From 94ea19c79159d7bc1ccdeb99d98a2afe0300ba5d Mon Sep 17 00:00:00 2001
From: Simo Kinnunen <simo@shoqolate.com>
Date: Mon, 27 Apr 2015 17:01:13 +0900
Subject: [PATCH] Add a very simple image pool to limit the amount of new
 images loaded. Hoping it will fix the screen sometimes stopping.

---
 res/app/components/stf/screen/imagepool.js    | 23 +++++++++++++++++++
 .../components/stf/screen/screen-directive.js |  4 +++-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 res/app/components/stf/screen/imagepool.js

diff --git a/res/app/components/stf/screen/imagepool.js b/res/app/components/stf/screen/imagepool.js
new file mode 100644
index 00000000..793ca5dc
--- /dev/null
+++ b/res/app/components/stf/screen/imagepool.js
@@ -0,0 +1,23 @@
+function ImagePool(size) {
+  this.size = size
+  this.images = []
+  this.counter = 0
+}
+
+ImagePool.prototype.next = function() {
+  if (this.images.length < this.size) {
+    var image = new Image()
+    this.images.push(image)
+    return image
+  }
+  else {
+    if (this.counter >= this.size) {
+      // Reset for unlikely but theoretically possible overflow.
+      this.counter = 0
+    }
+
+    return this.images[this.counter++ % this.size]
+  }
+}
+
+module.exports = ImagePool
diff --git a/res/app/components/stf/screen/screen-directive.js b/res/app/components/stf/screen/screen-directive.js
index e475fa44..a2f5d676 100644
--- a/res/app/components/stf/screen/screen-directive.js
+++ b/res/app/components/stf/screen/screen-directive.js
@@ -1,5 +1,6 @@
 var _ = require('lodash')
 var rotator = require('./rotator')
+var ImagePool = require('./imagepool')
 
 module.exports = function DeviceScreenDirective(
   $document
@@ -208,6 +209,7 @@ module.exports = function DeviceScreenDirective(
               , cachedImageHeight = 0
               , cssRotation = 0
               , alwaysUpright = false
+              , imagePool = new ImagePool(6)
 
             function applyQuirks(banner) {
               element[0].classList.toggle(
@@ -288,7 +290,7 @@ module.exports = function DeviceScreenDirective(
                     type: 'image/jpeg'
                   })
 
-                  var img = new Image()
+                  var img = imagePool.next()
 
                   img.onload = function() {
                     updateImageArea(this)