From f19284f30d808e305953424ff2d52b02d0e9ba72 Mon Sep 17 00:00:00 2001
From: "Michael D. Lowis" <mike@mdlowis.com>
Date: Tue, 20 Dec 2016 22:13:51 -0500
Subject: [PATCH] undo/redo now select the re-inserted text

---
 TODO.md        |  8 +++-----
 inc/edit.h     |  4 ++--
 libedit/buf.c  | 26 +++++++++++---------------
 libedit/view.c |  4 ++--
 xedit.c        |  1 -
 5 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/TODO.md b/TODO.md
index 75150f6..ca6e2db 100644
--- a/TODO.md
+++ b/TODO.md
@@ -13,20 +13,18 @@
 
 Nice to haves: 
 
-* Undo/Redo should set selection to inserted text.
 * focus should follow mouse between regions
 * Expand tabs setting should be disabled if opened file contains tabs
 * Add a tools dir to namespace utility scripts only useful inside the editor
 * shift+click to extend selection
+* implement command diffing logic to optimize the undo/redo log
+* add command line flags to toggle options (Tabs, Indent, etc..)
+* check for file changes when window regains focus
 
 Need to reproduce:
 
 * drag with middle and right mouse buttons causes infinite loops
 * off by one error on scrolling up with wrapped lines
-* Implement minimal regex search (per Kernighan article)
-* check for file changes when window regains focus
-* add command line flags to toggle options (Tabs, Indent, etc..)
-* implement command diffing logic to optimize the undo/redo log
 
 # Auxillary Programs
 
diff --git a/inc/edit.h b/inc/edit.h
index 678a376..5006c78 100644
--- a/inc/edit.h
+++ b/inc/edit.h
@@ -65,8 +65,8 @@ unsigned buf_insert(Buf* buf, bool indent, unsigned off, Rune rune);
 unsigned buf_delete(Buf* buf, unsigned beg, unsigned end);
 unsigned buf_change(Buf* buf, unsigned beg, unsigned end);
 
-unsigned buf_undo(Buf* buf, unsigned pos);
-unsigned buf_redo(Buf* buf, unsigned pos);
+void buf_undo(Buf* buf, Sel* sel);
+void buf_redo(Buf* buf, Sel* sel);
 void buf_loglock(Buf* buf);
 
 bool buf_iseol(Buf* buf, unsigned pos);
diff --git a/libedit/buf.c b/libedit/buf.c
index 59e06f1..6f0d228 100644
--- a/libedit/buf.c
+++ b/libedit/buf.c
@@ -146,15 +146,16 @@ static int rune_match(Buf* buf, unsigned mbeg, unsigned mend, Rune* runes) {
     return 0;
 }
 
-static unsigned swaplog(Buf* buf, Log** from, Log** to, unsigned pos) {
+static void swaplog(Buf* buf, Log** from, Log** to, Sel* sel) {
     /* pop the last action */
     Log* log = *from;
-    if (!log) return pos;
+    if (!log) return;
     *from = log->next;
     /* invert the log type and move it to the destination */
     Log* newlog = (Log*)calloc(sizeof(Log), 1);
     newlog->transid = log->transid;
     if (log->insert) {
+        sel->beg = sel->end = log->data.ins.beg;
         newlog->insert = false;
         size_t n = (log->data.ins.end - log->data.ins.beg);
         newlog->data.del.off   = log->data.ins.beg;
@@ -164,20 +165,17 @@ static unsigned swaplog(Buf* buf, Log** from, Log** to, unsigned pos) {
             newlog->data.del.runes[i] = buf_get(buf, log->data.ins.beg);
             delete(buf, log->data.ins.beg);
         }
-        pos = newlog->data.del.off;
     } else {
         newlog->insert = true;
-        newlog->data.ins.beg = log->data.del.off;
+        sel->beg = newlog->data.ins.beg = log->data.del.off;
         newlog->data.ins.end = newlog->data.ins.beg;
-        //newlog->data.ins.end = log->data.del.off + log->data.del.len;
         for (size_t i = log->data.del.len; i > 0; i--) {
             newlog->data.ins.end += insert(buf, newlog->data.ins.beg, log->data.del.runes[i-1]);
         }
-        pos = newlog->data.ins.end;
+        sel->end = newlog->data.ins.end;
     }
     newlog->next = *to;
     *to = newlog;
-    return pos;
 }
 
 /*****************************************************************************/
@@ -320,20 +318,18 @@ unsigned buf_change(Buf* buf, unsigned beg, unsigned end) {
 
 /*****************************************************************************/
 
-unsigned buf_undo(Buf* buf, unsigned pos) {
-    if (!buf->undo) return pos;
+void buf_undo(Buf* buf, Sel* sel) {
+    if (!buf->undo) return;
     uint transid = buf->undo->transid;
     while (buf->undo && (buf->undo->transid == transid))
-        pos = swaplog(buf, &(buf->undo), &(buf->redo), pos);
-    return pos;
+        swaplog(buf, &(buf->undo), &(buf->redo), sel);
 }
 
-unsigned buf_redo(Buf* buf, unsigned pos) {
-    if (!buf->redo) return pos;
+void buf_redo(Buf* buf, Sel* sel) {
+    if (!buf->redo) return;
     uint transid = buf->redo->transid;
     while (buf->redo && (buf->redo->transid == transid))
-        pos = swaplog(buf, &(buf->redo), &(buf->undo), pos);
-    return pos;
+        swaplog(buf, &(buf->redo), &(buf->undo), sel);
 }
 
 void buf_loglock(Buf* buf) {
diff --git a/libedit/view.c b/libedit/view.c
index fa9e471..0c43c07 100644
--- a/libedit/view.c
+++ b/libedit/view.c
@@ -482,13 +482,13 @@ void view_eof(View* view, bool extsel) {
 }
 
 void view_undo(View* view) {
-    view->selection.beg = view->selection.end = buf_undo(&(view->buffer), view->selection.end);
+    buf_undo(&(view->buffer), &(view->selection));
     view->selection.col = buf_getcol(&(view->buffer), view->selection.end);
     view->sync_needed = true;
 }
 
 void view_redo(View* view) {
-    view->selection.beg = view->selection.end = buf_redo(&(view->buffer), view->selection.end);
+    buf_redo(&(view->buffer), &(view->selection));
     view->selection.col = buf_getcol(&(view->buffer), view->selection.end);
     view->sync_needed = true;
 }
diff --git a/xedit.c b/xedit.c
index 2c0aafd..1871a9b 100644
--- a/xedit.c
+++ b/xedit.c
@@ -618,7 +618,6 @@ static void add_indent(void) {
 
 static void eol_mode(void) {
     int crlf = getbuf(EDIT)->crlf;
-    printf("%d %d\n", crlf, !crlf);
     getbuf(EDIT)->crlf = !crlf;
     getbuf(TAGS)->crlf = !crlf;
     exec(crlf ? "|dos2unix" : "|unix2dos");
-- 
2.49.0