22 files changed, 454 insertions, 59 deletions

diff --git a/README b/README
index bf0ed55..a1c7a04 100644
--- a/README
+++ b/README
@@ -44,7 +44,7 @@ master branch and between releases until version 3.0 is released.__
 Features
 ========
 
-* Supports most of the [Video TECO](http://www.copters.com/teco.html) commands
+* Supports most of the [Video TECO](http://www.copters.com/teco.html) commands.
 * Improved parser compared to classic TECOs, making SciTECO
   more similar to other imperative languages.
 * Operator precedence in arithmetic expressions and an argument stack that may be modified
@@ -57,7 +57,8 @@ Features
   by the standard library `fnkeys.tes`.
   In fact, all keys with printable representation and control keys can be remapped using
   key macros - and they can be context-sensitive as well!
-* Scriptable mouse support via the key macro mechanism (see also `fnkeys.tes`)
+* There is scriptable mouse support via the key macro mechanism (see also `fnkeys.tes`).
+  Autocompletion popups can also be scrolled and clicked.
 * Many TECO-11 features, like that most commands have a colon-modified form, string-building
   characters, exotic match characters...
 * Interactivity: Immediate searching (similar to search-as-you-type) and
diff --git a/doc/sciteco.7.template b/doc/sciteco.7.template
index 97e1fd7..95c3503 100644
--- a/doc/sciteco.7.template
+++ b/doc/sciteco.7.template
@@ -303,7 +303,7 @@ current parser state (see below).
 .SCITECO_TOPIC ^KMOUSE
 .B ^KMOUSE
 Mouse event occurred.
-This may not be delivered unless bit 7 (64) is set in the
+This will not be delivered on Curses unless bit 7 (64) is set in the
 \fBED\fP flags.
 You can use \fBEJ\fP with negative keys to retrieve
 the event type, mouse coordinates and other information
@@ -755,10 +755,12 @@ Global and local Q-Registers are not affected by command line termination.
 .SS Auto Completion
 .
 .SCITECO_TOPIC autocomplete
-The immediate editing commands that perform auto-completions, do
+The immediate editing commands, that perform auto-completions, do
 so in a manner similar to Posix shells.
 Upon first invocation they try to fully or partially complete the file
 name (or token).
+If the token can be fully completed, the current command or Q-Register
+specification will also usually be terminated automatically.
 If no completion can be performed, the invocation will display a
 list of file names (or tokens) that begin with the token to complete
 in \*(ST's popup area.
@@ -770,6 +772,15 @@ of file names or tokens is displayed in the popup area.
 I.e. it is possible to cycle through long lists of possible
 auto-completions.
 .LP
+You can also scroll through the popup area with the mouse wheel.
+Furthermore, you can click on entries in the popup area with the
+mouse in order to fully complete them.
+Often this will also automatically terminate the current command or
+Q-Register specification, just like an unambiguous completion via
+immediate editing commands.
+On Curses, mouse events are not processed unless bit 7 (64) is set
+in the \fBED\fP flags.
+.LP
 When completing file names, hidden files are not considered for
 completion unless a prefix of the hidden file's name has already
 been typed.
@@ -789,6 +800,13 @@ file names with \(lq./\(rq.
 This is useful for writing cross-platform \*(ST macros (see
 .BR "FILE NAMES AND DIRECTORIES" ).
 .LP
+File name completions are case-sensitive or insensitive depending
+on operating system defaults.
+On some operating systems \*(ST can determine the case-sensitivity
+of individual directories as well.
+\# Should be supported on Mac OS and newer versions of Windows,
+\# but it's still untested.
+.LP
 Note that completions take place after string building and
 tilde-expansion is also performed by file name completions,
 so for instance both \(lq~/foo\(rq and \(lq^EQ[$HOME]/foo\(rq
diff --git a/src/cmdline.c b/src/cmdline.c
index d32df03..dde096d 100644
--- a/src/cmdline.c
+++ b/src/cmdline.c
@@ -614,7 +614,7 @@ teco_state_stringbuilding_start_process_edit_cmd(teco_machine_stringbuilding_t *
 		 */
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -645,6 +645,16 @@ teco_state_stringbuilding_start_process_edit_cmd(teco_machine_stringbuilding_t *
 }
 
 gboolean
+teco_state_stringbuilding_insert_completion(teco_machine_stringbuilding_t *ctx, const teco_string_t *str, GError **error)
+{
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(ctx, str->data, str->len, &str_escaped);
+	if (!str->len || !G_IS_DIR_SEPARATOR(str->data[str->len-1]))
+		teco_string_append_c(&str_escaped, ' ');
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_stringbuilding_escaped_process_edit_cmd(teco_machine_stringbuilding_t *ctx, teco_machine_t *parent_ctx,
                                                    gunichar key, GError **error)
 {
@@ -684,6 +694,14 @@ teco_state_expectstring_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_
 }
 
 gboolean
+teco_state_expectstring_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+	teco_state_t *stringbuilding_current = stringbuilding_ctx->parent.current;
+	return stringbuilding_current->insert_completion_cb(&stringbuilding_ctx->parent, str, error);
+}
+
+gboolean
 teco_state_insert_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
@@ -778,7 +796,7 @@ teco_state_expectfile_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -801,6 +819,20 @@ teco_state_expectfile_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t
 }
 
 gboolean
+teco_state_expectfile_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, str->data, str->len, &str_escaped);
+	if ((!str->len || !G_IS_DIR_SEPARATOR(str->data[str->len-1])) &&
+	    ctx->expectstring.nesting == 1)
+		teco_string_append_wc(&str_escaped,
+		                      ctx->expectstring.machine.escape_char == '{' ? '}' : ctx->expectstring.machine.escape_char);
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_expectglob_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
@@ -820,7 +852,7 @@ teco_state_expectglob_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -855,6 +887,21 @@ teco_state_expectglob_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t
 }
 
 gboolean
+teco_state_expectglob_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+
+	g_autofree gchar *pattern_escaped = teco_globber_escape_pattern(str->data);
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, pattern_escaped, strlen(pattern_escaped), &str_escaped);
+	if ((!str->len || !G_IS_DIR_SEPARATOR(str->data[str->len-1])) &&
+	    ctx->expectstring.nesting == 1)
+		teco_string_append_wc(&str_escaped,
+		                      ctx->expectstring.machine.escape_char == '{' ? '}' : ctx->expectstring.machine.escape_char);
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_expectdir_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
@@ -874,7 +921,7 @@ teco_state_expectdir_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -898,6 +945,19 @@ teco_state_expectdir_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *
 }
 
 gboolean
+teco_state_expectdir_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+
+	/*
+	 * FIXME: We might terminate the command in case of leaf directories.
+	 */
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, str->data, str->len, &str_escaped);
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_expectqreg_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	g_assert(ctx->expectqreg != NULL);
@@ -910,6 +970,18 @@ teco_state_expectqreg_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t
 }
 
 gboolean
+teco_state_expectqreg_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	g_assert(ctx->expectqreg != NULL);
+	/*
+	 * NOTE: teco_machine_qregspec_t is private, so we downcast to teco_machine_t.
+	 * Otherwise, we'd have to move this callback into qreg.c.
+	 */
+	teco_state_t *expectqreg_current = ((teco_machine_t *)ctx->expectqreg)->current;
+	return expectqreg_current->insert_completion_cb((teco_machine_t *)ctx->expectqreg, str, error);
+}
+
+gboolean
 teco_state_qregspec_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	switch (key) {
@@ -919,7 +991,7 @@ teco_state_qregspec_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -945,6 +1017,12 @@ teco_state_qregspec_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_
 }
 
 gboolean
+teco_state_qregspec_insert_completion(teco_machine_qregspec_t *ctx, const teco_string_t *str, GError **error)
+{
+	return teco_cmdline_insert(str->data, str->len, error);
+}
+
+gboolean
 teco_state_qregspec_string_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = teco_machine_qregspec_get_stringbuilding(ctx);
@@ -967,7 +1045,7 @@ teco_state_qregspec_string_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_m
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -985,6 +1063,17 @@ teco_state_qregspec_string_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_m
 }
 
 gboolean
+teco_state_qregspec_string_insert_completion(teco_machine_qregspec_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = teco_machine_qregspec_get_stringbuilding(ctx);
+
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, str->data, str->len, &str_escaped);
+	teco_string_append_c(&str_escaped, ']');
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_execute_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
@@ -1003,14 +1092,14 @@ teco_state_execute_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *pa
 			break;
 
 		/*
-		 * In the EC command, <TAB> completes files just like ^T
+		 * In the EC command, <TAB> completes files just like ^G<TAB>.
 		 *
 		 * TODO: Implement shell-command completion by iterating
 		 * executables in $PATH
 		 */
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -1049,7 +1138,7 @@ teco_state_scintilla_symbols_process_edit_cmd(teco_machine_main_t *ctx, teco_mac
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -1075,6 +1164,17 @@ teco_state_scintilla_symbols_process_edit_cmd(teco_machine_main_t *ctx, teco_mac
 }
 
 gboolean
+teco_state_scintilla_symbols_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, str->data, str->len, &str_escaped);
+	teco_string_append_c(&str_escaped, ',');
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_goto_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
@@ -1094,7 +1194,7 @@ teco_state_goto_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *paren
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -1122,6 +1222,20 @@ teco_state_goto_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *paren
 }
 
 gboolean
+teco_state_goto_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, str->data, str->len, &str_escaped);
+	/*
+	 * FIXME: This does not escape `,`. Cannot be escaped via ^Q currently?
+	 */
+	teco_string_append_c(&str_escaped, ',');
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
+gboolean
 teco_state_help_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error)
 {
 	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
@@ -1141,7 +1255,7 @@ teco_state_help_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *paren
 
 		if (teco_interface_popup_is_shown()) {
 			/* cycle through popup pages */
-			teco_interface_popup_show();
+			teco_interface_popup_scroll();
 			return TRUE;
 		}
 
@@ -1163,6 +1277,19 @@ teco_state_help_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *paren
 	return stringbuilding_current->process_edit_cmd_cb(&stringbuilding_ctx->parent, &ctx->parent, key, error);
 }
 
+gboolean
+teco_state_help_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	teco_machine_stringbuilding_t *stringbuilding_ctx = &ctx->expectstring.machine;
+
+	g_auto(teco_string_t) str_escaped;
+	teco_machine_stringbuilding_escape(stringbuilding_ctx, str->data, str->len, &str_escaped);
+	if (ctx->expectstring.nesting == 1)
+		teco_string_append_wc(&str_escaped,
+		                      ctx->expectstring.machine.escape_char == '{' ? '}' : ctx->expectstring.machine.escape_char);
+	return teco_cmdline_insert(str_escaped.data, str_escaped.len, error);
+}
+
 /*
  * Command states
  */
diff --git a/src/file-utils.c b/src/file-utils.c
index fc5e410..02816b4 100644
--- a/src/file-utils.c
+++ b/src/file-utils.c
@@ -483,7 +483,7 @@ teco_file_auto_complete(const gchar *filename, GFileTest file_test, teco_string_
 			                         strlen((gchar *)file->data), is_buffer);
 		}
 
-		teco_interface_popup_show();
+		teco_interface_popup_show(filename ? strlen(filename) : 0);
 	}
 
 	/*
diff --git a/src/glob.h b/src/glob.h
index e3286dd..d11fbce 100644
--- a/src/glob.h
+++ b/src/glob.h
@@ -48,6 +48,7 @@ GRegex *teco_globber_compile_pattern(const gchar *pattern);
 
 /* in cmdline.c */
 gboolean teco_state_expectglob_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_expectglob_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error);
 
 /**
  * @interface TECO_DEFINE_STATE_EXPECTGLOB
@@ -58,6 +59,8 @@ gboolean teco_state_expectglob_process_edit_cmd(teco_machine_main_t *ctx, teco_m
 	TECO_DEFINE_STATE_EXPECTFILE(NAME, \
 		.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t) \
 		                       teco_state_expectglob_process_edit_cmd, \
+		.insert_completion_cb = (teco_state_insert_completion_cb_t) \
+		                        teco_state_expectglob_insert_completion, \
 		##__VA_ARGS__ \
 	)
 
diff --git a/src/goto-commands.c b/src/goto-commands.c
index b87fc32..99288c1 100644
--- a/src/goto-commands.c
+++ b/src/goto-commands.c
@@ -157,7 +157,10 @@ teco_state_goto_done(teco_machine_main_t *ctx, const teco_string_t *str, GError
 }
 
 /* in cmdline.c */
-gboolean teco_state_goto_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar chr, GError **error);
+gboolean teco_state_goto_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx,
+                                          gunichar chr, GError **error);
+gboolean teco_state_goto_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str,
+                                           GError **error);
 
 /*$ O
  * Olabel$ -- Go to label
@@ -186,7 +189,8 @@ gboolean teco_state_goto_process_edit_cmd(teco_machine_main_t *ctx, teco_machine
  * terminate the command-line.
  */
 TECO_DEFINE_STATE_EXPECTSTRING(teco_state_goto,
-	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_goto_process_edit_cmd
+	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_goto_process_edit_cmd,
+	.insert_completion_cb = (teco_state_insert_completion_cb_t)teco_state_goto_insert_completion
 );
 
 /*
diff --git a/src/help.c b/src/help.c
index 886354c..a093032 100644
--- a/src/help.c
+++ b/src/help.c
@@ -314,7 +314,10 @@ teco_state_help_done(teco_machine_main_t *ctx, const teco_string_t *str, GError
 }
 
 /* in cmdline.c */
-gboolean teco_state_help_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar chr, GError **error);
+gboolean teco_state_help_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx,
+                                          gunichar chr, GError **error);
+gboolean teco_state_help_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str,
+                                           GError **error);
 
 /*$ "?" help
  * ?[topic]$ -- Get help for topic
@@ -384,5 +387,6 @@ gboolean teco_state_help_process_edit_cmd(teco_machine_main_t *ctx, teco_machine
 TECO_DEFINE_STATE_EXPECTSTRING(teco_state_help,
 	.initial_cb = (teco_state_initial_cb_t)teco_state_help_initial,
 	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_help_process_edit_cmd,
+	.insert_completion_cb = (teco_state_insert_completion_cb_t)teco_state_help_insert_completion,
 	.expectstring.string_building = FALSE
 );
diff --git a/src/interface-curses/curses-info-popup.c b/src/interface-curses/curses-info-popup.c
index 9525391..e470879 100644
--- a/src/interface-curses/curses-info-popup.c
+++ b/src/interface-curses/curses-info-popup.c
@@ -200,6 +200,61 @@ teco_curses_info_popup_show(teco_curses_info_popup_t *ctx, attr_t attr)
 	wmove(ctx->window, bar_y, cols-1);
 	wattron(ctx->window, A_REVERSE);
 	wvline(ctx->window, ' ', bar_height);
+}
+
+/**
+ * Find the entry at the given character coordinates.
+ *
+ * @param ctx The popup widget to look up
+ * @param y The pointer's Y position, relative to the popup's window
+ * @param x The pointer's X position, relative to the popup's window
+ * @return Pointer to the entry's string under the pointer or NULL.
+ *   This string is owned by the popup and is only valid until the
+ *   popup is cleared.
+ *
+ * @note This must match the calculations in teco_curses_info_popup_init_pad().
+ */
+const teco_string_t *
+teco_curses_info_popup_getentry(teco_curses_info_popup_t *ctx, gint y, gint x)
+{
+	int cols = getmaxx(stdscr);	/**! screen width */
+	gint pad_cols;			/**! entry columns */
+	gint pad_colwidth;		/**! width per entry column */
+
+	/*
+	 * With Unicode icons enabled, we reserve 2 characters at the beginning and one
+	 * after the filename/directory.
+	 * Otherwise 2 characters after the entry.
+	 */
+	gint reserve = teco_ed & TECO_ED_ICONS ? 2+1 : 2;
+	pad_colwidth = MIN(ctx->longest + reserve, cols - 2);
+
+	/* pad_cols = floor((cols - 2) / pad_colwidth) */
+	pad_cols = (cols - 2) / pad_colwidth;
+
+	gint cur_col = 0;
+	for (teco_stailq_entry_t *cur = ctx->list.first; cur != NULL; cur = cur->next) {
+		teco_popup_entry_t *entry = (teco_popup_entry_t *)cur;
+		gint cur_line = cur_col/pad_cols + 1;
+
+		if (cur_line > ctx->pad_first_line+y)
+			break;
+		if (cur_line == ctx->pad_first_line+y &&
+		    x > (cur_col % pad_cols)*pad_colwidth && x <= ((cur_col % pad_cols)+1)*pad_colwidth)
+			return &entry->name;
+
+		cur_col++;
+	}
+
+	return NULL;
+}
+
+void
+teco_curses_info_popup_scroll_page(teco_curses_info_popup_t *ctx)
+{
+	gint lines = getmaxy(stdscr);
+	gint pad_lines = getmaxy(ctx->pad);
+	gint popup_lines = MIN(pad_lines + 1, lines - 1);
 
 	/* progress scroll position */
 	ctx->pad_first_line += popup_lines - 1;
@@ -211,6 +266,19 @@ teco_curses_info_popup_show(teco_curses_info_popup_t *ctx, attr_t attr)
 }
 
 void
+teco_curses_info_popup_scroll(teco_curses_info_popup_t *ctx, gint delta)
+{
+	gint lines = getmaxy(stdscr);
+	gint pad_lines = getmaxy(ctx->pad);
+	gint popup_lines = MIN(pad_lines + 1, lines - 1);
+
+	ctx->pad_first_line = MAX(ctx->pad_first_line+delta, 0);
+	if (pad_lines - ctx->pad_first_line < popup_lines - 1)
+		/* show last page */
+		ctx->pad_first_line = pad_lines - (popup_lines - 1);
+}
+
+void
 teco_curses_info_popup_clear(teco_curses_info_popup_t *ctx)
 {
 	if (ctx->window)
diff --git a/src/interface-curses/curses-info-popup.h b/src/interface-curses/curses-info-popup.h
index 96dee5a..6f2ac9a 100644
--- a/src/interface-curses/curses-info-popup.h
+++ b/src/interface-curses/curses-info-popup.h
@@ -23,6 +23,7 @@
 #include <curses.h>
 
 #include "list.h"
+#include "string-utils.h"
 #include "interface.h"
 
 typedef struct {
@@ -49,6 +50,10 @@ void teco_curses_info_popup_add(teco_curses_info_popup_t *ctx, teco_popup_entry_
                                 const gchar *name, gsize name_len, gboolean highlight);
 
 void teco_curses_info_popup_show(teco_curses_info_popup_t *ctx, attr_t attr);
+const teco_string_t *teco_curses_info_popup_getentry(teco_curses_info_popup_t *ctx, gint y, gint x);
+void teco_curses_info_popup_scroll_page(teco_curses_info_popup_t *ctx);
+void teco_curses_info_popup_scroll(teco_curses_info_popup_t *ctx, gint delta);
+
 static inline bool
 teco_curses_info_popup_is_shown(teco_curses_info_popup_t *ctx)
 {
@@ -58,8 +63,10 @@ teco_curses_info_popup_is_shown(teco_curses_info_popup_t *ctx)
 static inline void
 teco_curses_info_popup_noutrefresh(teco_curses_info_popup_t *ctx)
 {
-	if (ctx->window)
-		wnoutrefresh(ctx->window);
+	if (!ctx->window)
+		return;
+	redrawwin(ctx->window);
+	wnoutrefresh(ctx->window);
 }
 
 void teco_curses_info_popup_clear(teco_curses_info_popup_t *ctx);
diff --git a/src/interface-curses/interface.c b/src/interface-curses/interface.c
index 9480822..3be1001 100644
--- a/src/interface-curses/interface.c
+++ b/src/interface-curses/interface.c
@@ -356,6 +356,7 @@ static struct {
 	GQueue *input_queue;
 
 	teco_curses_info_popup_t popup;
+	gsize popup_prefix_len;
 
 	/**
 	 * GError "thrown" by teco_interface_event_loop_iter().
@@ -1480,7 +1481,7 @@ teco_interface_popup_add(teco_popup_entry_type_t type, const gchar *name, gsize
 }
 
 void
-teco_interface_popup_show(void)
+teco_interface_popup_show(gsize prefix_len)
 {
 	if (!teco_interface.cmdline_window)
 		/* batch mode */
@@ -1489,9 +1490,21 @@ teco_interface_popup_show(void)
 	short fg = teco_rgb2curses(teco_interface_ssm(SCI_STYLEGETFORE, STYLE_CALLTIP, 0));
 	short bg = teco_rgb2curses(teco_interface_ssm(SCI_STYLEGETBACK, STYLE_CALLTIP, 0));
 
+	teco_interface.popup_prefix_len = prefix_len;
 	teco_curses_info_popup_show(&teco_interface.popup, SCI_COLOR_ATTR(fg, bg));
 }
 
+void
+teco_interface_popup_scroll(void)
+{
+	if (!teco_interface.cmdline_window)
+		/* batch mode */
+		return;
+
+	teco_curses_info_popup_scroll_page(&teco_interface.popup);
+	teco_interface_popup_show(teco_interface.popup_prefix_len);
+}
+
 gboolean
 teco_interface_popup_is_shown(void)
 {
@@ -1583,6 +1596,11 @@ teco_interface_refresh(void)
 	teco_view_noutrefresh(teco_interface_current_view);
 	wnoutrefresh(teco_interface.msg_window);
 	wnoutrefresh(teco_interface.cmdline_window);
+	/*
+	 * FIXME: Why do we have to redrawwin() the popup window
+	 * to keep it on the screen?
+	 * Perhaps something is causing a redraw of the entire Scinterm view.
+	 */
 	teco_curses_info_popup_noutrefresh(&teco_interface.popup);
 	doupdate();
 }
@@ -1596,20 +1614,59 @@ teco_interface_refresh(void)
 	(BUTTON1_##X | BUTTON2_##X | BUTTON3_##X | BUTTON4_##X | BUTTON5_##X)
 
 static gboolean
-teco_interface_getmouse(void)
+teco_interface_getmouse(GError **error)
 {
 	MEVENT event;
-	WINDOW *current = teco_view_get_window(teco_interface_current_view);
+
+	if (getmouse(&event) != OK)
+		return TRUE;
+
+	if (teco_curses_info_popup_is_shown(&teco_interface.popup) &&
+	    wmouse_trafo(teco_interface.popup.window, &event.y, &event.x, FALSE)) {
+		/*
+		 * NOTE: Not all curses variants report the RELEASED event,
+		 * but may also return REPORT_MOUSE_POSITION.
+		 * So we might react to all button presses as well.
+		 */
+		if (event.bstate & (BUTTON1_RELEASED | REPORT_MOUSE_POSITION)) {
+			teco_machine_t *machine = &teco_cmdline.machine.parent;
+			const teco_string_t *insert = teco_curses_info_popup_getentry(&teco_interface.popup, event.y, event.x);
+
+			if (insert && machine->current->insert_completion_cb) {
+				/* successfully clicked popup item */
+				const teco_string_t insert_suffix = {insert->data + teco_interface.popup_prefix_len,
+				                                     insert->len - teco_interface.popup_prefix_len};
+				if (!machine->current->insert_completion_cb(machine, &insert_suffix, error))
+					return FALSE;
+
+				teco_interface_popup_clear();
+				teco_interface_msg_clear();
+				teco_interface_cmdline_update(&teco_cmdline);
+			}
+
+			return TRUE;
+		}
+		if (event.bstate & BUTTON_NUM(4))
+			teco_curses_info_popup_scroll(&teco_interface.popup, -1);
+		else if (event.bstate & BUTTON_NUM(5))
+			teco_curses_info_popup_scroll(&teco_interface.popup, +1);
+
+		short fg = teco_rgb2curses(teco_interface_ssm(SCI_STYLEGETFORE, STYLE_CALLTIP, 0));
+		short bg = teco_rgb2curses(teco_interface_ssm(SCI_STYLEGETBACK, STYLE_CALLTIP, 0));
+		teco_curses_info_popup_show(&teco_interface.popup, SCI_COLOR_ATTR(fg, bg));
+
+		return TRUE;
+	}
 
 	/*
 	 * Return mouse coordinates relative to the view.
 	 * They will be in characters, but that's what SCI_POSITIONFROMPOINT
 	 * expects on Scinterm anyway.
 	 */
-	if (getmouse(&event) != OK ||
-	    !wmouse_trafo(current, &event.y, &event.x, FALSE))
+	WINDOW *current = teco_view_get_window(teco_interface_current_view);
+	if (!wmouse_trafo(current, &event.y, &event.x, FALSE))
 		/* no event inside of current view */
-		return FALSE;
+		return TRUE;
 
 	/*
 	 * NOTE: There will only be one of the button bits
@@ -1654,7 +1711,7 @@ teco_interface_getmouse(void)
 	if (event.bstate & BUTTON_ALT)
 		teco_mouse.mods |= TECO_MOUSE_ALT;
 
-	return TRUE;
+	return teco_cmdline_keymacro("MOUSE", -1, error);
 }
 
 #endif /* NCURSES_MOUSE_VERSION >= 2 */
@@ -1789,8 +1846,7 @@ teco_interface_event_loop_iter(void)
 #if NCURSES_MOUSE_VERSION >= 2
 	case KEY_MOUSE:
 		/* ANY of the mouse events */
-		if (teco_interface_getmouse() &&
-		    !teco_cmdline_keymacro("MOUSE", -1, error))
+		if (!teco_interface_getmouse(error))
 			return;
 		break;
 #endif
diff --git a/src/interface-gtk/gtk-info-popup.c b/src/interface-gtk/gtk-info-popup.c
index 29a1fa9..b9ca41c 100644
--- a/src/interface-gtk/gtk-info-popup.c
+++ b/src/interface-gtk/gtk-info-popup.c
@@ -53,6 +53,8 @@ struct _TecoGtkInfoPopup {
 	gboolean frozen;
 };
 
+static guint teco_gtk_info_popup_clicked_signal;
+
 static gboolean teco_gtk_info_popup_scroll_event(GtkWidget *widget, GdkEventScroll *event);
 static void teco_gtk_info_popup_show(GtkWidget *widget);
 static void teco_gtk_info_popup_vadjustment_changed(GtkAdjustment *vadjustment, GtkWidget *scrollbar);
@@ -82,6 +84,31 @@ teco_gtk_info_popup_class_init(TecoGtkInfoPopupClass *klass)
 	GTK_WIDGET_CLASS(klass)->scroll_event = teco_gtk_info_popup_scroll_event;
 	GTK_WIDGET_CLASS(klass)->show = teco_gtk_info_popup_show;
 	G_OBJECT_CLASS(klass)->finalize = teco_gtk_info_popup_finalize;
+
+	teco_gtk_info_popup_clicked_signal =
+			g_signal_new("clicked", G_TYPE_FROM_CLASS(klass),
+			             G_SIGNAL_RUN_LAST | G_SIGNAL_NO_RECURSE | G_SIGNAL_NO_HOOKS,
+			             0, NULL, NULL, NULL,
+			             G_TYPE_NONE, 2, G_TYPE_STRING, G_TYPE_ULONG);
+}
+
+static void
+teco_gtk_info_popup_activated_cb(GtkFlowBox *box, GtkFlowBoxChild *child, gpointer user_data)
+{
+	TecoGtkInfoPopup *popup = TECO_GTK_INFO_POPUP(user_data);
+
+	/*
+	 * Find the TecoGtkLabel in the flow box child.
+	 */
+	GtkWidget *hbox = gtk_bin_get_child(GTK_BIN(child));
+	g_autoptr(GList) child_list = gtk_container_get_children(GTK_CONTAINER(hbox));
+	GList *entry;
+	for (entry = child_list; entry != NULL && !TECO_IS_GTK_LABEL(entry->data); entry = g_list_next(entry));
+	g_assert(entry != NULL);
+	const teco_string_t *str = teco_gtk_label_get_text(TECO_GTK_LABEL(entry->data));
+
+	g_signal_emit(popup, teco_gtk_info_popup_clicked_signal, 0,
+	              str->data, (gulong)str->len);
 }
 
 static void
@@ -106,6 +133,8 @@ teco_gtk_info_popup_init(TecoGtkInfoPopup *self)
 	                 G_CALLBACK(teco_gtk_info_popup_vadjustment_changed), scrollbar);
 
 	self->flow_box = gtk_flow_box_new();
+	g_signal_connect(self->flow_box, "child-activated",
+	                 G_CALLBACK(teco_gtk_info_popup_activated_cb), self);
 	/* take as little height as necessary */
 	gtk_orientable_set_orientation(GTK_ORIENTABLE(self->flow_box),
 	                               GTK_ORIENTATION_HORIZONTAL);
@@ -311,12 +340,6 @@ teco_gtk_info_popup_idle_add(TecoGtkInfoPopup *self, teco_popup_entry_type_t typ
 	gtk_widget_set_halign(label, GTK_ALIGN_START);
 	gtk_widget_set_valign(label, GTK_ALIGN_CENTER);
 
-	/*
-	 * FIXME: This makes little sense once we've got mouse support.
-	 * But for the time being, it's a useful setting.
-	 */
-	gtk_label_set_selectable(GTK_LABEL(label), TRUE);
-
 	switch (type) {
 	case TECO_POPUP_PLAIN:
 		gtk_label_set_ellipsize(GTK_LABEL(label), PANGO_ELLIPSIZE_START);
@@ -417,12 +440,10 @@ teco_gtk_info_popup_scroll_page(TecoGtkInfoPopup *self)
 		 * Adjust this so only complete entries are shown.
 		 * Effectively, this rounds down to the line height.
 		 */
-		GList *child_list = gtk_container_get_children(GTK_CONTAINER(self->flow_box));
-		if (child_list) {
+		g_autoptr(GList) child_list = gtk_container_get_children(GTK_CONTAINER(self->flow_box));
+		if (child_list)
 			new_value -= (gint)new_value %
 			             gtk_widget_get_allocated_height(GTK_WIDGET(child_list->data));
-			g_list_free(child_list);
-		}
 
 		/* clip to the maximum possible value */
 		new_value = MIN(new_value, gtk_adjustment_get_upper(adj));
diff --git a/src/interface-gtk/gtk-label.c b/src/interface-gtk/gtk-label.c
index ebbb40e..ef370a2 100644
--- a/src/interface-gtk/gtk-label.c
+++ b/src/interface-gtk/gtk-label.c
@@ -269,3 +269,9 @@ teco_gtk_label_set_text(TecoGtkLabel *self, const gchar *str, gssize len)
 
 	gtk_label_set_text(GTK_LABEL(self), plaintext);
 }
+
+const teco_string_t *
+teco_gtk_label_get_text(TecoGtkLabel *self)
+{
+	return &self->string;
+}
diff --git a/src/interface-gtk/gtk-label.h b/src/interface-gtk/gtk-label.h
index e852104..c52d073 100644
--- a/src/interface-gtk/gtk-label.h
+++ b/src/interface-gtk/gtk-label.h
@@ -27,6 +27,7 @@ G_DECLARE_FINAL_TYPE(TecoGtkLabel, teco_gtk_label, TECO, GTK_LABEL, GtkLabel)
 GtkWidget *teco_gtk_label_new(const gchar *str, gssize len);
 
 void teco_gtk_label_set_text(TecoGtkLabel *self, const gchar *str, gssize len);
+const teco_string_t *teco_gtk_label_get_text(TecoGtkLabel *self);
 
 void teco_gtk_label_parse_string(const gchar *str, gssize len,
                                  PangoColor *fg, guint16 fg_alpha,
diff --git a/src/interface-gtk/interface.c b/src/interface-gtk/interface.c
index ed9271b..9c740a6 100644
--- a/src/interface-gtk/interface.c
+++ b/src/interface-gtk/interface.c
@@ -70,6 +70,8 @@ static void teco_interface_size_allocate_cb(GtkWidget *widget,
                                             gpointer user_data);
 static gboolean teco_interface_input_cb(GtkWidget *widget, GdkEvent *event,
                                         gpointer user_data);
+static void teco_interface_popup_clicked_cb(GtkWidget *popup, gchar *str, gulong len,
+                                            gpointer user_data);
 static gboolean teco_interface_window_delete_cb(GtkWidget *widget, GdkEventAny *event,
                                                 gpointer user_data);
 static gboolean teco_interface_sigterm_handler(gpointer user_data) G_GNUC_UNUSED;
@@ -194,6 +196,7 @@ static struct {
 	GtkIMContext *input_method;
 
 	GtkWidget *popup_widget;
+	gsize popup_prefix_len;
 
 	GtkWidget *current_view_widget;
 
@@ -381,6 +384,8 @@ teco_interface_init(void)
 	 */
 	teco_interface.popup_widget = teco_gtk_info_popup_new();
 	gtk_widget_set_name(teco_interface.popup_widget, "sciteco-info-popup");
+	g_signal_connect(teco_interface.popup_widget, "clicked",
+	                 G_CALLBACK(teco_interface_popup_clicked_cb), NULL);
 	gtk_overlay_add_overlay(GTK_OVERLAY(overlay_widget), teco_interface.popup_widget);
 	g_signal_connect(overlay_widget, "get-child-position",
 	                 G_CALLBACK(teco_gtk_info_popup_get_position_in_overlay), NULL);
@@ -754,12 +759,16 @@ teco_interface_popup_add(teco_popup_entry_type_t type, const gchar *name, gsize
 }
 
 void
-teco_interface_popup_show(void)
+teco_interface_popup_show(gsize prefix_len)
+{
+	teco_interface.popup_prefix_len = prefix_len;
+	gtk_widget_show(teco_interface.popup_widget);
+}
+
+void
+teco_interface_popup_scroll(void)
 {
-	if (gtk_widget_get_visible(teco_interface.popup_widget))
-		teco_gtk_info_popup_scroll_page(TECO_GTK_INFO_POPUP(teco_interface.popup_widget));
-	else
-		gtk_widget_show(teco_interface.popup_widget);
+	teco_gtk_info_popup_scroll_page(TECO_GTK_INFO_POPUP(teco_interface.popup_widget));
 }
 
 gboolean
@@ -1349,7 +1358,6 @@ static gboolean
 teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 {
 	static gboolean recursed = FALSE;
-	g_autoptr(GError) error = NULL;
 
 #ifdef DEBUG
 	if (event->type == GDK_KEY_PRESS)
@@ -1393,6 +1401,8 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 	GdkWindow *top_window = gdk_window_get_toplevel(gtk_widget_get_window(teco_interface.window));
 
 	do {
+		g_autoptr(GError) error = NULL;
+
 		/*
 		 * The event queue might be filled when pressing keys when SciTECO
 		 * is busy executing code.
@@ -1461,6 +1471,28 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 	return TRUE;
 }
 
+static void
+teco_interface_popup_clicked_cb(GtkWidget *popup, gchar *str, gulong len, gpointer user_data)
+{
+	g_assert(len >= teco_interface.popup_prefix_len);
+	const teco_string_t insert = {str+teco_interface.popup_prefix_len, len-teco_interface.popup_prefix_len};
+	teco_machine_t *machine = &teco_cmdline.machine.parent;
+
+	const teco_view_t *last_view = teco_interface_current_view;
+
+	/*
+	 * NOTE: It shouldn't really be necessary to catch TECO_ERROR_QUIT here.
+	 * A auto completion should never result in program termination.
+	 */
+	if (machine->current->insert_completion_cb &&
+	    !machine->current->insert_completion_cb(machine, &insert, NULL))
+		return;
+	teco_interface_popup_clear();
+	teco_interface_cmdline_update(&teco_cmdline);
+
+	teco_interface_refresh(teco_interface_current_view != last_view);
+}
+
 static gboolean
 teco_interface_window_delete_cb(GtkWidget *widget, GdkEventAny *event, gpointer user_data)
 {
diff --git a/src/interface.h b/src/interface.h
index 967f14d..33b094b 100644
--- a/src/interface.h
+++ b/src/interface.h
@@ -132,7 +132,9 @@ typedef enum {
 void teco_interface_popup_add(teco_popup_entry_type_t type,
                               const gchar *name, gsize name_len, gboolean highlight);
 /** @pure */
-void teco_interface_popup_show(void);
+void teco_interface_popup_show(gsize prefix_len);
+/** @pure */
+void teco_interface_popup_scroll(void);
 /** @pure */
 gboolean teco_interface_popup_is_shown(void);
 /** @pure */
diff --git a/src/parser.c b/src/parser.c
index c17186e..295c635 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -447,11 +447,14 @@ teco_state_stringbuilding_start_input(teco_machine_stringbuilding_t *ctx, gunich
 /* in cmdline.c */
 gboolean teco_state_stringbuilding_start_process_edit_cmd(teco_machine_stringbuilding_t *ctx, teco_machine_t *parent_ctx,
                                                           gunichar key, GError **error);
+gboolean teco_state_stringbuilding_insert_completion(teco_machine_stringbuilding_t *ctx, const teco_string_t *str, GError **error);
 
 TECO_DEFINE_STATE(teco_state_stringbuilding_start,
 		.is_start = TRUE,
 		.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)
-		                       teco_state_stringbuilding_start_process_edit_cmd
+		                       teco_state_stringbuilding_start_process_edit_cmd,
+		.insert_completion_cb = (teco_state_insert_completion_cb_t)
+		                        teco_state_stringbuilding_insert_completion
 );
 
 static teco_state_t *
diff --git a/src/parser.h b/src/parser.h
index f8bae90..fe8e764 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -110,6 +110,7 @@ typedef gboolean (*teco_state_refresh_cb_t)(teco_machine_t *ctx, GError **error)
 typedef gboolean (*teco_state_end_of_macro_cb_t)(teco_machine_t *ctx, GError **error);
 typedef gboolean (*teco_state_process_edit_cmd_cb_t)(teco_machine_t *ctx, teco_machine_t *parent_ctx,
                                                      gunichar key, GError **error);
+typedef gboolean (*teco_state_insert_completion_cb_t)(teco_machine_t *ctx, const teco_string_t *str, GError **error);
 
 typedef enum {
 	TECO_KEYMACRO_MASK_START		= (1 << 0),
@@ -187,6 +188,19 @@ struct teco_state_t {
 	teco_state_process_edit_cmd_cb_t process_edit_cmd_cb;
 
 	/**
+	 * Insert completion after clicking an entry in the popup
+	 * window.
+	 *
+	 * All implementations of this method are currently
+	 * defined in cmdline.c.
+	 *
+	 * It can be NULL if not required.
+	 *
+	 * @fixme Perhaps move all implementations to interface.c.
+	 */
+	teco_state_insert_completion_cb_t insert_completion_cb;
+
+	/**
 	 * Whether this state is a start state (i.e. not within any
 	 * escape sequence etc.).
 	 * This is separate of TECO_KEYMACRO_MASK_START which is set
@@ -241,11 +255,12 @@ gboolean teco_state_process_edit_cmd(teco_machine_t *ctx, teco_machine_t *parent
 #define TECO_DEFINE_STATE(NAME, ...) \
 	/** @ingroup states */ \
 	teco_state_t NAME = { \
-		.initial_cb = NULL,	/* do nothing */ \
+		.initial_cb = NULL,		/* do nothing */ \
 		.input_cb = (teco_state_input_cb_t)NAME##_input, /* always required */ \
-		.refresh_cb = NULL,	/* do nothing */ \
+		.refresh_cb = NULL,		/* do nothing */ \
 		.end_of_macro_cb = teco_state_end_of_macro, \
 		.process_edit_cmd_cb = teco_state_process_edit_cmd, \
+		.insert_completion_cb = NULL,	/* do nothing */ \
 		.is_start = FALSE, \
 		.keymacro_mask = TECO_KEYMACRO_MASK_DEFAULT, \
 		.style = SCE_SCITECO_DEFAULT, \
@@ -552,7 +567,10 @@ teco_state_t *teco_state_expectstring_input(teco_machine_main_t *ctx, gunichar c
 gboolean teco_state_expectstring_refresh(teco_machine_main_t *ctx, GError **error);
 
 /* in cmdline.c */
-gboolean teco_state_expectstring_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_expectstring_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx,
+                                                  gunichar key, GError **error);
+gboolean teco_state_expectstring_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str,
+                                                   GError **error);
 
 /**
  * @interface TECO_DEFINE_STATE_EXPECTSTRING
@@ -577,6 +595,8 @@ gboolean teco_state_expectstring_process_edit_cmd(teco_machine_main_t *ctx, teco
 		.refresh_cb = (teco_state_refresh_cb_t)teco_state_expectstring_refresh, \
 		.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t) \
 		                       teco_state_expectstring_process_edit_cmd, \
+		.insert_completion_cb = (teco_state_insert_completion_cb_t) \
+		                        teco_state_expectstring_insert_completion, \
 		.keymacro_mask = TECO_KEYMACRO_MASK_STRING, \
 		.style = SCE_SCITECO_STRING, \
 		.expectstring.string_building = TRUE, \
@@ -591,6 +611,7 @@ gboolean teco_state_expectfile_process(teco_machine_main_t *ctx, const teco_stri
 
 /* in cmdline.c */
 gboolean teco_state_expectfile_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_expectfile_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error);
 
 /**
  * @interface TECO_DEFINE_STATE_EXPECTFILE
@@ -601,12 +622,15 @@ gboolean teco_state_expectfile_process_edit_cmd(teco_machine_main_t *ctx, teco_m
 	TECO_DEFINE_STATE_EXPECTSTRING(NAME, \
 		.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t) \
 		                       teco_state_expectfile_process_edit_cmd, \
+		.insert_completion_cb = (teco_state_insert_completion_cb_t) \
+		                        teco_state_expectfile_insert_completion, \
 		.expectstring.process_cb = teco_state_expectfile_process, \
 		##__VA_ARGS__ \
 	)
 
 /* in cmdline.c */
 gboolean teco_state_expectdir_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_expectdir_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str, GError **error);
 
 /**
  * @interface TECO_DEFINE_STATE_EXPECTDIR
@@ -617,5 +641,7 @@ gboolean teco_state_expectdir_process_edit_cmd(teco_machine_main_t *ctx, teco_ma
 	TECO_DEFINE_STATE_EXPECTFILE(NAME, \
 		.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t) \
 		                       teco_state_expectdir_process_edit_cmd, \
+		.insert_completion_cb = (teco_state_insert_completion_cb_t) \
+		                        teco_state_expectdir_insert_completion, \
 		##__VA_ARGS__ \
 	)
diff --git a/src/qreg-commands.h b/src/qreg-commands.h
index be31f23..6dbd1c4 100644
--- a/src/qreg-commands.h
+++ b/src/qreg-commands.h
@@ -37,7 +37,10 @@ gboolean teco_state_expectqreg_initial(teco_machine_main_t *ctx, GError **error)
 teco_state_t *teco_state_expectqreg_input(teco_machine_main_t *ctx, gunichar chr, GError **error);
 
 /* in cmdline.c */
-gboolean teco_state_expectqreg_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_expectqreg_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx,
+                                                gunichar key, GError **error);
+gboolean teco_state_expectqreg_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str,
+                                                 GError **error);
 
 /**
  * @interface TECO_DEFINE_STATE_EXPECTQREG
@@ -56,6 +59,8 @@ gboolean teco_state_expectqreg_process_edit_cmd(teco_machine_main_t *ctx, teco_m
 		.initial_cb = (teco_state_initial_cb_t)teco_state_expectqreg_initial, \
 		.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t) \
 		                       teco_state_expectqreg_process_edit_cmd, \
+		.insert_completion_cb = (teco_state_insert_completion_cb_t) \
+		                        teco_state_expectqreg_insert_completion, \
 		.style = SCE_SCITECO_QREG, \
 		.expectqreg.type = TECO_QREG_REQUIRED, \
 		.expectqreg.got_register_cb = NAME##_got_register, /* always required */ \
diff --git a/src/qreg.c b/src/qreg.c
index 68c8db8..4beea74 100644
--- a/src/qreg.c
+++ b/src/qreg.c
@@ -1445,11 +1445,15 @@ teco_state_qregspec_start_input(teco_machine_qregspec_t *ctx, gunichar chr, GErr
 }
 
 /* in cmdline.c */
-gboolean teco_state_qregspec_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_qregspec_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_t *parent_ctx,
+                                              gunichar key, GError **error);
+gboolean teco_state_qregspec_insert_completion(teco_machine_qregspec_t *ctx, const teco_string_t *str,
+                                               GError **error);
 
 TECO_DEFINE_STATE(teco_state_qregspec_start,
 	.is_start = TRUE,
-	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_qregspec_process_edit_cmd
+	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_qregspec_process_edit_cmd,
+	.insert_completion_cb = (teco_state_insert_completion_cb_t)teco_state_qregspec_insert_completion
 );
 
 static teco_state_t *
@@ -1585,9 +1589,12 @@ teco_state_qregspec_string_input(teco_machine_qregspec_t *ctx, gunichar chr, GEr
 /* in cmdline.c */
 gboolean teco_state_qregspec_string_process_edit_cmd(teco_machine_qregspec_t *ctx, teco_machine_t *parent_ctx,
                                                      gunichar key, GError **error);
+gboolean teco_state_qregspec_string_insert_completion(teco_machine_qregspec_t *ctx, const teco_string_t *str,
+                                                      GError **error);
 
 TECO_DEFINE_STATE(teco_state_qregspec_string,
-	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_qregspec_string_process_edit_cmd
+	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_qregspec_string_process_edit_cmd,
+	.insert_completion_cb = (teco_state_insert_completion_cb_t)teco_state_qregspec_string_insert_completion
 );
 
 /** @static @memberof teco_machine_qregspec_t */
diff --git a/src/rb3str.c b/src/rb3str.c
index e43b6ba..276b624 100644
--- a/src/rb3str.c
+++ b/src/rb3str.c
@@ -143,7 +143,7 @@ teco_rb3str_auto_complete(teco_rb3str_tree_t *tree, gboolean case_sensitive,
 			                         cur->key.data, cur->key.len, FALSE);
 		}
 
-		teco_interface_popup_show();
+		teco_interface_popup_show(str_len);
 	}
 
 	return prefixed_entries == 1;
diff --git a/src/ring.c b/src/ring.c
index 319d3c8..2c235af 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -413,7 +413,7 @@ teco_state_edit_file_initial(teco_machine_main_t *ctx, GError **error)
 			                         strlen(filename), cur == teco_ring_current);
 		}
 
-		teco_interface_popup_show();
+		teco_interface_popup_show(0);
 	} else if (id > 0) {
 		allow_filename = FALSE;
 		if (!teco_current_doc_undo_edit(error) ||
diff --git a/src/symbols.c b/src/symbols.c
index 17e0b29..7dcc601 100644
--- a/src/symbols.c
+++ b/src/symbols.c
@@ -155,7 +155,7 @@ teco_symbol_list_auto_complete(teco_symbol_list_t *ctx, const gchar *symbol, tec
 			                         strlen(entry->data), FALSE);
 		}
 
-		teco_interface_popup_show();
+		teco_interface_popup_show(symbol_len);
 	}
 
 	return glist_len == 1;
@@ -252,7 +252,10 @@ teco_state_scintilla_symbols_done(teco_machine_main_t *ctx, const teco_string_t
 }
 
 /* in cmdline.c */
-gboolean teco_state_scintilla_symbols_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx, gunichar key, GError **error);
+gboolean teco_state_scintilla_symbols_process_edit_cmd(teco_machine_main_t *ctx, teco_machine_t *parent_ctx,
+                                                       gunichar key, GError **error);
+gboolean teco_state_scintilla_symbols_insert_completion(teco_machine_main_t *ctx, const teco_string_t *str,
+                                                        GError **error);
 
 /*$ ES scintilla message
  * -- Send Scintilla message
@@ -332,6 +335,7 @@ gboolean teco_state_scintilla_symbols_process_edit_cmd(teco_machine_main_t *ctx,
  */
 TECO_DEFINE_STATE_EXPECTSTRING(teco_state_scintilla_symbols,
 	.process_edit_cmd_cb = (teco_state_process_edit_cmd_cb_t)teco_state_scintilla_symbols_process_edit_cmd,
+	.insert_completion_cb = (teco_state_insert_completion_cb_t)teco_state_scintilla_symbols_insert_completion,
 	.expectstring.last = FALSE
 );