[RFC v3 1/1] Emacs-like isearch for mconf.

From: Dirk Gouders
Date: Fri Jun 08 2018 - 05:43:59 EST


This patch implements isearch functionality for mconf as follows:

* isearch is started by pressing \ or CTRL-s; those keys can also be
used to find further matches of an already entered string.

* isearch is implemented as a ring search.

* Once isearch is started, all alphanumerical characters and <space>
are appended to a search string that is then be used to find matches
in the menu.

* Any other character pressed terminates isearch and -- except ESC ESC
-- that character is further processed, e.g. ENTER to enter a submenu
without further input.

* To be able to use CTRL-s to start isearch, the terminal has to be
put into raw mode and this can be done by setting the environment
variable MENUCONFIG_RAW_MODE to a numeric value != 0.

An input example to navigate into the USB support menu under device
drivers:

1) \ # start isearch
2) de # navigate to Device Drivers
3) ENTER # terminate isearch and enter submenu
4) \ # start isearch
5) USB # navigate to USB support
6) ENTER # terminate isearch and enter submenu

Signed-off-by: Dirk Gouders <dirk@xxxxxxxxxxx>
---
Documentation/kbuild/kconfig.txt | 18 +++-
scripts/kconfig/lxdialog/dialog.h | 6 ++
scripts/kconfig/lxdialog/menubox.c | 171 +++++++++++++++++++++++++++++++++++++
scripts/kconfig/lxdialog/util.c | 14 +++
scripts/kconfig/mconf.c | 47 ++++++++++
5 files changed, 254 insertions(+), 2 deletions(-)

diff --git a/Documentation/kbuild/kconfig.txt b/Documentation/kbuild/kconfig.txt
index 7233118f3a05..71270dcfa112 100644
--- a/Documentation/kbuild/kconfig.txt
+++ b/Documentation/kbuild/kconfig.txt
@@ -147,9 +147,11 @@ Its default value is "include/generated/autoconf.h".
menuconfig
--------------------------------------------------

-SEARCHING for CONFIG symbols
+Menuconfig offers two search capabilities:
+ 1) SEARCHING for CONFIG symbols
+ 2) Incremental search in menus

-Searching in menuconfig:
+Searching for CONFIG symbols:

The Search function searches for kernel configuration symbol
names, so you have to know something close to what you are
@@ -178,6 +180,18 @@ Searching in menuconfig:
first (and in alphabetical order), then come all other symbols,
sorted in alphabetical order.

+Incremental search in menus:
+
+ Isearch is started by pressing <\>. After that, any alphanumerical
+ character typed in is used to form a growing string that is searched
+ for in the menu items.
+
+ Isearch is realized as a ring search, restarting at the top if it
+ reaches the last menu item.
+
+ Further matches of an already entered string can be found by
+ pressing <\> instead of more alphanumerical characters.
+
______________________________________________________________________
User interface options for 'menuconfig'

diff --git a/scripts/kconfig/lxdialog/dialog.h b/scripts/kconfig/lxdialog/dialog.h
index 0b00be5abaa6..271bd5a4bc13 100644
--- a/scripts/kconfig/lxdialog/dialog.h
+++ b/scripts/kconfig/lxdialog/dialog.h
@@ -50,6 +50,8 @@
#define TR(params) _tracef params

#define KEY_ESC 27
+#define KEY_CTRL_S 19
+#define KEY_ENTR 10
#define TAB 9
#define MAX_LEN 2048
#define BUF_SIZE (10*1024)
@@ -145,6 +147,7 @@ struct dialog_info {
extern struct dialog_info dlg;
extern char dialog_input_result[];
extern int saved_x, saved_y; /* Needed in signal handler in mconf.c */
+extern int raw_mode; /* Toggle raw mode */

/*
* Function prototypes
@@ -238,6 +241,9 @@ int dialog_checklist(const char *title, const char *prompt, int height,
int width, int list_height);
int dialog_inputbox(const char *title, const char *prompt, int height,
int width, const char *init);
+int do_isearch(char *str, int choice, int scroll);
+int dialog_isearch(WINDOW *menu, WINDOW *dialog, int *choice, int max_choice,
+ int box_x, int box_y, int menu_height, int *scroll);

/*
* This is the base for fictitious keys, which activate
diff --git a/scripts/kconfig/lxdialog/menubox.c b/scripts/kconfig/lxdialog/menubox.c
index d70cab36137e..20a14fa1c96f 100644
--- a/scripts/kconfig/lxdialog/menubox.c
+++ b/scripts/kconfig/lxdialog/menubox.c
@@ -56,8 +56,13 @@
* fscanf would read in 'scroll', and eventually that value would get used.
*/

+#include <string.h>
#include "dialog.h"

+#define ISEARCH_LEN 32
+#define ISEARCH_INDICATOR_LEN (ISEARCH_LEN + 8)
+static char isearch_str[ISEARCH_LEN] = "";
+
static int menu_width, item_x;

/*
@@ -105,6 +110,32 @@ do { \
do_print_item(menu, item_str(), choice, selected, !item_is_tag(':')); \
} while (0)

+
+/*
+* Print the isearch indicator.
+*/
+static void print_isearch(WINDOW * win, int y, int x, int height, bool isearch)
+{
+ unsigned char i = 0;
+
+ wmove(win, y, x);
+
+ y = y + height + 1;
+ wmove(win, y, x);
+
+ if (isearch) {
+ wattrset(win, dlg.button_key_inactive.atr);
+ waddstr(win, "isearch: ");
+ waddstr(win, isearch_str);
+ i = ISEARCH_INDICATOR_LEN - strlen(isearch_str);
+ }
+
+ wattrset(win, dlg.menubox_border.atr);
+
+ for ( ; i < ISEARCH_INDICATOR_LEN; i++ )
+ waddch(win, ACS_HLINE);
+}
+
/*
* Print the scroll indicators.
*/
@@ -178,6 +209,130 @@ static void do_scroll(WINDOW *win, int *scroll, int n)
wrefresh(win);
}

+/*
+ * Incremental search for text in dialog menu entries.
+ * The search operates as a ring search, continuing at the top after
+ * the last entry has been visited.
+ *
+ * Returned is -1 if no match was found, else the absolute index of
+ * the matching item.
+ */
+int do_isearch(char *str, int choice, int scroll)
+{
+ int found = 0;
+ int i;
+
+ for (i = 0; i < item_count(); i++) {
+ item_set((choice + scroll + i)%item_count());
+ if (strcasestr(item_str(), str)) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (found)
+ return (choice + scroll + i)%item_count();
+ return -1;
+}
+
+/*
+ * Incremental search in dialog menu
+ *
+ * This function is executed after CTRL-S or \ has been pressed and it
+ * navigates to and highlights menu entries that match the string
+ * formed by subsequently entered characters. To find further matches
+ * of an entered string, CTRL-S or \ has to be entered instead of
+ * further characters.
+ *
+ * Subsequently pressing just CTRL-S or \ keys results in searches for
+ * empty strings (any line matches) and thus results in navigating through
+ * the menu, line by line.
+ *
+ * Incremental search is terminated by pressing any other key than
+ * alnum characters or blank.
+ *
+ * Isearch returns -1 when it is terminatet with ESC ESC, otherwise
+ * the pressed key is returned.
+ */
+int dialog_isearch(WINDOW *menu, WINDOW *dialog, int *choice, int max_choice,
+ int box_x, int box_y, int menu_height, int *scroll)
+{
+ int i;
+ int key = KEY_CTRL_S;
+
+ print_isearch(dialog, box_y, box_x + item_x + 5, menu_height, true);
+ wnoutrefresh(dialog);
+ wrefresh(menu);
+
+ while ( 1 ) {
+ key = wgetch(menu);
+
+ if (key == KEY_CTRL_S || key == '\\') {
+ /* Remove highligt of current item */
+ print_item(*scroll + *choice, *choice, FALSE);
+ i = do_isearch(isearch_str, *choice + 1, *scroll);
+ } else {
+ if ( key == KEY_BACKSPACE && isearch_str[0] ) {
+ isearch_str[i = (strlen(isearch_str) - 1)] = '\0';
+ } else {
+ if ( key < 256 && (isalnum(key) || key == ' ')) {
+ if (strlen(isearch_str) < ISEARCH_LEN - 1) {
+ isearch_str[i = strlen(isearch_str)] = key;
+ isearch_str[i+1] = '\0';
+ } else
+ continue;
+ } else
+ goto exit_isearch;
+ }
+ /* Remove highligt of current item */
+ print_item(*scroll + *choice, *choice, FALSE);
+ i = do_isearch(isearch_str, *choice, *scroll);
+ }
+
+ /*
+ * Handle matches
+ */
+ if (i >= 0) {
+ i -= *scroll;
+
+ if (i >= max_choice)
+ /*
+ * Handle matches below the currently visible menu entries.
+ */
+ while (i >= max_choice) {
+ do_scroll(menu, scroll, 1);
+ i--;
+ print_item(max_choice + *scroll - 1, max_choice - 1, false);
+ }
+ else if (i < 0)
+ /*
+ * Handle matches higher in the menu (ring search).
+ */
+ while (i < 0) {
+ do_scroll(menu, scroll, -1);
+ i++;
+ print_item(*scroll, 0, false);
+ }
+ *choice = i;
+ }
+
+ print_item(*scroll + *choice, *choice, TRUE);
+ print_isearch(dialog, box_y, box_x + item_x + 5, menu_height, true);
+ print_arrows(dialog, item_count(), *scroll,
+ box_y, box_x + item_x + 1, menu_height);
+
+ wnoutrefresh(dialog);
+ wrefresh(menu);
+ }
+exit_isearch:
+ isearch_str[0] = '\0';
+ print_isearch(dialog, box_y, box_x + item_x + 5, menu_height, false);
+ print_arrows(dialog, item_count(), *scroll,
+ box_y, box_x + item_x + 1, menu_height);
+ print_item(*scroll + *choice, *choice, true);
+ return key == KEY_ESC ? -1 : key;
+}
+
/*
* Display a menu for choosing among a number of options
*/
@@ -281,6 +436,22 @@ int dialog_menu(const char *title, const char *prompt,

while (key != KEY_ESC) {
key = wgetch(menu);
+ /*
+ * CTRL-s works only if MENUCONFIG_RAW_MODE is set and
+ * != 0. Otherwise, only \ can be used to start isearch.
+ */
+ if (key == KEY_CTRL_S || key == '\\') {
+ key = dialog_isearch(menu, dialog, &choice, max_choice,
+ box_x, box_y, menu_height, &scroll);
+ /*
+ * dialog_isearch returns -1 if it was
+ * terminated with ESC ESC, otherwise the
+ * pressed key (e.g. ENTER) so that it can be
+ * further processed, here.
+ */
+ if (key == -1)
+ continue;
+ }

if (key < 256 && isalpha(key))
key = tolower(key);
diff --git a/scripts/kconfig/lxdialog/util.c b/scripts/kconfig/lxdialog/util.c
index f7abdeb92af0..d61cffd8c011 100644
--- a/scripts/kconfig/lxdialog/util.c
+++ b/scripts/kconfig/lxdialog/util.c
@@ -28,6 +28,8 @@ int saved_x, saved_y;

struct dialog_info dlg;

+int raw_mode; /* Toggle raw mode */
+
static void set_mono_theme(void)
{
dlg.screen.atr = A_NORMAL;
@@ -236,6 +238,17 @@ static void color_setup(const char *theme)
set_mono_theme();
}

+/*
+ * Setup raw mode if MENUCONFIG_RAW_MODE
+ */
+static void raw_setup(const char *val)
+{
+ if (val && atoi(val)) {
+ raw_mode = 1;
+ raw(); /* Enable CTRL-sequences*/
+ }
+}
+
/*
* Set window to attribute 'attr'
*/
@@ -332,6 +345,7 @@ int init_dialog(const char *backtitle)

keypad(stdscr, TRUE);
cbreak();
+ raw_setup(getenv("MENUCONFIG_RAW_MODE"));
noecho();
dialog_clear();

diff --git a/scripts/kconfig/mconf.c b/scripts/kconfig/mconf.c
index 5294ed159b98..b46bb24b01fe 100644
--- a/scripts/kconfig/mconf.c
+++ b/scripts/kconfig/mconf.c
@@ -73,6 +73,52 @@ static const char mconf_readme[] =
"\n"
"o To toggle the display of hidden options, press <Z>.\n"
"\n"
+"o Searching\n"
+" There are two search capabilities in mconf:\n"
+" 1) Search for config symbols\n"
+" 2) Incremental search in menus\n"
+"\n"
+" Searching for config symbols\n"
+" ----------------------------\n"
+" The Search function searches for kernel configuration symbol names,\n"
+" so you have to know something close to what you are looking for.\n"
+"\n"
+" Example:\n"
+" /hotplug\n"
+" This lists all config symbols that contain \"hotplug\",\n"
+" e.g., HOTPLUG_CPU, MEMORY_HOTPLUG.\n"
+"\n"
+" For search help, enter / followed TAB-TAB-TAB (to highlight <Help>)\n"
+" and Enter. This will tell you that you can also use regular\n"
+" expressions (regexes) in the search string, so if you are not\n"
+" interested in MEMORY_HOTPLUG, you could try\n"
+"\n"
+" /^hotplug\n"
+"\n"
+" When searching, symbols are sorted thus:\n"
+" - first, exact matches, sorted alphabetically (an exact match is\n"
+" when the search matches the complete symbol name);\n"
+" - then, other matches, sorted alphabetically.\n"
+" For example: ^ATH.K matches:\n"
+" ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG\n"
+" [...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...]\n"
+" of which only ATH5K and ATH9K match exactly and so are sorted\n"
+" first (and in alphabetical order), then come all other symbols,\n"
+" sorted in alphabetical order.\n"
+"\n"
+" Incremental search in menus\n"
+" ---------------------------\n"
+" Isearch is started by pressing <\\>. After that, any alphanumerical\n"
+" character typed in is used to form a growing string that is searched\n"
+" for in the menu items.\n"
+"\n"
+" Isearch is realized as a ring search, restarting at the top if it\n"
+" reaches the last menu item.\n"
+"\n"
+" Further matches of an already entered string can be found by\n"
+" pressing <\\> instead of more alphanumerical characters.\n"
+""
+"\n"
"\n"
"Radiolists (Choice lists)\n"
"-----------\n"
@@ -177,6 +223,7 @@ menu_instructions[] =
"Highlighted letters are hotkeys. "
"Pressing <Y> includes, <N> excludes, <M> modularizes features. "
"Press <Esc><Esc> to exit, <?> for Help, </> for Search. "
+ "Press <Esc><Esc> to exit, <?> for Help, </> for Search, <\\> for isearch. "
"Legend: [*] built-in [ ] excluded <M> module < > module capable",
radiolist_instructions[] =
"Use the arrow keys to navigate this window or "
--
2.16.4