From 45dec1039cd919aa7d6d8a6d68bb6168b4536805 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sun, 2 Jun 2013 22:29:26 -0500
Subject: [PATCH] first working scrollable box.

---
 lib/high-test.js | 20 +++++------
 lib/high.js      | 88 ++++++++++++++++--------------------------------
 2 files changed, 39 insertions(+), 69 deletions(-)

diff --git a/lib/high-test.js b/lib/high-test.js
index 4dfc837..01309de 100644
--- a/lib/high-test.js
+++ b/lib/high-test.js
@@ -65,16 +65,16 @@ screen.append(new blessed.List({
   left: 'center',
   selectedBg: 2,
   items: [
-    { content: 'one' },
-    { content: 'two' },
-    { content: 'three' },
-    { content: 'four' },
-    { content: 'five' },
-    { content: 'six' },
-    { content: 'seven' },
-    { content: 'eight' },
-    { content: 'nine' },
-    { content: 'ten' }
+    'one',
+    'two',
+    'three',
+    'four',
+    'five',
+    'six',
+    'seven',
+    'eight',
+    'nine',
+    'ten'
   ]
 }));
 
diff --git a/lib/high.js b/lib/high.js
index 2830938..f4b3b03 100644
--- a/lib/high.js
+++ b/lib/high.js
@@ -533,7 +533,8 @@ Text.prototype.render = function() {
     , attr
     , ch
     , ci = 0
-    , cl = this.content.length;
+    , cl = this.content.length
+    , ended = -1;
 
   if (this.position.width) {
     xl = xi + this.width;
@@ -547,11 +548,19 @@ Text.prototype.render = function() {
     xl = xi + this.parent.width - (this.parent.border ? 2 : 0) - this.rleft - this.rright;
   }
 
-  //if (this.parent.childOffset) {
-  //  yi -= this.parent.childOffset;
-  //}
+  if (this.parent.childBase != null && ~this.parent.items.indexOf(this)) {
+    var rtop = this.rtop - (this.parent.border ? 1 : 0)
+      , visible = this.parent.height - (this.parent.border ? 2 : 0);
 
-  var ended = -1;
+    yi -= this.parent.childBase;
+
+    if (rtop - this.parent.childBase < 0) {
+      return;
+    }
+    if (rtop - this.parent.childBase >= visible) {
+      return;
+    }
+  }
 
   for (; yi < yl; yi++) {
     for (xi = this.left; xi < xl; xi++) {
@@ -586,32 +595,11 @@ Text.prototype.render = function() {
 function ScrollableBox(options) {
   Box.call(this, options);
   this.childOffset = 0;
+  this.childBase = 0;
 }
 
 ScrollableBox.prototype.__proto__ = Box.prototype;
 
-ScrollableBox.prototype.scroll = function(offset) {
-  if (typeof offset === 'object') {
-    this.childOffset = this.children.indexOf(offset);
-    return;
-  }
-  this.childOffset += offset;
-  if (this.childOffset < 0) {
-    this.childOffset = 0;
-  } else if (this.childOffset > this.children.length - 1) {
-    this.childOffset = this.children.length - 1;
-  }
-};
-
-ScrollableBox.prototype._render = ScrollableBox.prototype.render;
-ScrollableBox.prototype.render = function() {
-  var children = this.children;
-  this.children = this.children.slice(this.childOffset,
-    this.childOffset + this.height - (this.border ? 1 : 0));
-  this._render();
-  this.children = children;
-};
-
 /**
  * List
  */
@@ -647,8 +635,8 @@ List.prototype.add = function(item) {
     parent: this,
     fg: this.fg,
     bg: this.bg,
-    content: item.content,
-    top: this.children.length + (this.border ? 1 : 0),
+    content: item.content || item,
+    top: this.items.length + (this.border ? 1 : 0),
     left: (this.border ? 1 : 0) + 1,
     full: true,
     height: 1
@@ -700,24 +688,20 @@ List.prototype.select = function(index) {
     this.items[index].underline = this.selectedUnderline;
   }
 
+  var diff = index - this.selected;
+  this.childOffset += diff;
+
   this.selected = index;
 
-  // Find the number of non-item children preceding the items.
-  var self = this;
-  var sawNon = false;
-  var children = this.children.filter(function(c, i) {
-    if (sawNon) return;
-    if (~self.items.indexOf(c)) {
-      sawNon = true;
-      return;
-    }
-    return !self.border || c.position.top > 0;
-  }).length;
-
-  //var height = this.height - (this.children.length - this.items.length);
-  var height = this.height - children;
-  if (this.selected >= height) {
-    this.scroll(this.selected - height);
+  var visible = this.height - (this.border ? 2 : 0);
+  if (this.childOffset > visible - 1) {
+    var d = this.childOffset - (visible - 1);
+    this.childOffset -= d;
+    this.childBase += d;
+  } else if (this.childOffset < 0) {
+    var d = this.childOffset;
+    this.childOffset += -d;
+    this.childBase += d;
   }
 };
 
@@ -733,20 +717,6 @@ List.prototype.down = function(offset) {
   this.move(offset || 1);
 };
 
-//List.prototype.remove = function(index) {
-//  if (typeof index === 'object') {
-//    index = this.children.indexOf(index);
-//  }
-//  this.children.splice(index, 1);
-//};
-
-/*
-List.prototype._render = List.prototype.render;
-List.prototype.render = function() {
-  this._render();
-};
-*/
-
 /**
  * Input
  */