     beginning_of_buffer,
     end_of_buffer,
+    repaint_mode,
     repaint,
     force_repaint,
     up_line,

src/reader.cpp

@@ -357,6 +357,7 @@ class reader_data_t : public std::enable_shared_from_this<reader_data_t> {
     wcstring right_prompt;
     /// The output of the last evaluation of the prompt command.
     wcstring left_prompt_buff;
+    wcstring mode_prompt_buff;
     /// The output of the last evaluation of the right prompt command.
     wcstring right_prompt_buff;
     /// Completion support.
@@ -461,6 +462,7 @@ class reader_data_t : public std::enable_shared_from_this<reader_data_t> {
 
     void highlight_search();
     void highlight_complete(highlight_result_t result);
+    void exec_mode_prompt();
     void exec_prompt();
 
     bool jump(jump_direction_t dir, jump_precision_t precision, editable_line_t *el,
@@ -641,7 +643,8 @@ void reader_data_t::repaint() {
     bool focused_on_pager = active_edit_line() == &pager.search_field_line;
     size_t cursor_position = focused_on_pager ? pager.cursor_position() : cmd_line->position;
 
-    s_write(&screen, left_prompt_buff, right_prompt_buff, full_line, cmd_line->size(), colors,
+    // Prepend the mode prompt to the left prompt.
+    s_write(&screen, mode_prompt_buff + left_prompt_buff, right_prompt_buff, full_line, cmd_line->size(), colors,
             indents, cursor_position, current_page_rendering, focused_on_pager);
 
     repaint_needed = false;
@@ -904,6 +907,20 @@ void reader_write_title(const wcstring &cmd, bool reset_cursor_position) {
     }
 }
 
+void reader_data_t::exec_mode_prompt() {
+    mode_prompt_buff.clear();
+    if (function_exists(MODE_PROMPT_FUNCTION_NAME)) {
+        wcstring_list_t mode_indicator_list;
+        exec_subshell(MODE_PROMPT_FUNCTION_NAME, parser(), mode_indicator_list,
+                      false);
+        // We do not support multiple lines in the mode indicator, so just concatenate all of
+        // them.
+        for (size_t i = 0; i < mode_indicator_list.size(); i++) {
+            mode_prompt_buff += mode_indicator_list.at(i);
+        }
+    }
+}
+
 /// Reexecute the prompt command. The output is inserted into prompt_buff.
 void reader_data_t::exec_prompt() {
     // Clear existing prompts.
@@ -921,17 +938,7 @@ void reader_data_t::exec_prompt() {
     if (left_prompt.size() || right_prompt.size()) {
         proc_push_interactive(0);
 
-        // Prepend any mode indicator to the left prompt (issue #1988).
+        exec_mode_prompt();
-        if (function_exists(MODE_PROMPT_FUNCTION_NAME)) {
-            wcstring_list_t mode_indicator_list;
-            exec_subshell(MODE_PROMPT_FUNCTION_NAME, parser(), mode_indicator_list,
-                          apply_exit_status);
-            // We do not support multiple lines in the mode indicator, so just concatenate all of
-            // them.
-            for (size_t i = 0; i < mode_indicator_list.size(); i++) {
-                left_prompt_buff += mode_indicator_list.at(i);
-            }
-        }
 
         if (!left_prompt.empty()) {
             wcstring_list_t prompt_list;
@@ -2503,6 +2510,16 @@ void reader_data_t::handle_readline_command(readline_cmd_t c, readline_loop_stat
             // The only thing we can cancel right now is paging, which we handled up above.
             break;
         }
+        case rl::repaint_mode: {
+            // Repaint the mode-prompt only if it exists.
+            // This is an optimization basically exclusively for vi-mode, since the prompt
+            // may sometimes take a while but when switching the mode all we care about is the mode-prompt.
+            exec_mode_prompt();
+            s_reset(&screen, screen_reset_current_line_and_prompt);
+            screen_reset_needed = false;
+            repaint();
+            break;
+        }
         case rl::force_repaint:
         case rl::repaint: {
             if (!rls.coalescing_repaints) {