Implement and document new -P / --paging-mode flags to commandline, to support new

pager

4 files changed, 62 insertions, 71 deletions

diff --git a/builtin_commandline.cpp b/builtin_commandline.cpp
index 8b6c409a..564eee7b 100644
--- a/builtin_commandline.cpp
+++ b/builtin_commandline.cpp
@@ -213,6 +213,7 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
     int cursor_mode = 0;
     int line_mode = 0;
     int search_mode = 0;
+    int paging_mode = 0;
     const wchar_t *begin, *end;
 
     current_buffer = (wchar_t *)builtin_complete_get_temporary_buffer();
@@ -251,71 +252,24 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
         static const struct woption
                 long_options[] =
         {
-            {
-                L"append", no_argument, 0, 'a'
-            }
-            ,
-            {
-                L"insert", no_argument, 0, 'i'
-            }
-            ,
-            {
-                L"replace", no_argument, 0, 'r'
-            }
-            ,
-            {
-                L"current-job", no_argument, 0, 'j'
-            }
-            ,
-            {
-                L"current-process", no_argument, 0, 'p'
-            }
-            ,
-            {
-                L"current-token", no_argument, 0, 't'
-            }
-            ,
-            {
-                L"current-buffer", no_argument, 0, 'b'
-            }
-            ,
-            {
-                L"cut-at-cursor", no_argument, 0, 'c'
-            }
-            ,
-            {
-                L"function", no_argument, 0, 'f'
-            }
-            ,
-            {
-                L"tokenize", no_argument, 0, 'o'
-            }
-            ,
-            {
-                L"help", no_argument, 0, 'h'
-            }
-            ,
-            {
-                L"input", required_argument, 0, 'I'
-            }
-            ,
-            {
-                L"cursor", no_argument, 0, 'C'
-            }
-            ,
-            {
-                L"line", no_argument, 0, 'L'
-            }
-            ,
-            {
-                L"search-mode", no_argument, 0, 'S'
-            }
-            ,
-            {
-                0, 0, 0, 0
-            }
-        }
-        ;
+            { L"append", no_argument, 0, 'a' },
+            { L"insert", no_argument, 0, 'i' },
+            { L"replace", no_argument, 0, 'r' },
+            { L"current-job", no_argument, 0, 'j' },
+            { L"current-process", no_argument, 0, 'p' },
+            { L"current-token", no_argument, 0, 't' },
+            { L"current-buffer", no_argument, 0, 'b' },
+            { L"cut-at-cursor", no_argument, 0, 'c' },
+            { L"function", no_argument, 0, 'f' },
+            { L"tokenize", no_argument, 0, 'o' },
+            { L"help", no_argument, 0, 'h' },
+            { L"input", required_argument, 0, 'I' },
+            { L"cursor", no_argument, 0, 'C' },
+            { L"line", no_argument, 0, 'L' },
+            { L"search-mode", no_argument, 0, 'S' },
+            { L"paging-mode", no_argument, 0, 'P' },
+            { 0, 0, 0, 0 }
+        };
 
         int opt_index = 0;
 
@@ -397,6 +351,10 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
             case 'S':
                 search_mode = 1;
                 break;
+                
+            case 'P':
+                paging_mode = 1;
+                break;
 
             case 'h':
                 builtin_print_help(parser, argv[0], stdout_buffer);
@@ -415,7 +373,7 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
         /*
           Check for invalid switch combinations
         */
-        if (buffer_part || cut_at_cursor || append_mode || tokenize || cursor_mode || line_mode || search_mode)
+        if (buffer_part || cut_at_cursor || append_mode || tokenize || cursor_mode || line_mode || search_mode || paging_mode)
         {
             append_format(stderr_buffer,
                           BUILTIN_ERR_COMBO,
@@ -464,7 +422,7 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
     /*
       Check for invalid switch combinations
     */
-    if ((search_mode || line_mode || cursor_mode) && (argc-woptind > 1))
+    if ((search_mode || line_mode || cursor_mode || paging_mode) && (argc-woptind > 1))
     {
 
         append_format(stderr_buffer,
@@ -475,7 +433,7 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
         return 1;
     }
 
-    if ((buffer_part || tokenize || cut_at_cursor) && (cursor_mode || line_mode || search_mode))
+    if ((buffer_part || tokenize || cut_at_cursor) && (cursor_mode || line_mode || search_mode || paging_mode))
     {
         append_format(stderr_buffer,
                       BUILTIN_ERR_COMBO,
@@ -564,7 +522,12 @@ static int builtin_commandline(parser_t &parser, wchar_t **argv)
 
     if (search_mode)
     {
-        return !reader_search_mode();
+        return ! reader_search_mode();
+    }
+    
+    if (paging_mode)
+    {
+        return ! reader_has_pager_contents();
     }
 
 
diff --git a/doc_src/commandline.txt b/doc_src/commandline.txt
index ab771e96..1d13f79e 100644
--- a/doc_src/commandline.txt
+++ b/doc_src/commandline.txt
@@ -57,6 +57,16 @@ If \c commandline is called during a call to complete a given string
 using <code>complete -C STRING</code>, \c commandline will consider the
 specified string to be the current contents of the command line.
 
+The following options output metadata about the commandline state:
+
+- \c -L or \c --line print the line that the cursor is on, with the topmost
+line starting at 1
+- \c -S or \c --search-mode evaluates to true if the commandline is performing
+a history search
+- \c -P or \c --paging-mode evaluates to true if the commandline is showing
+pager contents, such as tab completions
+
+
 \subsection commandline-example Example
 
 <tt>commandline -j $history[3]</tt> replaces the job under the cursor with the
diff --git a/reader.cpp b/reader.cpp
index 95fa15bb..8c6d484e 100644
--- a/reader.cpp
+++ b/reader.cpp
@@ -3872,7 +3872,17 @@ int reader_search_mode()
         return -1;
     }
 
-    return !!data->search_mode;
+    return !! data->search_mode;
+}
+
+int reader_has_pager_contents()
+{
+    if (!data)
+    {
+        return -1;
+    }
+
+    return data->current_page_rendering.screen_data.empty() ? 1 : 0;
 }
 
 
diff --git a/reader.h b/reader.h
index cd32e751..82694e21 100644
--- a/reader.h
+++ b/reader.h
@@ -239,10 +239,18 @@ int reader_shell_test(const wchar_t *b);
 /**
    Test whether the interactive reader is in search mode.
 
-   \return o if not in search mode, 1 if in search mode and -1 if not in interactive mode
+   \return 0 if not in search mode, 1 if in search mode and -1 if not in interactive mode
  */
 int reader_search_mode();
 
+/**
+   Test whether the interactive reader has visible pager contents.
+
+   \return 0 if it has pager contents, 1 if it does not have pager contents, and -1 if not in interactive mode
+ */
+int reader_has_pager_contents();
+
+
 /* Given a command line and an autosuggestion, return the string that gets shown to the user. Exposed for testing purposes only. */
 wcstring combine_command_and_autosuggestion(const wcstring &cmdline, const wcstring &autosuggestion);