Ticket #4256: scrollbars_improvements.patch

lib/widget/listbox.c

@@ -85 +85 @@
 
 /* --------------------------------------------------------------------------------------------- */
 
-static void
-listbox_drawscroll (WListbox * l)
-{
-    Widget *w = WIDGET (l);
-    int max_line = w->lines - 1;
-    int line = 0;
-    int i;
-    int length;
-
-    /* Are we at the top? */
-    widget_gotoyx (w, 0, w->cols);
-    if (l->top == 0)
-        tty_print_one_vline (TRUE);
-    else
-        tty_print_char ('^');
-
-    length = g_queue_get_length (l->list);
-
-    /* Are we at the bottom? */
-    widget_gotoyx (w, max_line, w->cols);
-    if (l->top + w->lines == length || w->lines >= length)
-        tty_print_one_vline (TRUE);
-    else
-        tty_print_char ('v');
-
-    /* Now draw the nice relative pointer */
-    if (!g_queue_is_empty (l->list))
-        line = 1 + ((l->pos * (w->lines - 2)) / length);
-
-    for (i = 1; i < max_line; i++)
-    {
-        widget_gotoyx (w, i, w->cols);
-        if (i != line)
-            tty_print_one_vline (TRUE);
-        else
-            tty_print_char ('*');
-    }
-}
-
-/* --------------------------------------------------------------------------------------------- */
-
 static void
 listbox_draw (WListbox * l, gboolean focused)
 {
@@ -183 +142 @@
 
     l->cursor_y = sel_line;
 
-    if (l->scrollbar && length > w->lines)
+    if (l->draw_scrollbar)
     {
         tty_setcolor (normalc);
-        listbox_drawscroll (l);
+        scrollbar_set_state (l->scrollbar, w->y - 1, w->x + w->cols - 1, w->lines + 2, g_queue_get_length (l->list), w->lines, l->top);
+        WIDGET (l->scrollbar)->callback (WIDGET (l->scrollbar), NULL, MSG_DRAW, 0, NULL);
     }
 }
 
@@ -440 +400 @@
 static inline void
 listbox_destroy (WListbox * l)
 {
+    widget_destroy (WIDGET (l->scrollbar));
     listbox_remove_list (l);
 }
 
@@ -564 +525 @@
     l->deletable = deletable;
     l->callback = callback;
     l->allow_duplicates = TRUE;
-    l->scrollbar = !mc_global.tty.slow_terminal;
+    l->draw_scrollbar = !mc_global.tty.slow_terminal;
+    l->scrollbar = scrollbar_new (y, x + width - 1, height, TRUE);
 
     return l;
 }

lib/widget/Makefile.am

@@ -24 +24 @@
         quick.c quick.h \
         radio.c radio.h \
         rect.c rect.h \
+        scrollbar.c scrollbar.h \
         widget-common.c widget-common.h \
         wtools.c wtools.h
 

doc/man/mc.1.in

@@ -1989 +1989 @@
 .I Show free space.
 If enabled, free space and total space of current file system is shown
 at the bottom frame of panel. Enabled by default.
+.PP
+.I Panel scrollbars.
+Show scrollbars in main panels (on the right side). Enabled by default.
 .\"NODE "    Panel options"
 .SH "    Panel options"
 .B Main panel options

lib/widget/listbox.h

@@ -48 +48 @@
     int pos;                    /* The current element displayed */
     int top;                    /* The first element displayed */
     gboolean allow_duplicates;  /* Do we allow duplicates on the list? */
-    gboolean scrollbar;         /* Draw a scrollbar? */
+    gboolean draw_scrollbar;    /* Draw a scrollbar? */
+    WScrollbar *scrollbar;      /* Scrollbar widget */
     gboolean deletable;         /* Can list entries be deleted? */
     lcback_fn callback;         /* The callback function */
     int cursor_x, cursor_y;     /* Cache the values */

src/filemanager/panel.h

@@ -105 +105 @@
 
     dir_list dir;               /* Directory contents */
     struct stat dir_stat;       /* Stat of current dir: used by execute () */
+    WScrollbar *scrollbar;      /* scrollbar of panel */
 
     vfs_path_t *cwd_vpath;      /* Current Working Directory */
     vfs_path_t *lwd_vpath;      /* Last Working Directory */

src/filemanager/layout.h

@@ -46 +46 @@
 extern int output_start_y;
 extern gboolean xterm_title;
 extern gboolean free_space;
+extern gboolean panel_scrollbars;
 extern gboolean nice_rotating_dash;
 
 extern int ok_to_refresh;

src/setup.c

@@ -274 +274 @@
     { "command_prompt", &command_prompt },
     { "menubar_visible", &menubar_visible },
     { "free_space", &free_space },
+    { "panel_scrollbars", &panel_scrollbars },
     { "horizontal_split", &panels_layout.horizontal_split },
     { "vertical_equal", &panels_layout.vertical_equal },
     { "horizontal_equal", &panels_layout.horizontal_equal },

lib/widget.h

@@ -29 +29 @@
 #include "lib/widget/gauge.h"
 #include "lib/widget/groupbox.h"
 #include "lib/widget/label.h"
+#include "lib/widget/scrollbar.h"
 #include "lib/widget/listbox.h"
 #include "lib/widget/menu.h"
 #include "lib/widget/radio.h"

src/filemanager/layout.c

@@ -100 +100 @@
 /* Set to show free space on device assigned to current directory */
 gboolean free_space = TRUE;
 
+/* Set to show scrollbars on main panels */
+gboolean panel_scrollbars = TRUE;
+
 /* The starting line for the output of the subprogram */
 int output_start_y = 0;
 
@@ -133 +136 @@
     gboolean message_visible;
     gboolean xterm_title;
     gboolean free_space;
+    gboolean panel_scrollbars;
     int output_lines;
 } layout_t;
 
@@ -176 +180 @@
     { N_("&Keybar visible"), &mc_global.keybar_visible, NULL },
     { N_("H&intbar visible"), &mc_global.message_visible, NULL },
     { N_("&XTerm window title"), &xterm_title, NULL },
-    { N_("&Show free space"), &free_space, NULL }
+    { N_("&Show free space"), &free_space, NULL },
+    { N_("&Panel scrollbars"), &panel_scrollbars, NULL }
     /* *INDENT-ON* */
 };
 
@@ -466 +471 @@
                 xterm_title = check_options[5].widget->state;
             else if (sender == WIDGET (check_options[6].widget))
                 free_space = check_options[6].widget->state;
+            else if (sender == WIDGET (check_options[7].widget))
+                panel_scrollbars = check_options[7].widget->state;
             else
                 ok = FALSE;
 
@@ -678 +685 @@
     old_layout.message_visible = mc_global.message_visible;
     old_layout.xterm_title = xterm_title;
     old_layout.free_space = free_space;
+    old_layout.panel_scrollbars = panel_scrollbars;
     old_layout.output_lines = -1;
 
     _output_lines = output_lines;
@@ -696 +704 @@
     mc_global.message_visible = old_layout.message_visible;
     xterm_title = old_layout.xterm_title;
     free_space = old_layout.free_space;
+    panel_scrollbars = old_layout.panel_scrollbars;
     output_lines = old_layout.output_lines;
 
     panels_layout = old_panels_layout;

src/filemanager/panel.c

@@ -1258 +1258 @@
 {
     const Widget *w = CONST_WIDGET (panel);
     gchar *tmp;
+    int lines;
 
     set_colors (panel);
     tty_draw_box (w->y, w->x, w->lines, w->cols, FALSE);
+    lines = panel_lines (panel);
 
     if (panels_options.show_mini_info)
     {
         int y;
 
-        y = panel_lines (panel) + 2;
+        y = lines + 2;
 
         widget_gotoyx (w, y, 0);
         tty_print_alt_char (ACS_LTEE, FALSE);
@@ -1274 +1276 @@
         tty_print_alt_char (ACS_RTEE, FALSE);
     }
 
+    if (panel_scrollbars) {
+        scrollbar_set_state (panel->scrollbar, w->y + 1, w->x + w->cols - 1, lines + 2, panel->dir.len,
+                             lines * panel->list_cols, panel->top_file);
+    }
+
     widget_gotoyx (w, 0, 1);
     tty_print_string (panel_history_prev_item_char);
 
@@ -1314 +1321 @@
     {
         if (panel->marked == 0)
         {
-            /* Show size of curret file in the bottom of panel */
+            /* Show size of current file in the bottom of panel */
             if (S_ISREG (panel->dir.list[panel->selected].st.st_mode))
             {
                 char buffer[BUF_SMALL];
@@ -3648 +3655 @@
         mc_event_add (h->event_group, MCEVENT_HISTORY_LOAD, panel_load_history, w, NULL);
         /* subscribe to "history_save" event */
         mc_event_add (h->event_group, MCEVENT_HISTORY_SAVE, panel_save_history, w, NULL);
+        panel->scrollbar = scrollbar_new (w->y + 1, w->x + w->cols - 1, w->lines, FALSE);
+        return MSG_HANDLED;
+
+    case MSG_RESIZE:
+        widget_default_callback (w, NULL, MSG_RESIZE, 0, data);
+        if (panel->scrollbar != NULL)
+            WIDGET (panel->scrollbar)->callback (WIDGET (panel->scrollbar), NULL, MSG_RESIZE, 0, NULL);
         return MSG_HANDLED;
 
     case MSG_DRAW:
         /* Repaint everything, including frame and separator */
         widget_erase (w);
         show_dir (panel);
+        mini_info_separator (panel);
         panel_print_header (panel);
         adjust_top_file (panel);
         paint_dir (panel);
-        mini_info_separator (panel);
         display_mini_info (panel);
+
+        if (panel_scrollbars)
+            WIDGET (panel->scrollbar)->callback (WIDGET (panel->scrollbar), NULL, MSG_DRAW, 0, NULL);
+
         panel->dirty = FALSE;
         return MSG_HANDLED;
 
@@ -3706 +3724 @@
         mc_event_del (h->event_group, MCEVENT_HISTORY_LOAD, panel_load_history, w);
         /* unsubscribe from "history_save" event */
         mc_event_del (h->event_group, MCEVENT_HISTORY_SAVE, panel_save_history, w);
+        widget_destroy (WIDGET (panel->scrollbar));
         panel_destroy (panel);
         free_my_statfs ();
         return MSG_HANDLED;

new file lib/widget/scrollbar.c

@@ +1 @@
+/*
+   Widgets for the Midnight Commander
+
+   Copyright (C) 2021
+   Free Software Foundation, Inc.
+
+   This file is part of the Midnight Commander.
+
+   The Midnight Commander is free software: you can redistribute it
+   and/or modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   The Midnight Commander is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file scrollbar.c
+ *  \brief Source: WScrollbar widget
+ */
+
+#include <config.h>
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lib/global.h"
+
+#include "lib/tty/tty.h"
+#include "lib/tty/color.h"
+#include "lib/skin.h"
+#include "lib/strutil.h"
+#include "lib/widget.h"
+
+/*** global variables ****************************************************************************/
+
+/*** file scope macro definitions ****************************************************************/
+
+/*** file scope type declarations ****************************************************************/
+
+/*** file scope variables ************************************************************************/
+
+/*** file scope functions ************************************************************************/
+
+static cb_ret_t
+scrollbar_callback (Widget * w, Widget * sender, widget_msg_t msg, int parm, void *data)
+{
+    WScrollbar *s = SCROLLBAR (w);
+
+    switch (msg)
+    {
+    case MSG_RESIZE:
+        {
+            widget_default_callback (w, NULL, MSG_RESIZE, 0, data);
+            return MSG_HANDLED;
+        }
+
+    case MSG_DRAW:
+        {
+            int scrollbar_values_per_char;
+            int scrollbar_values_total;
+            int scrollbox_length;
+            int top_possibilities;
+            int scrollbox_pos_start;
+            int i;
+            int scrollbar_position;
+
+            if (s->data_items <= s->data_visible_items)
+                return MSG_HANDLED;
+
+            /* Are we at the top? */
+            widget_gotoyx (w, 0, 0);
+            if (s->data_visible_start_position == 0)
+                tty_print_string (mc_global.tty.ugly_line_drawing ? "" : "△");
+            else
+                tty_print_string (mc_global.tty.ugly_line_drawing ? "^" : "▲");
+
+            /* Are we at the bottom? */
+            widget_gotoyx (w, w->lines - 1, 0);
+            if (s->data_visible_start_position + s->data_visible_items >= s->data_items)
+                tty_print_string (mc_global.tty.ugly_line_drawing ? "" : "▽");
+            else
+                tty_print_string (mc_global.tty.ugly_line_drawing ? "v" : "▼");
+
+            if (w->lines <= 2)           /* there is no enough space for actual scrollbar */
+                return MSG_HANDLED;
+
+            /* Now draw the nice relative pointer */
+            scrollbar_values_per_char = (s->has_subchars && !mc_global.tty.ugly_line_drawing ? 2 : 1);
+            scrollbar_values_total = (w->lines - 2) * scrollbar_values_per_char;
+            scrollbox_length = MAX (1, scrollbar_values_total * s->data_visible_items / s->data_items);
+            top_possibilities = s->data_items - s->data_visible_items + 1;
+            scrollbox_pos_start = (2 * s->data_visible_start_position * (scrollbar_values_total - scrollbox_length)
+                    / (top_possibilities - 1) + 1) / 2;
+
+            for (i = 0; i < w->lines - 2; i++)
+            {
+                widget_gotoyx (w, i + 1, 0);
+                scrollbar_position = i * scrollbar_values_per_char;
+
+                if (scrollbar_values_per_char == 2
+                        && scrollbar_position + 1 == scrollbox_pos_start)
+                    tty_print_string ("▄");
+                else if (scrollbar_values_per_char == 2
+                        && scrollbar_position >= scrollbox_pos_start
+                        && scrollbar_position + 1 == scrollbox_pos_start + scrollbox_length)
+                    tty_print_string ("▀");
+                else if (scrollbar_position >= scrollbox_pos_start
+                        && scrollbar_position + scrollbar_values_per_char <= scrollbox_pos_start + scrollbox_length)
+                    tty_print_string (mc_global.tty.ugly_line_drawing ? "#" : (s->has_subchars ? "█" : "▓"));
+                else
+                    tty_print_string (s->has_subchars || mc_global.tty.ugly_line_drawing ? " " : "░");
+            }
+
+            return MSG_HANDLED;
+        }
+
+    default:
+        return widget_default_callback (w, sender, msg, parm, data);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/*** public functions ****************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+WScrollbar *
+scrollbar_new (int y, int x, int lines, gboolean has_subchars)
+{
+    WScrollbar *scrollbar;
+    Widget *w;
+
+    scrollbar = g_new (WScrollbar, 1);
+    w = WIDGET (scrollbar);
+    widget_init (w, y, x, lines, 1, scrollbar_callback, NULL);
+
+    scrollbar->has_subchars = has_subchars;
+    scrollbar->data_items = 0;
+    scrollbar->data_visible_items = 0;
+    scrollbar->data_visible_start_position = 0;
+
+    return scrollbar;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+void
+scrollbar_set_state(WScrollbar * scrollbar, int y, int x, int lines, int data_length,
+                    int data_visible_length, int data_position)
+{
+    Widget *w = WIDGET (scrollbar);
+
+    w->y = y;
+    w->x = x;
+    w->lines = lines;
+    scrollbar->data_items = data_length;
+    scrollbar->data_visible_items = data_visible_length;
+    scrollbar->data_visible_start_position = data_position;
+
+    widget_draw (w);
+}
+
+/* --------------------------------------------------------------------------------------------- */

new file lib/widget/scrollbar.h

@@ +1 @@
+
+/** \file scrollbar.h
+ *  \brief Header: WScrollbar widget
+ */
+
+#ifndef MC__WIDGET_SCROLLBAR_H
+#define MC__WIDGET_SCROLLBAR_H
+
+/*** typedefs(not structures) and defined constants **********************************************/
+
+#define SCROLLBAR(x) ((WScrollbar *)(x))
+
+/*** enums ***************************************************************************************/
+
+/*** structures declarations (and typedefs of structures)*****************************************/
+
+typedef struct
+{
+    Widget widget;
+    gboolean has_subchars;   /* if uses sub-characters (2 states per character). Also, this
+                                turns off scrollbar background */
+    int data_items;         /* how many items are in the background data */
+    int data_visible_items; /* how many items from data are actually visible */
+    int data_visible_start_position;       /* position of first visible item in data */
+} WScrollbar;
+
+/*** global variables defined in .c file *********************************************************/
+
+/*** declarations of public functions ************************************************************/
+
+WScrollbar *scrollbar_new (int y, int x, int height, gboolean has_subchars);
+void scrollbar_set_state (WScrollbar * scrollbar, int y, int x, int lines, int data_length,
+                          int data_visible_length, int data_position);
+
+/*** inline functions ****************************************************************************/
+
+#endif /* MC__WIDGET_SCROLLBAR_H */