buffer everything. cancel acs at the end of draw() if necessary.

lib/program.js

@@ -66,6 +66,10 @@ function Program(options) {
     || process.env.TERM
     || 'xterm';
 
+  this._buf = '';
+  this.__flush = this._flush.bind(this);
+  process.on('exit', this.__flush);
+
   if (!Program.global) {
     Program.global = this;
   }
@@ -1233,16 +1237,42 @@ Program.prototype._parseChar = function(text, attr) {
   }
 };
 
+Program.prototype._buffer = function(text) {
+  if (process._exiting) {
+    this._flush();
+    this.output.write(text);
+    return;
+  }
+
+  if (this._buf) {
+    this._buf += text;
+    return;
+  }
+
+  this._buf = text;
+
+  process.nextTick(this.__flush);
+};
+
+Program.prototype._flush = function(text) {
+  if (!this._buf) return;
+  this.output.write(this._buf);
+  this._buf = '';
+};
+
 Program.prototype._write = function(text) {
   if (this.ret) return text;
+  if (this.options.buffer) {
+    return this._buffer(text);
+  }
   return this.output.write(text);
 };
 
 Program.prototype.echo =
 Program.prototype.write = function(text, attr) {
   return attr
-    ? this.output.write(this.text(text, attr))
-    : this.output.write(text);
+    ? this._write(this.text(text, attr))
+    : this._write(text);
 };
 
 Program.prototype._ncoords = function() {
@@ -3480,6 +3510,28 @@ Program.prototype.resume = function(callback) {
   if (this._resume) return this._resume();
 };
 
+/**
+ * Helpers
+ */
+
+// We could do this easier by just manipulating the _events object, or for
+// older versions of node, manipulating the array returned by listeners(), but
+// neither of these methods are guaranteed to work in future versions of node.
+function unshiftEvent(obj, event, listener) {
+  var listeners = obj.listeners(event);
+  obj.removeAllListeners(event);
+  obj.on(event, listener);
+  listeners.forEach(function(listener) {
+    obj.on(event, listener);
+  });
+};
+
+// Ensure _exiting is set for future versions of node that may remove it.
+// We need this to be the first listener executed.
+unshiftEvent(process, 'exit', function() {
+  process._exiting = true;
+});
+
 /**
  * Expose
  */

lib/widget.js

@@ -267,6 +267,7 @@ function Screen(options) {
     options = { program: options };
   }
 
+  options.buffer = true;
   options.program = options.program
     || require('./program').global
     || new (require('./program'))(options);
@@ -280,7 +281,6 @@ function Screen(options) {
   this.program = options.program;
   this.program.zero = true;
   this.tput = this.program.tput;
-  this.output = this.program.output;
 
   this.autoPadding = options.autoPadding;
 
@@ -1122,6 +1122,11 @@ Screen.prototype.draw = function(start, end) {
     }
   }
 
+  if (acs) {
+    main += this.tput.rmacs();
+    acs = false;
+  }
+
   if (main) {
     var pre = ''
       , post = '';
@@ -1142,7 +1147,9 @@ Screen.prototype.draw = function(start, end) {
         : '\x1b[?25h';
     }
 
-    this.output.write(pre + main + post);
+    // this.program._flush();
+    // this.program.output.write(pre + main + post);
+    this.program._write(pre + main + post);
   }
 };