undo: preview shows command and time output

Makes hg undo -i and hg undo -p output show an "undo to time, before command"
message and adds directions (left, right, return, q).  Also adds pager check as
pager break interactiveui.

Testing: run hg undo -p and hg undo -i and see output

Differential Revision: https://phab.mercurial-scm.org/D448

hgext3rd/interactiveui.py

@@ -12,12 +12,19 @@ import sys
 import termios
 import tty
 
-def clearline():
+from mercurial.i18n import _
+
+from mercurial import (
+    error,
+)
+
+def clearline(n=1):
     w = sys.stdout
     # ANSI
     # ESC[#A : up # lines
     # ESC[K : clear to end of line
-    w.write('\033[1A\033[K')
+    for i in range(n):
+        w.write('\033[1A\033[K')
     w.flush()
 
 # From:
@@ -107,8 +114,10 @@ class viewframe(object):
 
 def view(viewobj):
     done = False
+    if viewobj.ui.pageractive:
+        raise error.Abort(_("interactiveui doesn't work with pager"))
     s = viewobj.render()
-    print(s)
+    sys.stdout.write(s)
     while not done:
         output = getchar(sys.stdin.fileno())
         if repr(output) == '\'q\'':
@@ -123,7 +132,6 @@ def view(viewobj):
             viewobj.rightarrow()
         if repr(output) == '\'\\x1b[D\'':
             viewobj.leftarrow()
-        for i in range(len(s.split("\n"))):
-            clearline()
+        clearline(s.count("\n"))
         s = viewobj.render()
-        print(s)
+        sys.stdout.write(s)

hgext3rd/undo.py

@@ -653,6 +653,10 @@ def undo(ui, repo, *args, **opts):
                 ui = self.ui
                 ui.pushbuffer()
                 _preview(ui, self.repo, self.index)
+                repo.ui.status(_("<-: next  "
+                                 "->: previous  "
+                                 "q: abort  "
+                                 "enter: confirm\n"))
                 return ui.popbuffer()
             def rightarrow(self):
                 self.index += 1
@@ -862,8 +866,8 @@ def _undoto(ui, repo, reverseindex, keep=False, branch=None):
     commandstr = _readnode(repo, "command.i", nodedict["command"])
     commandlist = commandstr.split("\0")[1:]
     commandstr = " ".join(commandlist)
-    uimessage = 'undone to %s, before %s\n' % (time, commandstr)
-    repo.ui.status(_(uimessage))
+    uimessage = _('undone to %s, before %s\n') % (time, commandstr)
+    repo.ui.status((uimessage))
 
 def _computerelative(repo, reverseindex, absolute=False, branch=""):
     # allows for relative undos using
@@ -1069,6 +1073,9 @@ def _preview(ui, repo, reverseindex):
     #   None
 
     # override "UNDOINDEX" as a variable usable in template
+    if not _gapcheck(ui, repo, reverseindex):
+        repo.ui.status(_("WARN: missing history between present and this"
+                         " state\n"))
     overrides = {
         ('templates', 'UNDOINDEX'): str(reverseindex),
     }
@@ -1082,6 +1089,17 @@ def _preview(ui, repo, reverseindex):
     try:
         with ui.configoverride(overrides):
             cmdutil.graphlog(ui, repo, None, opts)
+        # informative output
+        nodedict = _readindex(repo, reverseindex)
+        time = _readnode(repo, "date.i", nodedict["date"])
+        time = util.datestr([float(x) for x in time.split(" ")])
+
+        nodedict = _readindex(repo, reverseindex - 1)
+        commandstr = _readnode(repo, "command.i", nodedict["command"])
+        commandlist = commandstr.split("\0")[1:]
+        commandstr = " ".join(commandlist)
+        uimessage = _('undo to %s, before %s\n') % (time, commandstr)
+        repo.ui.status((uimessage))
     except IndexError:
         # don't print anything
         pass

tests/test-undo.t

@@ -734,6 +734,7 @@ hg undo --preview test
   o
   |
   ~
+  undo to *, before ci -m prev1 (glob)
   $ hg undo -p -n 2
   @  Undone
   |
@@ -754,6 +755,7 @@ hg undo --preview test
   o
   |
   ~
+  undo to *, before undo -b 3532 (glob)
 
 hg redo tests
   $ hg log -G -T compact