X-Git-Url: https://plomlompom.com/repos/?a=blobdiff_plain;f=src%2Fwindows.c;h=f71be6526af7d3322952369e57e312e581f2901f;hb=350ef2e2d17e8122e2991466f76a9a083a6303e7;hp=861b737681b2b1b6c4ae5b92273e4523df7ae668;hpb=8ca457975bc2d07cb8dd5c36a0bd5314d9b9c93a;p=plomrogue

diff --git a/src/windows.c b/src/windows.c
index 861b737..f71be65 100644
--- a/src/windows.c
+++ b/src/windows.c
@@ -1,123 +1,111 @@
 /* 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(), delwin(), mvwaddch(), mvwaddstr(),      */
+                       /* newpad(), wnoutrefres(), erase(), werase(),        */
+                       /* pnoutrefresh(), doupdate(), getmaxyx()   */
 #include <stdlib.h>    /* for malloc(), free() */
-#include <string.h>    /* for strlen(), 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;
-};
+#include <string.h>    /* for strlen(), strnlen(), memcpy() */
+#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 void 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 void 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_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();
+static void shift_win_backward();
 
 
-static void refit_pad(struct WinMeta * wmeta)
+
+static void refit_pad()
 {
     /* Determine rightmost window column. */
-    uint16_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 (w_p->start.x + w_p->frame.size.x > lastwincol + 1)
+        if ((uint32_t) wp->start.x + (uint32_t) wp->framesize.x > lastwcol + 1)
         {
-            lastwincol = w_p->start.x + 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->pad.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)
     {
-        wresize(wmeta->pad.curses_win,
-                getmaxy(wmeta->pad.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);
     }
 }
 
 
 
-static void 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);
-    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);
+    place_win(w);
+    refit_pad();
     if (0 != w->next)
     {
-        update_wins (wmeta, w->next);
+        update_wins(w->next);
     }
 }
 
 
 
-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;
@@ -131,15 +119,14 @@ static void place_win (struct WinMeta * wmeta, struct Win * w)
         {
             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->pad.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;
@@ -164,14 +151,13 @@ static void place_win (struct WinMeta * wmeta, struct Win * w)
                     }
                     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->pad.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.x = w_up->start.x + w_up->framesize.x + 1 ;
                     w->start.y = w_prev_maxy + 1;
                     break;
                 }
@@ -183,52 +169,149 @@ 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)
+{
+    /* 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)
 {
-    delwin(w->frame.curses_win);
-    w->frame.curses_win = 0;
+    struct yx_uint16 start;
+    start.y = 0;
+    start.x = world.wmeta->pad_offset;
+    scroll_hint(world.wmeta->padsize, dir, dist, "columns", start);
 }
 
 
 
-static void draw_wins (struct Win * w)
+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);
+    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);
     }
 }
 
 
 
-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++)
+    for (y = w->start.y; y <= w->start.y + w->framesize.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->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(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->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;
-        }                                     /* +2 is for padding/decoration */
-        uint16_t length_visible = strnlen(w->title, w->frame.size.x - 2);
+            title_offset = (w->framesize.x - (strlen(w->title) + 2)) / 2;
+        }                                    /* +2 is for padding/decoration */
+        uint16_t length_visible = strnlen(w->title, w->framesize.x - 2);
         char title[length_visible + 3];
         char decoration = ' ';
         if (1 == active)
@@ -238,118 +321,245 @@ 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);
     }
 }
 
 
 
-extern struct WinMeta init_win_meta(WINDOW * screen)
+static void draw_wins_bordercorners(struct Win * w, WINDOW * pad)
 {
-    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;
+    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);
+    }
 }
 
 
 
-extern struct Win init_win(struct WinMeta * wmeta, char * title,
-                           void * data, void * func)
+static void shift_win_forward()
 {
-    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;
+    if (world.wmeta->active == world.wmeta->chain_end)
+    {
+        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 = world.wmeta->active->prev;
+        struct Win * old_next = world.wmeta->active->next;
+        if (world.wmeta->chain_end == world.wmeta->active->next)
+        {
+            world.wmeta->chain_end = world.wmeta->active;
+            world.wmeta->active->next = 0;
+        }
+        else
+        {
+            world.wmeta->active->next = old_next->next;
+            world.wmeta->active->next->prev = world.wmeta->active;
+        }
+        if (world.wmeta->chain_start == world.wmeta->active)
+        {
+            world.wmeta->chain_start = old_next;
+        }
+        else
+        {
+            old_prev->next = old_next;
+        }
+        old_next->prev = old_prev;
+        old_next->next = world.wmeta->active;
+        world.wmeta->active->prev = old_next;
+    }
 }
 
 
 
-extern void append_win(struct WinMeta * wmeta, struct Win * w)
+static void shift_win_backward()
 {
-    if (0 != wmeta->chain_start)
+    if (world.wmeta->active == world.wmeta->chain_start)
     {
-        w->prev = wmeta->chain_end;
-        wmeta->chain_end->next = w;
+        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
     {
-        wmeta->active = w;
-        wmeta->chain_start = w;
+        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)
+        {
+            world.wmeta->chain_start = world.wmeta->active;
+            world.wmeta->active->prev = 0;
+        }
+        else
+        {
+            world.wmeta->active->prev = old_prev->prev;
+            world.wmeta->active->prev->next = world.wmeta->active;
+        }
+        if (world.wmeta->chain_end == world.wmeta->active)
+        {
+            world.wmeta->chain_end = old_prev;
+        }
+        else
+        {
+            old_next->prev = old_prev;
+        }
+        old_prev->next = old_next;
+        old_prev->prev = world.wmeta->active;
+        world.wmeta->active->next = old_prev;
     }
-    wmeta->chain_end = w;
-    update_wins(wmeta, w);
 }
 
 
 
-extern void suspend_win(struct WinMeta * wmeta, struct Win * w)
+extern void init_win_meta(WINDOW * screen)
 {
-    destroy_win(w);
+    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;
+}
+
+
 
-    if (wmeta->chain_start != w)
+extern void init_win(struct Win ** wp, char * title, int16_t height,
+                     int16_t width, void * 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->framesize.x = width;
+    }
+    else if (0 >= width)
+    {
+        w->framesize.x = world.wmeta->padsize.x + width;
+    }
+    if      (0 < height && height <= world.wmeta->padsize.y - 1)
+    {
+        w->framesize.y = height;
+    }
+    else if (0 >= height && world.wmeta->padsize.y + (height - 1) > 0)
+    {
+        w->framesize.y = world.wmeta->padsize.y + (height - 1);
+    }
+    *wp = w;
+}
+
+
+
+extern void free_winmeta()
+{
+    delwin(world.wmeta->pad);
+    free(world.wmeta);
+}
+
+
+
+extern void free_win(struct Win * win)
+{
+    free(win->title);
+    free(win);
+}
+
+
+
+extern void append_win(struct Win * w)
+{
+    if (0 != world.wmeta->chain_start)
+    {
+        w->prev = world.wmeta->chain_end;
+        world.wmeta->chain_end->next = w;
+    }
+    else
+    {
+        world.wmeta->active = w;
+        world.wmeta->chain_start = w;
+    }
+    world.wmeta->chain_end = w;
+    update_wins(w);
+}
+
+
+
+extern void suspend_win(struct Win * w)
+{
+    if (world.wmeta->chain_start != w)
     {
         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)
+        if (world.wmeta->active == w)
         {
-            wmeta->active = w->next;
+            world.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.     */
+        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;
         }
     }
 
@@ -358,61 +568,60 @@ extern void suspend_win(struct WinMeta * wmeta, struct Win * w)
 
     if (0 == pad_refitted)
     {
-        refit_pad(wmeta);
+        refit_pad();
     }
 }
 
 
 
-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->pad.size.x < getmaxx(wmeta->pad.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 void 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->pad.size.y)
+    if (0 != world.wmeta->active
+        && size.x > 0 && size.y > 0 && size.y < world.wmeta->padsize.y)
     {
-        wmeta->active->frame.size = size;
-        update_wins(wmeta, wmeta->chain_start);   /* Positioning of successor */
+        world.wmeta->active->framesize = size;
+        update_wins(world.wmeta->active);         /* Positioning of following */
     }                                             /* windows may be affected. */
 }
 
 
 
-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 ('n' == dir)
+        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;
             }
         }
     }
@@ -420,194 +629,58 @@ extern void cycle_active_win(struct WinMeta * wmeta, char dir)
 
 
 
-extern void shift_active_win(struct WinMeta * wmeta, char dir)
+extern void shift_active_win(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 == world.wmeta->active  /* No shifting with < 2 windows visible. */
+        || world.wmeta->chain_start == world.wmeta->chain_end)
     {
-        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;
+    }
+    if ('f' == dir)
+    {
+        shift_win_forward();
+    }
+    else
+    {
+        shift_win_backward();
     }
+    update_wins(world.wmeta->chain_start);
 }
 
 
 
-extern void draw_all_wins(struct WinMeta * wmeta)
+extern void draw_all_wins()
 {
     /* Empty everything before filling it a-new. */
     erase();
-    wnoutrefresh(wmeta->screen);
-    werase(wmeta->pad.curses_win);
-    if (wmeta->chain_start)
+    wnoutrefresh(world.wmeta->screen);
+    werase(world.wmeta->pad);
+    if (world.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' 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)
         {
-            draw_scroll_hint(&wmeta->pad,
-                             wmeta->pad_offset, wmeta->pad_offset + 1, '<');
+            padscroll_hint('<', world.wmeta->pad_offset + 1);
         }
-        if (wmeta->pad_offset + wmeta->pad.size.x
-            < getmaxx(wmeta->pad.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)
         {
-            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), '>');
+            padscroll_hint('>', size_x - right_edge);
         }
 
-        /* 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);
+        /* 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();
 }
-
-
-
-extern void 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 */
-    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);
-}