Introduce lazy-refilter mode for long lists.

config/config.def.c

@@ -108,6 +108,8 @@ Settings config = {
     /** Height of an element in #chars */
     .element_height    =                                   1,
     /** Sidebar mode, show the switchers */
-    .sidebar_mode      = FALSE
+    .sidebar_mode      = FALSE,
+    /** Lazy mode setting */
+    .lazy_filter_limit = 5000
 };
 

doc/rofi-manpage.markdown

@@ -14,7 +14,7 @@ rofi - A window switcher, run dialog and dmenu replacement
 *command* ] [ -now ] [ -rnow ] [ -snow ] [ -version ] [ -help] [ -dump-xresources ] [
 -disable-history ] [ -levenshtein-sort ] [ -case-sensitive ] [ -show *mode* ] [ -switcher *mode1,
 mode2* ] [ -e *message*] [ -sep *separator* ] [ -eh *element height* ] [ -l *selected line* ] [
--run-list-command *cmd* ]
+-run-list-command *cmd* ] [ -lazy-filter-limit *limit* ]
 
 ## DESCRIPTION
 
@@ -252,6 +252,12 @@ The default key combinations are:
 
         rofi -rnow -sidebar-mode -lines 0
 
+`-lazy-filter-limit` *limit*
+
+   The number of entries required for Rofi to go into lazy filter mode.
+   In lazy filter mode, it won't refilter the list on each keypress, but only after rofi been idle
+   for 250ms. Default is 5000 lines, set to 0 to always enable.
+
 ### Pattern setting
 
 `-terminal`

doc/rofi.1

@@ -12,7 +12,7 @@ rofi \- A window switcher, run dialog and dmenu replacement
 \fIcommand\fP ] [ \-now ] [ \-rnow ] [ \-snow ] [ \-version ] [ \-help] [ \-dump\-xresources ] [
 \-disable\-history ] [ \-levenshtein\-sort ] [ \-case\-sensitive ] [ \-show \fImode\fP ] [ \-switcher \fImode1,
 mode2\fP ] [ \-e \fImessage\fP] [ \-sep \fIseparator\fP ] [ \-eh \fIelement height\fP ] [ \-l \fIselected line\fP ] [
-\-run\-list\-command \fIcmd\fP ]
+\-run\-list\-command \fIcmd\fP ] [ \-lazy\-filter\-limit \fIlimit\fP ]
 .SH DESCRIPTION
 .PP
 \fBrofi\fP is an X11 popup window switcher. A list is displayed center\-screen showing open window titles, WM_CLASS, and desktop number.
@@ -332,6 +332,12 @@ To show sidebar use:
     rofi \-rnow \-sidebar\-mode \-lines 0
 .fi
 .RE
+.PP
+\fB\fC\-lazy\-filter\-limit\fR \fIlimit\fP
+.PP
+   The number of entries required for Rofi to go into lazy filter mode.
+   In lazy filter mode, it won't refilter the list on each keypress, but only after rofi been idle
+   for 250ms. Default is 5000 lines, set to 0 to always enable.
 .SS Pattern setting
 .PP
 \fB\fC\-terminal\fR
@@ -539,14 +545,18 @@ Check quotes used on the commandline: e.g. used “ instead of ".
 .SH WEBSITE
 .PP
 \fBrofi\fP website can be found at here
-\[la]https://davedavenport.github.io/rofi/\[ra]
+.UR https://davedavenport.github.io/rofi/
+.UE
 .PP
 \fBrofi\fP bugtracker can be found here
-\[la]https://github.com/DaveDavenport/rofi/issues\[ra]
+.UR https://github.com/DaveDavenport/rofi/issues
+.UE
 .SH AUTHOR
 .PP
 Qball Cow 
-\[la]qball@gmpclient.org\[ra]
+.MT qball@gmpclient.org
+.ME
 .PP
 Original code based on work by: Sean Pringle 
-\[la]sean.pringle@gmail.com\[ra]
+.MT sean.pringle@gmail.com
+.ME

include/rofi.h

@@ -205,6 +205,8 @@ typedef struct _Settings
     int            element_height;
     /** Sidebar mode, show the switchers */
     int            sidebar_mode;
+    /** Lazy filter limit. */
+    unsigned int   lazy_filter_limit;
 } Settings;
 
 /** Global Settings structure. */

source/rofi.c

@@ -1659,11 +1659,10 @@ MenuReturn menu ( char **lines, unsigned int num_lines, char **input, char *prom
         }
 
         state.quit = FALSE;
+        menu_refilter ( &state, lines, mmc, mmc_data, sorting, config.case_sensitive );
+
+        int x11_fd = ConnectionNumber ( display );
         while ( !state.quit ) {
-            // If something changed, refilter the list. (paste or text entered)
-            if ( state.refilter ) {
-                menu_refilter ( &state, lines, mmc, mmc_data, sorting, config.case_sensitive );
-            }
             // Update if requested.
             if ( state.update ) {
                 menu_update ( &state );
@@ -1671,6 +1670,34 @@ MenuReturn menu ( char **lines, unsigned int num_lines, char **input, char *prom
 
             // Wait for event.
             XEvent ev;
+            // Only use lazy mode above 5000 lines.
+            if ( state.num_lines > config.lazy_filter_limit ) {
+                // No message waiting, update been set, do timeout trick.
+                if ( state.refilter && !XPending ( display ) ) {
+                    // This implements a lazy re-filtering.
+                    struct timeval tv;
+                    fd_set         in_fds;
+                    // Create a File Description Set containing x11_fd
+                    FD_ZERO ( &in_fds );
+                    FD_SET ( x11_fd, &in_fds );
+
+                    // Set our timer.  200ms is a decent delay
+                    tv.tv_usec = 200000;
+                    tv.tv_sec  = 0;
+                    // Wait for X Event or a Timer
+                    if ( select ( x11_fd + 1, &in_fds, 0, 0, &tv ) == 0 ) {
+                        // Timer expired, update.
+                        menu_refilter ( &state, lines, mmc, mmc_data, sorting, config.case_sensitive );
+                        menu_update ( &state );
+                    }
+                }
+            }
+            else {
+                if ( state.refilter ) {
+                    menu_refilter ( &state, lines, mmc, mmc_data, sorting, config.case_sensitive );
+                    menu_update ( &state );
+                }
+            }
             XNextEvent ( display, &ev );
 
             // Handle event.
@@ -1697,10 +1724,6 @@ MenuReturn menu ( char **lines, unsigned int num_lines, char **input, char *prom
             // Key press event.
             else if ( ev.type == KeyPress ) {
                 do {
-                    //    while ( XCheckTypedEvent ( display, KeyPress, &ev ) ) {
-                    //        ;
-                    //    }
-
                     if ( time ) {
                         *time = ev.xkey.time;
                     }
@@ -2365,6 +2388,8 @@ static void parse_cmd_options ( int argc, char ** argv )
 
     find_arg_int ( argc, argv, "-eh", &( config.element_height ) );
 
+    find_arg_int ( argc, argv, "-lazy-filter-limit", &( config.lazy_filter_limit ) );
+
     if ( find_arg ( argc, argv, "-sidebar-mode" ) >= 0 ) {
         config.sidebar_mode = TRUE;
     }

source/xrmoptions.c

@@ -113,7 +113,8 @@ static XrmOption xrmOptions[] = {
     { xrm_String,  "key",                  { .str  = &config.window_key            }, NULL },
     { xrm_String,  "rkey",                 { .str  = &config.run_key               }, NULL },
     { xrm_String,  "skey",                 { .str  = &config.ssh_key               }, NULL },
-    { xrm_Boolean, "sidebar-mode",         { .num  = &config.sidebar_mode          }, NULL }
+    { xrm_Boolean, "sidebar-mode",         { .num  = &config.sidebar_mode          }, NULL },
+    { xrm_Number,  "lazy-filter-limit",    { .num  = &config.lazy_filter_limit     }, NULL }
 };