X-Git-Url: https://plomlompom.com/repos/?a=blobdiff_plain;f=src%2Fwindows.c;h=b62bfc5b7af2bb5cb5d431e1e63840c060d4b07c;hb=0dabaa36270dbe843f1da82e4d325b280e6d8e91;hp=072ae0165a6621936bf7f2aa58de162ded04a37d;hpb=8ff69b3f8b0c10d3f7cea754d2b4e9e97f0df9b6;p=plomrogue

diff --git a/src/windows.c b/src/windows.c
index 072ae01..b62bfc5 100644
--- a/src/windows.c
+++ b/src/windows.c
@@ -1,25 +1,30 @@
 /* windows.c */
 
 #include "windows.h"
-#include <stdint.h>    /* for uint16_t, uint32_t */
-#include <ncurses.h>   /* for LOTS of stuff */
+#include <stdint.h>    /* for uint8_t, uint16_t, uint32_t */
+#include <ncurses.h>   /* for typedefs WINDOW, chtype, wresize(), getmaxx(), */
+                       /* getmaxy(), supbad(), delwin(), mvwaddch(),         */
+                       /* mvwaddstr(), newpad(), wnoutrefres(), erase(),     */
+                       /* werase(), pnoutrefresh(), doupdate()               */
 #include <stdlib.h>    /* for malloc(), free() */
-#include <string.h>    /* for strlen(), memcpy() */
+#include <string.h>    /* for strlen(), strnlen(), memcpy() */
 #include "yx_uint16.h" /* for yx_uint16 coordinates */
 
 
 
 /* Fit virtual screen's width to minimum width demanded by current windows'
- * geometries.
+ * geometries. Returns 0 on success, 1 on (pad memory allocation) error.
  */
-static void refit_pad(struct WinMeta * wmeta);
+static uint8_t refit_pad(struct WinMeta * wmeta);
 
 
 
 /* Update geometry (sizes, positions) of window "w" and its successors in the
  * window chain. For the positioning algorithm place_win() is used.
+ *
+ * update_wins() returns 0 on success, 1 on (pad/window memory alloc.) error.
  */
-static void update_wins(struct WinMeta * wmeta, struct Win * w);
+static uint8_t update_wins(struct WinMeta * wmeta, struct Win * w);
 static void place_win(struct WinMeta * wmeta, struct Win * w);
 
 
@@ -35,9 +40,9 @@ static void draw_wins(struct Win * w);
 
 
 /* draw_win_borderlines() draws the vertical and horizontal borders of window
- * "w" sans corners, and draws the top border line as the windows' title bar
- * (highlighted if the window is described active by "active" being set).
- * draw_wins_borderlines().
+ * "w" sans corners into the virtual screen "pad", and draws the top border
+ * line as the windows' title bar (highlighted if the window is described
+ * active by "active" being set). draw_wins_borderlines().
  *
  * draw_wins_borderlines() calls draw_win_borderlines() recursively on all
  * windows from "w" on. "w_active" is a pointer to the one window that
@@ -46,81 +51,99 @@ static void draw_wins(struct Win * w);
  * Finally, draw_wins_bordercorners draws into "pad" the borders of window "w"
  * and all its successors.
  */
-static void draw_win_borderlines(struct Win * w, char active);
-static void draw_wins_borderlines(struct Win * w, struct Win * w_active);
+static void draw_win_borderlines(struct Win * w, char active, WINDOW * pad);
+static void draw_wins_borderlines(struct Win * w, struct Win * w_active,
+                                  WINDOW * pad);
 static void draw_wins_bordercorners(struct Win * w, WINDOW * pad);
 
 
 
-static void refit_pad(struct WinMeta * wmeta)
+/* Shift active window forwards / backwards in window chain. */
+static void shift_win_forward(struct WinMeta * wmeta);
+static void shift_win_backward(struct WinMeta * wmeta);
+
+
+
+static uint8_t refit_pad(struct WinMeta * wmeta)
 {
     /* Determine rightmost window column. */
     uint16_t lastwincol = 0;
-    struct Win * w_p = wmeta->chain_start;
+    struct Win * w_p = wmeta->_chain_start;
     while (w_p != 0)
     {
-        if (w_p->start.x + w_p->frame.size.x > lastwincol + 1)
+        if (w_p->_start.x + w_p->frame.size.x > lastwincol + 1)
         {
-            lastwincol = w_p->start.x + w_p->frame.size.x - 1;
+            lastwincol = w_p->_start.x + w_p->frame.size.x - 1;
         }
-        w_p = w_p->next;
+        w_p = w_p->_next;
     }
 
     /* Only resize the pad if the rightmost window column has changed. */
-    if (getmaxx(wmeta->pad.curses_win) != lastwincol)
+    if (getmaxx(wmeta->padframe.curses_win) != lastwincol)
     {
-        wresize(wmeta->pad.curses_win,
-                getmaxy(wmeta->pad.curses_win), lastwincol + 2);
+        return (ERR == wresize(wmeta->padframe.curses_win,
+                               getmaxy(wmeta->padframe.curses_win),
+                               lastwincol + 2));
     }
+    return 0;
 }
 
 
 
-static void update_wins (struct WinMeta * wmeta, struct Win * w)
+static uint8_t update_wins(struct WinMeta * wmeta, struct Win * w)
 {
     if (0 != w->frame.curses_win)
     {
-        destroy_win (w);
+        destroy_win(w);
     }
     place_win(wmeta, w);
-    refit_pad(wmeta);
-    w->frame.curses_win = subpad(wmeta->pad.curses_win,
-                                 w->frame.size.y, w->frame.size.x,
-                                 w->start.y, w->start.x);
-    if (0 != w->next)
+    if (0 != refit_pad(wmeta))
     {
-        update_wins (wmeta, w->next);
+        return 1;
     }
+    WINDOW * test = subpad(wmeta->padframe.curses_win,
+                           w->frame.size.y, w->frame.size.x,
+                           w->_start.y, w->_start.x);
+    if (NULL == test)
+    {
+        return 1;
+    }
+    w->frame.curses_win = test;
+    if (0 != w->_next)
+    {
+        return update_wins(wmeta, w->_next);
+    }
+    return 0;
 }
 
 
 
-static void place_win (struct WinMeta * wmeta, struct Win * w)
+static void place_win(struct WinMeta * wmeta, struct Win * w)
 {
     /* First window goes into the upper-left corner. */
-    w->start.x = 0;
-    w->start.y = 1;                             /* Leave space for title bar. */
-    if (0 != w->prev)
+    w->_start.x = 0;
+    w->_start.y = 1;                            /* Leave space for title bar. */
+    if (0 != w->_prev)
     {
 
         /* Non-first window fallbacks to: fit rightwards of rightmost border. */
-        struct Win * w_top = w->prev;
-        while (w_top->start.y != 1)
+        struct Win * w_top = w->_prev;
+        while (w_top->_start.y != 1)
         {
-            w_top = w_top->prev;
+            w_top = w_top->_prev;
         }
-        w->start.x = w_top->start.x + w_top->frame.size.x + 1;
+        w->_start.x = w_top->_start.x + w_top->frame.size.x + 1;
 
         /* Fit window below its predecessor if that one directly thrones over
          * empty space wide and high enough.
          */
-        uint16_t w_prev_maxy = w->prev->start.y
-                               + getmaxy(w->prev->frame.curses_win);
-        if (   w->frame.size.x <= w->prev->frame.size.x
-            && w->frame.size.y <  wmeta->pad.size.y - w_prev_maxy)
+        uint16_t w_prev_maxy = w->_prev->_start.y
+                               + getmaxy(w->_prev->frame.curses_win);
+        if (   w->frame.size.x <= w->_prev->frame.size.x
+            && w->frame.size.y <  wmeta->padframe.size.y - w_prev_maxy)
         {
-            w->start.x = w->prev->start.x;
-            w->start.y = w_prev_maxy + 1;
+            w->_start.x = w->_prev->_start.x;
+            w->_start.y = w_prev_maxy + 1;
         }
 
         /* Failing that, try to open a new sub column below the nearest
@@ -128,29 +151,29 @@ static void place_win (struct WinMeta * wmeta, struct Win * w)
          */
         else
         {
-            struct Win * w_up = w->prev;
+            struct Win * w_up = w->_prev;
             struct Win * w_upup = w_up;
             uint16_t widthdiff;
             while (w_up != w_top)
             {
-                w_upup = w_up->prev;
+                w_upup = w_up->_prev;
                 while (1)
                 {
-                    if (w_up->start.y != w_upup->start.y)
+                    if (w_up->_start.y != w_upup->_start.y)
                     {
                         break;
                     }
-                    w_upup = w_upup->prev;
+                    w_upup = w_upup->_prev;
                 }
-                w_prev_maxy = w_upup->start.y
+                w_prev_maxy = w_upup->_start.y
                               + getmaxy(w_upup->frame.curses_win);
-                widthdiff = (w_upup->start.x + w_upup->frame.size.x)
-                            - (w_up->start.x + w_up->frame.size.x);
-                if (   w->frame.size.y < wmeta->pad.size.y - w_prev_maxy
+                widthdiff = (w_upup->_start.x + w_upup->frame.size.x)
+                            - (w_up->_start.x + w_up->frame.size.x);
+                if (   w->frame.size.y < wmeta->padframe.size.y - w_prev_maxy
                     && w->frame.size.x < widthdiff)
                 {
-                    w->start.x = w_up->start.x + w_up->frame.size.x + 1 ;
-                    w->start.y = w_prev_maxy + 1;
+                    w->_start.x = w_up->_start.x + w_up->frame.size.x + 1 ;
+                    w->_start.y = w_prev_maxy + 1;
                     break;
                 }
                 w_up = w_upup;
@@ -161,7 +184,7 @@ static void place_win (struct WinMeta * wmeta, struct Win * w)
 
 
 
-static void destroy_win (struct Win * w)
+static void destroy_win(struct Win * w)
 {
     delwin(w->frame.curses_win);
     w->frame.curses_win = 0;
@@ -169,32 +192,30 @@ static void destroy_win (struct Win * w)
 
 
 
-static void draw_wins (struct Win * w)
+static void draw_wins(struct Win * w)
 {
-    w->draw(w);
-    if (0 != w->next)
+    w->_draw(w);
+    if (0 != w->_next)
     {
-        draw_wins (w->next);
+        draw_wins(w->_next);
     }
 }
 
 
 
-static void draw_win_borderlines(struct Win * w, char active)
+static void draw_win_borderlines(struct Win * w, char active, WINDOW * pad)
 {
     /* Draw vertical and horizontal border lines. */
     uint16_t y, x;
-    for (y = w->start.y; y <= w->start.y + w->frame.size.y; y++)
+    for (y = w->_start.y; y <= w->_start.y + w->frame.size.y; y++)
     {
-        mvwaddch(wgetparent(w->frame.curses_win), y, w->start.x - 1, '|');
-        mvwaddch(wgetparent(w->frame.curses_win),
-                 y, w->start.x + w->frame.size.x, '|');
+        mvwaddch(pad, y, w->_start.x - 1,               '|');
+        mvwaddch(pad, y, w->_start.x + w->frame.size.x, '|');
     }
-    for (x = w->start.x; x <= w->start.x + w->frame.size.x; x++)
+    for (x = w->_start.x; x <= w->_start.x + w->frame.size.x; x++)
     {
-        mvwaddch(wgetparent(w->frame.curses_win), w->start.y - 1, x, '-');
-        mvwaddch(wgetparent(w->frame.curses_win),
-                 w->start.y + w->frame.size.y, x, '-');
+        mvwaddch(pad, w->_start.y - 1,               x, '-');
+        mvwaddch(pad, w->_start.y + w->frame.size.y, x, '-');
     }
 
     /* Draw as much as possible of the title into center of top border line. */
@@ -202,38 +223,38 @@ static void draw_win_borderlines(struct Win * w, char active)
     if (w->frame.size.x >= min_title_length_visible)
     {
         uint16_t title_offset = 0;
-        if (w->frame.size.x > strlen(w->title) + 2)
+        if (w->frame.size.x > strlen(w->_title) + 2)
         {
-            title_offset = (w->frame.size.x - (strlen(w->title) + 2)) / 2;
-        }                                     /* +2 is for padding/decoration */
-        uint16_t length_visible = strnlen(w->title, w->frame.size.x - 2);
+            title_offset = (w->frame.size.x - (strlen(w->_title) + 2)) / 2;
+        }                                    /* +2 is for padding/decoration */
+        uint16_t length_visible = strnlen(w->_title, w->frame.size.x - 2);
         char title[length_visible + 3];
         char decoration = ' ';
         if (1 == active)
         {
             decoration = '$';
         }
-        memcpy(title + 1, w->title, length_visible);
+        memcpy(title + 1, w->_title, length_visible);
         title[0] = title[length_visible + 1] = decoration;
         title[length_visible + 2] = '\0';
-        mvwaddstr(wgetparent(w->frame.curses_win),
-                  w->start.y - 1, w->start.x + title_offset, title);
+        mvwaddstr(pad, w->_start.y - 1, w->_start.x + title_offset, title);
     }
 }
 
 
 
-static void draw_wins_borderlines(struct Win * w, struct Win * w_active)
+static void draw_wins_borderlines(struct Win * w, struct Win * w_active,
+                                  WINDOW * pad)
 {
     char active = 0;
     if (w == w_active)
     {
         active = 1;
     }
-    draw_win_borderlines(w, active);
-    if (0 != w->next)
+    draw_win_borderlines(w, active, pad);
+    if (0 != w->_next)
     {
-        draw_wins_borderlines (w->next, w_active);
+        draw_wins_borderlines(w->_next, w_active, pad);
     }
 }
 
@@ -241,109 +262,215 @@ static void draw_wins_borderlines(struct Win * w, struct Win * w_active)
 
 static void draw_wins_bordercorners(struct Win * w, WINDOW * pad)
 {
-    mvwaddch(pad, w->start.y - 1, w->start.x - 1, '+');
-    mvwaddch(pad, w->start.y - 1, w->start.x + w->frame.size.x, '+');
-    mvwaddch(pad, w->start.y + w->frame.size.y, w->start.x - 1, '+');
+    mvwaddch(pad, w->_start.y - 1, w->_start.x - 1, '+');
+    mvwaddch(pad, w->_start.y - 1, w->_start.x + w->frame.size.x, '+');
+    mvwaddch(pad, w->_start.y + w->frame.size.y, w->_start.x - 1, '+');
     mvwaddch(pad,
-             w->start.y + w->frame.size.y, w->start.x + w->frame.size.x, '+');
-    if (0 != w->next)
+             w->_start.y + w->frame.size.y, w->_start.x + w->frame.size.x, '+');
+    if (0 != w->_next)
+    {
+        draw_wins_bordercorners(w->_next, pad);
+    }
+}
+
+
+
+static void shift_win_forward(struct WinMeta * wmeta)
+{
+    if (wmeta->active == wmeta->_chain_end)
+    {
+        wmeta->_chain_end = wmeta->active->_prev;
+        wmeta->_chain_end->_next = 0;
+        wmeta->active->_next = wmeta->_chain_start;
+        wmeta->active->_next->_prev = wmeta->active;
+        wmeta->_chain_start = wmeta->active;
+        wmeta->_chain_start->_prev = 0;
+    }
+    else
+    {
+        struct Win * old_prev = wmeta->active->_prev;
+        struct Win * old_next = wmeta->active->_next;
+        if (wmeta->_chain_end == wmeta->active->_next)
+        {
+            wmeta->_chain_end = wmeta->active;
+            wmeta->active->_next = 0;
+        }
+        else
+        {
+            wmeta->active->_next = old_next->_next;
+            wmeta->active->_next->_prev = wmeta->active;
+        }
+        if (wmeta->_chain_start == wmeta->active)
+        {
+            wmeta->_chain_start = old_next;
+        }
+        else
+        {
+            old_prev->_next = old_next;
+        }
+        old_next->_prev = old_prev;
+        old_next->_next = wmeta->active;
+        wmeta->active->_prev = old_next;
+    }
+}
+
+
+
+static void shift_win_backward(struct WinMeta * wmeta)
+{
+    if (wmeta->active == wmeta->_chain_start)
+    {
+        wmeta->_chain_start = wmeta->active->_next;
+        wmeta->_chain_start->_prev = 0;
+        wmeta->active->_prev = wmeta->_chain_end;
+        wmeta->active->_prev->_next = wmeta->active;
+        wmeta->_chain_end = wmeta->active;
+        wmeta->_chain_end->_next = 0;
+    }
+    else
     {
-        draw_wins_bordercorners(w->next, pad);
+        struct Win * old_prev = wmeta->active->_prev;
+        struct Win * old_next = wmeta->active->_next;
+        if (wmeta->_chain_start == wmeta->active->_prev)
+        {
+            wmeta->_chain_start = wmeta->active;
+            wmeta->active->_prev = 0;
+        }
+        else
+        {
+            wmeta->active->_prev = old_prev->_prev;
+            wmeta->active->_prev->_next = wmeta->active;
+        }
+        if (wmeta->_chain_end == wmeta->active)
+        {
+            wmeta->_chain_end = old_prev;
+        }
+        else
+        {
+            old_next->_prev = old_prev;
+        }
+        old_prev->_next = old_next;
+        old_prev->_prev = wmeta->active;
+        wmeta->active->_next = old_prev;
     }
 }
 
 
 
-extern struct WinMeta init_win_meta(WINDOW * screen)
+extern uint8_t init_win_meta(WINDOW * screen, struct WinMeta * wmeta)
 {
-    struct WinMeta wmeta;
-    wmeta.screen         = screen;
-    wmeta.pad.size.y     = getmaxy(screen);
-    wmeta.pad.size.x     = getmaxx(screen);
-    wmeta.chain_start    = 0;
-    wmeta.chain_end      = 0;
-    wmeta.pad_offset     = 0;
-    wmeta.pad.curses_win = newpad(wmeta.pad.size.y, 1);
-    wmeta.active         = 0;
-    return wmeta;
+    wmeta->_screen             = screen;
+    wmeta->padframe.size.y     = getmaxy(screen);
+    wmeta->padframe.size.x     = getmaxx(screen);
+    wmeta->_chain_start        = 0;
+    wmeta->_chain_end          = 0;
+    wmeta->pad_offset          = 0;
+    WINDOW * test;
+    test = newpad(wmeta->padframe.size.y, 1);
+    if (NULL == test)
+    {
+        return 1;
+    }
+    wmeta->padframe.curses_win = test;
+    wmeta->active              = 0;
+    return 0;
 }
 
 
 
 extern struct Win init_win(struct WinMeta * wmeta, char * title,
+                           uint16_t height, uint16_t width,
                            void * data, void * func)
 {
     struct Win w;
-    w.prev             = 0;
-    w.next             = 0;
-    w.frame.curses_win = 0;
-    w.title            = title;
-    w.frame.size.x     = 20;
-    w.frame.size.y     = wmeta->pad.size.y - 1;
-    w.data             = data;
-    w.draw             = func;
+    w._prev             = 0;
+    w._next             = 0;
+    w.frame.curses_win  = 0;
+    w._title            = title;
+    w.data              = data;
+    w._draw             = func;
+    if (width > 0)
+    {
+        w.frame.size.x = width;
+    }
+    else
+    {
+        w.frame.size.x = 1;
+    }
+    if (height > 0 && height <= wmeta->padframe.size.y - 1)
+    {
+        w.frame.size.y = height;
+    }
+    else
+    {
+        w.frame.size.y = wmeta->padframe.size.y - 1;
+    }
     return w;
 }
 
 
 
-extern void append_win(struct WinMeta * wmeta, struct Win * w)
+extern uint8_t append_win(struct WinMeta * wmeta, struct Win * w)
 {
-    if (0 != wmeta->chain_start)
+    if (0 != wmeta->_chain_start)
     {
-        w->prev = wmeta->chain_end;
-        wmeta->chain_end->next = w;
+        w->_prev = wmeta->_chain_end;
+        wmeta->_chain_end->_next = w;
     }
     else
     {
         wmeta->active = w;
-        wmeta->chain_start = w;
+        wmeta->_chain_start = w;
     }
-    wmeta->chain_end = w;
-    update_wins(wmeta, w);
+    wmeta->_chain_end = w;
+    return update_wins(wmeta, w);
 }
 
 
 
-extern void suspend_win(struct WinMeta * wmeta, struct Win * w)
+extern uint8_t suspend_win(struct WinMeta * wmeta, struct Win * w)
 {
     destroy_win(w);
 
-    if (wmeta->chain_start != w)
+    if (wmeta->_chain_start != w)
     {
-        w->prev->next = w->next;
+        w->_prev->_next = w->_next;
     }
     else
     {
-        wmeta->chain_start = w->next;
+        wmeta->_chain_start = w->_next;
     }
     char pad_refitted = 0;
-    if (wmeta->chain_end != w)
+    if (wmeta->_chain_end != w)
     {
-        w->next->prev = w->prev;
+        w->_next->_prev = w->_prev;
         if (wmeta->active == w)
         {
-            wmeta->active = w->next;
+            wmeta->active = w->_next;
         }
-        update_wins(wmeta, w->next); /* Positioning of successor windows may  */
-        pad_refitted = 1;            /* be affected / need correction. Note   */
-    }                                /* that update_wins() already refits the */
-    else                             /* pad, voiding later need for that.     */
+        if (0 != update_wins(wmeta, w->_next))  /* Positioning of successor   */
+        {                                       /* windows may be affected /  */
+            return 1;                           /* need correction. Note that */
+        }                                       /* update_wins() already      */
+        pad_refitted = 1;                       /* refits the pad, voiding    */
+    }                                           /* later need for that.       */
+    else
     {
-        wmeta->chain_end = w->prev;
+        wmeta->_chain_end = w->_prev;
         if (wmeta->active == w)
         {
-            wmeta->active = w->prev;
+            wmeta->active = w->_prev;
         }
     }
 
-    w->prev = 0;
-    w->next = 0;
+    w->_prev = 0;
+    w->_next = 0;
 
     if (0 == pad_refitted)
     {
-        refit_pad(wmeta);
+        return refit_pad(wmeta);
     }
+    return 0;
 }
 
 
@@ -352,7 +479,8 @@ extern void reset_pad_offset(struct WinMeta * wmeta, uint16_t new_offset)
 {
     if (new_offset >= 0
         && (new_offset < wmeta->pad_offset
-            || new_offset + wmeta->pad.size.x < getmaxx(wmeta->pad.curses_win)))
+            || new_offset + wmeta->padframe.size.x
+               < getmaxx(wmeta->padframe.curses_win)))
     {
         wmeta->pad_offset = new_offset;
     }
@@ -360,17 +488,18 @@ extern void reset_pad_offset(struct WinMeta * wmeta, uint16_t new_offset)
 
 
 
-extern void resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size)
+extern uint8_t resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size)
 {
     if (0 != wmeta->active
         && size.x > 0 && size.y > 0
-        && size.y < wmeta->pad.size.y)
+        && size.y < wmeta->padframe.size.y)
     {
         wmeta->active->frame.size = size;
-        update_wins(wmeta, wmeta->chain_start);   /* Positioning of successor */
-    }                                             /* windows may be affected. */
-}
-
+        return update_wins(wmeta, wmeta->_chain_start); /* Following windows' */
+    }                                                   /* positioning may be */
+    return 0;                                           /* affected.          */
+}                                                       /* TODO: Why start at */
+                                                        /* chain_start then?  */
 
 
 extern void cycle_active_win(struct WinMeta * wmeta, char dir)
@@ -379,24 +508,24 @@ extern void cycle_active_win(struct WinMeta * wmeta, char dir)
     {
         if ('n' == dir)
         {
-            if (wmeta->active->next != 0)
+            if (wmeta->active->_next != 0)
             {
-                wmeta->active = wmeta->active->next;
+                wmeta->active = wmeta->active->_next;
             }
             else
             {
-                wmeta->active = wmeta->chain_start;
+                wmeta->active = wmeta->_chain_start;
             }
         }
         else
         {
-            if (wmeta->active->prev != 0)
+            if (wmeta->active->_prev != 0)
             {
-                wmeta->active = wmeta->active->prev;
+                wmeta->active = wmeta->active->_prev;
             }
             else
             {
-                wmeta->active = wmeta->chain_end;
+                wmeta->active = wmeta->_chain_end;
             }
         }
     }
@@ -404,129 +533,79 @@ extern void cycle_active_win(struct WinMeta * wmeta, char dir)
 
 
 
-extern void shift_active_win(struct WinMeta * wmeta, char dir)
+extern uint8_t shift_active_win(struct WinMeta * wmeta, char dir)
 {
-    if (0 != wmeta->active                        /* No shifting with less    */
-        && wmeta->chain_start != wmeta->chain_end /* than one window visible. */
-        && (dir == 'f' || dir == 'b'))
+    if (   0 == wmeta->active                        /* No shifting with <2   */
+        || wmeta->_chain_start == wmeta->_chain_end  /* windows visible or    */
+        || (dir != 'f' && dir != 'b'))               /* wrong direction char. */
     {
-        struct Win * w_shift = wmeta->active, * w_p, * w_p_next;
-
-        /* Check if shifting will lead to wrapping. */
-        char wrap = 0;
-        if (   (dir == 'f' && w_shift == wmeta->chain_end)
-            || (dir == 'b' && w_shift == wmeta->chain_start))
-        {
-            wrap = 1;
-        }
-
-        /* Suspend all visible windows, remember their order in wins[]. */
-        uint16_t i, i_max;
-        for (w_p  = wmeta->chain_start, i_max = 1;
-             w_p != wmeta->chain_end;
-             w_p  = w_p->next)
-        {
-            i_max++;
-        }
-        struct Win ** wins = malloc(i_max * sizeof(struct Win *));
-        for (i = 0, w_p = wmeta->chain_start;
-             i < i_max;
-             i++)
-        {
-            w_p_next = w_p->next;
-            suspend_win(wmeta, w_p);
-            wins[i] = w_p;
-            w_p = w_p_next;
-        }
-
-        /* Re-append all previously visible windows in the new order. */
-        if (wrap)
-        {
-            if (dir == 'f')
-            {
-                append_win(wmeta, w_shift);
-                for (i = 0; i < i_max - 1; i++)
-                {
-                    append_win(wmeta, wins[i]);
-                }
-            }
-            else
-            {
-                for (i = 1; i < i_max; i++)
-                {
-                    append_win(wmeta, wins[i]);
-                }
-                append_win(wmeta, w_shift);
-            }
-        }
-        else
-        {
-            for (i = 0; i < i_max; i++)
-            {
-                if (   (dir == 'f' && w_shift == wins[i])
-                    || (dir == 'b' && w_shift == wins[i+1]))
-                {
-                    append_win(wmeta, wins[i+1]);
-                    append_win(wmeta, wins[i]);
-                    i++;
-                }
-                else
-                {
-                    append_win(wmeta, wins[i]);
-                }
-            }
-        }
-        free(wins);
-
-        wmeta->active = w_shift;  /* Otherwise lastly appended win is active. */
+        return 0;
+    }
+    if ('f' == dir)
+    {
+        shift_win_forward(wmeta);
+    }
+    else
+    {
+        shift_win_backward(wmeta);
     }
+    return update_wins(wmeta, wmeta->_chain_start);
 }
 
 
 
-extern void draw_all_wins(struct WinMeta * wmeta)
+extern uint8_t draw_all_wins(struct WinMeta * wmeta)
 {
     /* Empty everything before filling it a-new. */
     erase();
-    wnoutrefresh(wmeta->screen);
-    werase(wmeta->pad.curses_win);
-    if (wmeta->chain_start)
+    wnoutrefresh(wmeta->_screen);
+    werase(wmeta->padframe.curses_win);
+    if (wmeta->_chain_start)
     {
 
         /* Draw windows' contents first, then their borders. */
-        draw_wins(wmeta->chain_start);
-        draw_wins_borderlines(wmeta->chain_start, wmeta->active);
-        draw_wins_bordercorners(wmeta->chain_start, wmeta->pad.curses_win);
+        draw_wins(wmeta->_chain_start);
+        draw_wins_borderlines(wmeta->_chain_start, wmeta->active,
+                              wmeta->padframe.curses_win);
+        draw_wins_bordercorners(wmeta->_chain_start,wmeta->padframe.curses_win);
 
         /* Draw virtual screen scroll hints. */
         if (wmeta->pad_offset > 0)
         {
-            draw_scroll_hint(&wmeta->pad,
-                             wmeta->pad_offset, wmeta->pad_offset + 1, '<');
+            if (draw_scroll_hint(&wmeta->padframe,
+                                 wmeta->pad_offset, wmeta->pad_offset + 1, '<'))
+            {
+                return 1;
+            }
         }
-        if (wmeta->pad_offset + wmeta->pad.size.x
-            < getmaxx(wmeta->pad.curses_win) - 1)
+        if (wmeta->pad_offset + wmeta->padframe.size.x
+            < getmaxx(wmeta->padframe.curses_win) - 1)
         {
-            draw_scroll_hint(&wmeta->pad,
-                             wmeta->pad_offset + wmeta->pad.size.x - 1,
-                             getmaxx(wmeta->pad.curses_win)
-                             - (wmeta->pad_offset + wmeta->pad.size.x), '>');
+            if (draw_scroll_hint(&wmeta->padframe,
+                                 wmeta->pad_offset + wmeta->padframe.size.x - 1,
+                                 getmaxx(wmeta->padframe.curses_win)
+                                 - (wmeta->pad_offset + wmeta->padframe.size.x),
+                                 '>'))
+            {
+                return 1;
+            }
         }
 
         /* Write virtual screen segment to be shown on physical screen into */
         /* ncurses screen buffer. */
-        pnoutrefresh(wmeta->pad.curses_win, 0, wmeta->pad_offset, 0, 0,
-                     wmeta->pad.size.y, wmeta->pad.size.x-1);
+        pnoutrefresh(wmeta->padframe.curses_win, 0, wmeta->pad_offset, 0, 0,
+                     wmeta->padframe.size.y, wmeta->padframe.size.x-1);
     }
 
     /* Only at the end write accumulated changes to the physical screen. */
     doupdate();
+    return 0;
 }
 
 
 
-extern void draw_scroll_hint(struct Frame * frame, uint16_t pos, uint32_t dist,
-                             char dir)
+extern uint8_t draw_scroll_hint(struct Frame * frame, uint16_t pos,
+                                uint32_t dist, char dir)
 {
     /* Decide on alignment (vertical/horizontal?), thereby scroll hint text. */
     char * more = "more";
@@ -541,6 +620,10 @@ extern void draw_scroll_hint(struct Frame * frame, uint16_t pos, uint32_t dist,
     }
     char * scrolldsc = malloc((4 * sizeof(char)) + strlen(more) + strlen(unit)
                               + 10);                /* 10 = uint32 max strlen */
+    if (NULL == scrolldsc)
+    {
+        return 1;
+    }
     sprintf(scrolldsc, " %d %s %s ", dist, more, unit);
 
     /* Decide on offset of the description text inside the scroll hint line. */
@@ -573,4 +656,5 @@ extern void draw_scroll_hint(struct Frame * frame, uint16_t pos, uint32_t dist,
     }
 
     free(scrolldsc);
+    return 0;
 }