X-Git-Url: https://plomlompom.com/repos/?a=blobdiff_plain;f=src%2Fwindows.c;h=df9674355a21a52985d554e8b1b0130b21c73639;hb=550d22ec0c3f530f5d317746f3f7e75251a1de4b;hp=362e10a475a3063a463ab3ce4fdb1e7d26ef24c9;hpb=322bd8d0b863f89bc6ce864a853b57b554a1cabf;p=plomrogue

diff --git a/src/windows.c b/src/windows.c
index 362e10a..df96743 100644
--- a/src/windows.c
+++ b/src/windows.c
@@ -1,53 +1,33 @@
 /* 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, UINT16_MAX */
+#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 */
 
 
 
-/* Stores a window's border corners. This is a helper to draw_all_wins() (and
- * filled by its helper draw_wins_borders()) which draws the horizontal and
- * vertical lines of all windows' borders first and the corner characters of
- * all windows only afterwards (so that corners are not overwritten by lines).
- * This delay of corner drawing necessitates temporarily storing their
- * coordinates (harvested during the previous border drawing activities) in a
- * series of such Corners structs to be released at the end.
- *
- * TODO: Maybe replace this complicated method by dropping the harvesting of
- * corners from draw_wins_borders() and instead collecting them in a second
- * border drawing cycle that repeats some cycles but works in a much more
- * straightforward way.
- */
-struct Corners
-{
-    struct yx_uint16 tl;
-    struct yx_uint16 tr;
-    struct yx_uint16 bl;
-    struct yx_uint16 br;
-};
-
-
-
 /* Fit virtual screen's width to minimum width demanded by current windows'
  * geometries.
  */
-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.
  */
-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);
 
 
 
-/* Destroy window "w"'s ncurses window (and set w.Frame.curses_win to 0). */
+/* Destroy window "w"'s ncurses WINDOW (and set w.Frame.curses_win to 0). */
 static void destroy_win(struct Win * w);
 
 
@@ -57,67 +37,93 @@ static void draw_wins(struct Win * w);
 
 
 
-/* draw_win_borders() 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_borders().
+/* draw_win_borderlines() draws the vertical and horizontal borders of window
+ * "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 == 1).
+ *
+ * draw_wins_borderlines() calls draw_win_borderlines() recursively on all
+ * windows from "w" on. "w_active" is a pointer to the one window that
+ * draw_win_borderlines() is supposed to handle as the active window.
  *
- * draw_wins_borders() calls draw_win_borders() recursively on all windows from
- * "w" on. It also fills "corners" with coordinates of each window's corners,
- * iterating over its Corners structs via the "i" index incremented by 1 over
- * each handled window. "w_active" is a pointer to the one window that
- * draw_win_borders() is supposed to handle as the active window.
+ * Finally, draw_wins_bordercorners() draws into "pad" the borders of window "w"
+ * and all its successors.
  */
-static void draw_win_borders(struct Win * w, char active);
-static void draw_wins_borders(struct Win * w, struct Win * w_active,
-                              struct Corners * corners, uint16_t i);
+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);
+
+
 
+/* 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 void refit_pad(struct WinMeta * wmeta)
+
+static uint8_t refit_pad(struct WinMeta * wmeta)
 {
     /* Determine rightmost window column. */
-    uint16_t lastwincol = 0;
+    uint32_t lastwincol = 0;
     struct Win * w_p = wmeta->chain_start;
     while (w_p != 0)
     {
-        if (w_p->start.x + w_p->frame.size.x > lastwincol + 1)
+        if ((uint32_t) w_p->start.x + (uint32_t) w_p->frame.size.x
+            > lastwincol + 1)
         {
-            lastwincol = w_p->start.x + w_p->frame.size.x - 1;
+            lastwincol = (uint32_t) w_p->start.x
+                         + (uint32_t) w_p->frame.size.x - 1;
         }
         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) + 1 != lastwincol)
     {
-        wresize(wmeta->pad.curses_win,
-                getmaxy(wmeta->pad.curses_win), lastwincol + 2);
+        if (lastwincol + 2 > UINT16_MAX)
+        {
+            return 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);
+    uint8_t test_refit = refit_pad(wmeta);
+    if (0 != test_refit)
+    {
+        return test_refit;
+    }
+    WINDOW * subpad_test = subpad(wmeta->padframe.curses_win,
+                                  w->frame.size.y, w->frame.size.x,
+                                  w->start.y, w->start.x);
+    if (NULL == subpad_test)
+    {
+        return 1;
+    }
+    w->frame.curses_win = subpad_test;
     if (0 != w->next)
     {
-        update_wins (wmeta, 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;
@@ -139,7 +145,7 @@ static void place_win (struct WinMeta * wmeta, struct Win * w)
         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)
+            && 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;
@@ -168,7 +174,7 @@ static void place_win (struct WinMeta * wmeta, struct Win * w)
                               + 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
+                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 ;
@@ -183,7 +189,7 @@ 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;
@@ -191,32 +197,30 @@ 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)
     {
-        draw_wins (w->next);
+        draw_wins(w->next);
     }
 }
 
 
 
-static void draw_win_borders(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++)
     {
-        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++)
     {
-        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. */
@@ -227,7 +231,7 @@ static void draw_win_borders(struct Win * w, char active)
         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 */
+        }                                    /* +2 is for padding/decoration */
         uint16_t length_visible = strnlen(w->title, w->frame.size.x - 2);
         char title[length_visible + 3];
         char decoration = ' ';
@@ -238,72 +242,217 @@ static void draw_win_borders(struct Win * w, char active)
         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_borders(struct Win * w, struct Win * w_active,
-                              struct Corners * corners, uint16_t i)
+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_borders(w, active);
-    corners[i].tl.y = w->start.y - 1;
-    corners[i].tl.x = w->start.x - 1;
-    corners[i].tr.y = w->start.y - 1;
-    corners[i].tr.x = w->start.x + w->frame.size.x;
-    corners[i].bl.y = w->start.y + w->frame.size.y;
-    corners[i].bl.x = w->start.x - 1;
-    corners[i].br.y = w->start.y + w->frame.size.y;
-    corners[i].br.x = w->start.x + w->frame.size.x;
+    draw_win_borderlines(w, active, pad);
     if (0 != w->next)
     {
-        draw_wins_borders (w->next, w_active, corners, i + 1);
+        draw_wins_borderlines(w->next, w_active, pad);
+    }
+}
+
+
+
+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 + 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
+    {
+        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 uint8_t init_win_meta(WINDOW * screen, struct WinMeta ** wmp)
+{
+    struct WinMeta * wmeta = malloc(sizeof(struct WinMeta));
+    wmeta->screen              = screen;
+    uint32_t maxy_test         = getmaxy(screen);
+    uint32_t maxx_test         = getmaxx(screen);
+    if (maxy_test > UINT16_MAX || maxx_test > UINT16_MAX)
+    {
+        return 2;
+    }
+    wmeta->padframe.size.y     = maxy_test;
+    wmeta->padframe.size.x     = maxx_test;
+    wmeta->chain_start         = 0;
+    wmeta->chain_end           = 0;
+    wmeta->pad_offset          = 0;
+    WINDOW * pad_test          = newpad(wmeta->padframe.size.y, 1);
+    if (NULL == pad_test)
+    {
+        return 1;
     }
+    wmeta->padframe.curses_win = pad_test;
+    wmeta->active              = 0;
+    *wmp = wmeta;
+    return 0;
 }
 
 
 
-extern struct WinMeta init_win_meta(WINDOW * screen)
+extern uint8_t init_win(struct WinMeta * wmeta, struct Win ** wp, char * title,
+                        int16_t height, int16_t width,
+                        void * data, void * func)
 {
-    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;
+    struct Win * w = malloc(sizeof(struct Win));
+    if (NULL == w)
+    {
+        return 1;
+    }
+    w->prev             = 0;
+    w->next             = 0;
+    w->frame.curses_win = 0;
+    w->title            = malloc(strlen(title) + 1);
+    if (NULL == w->title)
+    {
+        return 1;
+    }
+    sprintf(w->title, "%s", title);
+    w->data              = data;
+    w->draw             = func;
+    if      (0 < width)
+    {
+        w->frame.size.x = width;
+    }
+    else if (0 >= width)
+    {
+        w->frame.size.x = wmeta->padframe.size.x + width;
+    }
+    if      (0 < height && height <= wmeta->padframe.size.y - 1)
+    {
+        w->frame.size.y = height;
+    }
+    else if (0 >= height && wmeta->padframe.size.y + (height - 1) > 0)
+    {
+        w->frame.size.y = wmeta->padframe.size.y + (height - 1);
+    }
+    *wp = w;
+    return 0;
 }
 
 
 
-extern struct Win init_win(struct WinMeta * wmeta, char * title,
-                           void * data, void * func)
+extern void free_winmeta(struct WinMeta * wmeta)
 {
-    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;
-    return w;
+    delwin(wmeta->padframe.curses_win);
+    free(wmeta);
 }
 
 
 
-extern void append_win(struct WinMeta * wmeta, struct Win * w)
+extern void free_win(struct Win * win)
+{
+    if (0 != win->frame.curses_win)
+    {
+        delwin(win->frame.curses_win);
+    }
+    free(win->title);
+    free(win);
+}
+
+
+
+extern uint8_t append_win(struct WinMeta * wmeta, struct Win * w)
 {
     if (0 != wmeta->chain_start)
     {
@@ -316,12 +465,12 @@ extern void append_win(struct WinMeta * wmeta, struct Win * w)
         wmeta->chain_start = w;
     }
     wmeta->chain_end = w;
-    update_wins(wmeta, 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);
 
@@ -341,10 +490,14 @@ extern void suspend_win(struct WinMeta * wmeta, struct Win * w)
         {
             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.     */
+        uint8_t test = update_wins(wmeta, w->next); /* Positioning of         */
+        if (0 != test)                              /* successor windows may  */
+        {                                           /* be affected / need     */
+            return test;                            /* correction. Note that  */
+        }                                           /* update_wins() already  */
+        pad_refitted = 1;                           /* refits the pad, voiding*/
+    }                                               /* later need for that.   */
+    else
     {
         wmeta->chain_end = w->prev;
         if (wmeta->active == w)
@@ -358,8 +511,9 @@ extern void suspend_win(struct WinMeta * wmeta, struct Win * w)
 
     if (0 == pad_refitted)
     {
-        refit_pad(wmeta);
+        return refit_pad(wmeta);
     }
+    return 0;
 }
 
 
@@ -368,7 +522,8 @@ 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;
     }
@@ -376,15 +531,16 @@ 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 */
+        return update_wins(wmeta, wmeta->active); /* Positioning of following */
     }                                             /* windows may be affected. */
+    return 0;
 }
 
 
@@ -393,7 +549,7 @@ extern void cycle_active_win(struct WinMeta * wmeta, char dir)
 {
     if (0 != wmeta->active)
     {
-        if ('n' == dir)
+        if ('f' == dir)
         {
             if (wmeta->active->next != 0)
             {
@@ -420,148 +576,78 @@ 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.      */
     {
-        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. */
-        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;      /* TODO: Is this necessary? If so, why? */
+        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);
+    werase(wmeta->padframe.curses_win);
     if (wmeta->chain_start)
     {
 
-        /* Only draw the windows' *contents* first. */
-        draw_wins (wmeta->chain_start);
-
-        /* Draw windows' borders. Lines first, then line crossings / corners. */
-        uint16_t n_wins = 1, i;
-        struct Win * win_p = wmeta->chain_start;
-        while (0 != win_p->next)
-        {
-            win_p = win_p->next;
-            n_wins++;
-        }
-        struct Corners * all_corners = malloc(sizeof(struct Corners) * n_wins);
-        draw_wins_borders (wmeta->chain_start, wmeta->active, all_corners, 0);
-        for (i = 0; i < n_wins; i++)
-        {
-            mvwaddch(wmeta->pad.curses_win,
-                     all_corners[i].tl.y, all_corners[i].tl.x, '+');
-            mvwaddch(wmeta->pad.curses_win,
-                     all_corners[i].tr.y, all_corners[i].tr.x, '+');
-            mvwaddch(wmeta->pad.curses_win,
-                     all_corners[i].bl.y, all_corners[i].bl.x, '+');
-            mvwaddch(wmeta->pad.curses_win,
-                     all_corners[i].br.y, all_corners[i].br.x, '+');
-        }
-        free(all_corners);
+        /* Draw windows' contents first, then their borders. */
+        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";
@@ -576,6 +662,10 @@ 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. */
@@ -608,4 +698,5 @@ extern void draw_scroll_hint(struct Frame * frame, uint16_t pos, uint32_t dist,
     }
 
     free(scrolldsc);
+    return 0;
 }