Re: [PATCH] gdb/tui: add 'set tui mouse-events off' to restore mouse selection

[Andrew Burgess <aburgess@redhat.com>]

strager via Gdb-patches <gdb-patches@sourceware.org> writes:

> Oops, I forgot to cc gdb-patches@.
>
>> Instead of talking about overriding the terminal's behavior, this text
>> should say that the mouse events are interpreted either by GDB or by
>> the terminal.
>
> Thanks for the feedback. I removed the duplicate copy of 'set tui
> compact-source' documentation. I rewrote the 'set tui mouse-events'
> documentation to avoid mentioning 'overriding'. I also fixed a typo in
> the 'show tui mouse-events' command and fixed a typo in the commit
> message (see attached).
>
> ---
>  gdb/NEWS            |  6 ++++++
>  gdb/doc/gdb.texinfo |  6 ++++++
>  gdb/tui/tui-io.c    |  3 ++-
>  gdb/tui/tui-win.c   | 23 +++++++++++++++++++++++
>  gdb/tui/tui-win.h   |  3 +++
>  5 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git gdb/NEWS gdb/NEWS
> index 445d28efed9..21399e86caa 100644
> --- gdb/NEWS
> +++ gdb/NEWS
> @@ -38,6 +38,12 @@ maintenance print record-instruction [ N ]
>    prints how GDB would undo the N-th previous instruction, and if N is
>    positive, it prints how GDB will redo the N-th following instruction.
>
> +set tui mouse-events [on|off]
> +show tui mouse-events
> +  When on (default), mouse clicks control the TUI and can be accessed by
> +  plugins.  When off, mouse clicks are handled by the terminal.  This enables
> +  terminal-native text selection.
> +
>  * MI changes
>
>  ** mi now reports 'no-history' as a stop reason when hitting the end of the
> diff --git gdb/doc/gdb.texinfo gdb/doc/gdb.texinfo
> index 03033c7f9e3..02de9ad753a 100644
> --- gdb/doc/gdb.texinfo
> +++ gdb/doc/gdb.texinfo
> @@ -29888,6 +29888,12 @@ source text at the next tab stop; the compact
> display uses only as
>  much space as is needed for the line numbers in the current file, and
>  only a single space to separate the line numbers from the source.
>
> +@item set tui mouse-events @r{[}on@r{|}off@r{]}
> +@kindex set tui mouse-events
> +When on (default), mouse clicks control the TUI and can be accessed by plugins.
> +When off, mouse clicks are handled by the terminal. This enables
> terminal-native
> +text selection.
> +
>  @kindex set debug tui
>  @item set debug tui @r{[}on|off@r{]}
>  Turn on or off display of @value{GDBN} internal debug messages relating
> diff --git gdb/tui/tui-io.c gdb/tui/tui-io.c
> index a17cf38a1f2..45ef34aeab5 100644
> --- gdb/tui/tui-io.c
> +++ gdb/tui/tui-io.c
> @@ -655,7 +655,8 @@ static void
>  tui_prep_terminal (int notused1)
>  {
>  #ifdef NCURSES_MOUSE_VERSION
> -  mousemask (ALL_MOUSE_EVENTS, NULL);
> +  if (tui_enable_mouse)
> +    mousemask (ALL_MOUSE_EVENTS, NULL);
>  #endif
>  }
>
> diff --git gdb/tui/tui-win.c gdb/tui/tui-win.c
> index 008189eb99b..d7124592ca4 100644
> --- gdb/tui/tui-win.c
> +++ gdb/tui/tui-win.c
> @@ -897,6 +897,17 @@ tui_show_compact_source (struct ui_file *file,
> int from_tty,
>    gdb_printf (file, _("TUI source window compactness is %s.\n"), value);
>  }
>
> +bool tui_enable_mouse = true;
> +
> +/* Implement 'show tui mouse-events'.  */
> +
> +static void
> +show_tui_mouse_events (struct ui_file *file, int from_tty,
> +               struct cmd_list_element *c, const char *value)
> +{
> +  gdb_printf (file, _("TUI mouse events are %s.\n"), value);
> +}
> +
>  /* Set the tab width of the specified window.  */
>  static void
>  tui_set_tab_width_command (const char *arg, int from_tty)
> @@ -1284,6 +1295,18 @@ position indicator is styled."),
>                 &style_set_list,
>                 &style_show_list);
>
> +  add_setshow_boolean_cmd ("mouse-events", class_tui,
> +               &tui_enable_mouse, _("\
> +Set whether TUI mode handles mouse clicks."), _("\
> +Show whether TUI mode handles mouse clicks."), _("\
> +When on (default), mouse clicks control the TUI and can be accessed
> by plugins.\n\
> +When off, mouse clicks are handled by the terminal. This enables
> terminal-native\n\
> +text selection."),
> +
> +               NULL,
> +               show_tui_mouse_events,
> +               &tui_setlist, &tui_showlist);
> +
>    tui_border_style.changed.attach (tui_rehighlight_all, "tui-win");
>    tui_active_border_style.changed.attach (tui_rehighlight_all, "tui-win");
>  }
> diff --git gdb/tui/tui-win.h gdb/tui/tui-win.h
> index 4b33f1f2b54..039993fba34 100644
> --- gdb/tui/tui-win.h
> +++ gdb/tui/tui-win.h
> @@ -51,6 +51,9 @@ struct cmd_list_element **tui_get_cmd_list (void);
>  /* Whether compact source display should be used.  */
>  extern bool compact_source;
>
> +/* Whether the TUI should intercept terminal mouse events.  */
> +extern bool tui_enable_mouse;
> +
>  /* Whether to style the source and assembly code highlighted by the TUI's
>     current position indicator.  */
>  extern bool style_tui_current_position;
> -- 
> 2.29.2
> From 3ee6bc8ad0b5ac17725233ba88aa4d12167df4f7 Mon Sep 17 00:00:00 2001
> From: "Matthew \"strager\" Glazar" <strager.nds@gmail.com>
> Date: Fri, 27 Jan 2023 16:19:45 -0800
> Subject: [PATCH] gdb/tui: add 'set tui mouse-events off' to restore mouse
>  selection
>
> Rationale:
> I use the mouse with my terminal to select and copy text. In gdb, I use
> the mouse to select a function name to set a breakpoint, or a variable
> name to print, for example.
>
> When gdb is compiled with ncurses mouse support, gdb's TUI mode
> intercepts mouse events. Left-clicking and dragging, which would
> normally select text, seems to do nothing. This means I cannot select
> text using my mouse anymore. This makes it harder to set breakpoints,
> print variables, etc.
>
> Solution:
> I tried to fix this issue by editing the 'mousemask' call to only enable
> buttons 4 and 5. However, this still caused my terminal (gnome-terminal)
> to not allow text to be selected. The only way I could make it work is
> by calling 'mousemask (0, NULL);'. But doing so disables the mouse code
> entirely, which other people might want.
>
> I therefore decided to make a setting in gdb called 'tui mouse-events'.
> If enabled (the default), the behavior is as it is now: terminal mouse
> events are given to gdb, disabling the terminal's default behavior.
> If disabled (opt-in), the behavior is as it was before the year 2020:
> terminal mouse events are not given to gdb, therefore the mouse can be
> used to select and copy text.
>
> Notes:
> I am not attached to the setting name or its description. Feel free to
> suggest better wording.
>
> Testing:
> I tested this change in gnome-terminal by performing the following steps
> manually:
>
> 1. Run: gdb --args ./myprogram
> 2. Enable TUI: press ctrl-x ctrl-a
> 3. Click and drag text with the mouse. Observe no selection.
> 4. Input: set tui mouse-events off
> 5. Click and drag text with the mouse. Observe that selection works now.
> 6. Input: set tui mouse-events on.
> 7. Click and drag text with the mouse Observe no selection.
> ---
>  gdb/NEWS            |  6 ++++++
>  gdb/doc/gdb.texinfo |  6 ++++++
>  gdb/tui/tui-io.c    |  3 ++-
>  gdb/tui/tui-win.c   | 23 +++++++++++++++++++++++
>  gdb/tui/tui-win.h   |  3 +++
>  5 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git gdb/NEWS gdb/NEWS
> index 445d28efed9..21399e86caa 100644
> --- gdb/NEWS
> +++ gdb/NEWS
> @@ -38,6 +38,12 @@ maintenance print record-instruction [ N ]
>    prints how GDB would undo the N-th previous instruction, and if N is
>    positive, it prints how GDB will redo the N-th following instruction.
>  
> +set tui mouse-events [on|off]
> +show tui mouse-events
> +  When on (default), mouse clicks control the TUI and can be accessed by
> +  plugins.  When off, mouse clicks are handled by the terminal.  This enables
> +  terminal-native text selection.
> +
>  * MI changes
>  
>  ** mi now reports 'no-history' as a stop reason when hitting the end of the
> diff --git gdb/doc/gdb.texinfo gdb/doc/gdb.texinfo
> index 03033c7f9e3..02de9ad753a 100644
> --- gdb/doc/gdb.texinfo
> +++ gdb/doc/gdb.texinfo
> @@ -29888,6 +29888,12 @@ source text at the next tab stop; the compact display uses only as
>  much space as is needed for the line numbers in the current file, and
>  only a single space to separate the line numbers from the source.
>  
> +@item set tui mouse-events @r{[}on@r{|}off@r{]}
> +@kindex set tui mouse-events
> +When on (default), mouse clicks control the TUI and can be accessed by plugins.
> +When off, mouse clicks are handled by the terminal. This enables terminal-native
> +text selection.

I think it would be worth adding some text to the description of
Window.click in doc/python.texi, along with a cross-reference back to
this setting, as the Window.click is not going to work when this setting
is off.

Thanks,
Andrew

> +
>  @kindex set debug tui
>  @item set debug tui @r{[}on|off@r{]}
>  Turn on or off display of @value{GDBN} internal debug messages relating
> diff --git gdb/tui/tui-io.c gdb/tui/tui-io.c
> index a17cf38a1f2..45ef34aeab5 100644
> --- gdb/tui/tui-io.c
> +++ gdb/tui/tui-io.c
> @@ -655,7 +655,8 @@ static void
>  tui_prep_terminal (int notused1)
>  {
>  #ifdef NCURSES_MOUSE_VERSION
> -  mousemask (ALL_MOUSE_EVENTS, NULL);
> +  if (tui_enable_mouse)
> +    mousemask (ALL_MOUSE_EVENTS, NULL);
>  #endif
>  }
>  
> diff --git gdb/tui/tui-win.c gdb/tui/tui-win.c
> index 008189eb99b..d7124592ca4 100644
> --- gdb/tui/tui-win.c
> +++ gdb/tui/tui-win.c
> @@ -897,6 +897,17 @@ tui_show_compact_source (struct ui_file *file, int from_tty,
>    gdb_printf (file, _("TUI source window compactness is %s.\n"), value);
>  }
>  
> +bool tui_enable_mouse = true;
> +
> +/* Implement 'show tui mouse-events'.  */
> +
> +static void
> +show_tui_mouse_events (struct ui_file *file, int from_tty,
> +		       struct cmd_list_element *c, const char *value)
> +{
> +  gdb_printf (file, _("TUI mouse events are %s.\n"), value);
> +}
> +
>  /* Set the tab width of the specified window.  */
>  static void
>  tui_set_tab_width_command (const char *arg, int from_tty)
> @@ -1284,6 +1295,18 @@ position indicator is styled."),
>  			   &style_set_list,
>  			   &style_show_list);
>  
> +  add_setshow_boolean_cmd ("mouse-events", class_tui,
> +			   &tui_enable_mouse, _("\
> +Set whether TUI mode handles mouse clicks."), _("\
> +Show whether TUI mode handles mouse clicks."), _("\
> +When on (default), mouse clicks control the TUI and can be accessed by plugins.\n\
> +When off, mouse clicks are handled by the terminal. This enables terminal-native\n\
> +text selection."),
> +
> +			   NULL,
> +			   show_tui_mouse_events,
> +			   &tui_setlist, &tui_showlist);
> +
>    tui_border_style.changed.attach (tui_rehighlight_all, "tui-win");
>    tui_active_border_style.changed.attach (tui_rehighlight_all, "tui-win");
>  }
> diff --git gdb/tui/tui-win.h gdb/tui/tui-win.h
> index 4b33f1f2b54..039993fba34 100644
> --- gdb/tui/tui-win.h
> +++ gdb/tui/tui-win.h
> @@ -51,6 +51,9 @@ struct cmd_list_element **tui_get_cmd_list (void);
>  /* Whether compact source display should be used.  */
>  extern bool compact_source;
>  
> +/* Whether the TUI should intercept terminal mouse events.  */
> +extern bool tui_enable_mouse;
> +
>  /* Whether to style the source and assembly code highlighted by the TUI's
>     current position indicator.  */
>  extern bool style_tui_current_position;
> -- 
> 2.29.2