Add a new escape character 'E' to indicate whether the escape character has been pressed.

This can be used to show visual notification in the hardstatus/caption that the user has pressed the
escape character.

5 files changed, 36 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 1b29f87..d3936ff 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -53,6 +53,8 @@ Version 4.1.0 (??/??/20??):
     '%+p' expands to the PID of the frontend (display).
   * '%S' in caption/hardstatus string expands to the session name.
   * '%P' in the caption string evaluates to true if the region is in copy mode.
+  * '%E' in the caption string evaluates to true if the escape character has
+    currently been pressed.
 
   Window List:
   * Nested views when there are window groups (with 'windowlist -g').
diff --git a/src/doc/screen.1 b/src/doc/screen.1
index c175891..bbb5a3d 100644
--- a/src/doc/screen.1
+++ b/src/doc/screen.1
@@ -3692,6 +3692,8 @@ current time HH:MM in 12h format
 day number
 .IP D
 weekday name
+.IP E
+sets %? to true if the escape character has been pressed.
 .IP f
 flags of the window, see \*Qwindows\*U for meanings of the various flags
 .IP F
diff --git a/src/doc/screen.texinfo b/src/doc/screen.texinfo
index 08ca259..e39003a 100644
--- a/src/doc/screen.texinfo
+++ b/src/doc/screen.texinfo
@@ -5438,6 +5438,8 @@ current time @code{HH:MM} in 12h format
 day number
 @item D
 weekday name
+@item E
+sets %? to true if the escape character has been pressed.
 @item f
 flags of the window. @xref{Windows}, for meanings of the various flags.
 @item F
diff --git a/src/process.c b/src/process.c
index 70e59f3..d86c62c 100644
--- a/src/process.c
+++ b/src/process.c
@@ -908,12 +908,19 @@ int ilen;
 	  if (slen)
 	    DoProcess(fore, &ibuf, &slen, 0);
 	  if (--ilen == 0)
-	    D_ESCseen = ktab;
+	    {
+	      D_ESCseen = ktab;
+	      WindowChanged(fore, 'E');
+	    }
 	}
       if (ilen <= 0)
         return;
       ktabp = D_ESCseen ? D_ESCseen : ktab;
-      D_ESCseen = 0;
+      if (D_ESCseen)
+        {
+          D_ESCseen = 0;
+          WindowChanged(fore, 'E');
+        }
       ch = (unsigned char)*s;
 
       /* 
@@ -1863,10 +1870,18 @@ int key;
 	    }
 	  if (D_ESCseen != ktab || ktabp != ktab)
 	    {
-	      D_ESCseen = ktabp;
+	      if (D_ESCseen != ktabp)
+	        {
+	          D_ESCseen = ktabp;
+	          WindowChanged(fore, 'E');
+	        }
 	      break;
 	    }
-	  D_ESCseen = 0;
+	  if (D_ESCseen)
+	    {
+	      D_ESCseen = 0;
+	      WindowChanged(fore, 'E');
+	    }
 	}
       /* FALLTHROUGH */
     case RC_OTHER:
@@ -6470,6 +6485,7 @@ int i;
       if (act->nr != RC_ILLEGAL)
 	{
 	  D_ESCseen = 0;
+	  WindowChanged(fore, 'E');
           DoAction(act, i + 256);
 	  return 0;
 	}
@@ -6495,7 +6511,11 @@ int i;
 
   if (discard && (!act || act->nr != RC_COMMAND))
     {
-      D_ESCseen = 0;
+      if (D_ESCseen)
+        {
+          D_ESCseen = 0;
+          WindowChanged(fore, 'E');
+        }
       return 0;
     }
   D_mapdefault = 0;
diff --git a/src/screen.c b/src/screen.c
index b3c85d4..949df01 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -2855,6 +2855,11 @@ int rec;
 	    }
 #endif
 	  break;
+	case 'E':
+	  p--;
+	  if (display && D_ESCseen)
+	    qmflag = 1;
+	  break;
 	case '>':
 	  truncpos = p - winmsg_buf;
 	  truncper = num > 100 ? 100 : num;