X-Git-Url: https://plomlompom.com/repos/?a=blobdiff_plain;f=src%2Fwindows.c;h=f71be6526af7d3322952369e57e312e581f2901f;hb=350ef2e2d17e8122e2991466f76a9a083a6303e7;hp=f75544bd4753fa06d64f46382499a8b92f7fbfec;hpb=0399a31b31047ab82348f733d6c56524258d1188;p=plomrogue

diff --git a/src/windows.c b/src/windows.c
index f75544b..f71be65 100644
--- a/src/windows.c
+++ b/src/windows.c
@@ -3,40 +3,45 @@
 #include "windows.h"
 #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()               */
+                       /* getmaxy(), delwin(), mvwaddch(), mvwaddstr(),      */
+                       /* newpad(), wnoutrefres(), erase(), werase(),        */
+                       /* pnoutrefresh(), doupdate(), getmaxyx()   */
 #include <stdlib.h>    /* for malloc(), free() */
 #include <string.h>    /* for strlen(), strnlen(), memcpy() */
-#include "yx_uint16.h" /* for yx_uint16 coordinates */
+#include "yx_uint16.h" /* for struct yx_uint16 */
+#include "misc.h"      /* for center_offset(), try_malloc() */
+#include "main.h"      /* for world global */
+#include "rexit.h"     /* for exit_err() */
 
 
 
 /* Fit virtual screen's width to minimum width demanded by current windows'
  * geometries.
  */
-static uint8_t refit_pad(struct WinMeta * wmeta);
-
-
+static void refit_pad();
 
 /* Update geometry (sizes, positions) of window "w" and its successors in the
  * window chain. For the positioning algorithm place_win() is used.
  */
-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). */
-static void destroy_win(struct Win * w);
-
-
+static void update_wins(struct Win * w);
+static void place_win(struct Win * w);
+
+/* Draw scroll hint (a line saying that there are "dist" more elements of
+ * "unit" further into the direction symbolized by the "dir" char) into virtual
+ * screen pad, onto an appropriate edge of either a window or the screen; the
+ * left or right edge if "dir" is "<" or ">", or the upper or lower edge if it
+ * is "^" or "v". "start" should be either the start coordinate of a window's
+ * frame or .y=0, .x=wm->pad_offset if it describes the virtual screen pad.
+ * winscroll_hint() and padscroll_hint() are wrappers to simplify these uses.
+ */
+static void scroll_hint(struct yx_uint16 fsize, char dir, uint16_t dist,
+                        char * unit, struct yx_uint16 start);
+static void winscroll_hint(struct Win * w, char dir, uint16_t dist);
+static void padscroll_hint(char dir, uint16_t dist);
 
 /* Draw contents of all windows in window chain from window "w" onwards. */
 static void draw_wins(struct Win * w);
 
-
-
 /* 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
@@ -54,101 +59,77 @@ 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 shift_win_forward();
+static void shift_win_backward();
 
 
 
-static uint8_t refit_pad(struct WinMeta * wmeta)
+static void refit_pad()
 {
     /* Determine rightmost window column. */
-    uint32_t lastwincol = 0;
-    struct Win * w_p = wmeta->_chain_start;
-    while (w_p != 0)
+    uint32_t lastwcol = 0;
+    struct Win * wp = world.wmeta->chain_start;
+    while (wp != 0)
     {
-        if ((uint32_t) w_p->_start.x + (uint32_t) w_p->frame.size.x
-            > lastwincol + 1)
+        if ((uint32_t) wp->start.x + (uint32_t) wp->framesize.x > lastwcol + 1)
         {
-            lastwincol = (uint32_t) w_p->_start.x
-                         + (uint32_t) w_p->frame.size.x - 1;
+            lastwcol = (uint32_t) wp->start.x + (uint32_t) wp->framesize.x - 1;
         }
-        w_p = w_p->_next;
+        wp = wp->next;
     }
 
     /* Only resize the pad if the rightmost window column has changed. */
-    if (getmaxx(wmeta->padframe.curses_win) != lastwincol)
+    char * err_s = "refit_pad() extends virtual screen beyond legal sizes.";
+    char * err_m = "refit_pad() triggers memory alloc error via wresize().";
+    if (getmaxx(world.wmeta->pad) + 1 != lastwcol)
     {
-        if (lastwincol + 2 > UINT16_MAX)
-        {
-            return 2;
-        }
-        return (ERR == wresize(wmeta->padframe.curses_win,
-                               getmaxy(wmeta->padframe.curses_win),
-                               lastwincol + 2));
+        uint8_t t = (lastwcol + 2 > UINT16_MAX);
+        exit_err(t, err_s);
+        t = wresize(world.wmeta->pad, getmaxy(world.wmeta->pad), lastwcol + 2);
+        exit_err(t, err_m);
     }
-    return 0;
 }
 
 
 
-static uint8_t update_wins(struct WinMeta * wmeta, struct Win * w)
+static void update_wins(struct Win * w)
 {
-    if (0 != w->frame.curses_win)
-    {
-        destroy_win(w);
-    }
-    place_win(wmeta, w);
-    uint8_t test_refit = refit_pad(wmeta);
-    if (0 != test_refit)
+    place_win(w);
+    refit_pad();
+    if (0 != w->next)
     {
-        return test_refit;
+        update_wins(w->next);
     }
-    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)
-    {
-        return update_wins(wmeta, w->_next);
-    }
-    return 0;
 }
 
 
 
-static void place_win(struct WinMeta * wmeta, struct Win * w)
+static void place_win(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->framesize.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->padframe.size.y - w_prev_maxy)
+        uint16_t w_prev_maxy = w->prev->start.y + w->prev->framesize.y;
+        if (   w->framesize.x <= w->prev->framesize.x
+            && w->framesize.y <  world.wmeta->padsize.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
@@ -156,29 +137,28 @@ 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
-                              + 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->padframe.size.y - w_prev_maxy
-                    && w->frame.size.x < widthdiff)
+                w_prev_maxy = w_upup->start.y + w_upup->framesize.y;
+                widthdiff = (w_upup->start.x + w_upup->framesize.x)
+                            - (w_up->start.x + w_up->framesize.x);
+                if (   w->framesize.y < world.wmeta->padsize.y - w_prev_maxy
+                    && w->framesize.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->framesize.x + 1 ;
+                    w->start.y = w_prev_maxy + 1;
                     break;
                 }
                 w_up = w_upup;
@@ -189,20 +169,119 @@ static void place_win(struct WinMeta * wmeta, struct Win * w)
 
 
 
-static void destroy_win(struct Win * w)
+static void scroll_hint(struct yx_uint16 fsize, char dir, uint16_t dist,
+                        char * unit, struct yx_uint16 start)
 {
-    delwin(w->frame.curses_win);
-    w->frame.curses_win = 0;
+    /* Decide on alignment (vertical/horizontal?), thereby hint text space. */
+    char * more = "more";
+    uint16_t dsc_space = fsize.x;
+    if ('<' == dir || '>' == dir)
+    {
+        dsc_space = fsize.y;
+    }                                  /* vv-- 10 = max strlen for uint16_t */
+    char scrolldsc[1 + strlen(more) + 1 + 10 + 1 + strlen(unit) + 1 + 1];
+    sprintf(scrolldsc, " %d %s %s ", dist, more, unit);
+
+    /* Decide on offset of the description text inside the scroll hint line. */
+    uint16_t dsc_offset = 1;
+    if (dsc_space > strlen(scrolldsc) + 1)
+    {
+        dsc_offset = (dsc_space - strlen(scrolldsc)) / 2;
+    }
+
+    /* Draw scroll hint line as dir symbols bracketing description text. */
+    uint16_t draw_offset = 0;
+    if      ('>' == dir)
+    {
+        draw_offset = fsize.x - 1;
+    }
+    else if ('v' == dir)
+    {
+        draw_offset = fsize.y - 1;
+    }
+    uint16_t q = 0;
+    for (; q < dsc_space; q++)
+    {
+        chtype c = dir | A_REVERSE;
+        if (q >= dsc_offset && q < strlen(scrolldsc) + dsc_offset)
+        {
+            c = scrolldsc[q - dsc_offset] | A_REVERSE;
+        }
+        if ('<' == dir || '>' == dir)
+        {
+            mvwaddch(world.wmeta->pad, start.y + q, start.x + draw_offset, c);
+        }
+        else
+        {
+            mvwaddch(world.wmeta->pad, start.y + draw_offset, start.x + q, c);
+        }
+    }
+}
+
+
+static void padscroll_hint(char dir, uint16_t dist)
+{
+    struct yx_uint16 start;
+    start.y = 0;
+    start.x = world.wmeta->pad_offset;
+    scroll_hint(world.wmeta->padsize, dir, dist, "columns", start);
+}
+
+
+
+static void winscroll_hint(struct Win * w, char dir, uint16_t dist)
+{
+    char * unit = "lines";
+    if ('<' == dir || '>' == dir)
+    {
+        unit = "columns";
+    }
+    struct yx_uint16 start = w->start;
+    scroll_hint(w->framesize, dir, dist, unit, start);
 }
 
 
 
 static void draw_wins(struct Win * w)
 {
-    w->_draw(w);
-    if (0 != w->_next)
+    w->draw(w);
+    uint16_t y, x, size_y, size_x;
+    size_y = w->winmapsize.y;
+    size_x = w->winmapsize.x;
+    uint16_t offset_y = center_offset(w->center.y, size_y, w->framesize.y);
+    uint16_t offset_x = center_offset(w->center.x, size_x, w->framesize.x);
+    for (y = offset_y; y < w->framesize.y + offset_y && y < size_y; y++)
+    {
+        for (x = offset_x; x < w->framesize.x + offset_x && x < size_x; x++)
+        {
+            chtype ch = w->winmap[(y * w->winmapsize.x) + x];
+            mvwaddch(world.wmeta->pad, w->start.y + (y - offset_y),
+                                       w->start.x + (x - offset_x), ch);
+        }
+    }
+    free(w->winmap);
+    w->winmap = NULL;
+    w->winmapsize.y = 0;
+    w->winmapsize.x = 0;
+    if (offset_y > 0)
+    {
+        winscroll_hint(w, '^', offset_y + 1);
+    }
+    if (size_y > offset_y + w->framesize.y)
+    {
+        winscroll_hint(w, 'v', size_y - ((offset_y + w->framesize.y) - 1));
+    }
+    if (offset_x > 0)
+    {
+        winscroll_hint(w, '<', offset_x + 1);
+    }
+    if (size_x > offset_x + w->framesize.x)
+    {
+        winscroll_hint(w, '>', size_x - ((offset_x + w->framesize.x) - 1));
+    }
+    if (0 != w->next)
     {
-        draw_wins(w->_next);
+        return draw_wins(w->next);
     }
 }
 
@@ -212,37 +291,37 @@ 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->framesize.y; y++)
     {
-        mvwaddch(pad, y, w->_start.x - 1,               '|');
-        mvwaddch(pad, y, w->_start.x + w->frame.size.x, '|');
+        mvwaddch(pad, y, w->start.x - 1,              '|');
+        mvwaddch(pad, y, w->start.x + w->framesize.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->framesize.x; x++)
     {
-        mvwaddch(pad, w->_start.y - 1,               x, '-');
-        mvwaddch(pad, w->_start.y + w->frame.size.y, x, '-');
+        mvwaddch(pad, w->start.y - 1,              x, '-');
+        mvwaddch(pad, w->start.y + w->framesize.y, x, '-');
     }
 
     /* Draw as much as possible of the title into center of top border line. */
     char min_title_length_visible = 3;  /* min. 1 char + 2 padding/decoration */
-    if (w->frame.size.x >= min_title_length_visible)
+    if (w->framesize.x >= min_title_length_visible)
     {
         uint16_t title_offset = 0;
-        if (w->frame.size.x > strlen(w->_title) + 2)
+        if (w->framesize.x > strlen(w->title) + 2)
         {
-            title_offset = (w->frame.size.x - (strlen(w->_title) + 2)) / 2;
+            title_offset = (w->framesize.x - (strlen(w->title) + 2)) / 2;
         }                                    /* +2 is for padding/decoration */
-        uint16_t length_visible = strnlen(w->_title, w->frame.size.x - 2);
+        uint16_t length_visible = strnlen(w->title, w->framesize.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(pad, w->_start.y - 1, w->_start.x + title_offset, title);
+        mvwaddstr(pad, w->start.y - 1, w->start.x + title_offset, title);
     }
 }
 
@@ -257,9 +336,9 @@ static void draw_wins_borderlines(struct Win * w, struct Win * w_active,
         active = 1;
     }
     draw_win_borderlines(w, active, pad);
-    if (0 != w->_next)
+    if (0 != w->next)
     {
-        draw_wins_borderlines(w->_next, w_active, pad);
+        draw_wins_borderlines(w->next, w_active, pad);
     }
 }
 
@@ -267,302 +346,282 @@ 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 + w->frame.size.y, w->_start.x + w->frame.size.x, '+');
-    if (0 != w->_next)
+    mvwaddch(pad, w->start.y - 1, w->start.x - 1, '+');
+    mvwaddch(pad, w->start.y - 1, w->start.x + w->framesize.x, '+');
+    mvwaddch(pad, w->start.y + w->framesize.y, w->start.x - 1, '+');
+    mvwaddch(pad, w->start.y + w->framesize.y, w->start.x + w->framesize.x,'+');
+    if (0 != w->next)
     {
-        draw_wins_bordercorners(w->_next, pad);
+        draw_wins_bordercorners(w->next, pad);
     }
 }
 
 
 
-static void shift_win_forward(struct WinMeta * wmeta)
+static void shift_win_forward()
 {
-    if (wmeta->active == wmeta->_chain_end)
+    if (world.wmeta->active == world.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;
+        world.wmeta->chain_end = world.wmeta->active->prev;
+        world.wmeta->chain_end->next = 0;
+        world.wmeta->active->next = world.wmeta->chain_start;
+        world.wmeta->active->next->prev = world.wmeta->active;
+        world.wmeta->chain_start = world.wmeta->active;
+        world.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)
+        struct Win * old_prev = world.wmeta->active->prev;
+        struct Win * old_next = world.wmeta->active->next;
+        if (world.wmeta->chain_end == world.wmeta->active->next)
         {
-            wmeta->_chain_end = wmeta->active;
-            wmeta->active->_next = 0;
+            world.wmeta->chain_end = world.wmeta->active;
+            world.wmeta->active->next = 0;
         }
         else
         {
-            wmeta->active->_next = old_next->_next;
-            wmeta->active->_next->_prev = wmeta->active;
+            world.wmeta->active->next = old_next->next;
+            world.wmeta->active->next->prev = world.wmeta->active;
         }
-        if (wmeta->_chain_start == wmeta->active)
+        if (world.wmeta->chain_start == world.wmeta->active)
         {
-            wmeta->_chain_start = old_next;
+            world.wmeta->chain_start = old_next;
         }
         else
         {
-            old_prev->_next = old_next;
+            old_prev->next = old_next;
         }
-        old_next->_prev = old_prev;
-        old_next->_next = wmeta->active;
-        wmeta->active->_prev = old_next;
+        old_next->prev = old_prev;
+        old_next->next = world.wmeta->active;
+        world.wmeta->active->prev = old_next;
     }
 }
 
 
 
-static void shift_win_backward(struct WinMeta * wmeta)
+static void shift_win_backward()
 {
-    if (wmeta->active == wmeta->_chain_start)
+    if (world.wmeta->active == world.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;
+        world.wmeta->chain_start = world.wmeta->active->next;
+        world.wmeta->chain_start->prev = 0;
+        world.wmeta->active->prev = world.wmeta->chain_end;
+        world.wmeta->active->prev->next = world.wmeta->active;
+        world.wmeta->chain_end = world.wmeta->active;
+        world.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)
+        struct Win * old_prev = world.wmeta->active->prev;
+        struct Win * old_next = world.wmeta->active->next;
+        if (world.wmeta->chain_start == world.wmeta->active->prev)
         {
-            wmeta->_chain_start = wmeta->active;
-            wmeta->active->_prev = 0;
+            world.wmeta->chain_start = world.wmeta->active;
+            world.wmeta->active->prev = 0;
         }
         else
         {
-            wmeta->active->_prev = old_prev->_prev;
-            wmeta->active->_prev->_next = wmeta->active;
+            world.wmeta->active->prev = old_prev->prev;
+            world.wmeta->active->prev->next = world.wmeta->active;
         }
-        if (wmeta->_chain_end == wmeta->active)
+        if (world.wmeta->chain_end == world.wmeta->active)
         {
-            wmeta->_chain_end = old_prev;
+            world.wmeta->chain_end = old_prev;
         }
         else
         {
-            old_next->_prev = old_prev;
+            old_next->prev = old_prev;
         }
-        old_prev->_next = old_next;
-        old_prev->_prev = wmeta->active;
-        wmeta->active->_next = old_prev;
+        old_prev->next = old_next;
+        old_prev->prev = world.wmeta->active;
+        world.wmeta->active->next = old_prev;
     }
 }
 
 
 
-extern uint8_t init_win_meta(WINDOW * screen, struct WinMeta * wmeta)
+extern void init_win_meta(WINDOW * screen)
 {
-    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;
-    return 0;
+    char * f_name = "init_win_meta()";
+    char * err_s = "init_win_meta() creates virtual screen beyond legal size.";
+    char * err_m = "init_win_meta() triggers memory alloc error via newpad().";
+    world.wmeta         = try_malloc(sizeof(struct WinMeta), f_name);
+    world.wmeta->screen = screen;
+    uint32_t maxy_test  = getmaxy(screen);
+    uint32_t maxx_test  = getmaxx(screen);
+    uint8_t test = (maxy_test > UINT16_MAX || maxx_test > UINT16_MAX);
+    exit_err(test, err_s);
+    world.wmeta->padsize.y   = maxy_test;
+    world.wmeta->padsize.x   = maxx_test;
+    world.wmeta->chain_start = 0;
+    world.wmeta->chain_end   = 0;
+    world.wmeta->pad_offset  = 0;
+    world.wmeta->pad         = newpad(world.wmeta->padsize.y, 1);
+    exit_err(NULL == world.wmeta->pad, err_m);
+    world.wmeta->active      = 0;
 }
 
 
 
-extern uint8_t init_win(struct WinMeta * wmeta, struct Win ** wp, char * title,
-                        int16_t height, int16_t width,
-                        void * data, void * func)
+extern void init_win(struct Win ** wp, char * title, int16_t height,
+                     int16_t width, void * func)
 {
-    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;
+    char * f_name = "init_win()";
+    struct Win * w  = try_malloc(sizeof(struct Win), f_name);
+    w->prev         = 0;
+    w->next         = 0;
+    w->winmapsize.y = 0;
+    w->winmapsize.x = 0;
+    w->winmap = NULL;
+    w->title        = try_malloc(strlen(title) + 1, f_name);
+    sprintf(w->title, "%s", title);
+    w->draw         = func;
+    w->center.y     = 0;
+    w->center.x     = 0;
     if      (0 < width)
     {
-        w->frame.size.x = width;
-    }
-    else if (0 > width)
-    {
-        w->frame.size.x = wmeta->padframe.size.x + width;
+        w->framesize.x = width;
     }
-    else
+    else if (0 >= width)
     {
-        w->frame.size.x = wmeta->padframe.size.x;
+        w->framesize.x = world.wmeta->padsize.x + width;
     }
-    if      (0 < height && height <= wmeta->padframe.size.y - 1)
+    if      (0 < height && height <= world.wmeta->padsize.y - 1)
     {
-        w->frame.size.y = height;
+        w->framesize.y = height;
     }
-    else if (0 > height && wmeta->padframe.size.y + (height - 1) > 0)
+    else if (0 >= height && world.wmeta->padsize.y + (height - 1) > 0)
     {
-        w->frame.size.y = wmeta->padframe.size.y + (height - 1);
-    }
-    else
-    {
-        w->frame.size.y = wmeta->padframe.size.y - 1;
+        w->framesize.y = world.wmeta->padsize.y + (height - 1);
     }
     *wp = w;
-    return 0;
+}
+
+
+
+extern void free_winmeta()
+{
+    delwin(world.wmeta->pad);
+    free(world.wmeta);
 }
 
 
 
 extern void free_win(struct Win * win)
 {
-    free(win->_title);
+    free(win->title);
     free(win);
 }
 
 
 
-extern uint8_t append_win(struct WinMeta * wmeta, struct Win * w)
+extern void append_win(struct Win * w)
 {
-    if (0 != wmeta->_chain_start)
+    if (0 != world.wmeta->chain_start)
     {
-        w->_prev = wmeta->_chain_end;
-        wmeta->_chain_end->_next = w;
+        w->prev = world.wmeta->chain_end;
+        world.wmeta->chain_end->next = w;
     }
     else
     {
-        wmeta->active = w;
-        wmeta->_chain_start = w;
+        world.wmeta->active = w;
+        world.wmeta->chain_start = w;
     }
-    wmeta->_chain_end = w;
-    return update_wins(wmeta, w);
+    world.wmeta->chain_end = w;
+    update_wins(w);
 }
 
 
 
-extern uint8_t suspend_win(struct WinMeta * wmeta, struct Win * w)
+extern void suspend_win(struct Win * w)
 {
-    destroy_win(w);
-
-    if (wmeta->_chain_start != w)
+    if (world.wmeta->chain_start != w)
     {
-        w->_prev->_next = w->_next;
+        w->prev->next = w->next;
     }
     else
     {
-        wmeta->_chain_start = w->_next;
+        world.wmeta->chain_start = w->next;
     }
     char pad_refitted = 0;
-    if (wmeta->_chain_end != w)
+    if (world.wmeta->chain_end != w)
     {
-        w->_next->_prev = w->_prev;
-        if (wmeta->active == w)
+        w->next->prev = w->prev;
+        if (world.wmeta->active == w)
         {
-            wmeta->active = w->_next;
+            world.wmeta->active = w->next;
         }
-        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
+        update_wins(w->next);      /* Positioning of successor windows may be */
+        pad_refitted = 1;          /* affected / need correction. Note that   */
+    }                              /* update_wins() already refits the pad,   */
+    else                           /* voiding later need for that.            */
     {
-        wmeta->_chain_end = w->_prev;
-        if (wmeta->active == w)
+        world.wmeta->chain_end = w->prev;
+        if (world.wmeta->active == w)
         {
-            wmeta->active = w->_prev;
+            world.wmeta->active = w->prev;
         }
     }
 
-    w->_prev = 0;
-    w->_next = 0;
+    w->prev = 0;
+    w->next = 0;
 
     if (0 == pad_refitted)
     {
-        return refit_pad(wmeta);
+        refit_pad();
     }
-    return 0;
 }
 
 
 
-extern void reset_pad_offset(struct WinMeta * wmeta, uint16_t new_offset)
+extern void reset_pad_offset(uint16_t new_offset)
 {
     if (new_offset >= 0
-        && (new_offset < wmeta->pad_offset
-            || new_offset + wmeta->padframe.size.x
-               < getmaxx(wmeta->padframe.curses_win)))
+        && (new_offset < world.wmeta->pad_offset
+            || new_offset + world.wmeta->padsize.x < getmaxx(world.wmeta->pad)))
     {
-        wmeta->pad_offset = new_offset;
+        world.wmeta->pad_offset = new_offset;
     }
 }
 
 
 
-extern uint8_t resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size)
+extern void resize_active_win(struct yx_uint16 size)
 {
-    if (0 != wmeta->active
-        && size.x > 0 && size.y > 0
-        && size.y < wmeta->padframe.size.y)
+    if (0 != world.wmeta->active
+        && size.x > 0 && size.y > 0 && size.y < world.wmeta->padsize.y)
     {
-        wmeta->active->frame.size = size;
-        return update_wins(wmeta, wmeta->active); /* Positioning of following */
+        world.wmeta->active->framesize = size;
+        update_wins(world.wmeta->active);         /* Positioning of following */
     }                                             /* windows may be affected. */
-    return 0;
 }
 
 
 
-extern void cycle_active_win(struct WinMeta * wmeta, char dir)
+extern void cycle_active_win(char dir)
 {
-    if (0 != wmeta->active)
+    if (0 != world.wmeta->active)
     {
         if ('f' == dir)
         {
-            if (wmeta->active->_next != 0)
+            if (world.wmeta->active->next != 0)
             {
-                wmeta->active = wmeta->active->_next;
+                world.wmeta->active = world.wmeta->active->next;
             }
             else
             {
-                wmeta->active = wmeta->_chain_start;
+                world.wmeta->active = world.wmeta->chain_start;
             }
         }
         else
         {
-            if (wmeta->active->_prev != 0)
+            if (world.wmeta->active->prev != 0)
             {
-                wmeta->active = wmeta->active->_prev;
+                world.wmeta->active = world.wmeta->active->prev;
             }
             else
             {
-                wmeta->active = wmeta->_chain_end;
+                world.wmeta->active = world.wmeta->chain_end;
             }
         }
     }
@@ -570,127 +629,58 @@ extern void cycle_active_win(struct WinMeta * wmeta, char dir)
 
 
 
-extern uint8_t shift_active_win(struct WinMeta * wmeta, char dir)
+extern void shift_active_win(char dir)
 {
-    if (   0 == wmeta->active                        /* No shifting with < 2  */
-        || wmeta->_chain_start == wmeta->_chain_end) /* windows visible.      */
+    if (   0 == world.wmeta->active  /* No shifting with < 2 windows visible. */
+        || world.wmeta->chain_start == world.wmeta->chain_end)
     {
-        return 0;
+        return;
     }
     if ('f' == dir)
     {
-        shift_win_forward(wmeta);
+        shift_win_forward();
     }
     else
     {
-        shift_win_backward(wmeta);
+        shift_win_backward();
     }
-    return update_wins(wmeta, wmeta->_chain_start);
+    update_wins(world.wmeta->chain_start);
 }
 
 
 
-extern uint8_t draw_all_wins(struct WinMeta * wmeta)
+extern void draw_all_wins()
 {
     /* Empty everything before filling it a-new. */
     erase();
-    wnoutrefresh(wmeta->_screen);
-    werase(wmeta->padframe.curses_win);
-    if (wmeta->_chain_start)
+    wnoutrefresh(world.wmeta->screen);
+    werase(world.wmeta->pad);
+    if (world.wmeta->chain_start)
     {
 
-        /* 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 windows' borders first, then windows. */
+        draw_wins_borderlines(world.wmeta->chain_start, world.wmeta->active,
+                              world.wmeta->pad);
+        draw_wins_bordercorners(world.wmeta->chain_start, world.wmeta->pad);
+        draw_wins(world.wmeta->chain_start);
 
         /* Draw virtual screen scroll hints. */
-        if (wmeta->pad_offset > 0)
+        if (world.wmeta->pad_offset > 0)
         {
-            if (draw_scroll_hint(&wmeta->padframe,
-                                 wmeta->pad_offset, wmeta->pad_offset + 1, '<'))
-            {
-                return 1;
-            }
+            padscroll_hint('<', world.wmeta->pad_offset + 1);
         }
-        if (wmeta->pad_offset + wmeta->padframe.size.x
-            < getmaxx(wmeta->padframe.curses_win) - 1)
+        uint16_t size_x = getmaxx(world.wmeta->pad);
+        uint16_t right_edge = world.wmeta->pad_offset + world.wmeta->padsize.x;
+        if (right_edge < size_x - 1)
         {
-            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;
-            }
+            padscroll_hint('>', size_x - right_edge);
         }
 
-        /* Write virtual screen segment to be shown on physical screen into */
-        /* ncurses screen buffer. */
-        pnoutrefresh(wmeta->padframe.curses_win, 0, wmeta->pad_offset, 0, 0,
-                     wmeta->padframe.size.y, wmeta->padframe.size.x-1);
+        /* Write pad segment to be shown on physical screen to screen buffer. */
+        pnoutrefresh(world.wmeta->pad, 0, world.wmeta->pad_offset, 0, 0,
+                     world.wmeta->padsize.y, world.wmeta->padsize.x - 1);
     }
 
     /* Only at the end write accumulated changes to the physical screen. */
     doupdate();
-    return 0;
-}
-
-
-
-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";
-    char * unit_cols = "columns";
-    char * unit_rows = "lines";
-    uint16_t dsc_space = frame->size.x;
-    char * unit = unit_rows;
-    if ('<' == dir || '>' == dir)
-    {
-        dsc_space = frame->size.y;
-        unit = unit_cols;
-    }
-    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. */
-    char offset = 1, q;
-    if (dsc_space > strlen(scrolldsc) + 1)
-    {
-        offset = (dsc_space - strlen(scrolldsc)) / 2;
-    }
-
-    /* Draw scroll hint line as dir symbols bracketing description text. */
-    chtype symbol;
-    for (q = 0; q < dsc_space; q++)
-    {
-        if (q >= offset && q < strlen(scrolldsc) + offset)
-        {
-            symbol = scrolldsc[q - offset] | A_REVERSE;
-        }
-        else
-        {
-            symbol = dir | A_REVERSE;
-        }
-        if ('<' == dir || '>' == dir)
-        {
-            mvwaddch(frame->curses_win, q, pos, symbol);
-        }
-        else
-        {
-            mvwaddch(frame->curses_win, pos, q, symbol);
-        }
-    }
-
-    free(scrolldsc);
-    return 0;
 }