From e6c763a73c8a0a5207fd772909817669001c9ff6 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 1 May 2015 22:43:31 -0700
Subject: [PATCH] use onScreenEvent for element keys to prevent memory leaks.

---
 lib/widget.js | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/lib/widget.js b/lib/widget.js
index 1634297..38b7605 100644
--- a/lib/widget.js
+++ b/lib/widget.js
@@ -2520,13 +2520,23 @@ Element.prototype.sattr = function(style, fg, bg) {
 };
 
 Element.prototype.onScreenEvent = function(type, handler) {
-  this.screen.on(type, handler);
   var listeners = this._slisteners = this._slisteners || [];
   listeners.push({ type: type, handler: handler });
+  this.screen.on(type, handler);
+};
+
+Element.prototype.onceScreenEvent = function(type, handler) {
+  var listeners = this._slisteners = this._slisteners || [];
+  var entry = { type: type, handler: handler };
+  listeners.push(entry);
+  this.screen.once(type, function() {
+    var i = listeners.indexOf(entry);
+    if (~i) listeners.splice(i, 1);
+    return handler.apply(this, arguments);
+  });
 };
 
 Element.prototype.removeScreenEvent = function(type, handler) {
-  this.screen.removeListener(type, handler);
   var listeners = this._slisteners = this._slisteners || [];
   for (var i = 0; i < listeners.length; i++) {
     var listener = listeners[i];
@@ -2535,9 +2545,10 @@ Element.prototype.removeScreenEvent = function(type, handler) {
       if (this._slisteners.length === 0) {
         delete this._slisteners;
       }
-      return;
+      break;
     }
   }
+  this.screen.removeListener(type, handler);
 };
 
 Element.prototype.free = function() {
@@ -2552,7 +2563,6 @@ Element.prototype.free = function() {
 Element.prototype.destroy = function() {
   this.detach();
   this.free();
-  this.screen.render();
 };
 
 Element.prototype.hide = function() {
@@ -3099,17 +3109,29 @@ Element.prototype.disableDrag = function() {
   return this._draggable = false;
 };
 
-Element.prototype.key = function() {
-  return this.screen.program.key.apply(this, arguments);
+Element.prototype.key = function(key, listener) {
+  // return this.screen.program.key.apply(this, arguments);
+  if (typeof key === 'string') key = key.split(/\s*,\s*/);
+  key.forEach(function(key) {
+    return this.onScreenEvent('key ' + key, listener);
+  }, this);
 };
 
-Element.prototype.onceKey = function() {
-  return this.screen.program.onceKey.apply(this, arguments);
+Element.prototype.onceKey = function(key, listener) {
+  // return this.screen.program.onceKey.apply(this, arguments);
+  if (typeof key === 'string') key = key.split(/\s*,\s*/);
+  key.forEach(function(key) {
+    return this.onceScreenEvent('key ' + key, listener);
+  }, this);
 };
 
 Element.prototype.unkey =
-Element.prototype.removeKey = function() {
-  return this.screen.program.unkey.apply(this, arguments);
+Element.prototype.removeKey = function(key, listener) {
+  // return this.screen.program.unkey.apply(this, arguments);
+  if (typeof key === 'string') key = key.split(/\s*,\s*/);
+  key.forEach(function(key) {
+    return this.removeScreenEvent('key ' + key, listener);
+  }, this);
 };
 
 Element.prototype.setIndex = function(index) {