Merge branch 'scroll_work'

kevinansfield · Mar 25, 2013 · 4cc1b88 · 4cc1b88
2 parents 988a712 + ae2cfa3
commit 4cc1b88
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Showing 4 changed files with 158 additions and 148 deletions.
diff --git a/app/assets/javascripts/discourse/components/eyeline.js b/app/assets/javascripts/discourse/components/eyeline.js
@@ -14,7 +14,91 @@
 **/
 Discourse.Eyeline = function Eyeline(selector) {
   this.selector = selector;
-}
+};
+
+
+/**
+  Call this to analyze the positions of all the nodes in a set 
+
+  returns: a hash with top, bottom and onScreen items 
+          {top: , bottom:, onScreen:}
+ **/
+Discourse.Eyeline.analyze = function(rows) {
+  var current, goingUp, i, increment, offset, 
+      winHeight, winOffset, detected, onScreen,
+      bottom, top, outerHeight;
+
+  if (rows.length === 0) return;
+
+  i = parseInt(rows.length / 2, 10);
+  increment = parseInt(rows.length / 4, 10);
+  goingUp = undefined;
+  winOffset = window.pageYOffset || $('html').scrollTop();
+  winHeight = window.innerHeight || $(window).height();
+
+  while (true) {
+    if (i === 0 || (i >= rows.length - 1)) {
+      break;
+    }
+    current = $(rows[i]);
+    offset = current.offset();
+
+    if (offset.top - winHeight < winOffset) {
+      if (offset.top + current.outerHeight() - window.innerHeight > winOffset) {
+        break;
+      } else {
+        i = i + increment;
+        if (goingUp !== undefined && increment === 1 && !goingUp) {
+          break;
+        }
+        goingUp = true;
+      }
+    } else {
+      i = i - increment;
+      if (goingUp !== undefined && increment === 1 && goingUp) {
+        break;
+      }
+      goingUp = false;
+    }
+    if (increment > 1) {
+      increment = parseInt(increment / 2, 10);
+      goingUp = undefined;
+    }
+    if (increment === 0) {
+      increment = 1;
+      goingUp = undefined;
+    }
+  }
+
+  onScreen = [];
+  bottom = i;
+  // quick analysis of whats on screen
+  while(true) {
+    if(i < 0) { break;}
+
+    current = $(rows[i]);
+    offset = current.offset();
+    outerHeight = current.outerHeight();
+
+    // on screen
+    if(offset.top > winOffset && offset.top + outerHeight < winOffset + winHeight) {
+      onScreen.unshift(i);
+    } else {
+
+      if(offset.top < winOffset) {
+        top = i;
+        break;
+      } else {
+        // bottom
+      }
+    }
+    i -=1;
+  }
+
+  return({top: top, bottom: bottom, onScreen: onScreen});
+
+};
+
 
 /**
   Call this whenever you want to consider what is being seen by the browser
@@ -25,9 +109,6 @@ Discourse.Eyeline.prototype.update = function() {
   var $elements, atBottom, bottomOffset, docViewBottom, docViewTop, documentHeight, foundElement, windowHeight,
     _this = this;
 
-  // before anything ... let us not do anything if we have no focus
-  if (!Discourse.get('hasFocus')) { return; }
-
   docViewTop = $(window).scrollTop();
   windowHeight = $(window).height();
   docViewBottom = docViewTop + windowHeight;

diff --git a/app/assets/javascripts/discourse/components/screen_track.js b/app/assets/javascripts/discourse/components/screen_track.js
@@ -138,6 +138,9 @@ Discourse.ScreenTrack = Ember.Object.extend({
     this.topicTime += diff;
     docViewTop = $(window).scrollTop() + $('header').height();
     docViewBottom = docViewTop + $(window).height();
+
+    // TODO: Eyeline has a smarter more accurate function here
+
     return Object.keys(this.timings, function(id) {
       var $element, elemBottom, elemTop, timing;
       $element = $(id);

diff --git a/app/assets/javascripts/discourse/mixins/scrolling.js b/app/assets/javascripts/discourse/mixins/scrolling.js
@@ -10,14 +10,23 @@
 Discourse.Scrolling = Em.Mixin.create({
 
   /**
-    Begin watching for scroll events. They will be called at max every 100ms.
+    Begin watching for scroll events. By default they will be called at max every 100ms.
+    call with {debounce: N} for a diff time
 
     @method bindScrolling
   */
-  bindScrolling: function() {
+  bindScrolling: function(opts) {
     var onScroll,
       _this = this;
-    onScroll = Discourse.debounce(function() { return _this.scrolled(); }, 100);
+
+    opts = opts || {debounce: 100};
+
+    if (opts.debounce) {
+      onScroll = Discourse.debounce(function() { return _this.scrolled(); }, 100);
+    } else {
+      onScroll = function(){ return _this.scrolled(); };
+    }
+
     $(document).bind('touchmove.discourse', onScroll);
     $(window).bind('scroll.discourse', onScroll);
   },