New feature: double vertical split.

1 files changed, 99 insertions, 10 deletions

diff --git a/pw.c b/pw.c
index cb3e2be..9daaf5e 100644
--- a/pw.c
+++ b/pw.c
@@ -83,6 +83,7 @@ typedef struct pwstate {
   char **circbuf;
   int nlines;
   unsigned hpos;
+  unsigned vsplit1, vsplit2, vs2pos;
   unsigned hist;
   int columns;
   unsigned stat;
@@ -338,16 +339,65 @@ static void clreol(int nl)
 
 static void drawline(pwstate *pw, const char *line, int lineno)
 {
+  const char *oline = line;
   size_t len = dslen(line);
   int columns = pw->columns;
+  unsigned vsplit1 = pw->vsplit1;
+  unsigned vsplit2 = pw->vsplit2;
+  unsigned vs2pos = pw->vs2pos;
+  int endmark = 0;
 
   if (lineno >= 0)
     columns -= printf("%3d ", lineno);
 
-  if ((size_t) pw->hpos <= len) {
-    if (pw->hpos) {
-      line += pw->hpos;
-      len -= pw->hpos;
+  if (vsplit1 > 0) {
+    if (len <= vsplit1) {
+      fputs(line, stdout);
+      columns -= len;
+      len = 0;
+    } else {
+      for (unsigned i = 0; i < vsplit1; i++)
+        putchar(line[i]);
+      len -= vsplit1;
+      line += vsplit1;
+      columns -= vsplit1;
+      endmark = 1;
+    }
+  }
+
+  if (vsplit2 > 0) {
+    unsigned pos = line - oline;
+    unsigned delta = vs2pos - pos;
+    if (pos + len <= vs2pos) {
+      len = 0;
+    } else if (len - delta <= vsplit2) {
+      if (vsplit1) {
+        putchar('|');
+        delta++;
+      }
+      fputs(line + delta, stdout);
+      columns -= len;
+      len = 0;
+      endmark = 0;
+    } else {
+      unsigned start = 0;
+      if (vsplit1) {
+        putchar('|');
+        start++;
+      }
+      for (unsigned i = start; i < vsplit2; i++)
+        putchar(line[delta + i]);
+      line += vsplit2;
+      len -= vsplit2;
+      columns -= vsplit2;
+      endmark = 1;
+    }
+  }
+
+  if ((size_t) pw->hpos + 1 <= len) {
+    if (pw->hpos || vsplit1 || vsplit2) {
+      line += pw->hpos + 1;
+      len -= pw->hpos + 1;
       putchar('>');
       columns--;
     }
@@ -360,7 +410,8 @@ static void drawline(pwstate *pw, const char *line, int lineno)
       puts("<");
     }
   } else {
-    putchar('>');
+    if (endmark)
+      putchar('>');
     clreol(1);
   }
 }
@@ -1097,14 +1148,52 @@ int main(int argc, char **argv)
             }
             break;
           case 'h':
-            if (pw.hpos >= 8) {
-              pw.hpos -= 8;
+            if (cmdcount == UINT_MAX)
+              cmdcount = 8;
+            if (pw.hpos >= cmdcount)
+              pw.hpos -= cmdcount;
+            else
+              pw.hpos = 0;
+            pw.stat |= stat_force;
+            break;
+          case 'l':
+            if (cmdcount == UINT_MAX)
+              cmdcount = 8;
+            if (pw.hpos < 10000)
+              pw.hpos += cmdcount;
+            pw.stat |= stat_force;
+            break;
+          case ']':
+            if ((int) pw.vsplit1 < pw.columns - 2) {
+              pw.vsplit1++;
+              if (pw.vsplit2 > 0) {
+                pw.vsplit2--;
+                pw.vs2pos++;
+              }
               pw.stat |= stat_force;
             }
             break;
-          case 'l':
-            if (pw.hpos < 10000) {
-              pw.hpos += 8;
+          case '[':
+            if (pw.vsplit1 > 0) {
+              pw.vsplit1--;
+              if (pw.vsplit2 > 0) {
+                pw.vsplit2++;
+                pw.vs2pos--;
+              }
+              pw.stat |= stat_force;
+            }
+            break;
+          case '>':
+            if ((int) (pw.vsplit1 + pw.vsplit2) < pw.columns - 2) {
+              if (pw.vsplit2 == 0)
+                pw.vs2pos = pw.hpos + pw.vsplit1;
+              pw.vsplit2++;
+              pw.stat |= stat_force;
+            }
+            break;
+          case '<':
+            if (pw.vsplit2 > 0) {
+              pw.vsplit2--;
               pw.stat |= stat_force;
             }
             break;