Clean up pager on exit from interactive read

pager.cpp

@@ -270,7 +270,7 @@ static int print_max(const wcstring &str, highlight_spec_t color, int max, bool
 /**
    Print the specified item using at the specified amount of space
 */
-line_t pager_t::completion_print_item(const wcstring &prefix, const comp_t *c, size_t row, size_t column, int width, bool secondary, page_rendering_t *rendering) const
+line_t pager_t::completion_print_item(const wcstring &prefix, const comp_t *c, size_t row, size_t column, int width, bool secondary, bool selected, page_rendering_t *rendering) const
 {
     int comp_width=0, desc_width=0;
     int written=0;
@@ -302,6 +302,10 @@ line_t pager_t::completion_print_item(const wcstring &prefix, const comp_t *c, s
     }
     
     int bg_color = secondary ? highlight_spec_pager_secondary : highlight_spec_normal;
+    if (selected)
+    {
+        bg_color = highlight_spec_search_match;
+    }
     
     for (size_t i=0; i<c->comp.size(); i++)
     {
@@ -356,8 +360,6 @@ void pager_t::completion_print(int cols, int *width_per_column, int row_start, i
 
     size_t rows = (lst.size()-1)/cols+1;
 
-    fprintf(stderr, "prefix: %ls\n", prefix.c_str());
-
     for (size_t row = row_start; row < row_stop; row++)
     {
         for (size_t col = 0; col < cols; col++)
@@ -367,10 +369,12 @@ void pager_t::completion_print(int cols, int *width_per_column, int row_start, i
             if (lst.size() <= col * rows + row)
                 continue;
 
-            const comp_t *el = &lst.at(col * rows + row);
+            size_t idx = col * rows + row;
+            const comp_t *el = &lst.at(idx);
+            bool is_selected = (idx == this->selected_completion_idx);
 
             /* Print this completion on its own "line" */
-            line_t line = completion_print_item(prefix, el, row, col, width_per_column[col] - (is_last?0:2), row%2, rendering);
+            line_t line = completion_print_item(prefix, el, row, col, width_per_column[col] - (is_last?0:2), row%2, is_selected, rendering);
             
             /* If there's more to come, append two spaces */
             if (col + 1 < cols)
@@ -586,6 +590,11 @@ void pager_t::set_completions(const completion_list_t &raw_completions)
     measure_completion_infos(&completion_infos, prefix);
 }
 
+void pager_t::set_prefix(const wcstring &pref)
+{
+    prefix = pref;
+}
+
 void pager_t::set_term_size(int w, int h)
 {
     assert(w > 0);
@@ -882,3 +891,25 @@ page_rendering_t pager_t::render() const
     }
     return rendering;
 }
+
+pager_t::pager_t() : term_width(0), term_height(0), selected_completion_idx(-1)
+{
+}
+
+bool pager_t::empty() const
+{
+    return completions.empty();
+}
+
+void pager_t::set_selected_completion(size_t idx)
+{
+    this->selected_completion_idx = idx;
+}
+
+
+void pager_t::clear()
+{
+    completions.clear();
+    completion_infos.clear();
+    prefix.clear();
+}

pager.h

@@ -21,6 +21,8 @@ class pager_t
     
     completion_list_t completions;
     
+    size_t selected_completion_idx;
+    
     /** Data structure describing one or a group of related completions */
     public:
     struct comp_t
@@ -52,19 +54,40 @@ class pager_t
     typedef std::vector<comp_t> comp_info_list_t;
     comp_info_list_t completion_infos;
     
+    wcstring prefix;
+    
     int completion_try_print(int cols, const wcstring &prefix, const comp_info_list_t &lst, page_rendering_t *rendering) const;
     
     void recalc_min_widths(comp_info_list_t * lst) const;
     void measure_completion_infos(std::vector<comp_t> *infos, const wcstring &prefix) const;
     
     void completion_print(int cols, int *width_per_column, int row_start, int row_stop, const wcstring &prefix, const comp_info_list_t &lst, page_rendering_t *rendering) const;
-    line_t completion_print_item(const wcstring &prefix, const comp_t *c, size_t row, size_t column, int width, bool secondary, page_rendering_t *rendering) const;
+    line_t completion_print_item(const wcstring &prefix, const comp_t *c, size_t row, size_t column, int width, bool secondary, bool selected, page_rendering_t *rendering) const;
 
     
     public:
-    void set_completions(const completion_list_t &comp);
-    void set_term_size(int w, int h);
-    wcstring prefix;
     
+    /* Sets the set of completions */
+    void set_completions(const completion_list_t &comp);
+    
+    /* Sets the prefix */
+    void set_prefix(const wcstring &pref);
+    
+    /* Sets the terminal width and height */
+    void set_term_size(int w, int h);
+    
+    /* Sets the index of the selected completion */
+    void set_selected_completion(size_t completion_idx);
+    
+    /* Produces a rendering of the completions, at the given term size */
     page_rendering_t render() const;
+    
+    /* Indicates if there are no completions, and therefore nothing to render */
+    bool empty() const;
+    
+    /* Clears all completions and the prefix */
+    void clear();
+    
+    /* Constructor */
+    pager_t();
 };

reader.cpp

@@ -198,8 +198,11 @@ public:
     /** String containing the autosuggestion */
     wcstring autosuggestion;
     
-    /** Current completions */
-    page_rendering_t completion_page_rendering;
+    /** Current pager */
+    pager_t current_pager;
+    
+    /** Whether we are navigating the pager */
+    bool is_navigating_pager;
 
     /** Whether autosuggesting is allowed at all */
     bool allow_autosuggestion;
@@ -334,6 +337,7 @@ public:
 
     /** Constructor */
     reader_data_t() :
+        is_navigating_pager(0),
         allow_autosuggestion(0),
         suppress_autosuggestion(0),
         expand_abbreviations(0),
@@ -543,7 +547,7 @@ static void reader_repaint()
             &colors[0],
             &indents[0],
             data->buff_pos,
-            &data->completion_page_rendering.screen_data);
+            data->current_pager);
 
     data->repaint_needed = false;
 }
@@ -1859,9 +1863,9 @@ static bool handle_completions(const std::vector<completion_t> &comp)
                 {
                     pager_t pager;
                     pager.set_term_size(common_get_width(), common_get_height());
-                    pager.prefix = prefix;
+                    pager.set_prefix(prefix);
                     pager.set_completions(surviving_completions);
-                    data->completion_page_rendering = pager.render();
+                    data->current_pager = pager;
                 }
                 else
                 {
@@ -3143,6 +3147,9 @@ const wchar_t *reader_readline(void)
                 {
                     /* The user typed R_COMPLETE more than once in a row. Cycle through our available completions */
                     const completion_t *next_comp = cycle_competions(comp, cycle_command_line, &completion_cycle_idx);
+                    
+                    data->current_pager.set_selected_completion(completion_cycle_idx);
+                    
                     if (next_comp != NULL)
                     {
                         size_t cursor_pos = cycle_cursor_pos;
@@ -3815,6 +3822,14 @@ const wchar_t *reader_readline(void)
     }
 
     writestr(L"\n");
+    
+    /* Ensure we have no pager contents when we exit */
+    if (! data->current_pager.empty())
+    {
+        /* Clear to end of screen to erase the pager contents. TODO: this may fail if eos doesn't exist, in which case we should emit newlines */
+        screen_force_clear_to_end();
+        data->current_pager.clear();
+    }
 
     if (!reader_exit_forced())
     {

screen.cpp

@@ -45,6 +45,7 @@ efficient way for transforming that to the desired screen content.
 #include "highlight.h"
 #include "screen.h"
 #include "env.h"
+#include "pager.h"
 
 /** The number of characters to indent new blocks */
 #define INDENT_STEP 4
@@ -1027,7 +1028,7 @@ static void s_update(screen_t *scr, const wchar_t *left_prompt, const wchar_t *r
 
     if (! output.empty())
     {
-        write_loop(1, &output.at(0), output.size());
+        write_loop(STDOUT_FILENO, &output.at(0), output.size());
     }
 
     /* We have now synced our actual screen against our desired screen. Note that this is a big assignment! */
@@ -1236,7 +1237,7 @@ void s_write(screen_t *s,
              const highlight_spec_t *colors,
              const int *indent,
              size_t cursor_pos,
-             const screen_data_t *pager_data)
+             const pager_t &pager)
 {
     screen_data_t::cursor_t cursor_arr;
 
@@ -1325,9 +1326,10 @@ void s_write(screen_t *s,
     s->desired.cursor = cursor_arr;
     
     /* append pager_data */
-    if (pager_data != NULL)
+    if (! pager.empty())
     {
-        s->desired.append_lines(*pager_data);
+        const page_rendering_t rendering = pager.render();
+        s->desired.append_lines(rendering.screen_data);
     }
     
     s_update(s, layout.left_prompt.c_str(), layout.right_prompt.c_str());
@@ -1435,6 +1437,22 @@ void s_reset(screen_t *s, screen_reset_mode_t mode)
     fstat(2, &s->prev_buff_2);
 }
 
+bool screen_force_clear_to_end()
+{
+    bool result = false;
+    if (clr_eos)
+    {
+        data_buffer_t output;
+        s_write_mbs(&output, clr_eos);
+        if (! output.empty())
+        {
+            write_loop(STDOUT_FILENO, &output.at(0), output.size());
+            result = true;
+        }
+    }
+    return result;
+}
+
 screen_t::screen_t() :
     desired(),
     actual(),

screen.h

@@ -16,6 +16,8 @@
 #include <sys/stat.h>
 #include "highlight.h"
 
+class pager_t;
+
 /**
    A class representing a single line of a screen.
 */
@@ -203,7 +205,7 @@ void s_write(screen_t *s,
              const highlight_spec_t *colors,
              const int *indent,
              size_t cursor_pos,
-             const screen_data_t *pager_data);
+             const pager_t &pager_data);
 
 /**
     This function resets the screen buffers internal knowledge about
@@ -241,6 +243,9 @@ enum screen_reset_mode_t
 
 void s_reset(screen_t *s, screen_reset_mode_t mode);
 
+/* Issues an immediate clr_eos, returning if it existed */
+bool screen_force_clear_to_end();
+
 /* Returns the length of an escape code. Exposed for testing purposes only. */
 size_t escape_code_length(const wchar_t *code);