Feature/no slide looping

README.md

@@ -272,6 +272,8 @@ To navigate the slideshow:
 
 * **forward**: K, L, UP, RIGHT, PgDn, and Space
 * **reverse**: H, J, LEFT, DOWN, PgUp, and Backspace
+* **first slide**: Home
+* **last slide**: End
 
 The toggle fullscreen mode, press the **ENTER** key.
 

docs/options.md

@@ -82,6 +82,13 @@ Displays a small progress bar at the top of your document.
 
 **Default**: true
 
+### loop
+
+Allows looping from the last slide to the first, or backwards from the first to
+the last.
+
+**Default**: true
+
 ### encoding
 
 Content encoding to use on the rendered document.

lib/index.js

@@ -211,6 +211,7 @@ Cleaver.prototype.loadStaticAssets = function () {
 Cleaver.prototype.renderSlideshow = function () {
   var putControls = this.options.controls || (this.options.controls === undefined);
   var putProgress = this.options.progress || (this.options.progress === undefined);
+  var allowLooping = this.options.loop || (this.options.loop === undefined);
   var style, script, output;
 
   // Render the slides in a template (maybe as specified by the user)
@@ -253,6 +254,7 @@ Cleaver.prototype.renderSlideshow = function () {
     style: style,
     author: this.options.author,
     script: script,
+    allowLooping: allowLooping,
     options: this.options
   };
 

resources/script.js

@@ -5,6 +5,23 @@ function currentPosition() {
   return parseInt(document.querySelector('.slide:not(.hidden)').id.slice(6));
 }
 
+/**
+ * If passed to navigate, will move to the first slide, independent of the
+ * current location, rather than a relative amount.
+ */
+var FIRST_SLIDE = -9999999;
+
+/**
+ * If passed to navigate, will move to the last slide, independent of the
+ * current location, rather than a relative amount.
+ */
+var LAST_SLIDE = 9999999;
+
+/**
+ * Whether to allow looping from the last back to the first or backwards from
+ * the first to the last.
+ */
+var ALLOW_LOOPING = true;
 
 /**
  * Navigates forward n pages
@@ -13,12 +30,27 @@ function currentPosition() {
 function navigate(n) {
   var position = currentPosition();
   var numSlides = document.getElementsByClassName('slide').length;
-
-  /* Positions are 1-indexed, so we need to add and subtract 1 */
-  var nextPosition = (position - 1 + n) % numSlides + 1;
-
-  /* Normalize nextPosition in-case of a negative modulo result */
-  nextPosition = (nextPosition - 1 + numSlides) % numSlides + 1;
+  var nextPosition;
+  if (n === FIRST_SLIDE) {
+      nextPosition = 1;
+  } else if (n === LAST_SLIDE) {
+      nextPosition = numSlides;
+  } else {
+      if (! ALLOW_LOOPING) {
+          if (n < 0 && position <= 1) {
+            return;
+          }
+          if (n > 0 && position >= numSlides) {
+            return;
+          }
+      }
+
+      /* Positions are 1-indexed, so we need to add and subtract 1 */
+      nextPosition = (position - 1 + n) % numSlides + 1;
+
+      /* Normalize nextPosition in-case of a negative modulo result */
+      nextPosition = (nextPosition - 1 + numSlides) % numSlides + 1;
+  }
 
   document.getElementById('slide-' + position).classList.add('hidden');
   document.getElementById('slide-' + nextPosition).classList.remove('hidden');
@@ -130,6 +162,10 @@ document.addEventListener('DOMContentLoaded', function () {
       navigate(-1);
     } else if (kc === 38 || kc === 39 || kc === 32 || kc === 75 || kc === 76 || kc === 34) {
       navigate(1);
+    } else if (kc === 36) {
+      navigate(FIRST_SLIDE);
+    } else if (kc === 35) {
+      navigate(LAST_SLIDE);
     } else if (kc === 13) {
       toggleFullScreen();
     }

templates/layout.mustache

@@ -16,6 +16,7 @@
 
   <script type="text/javascript">
     {{{script}}}
+    ALLOW_LOOPING = {{#allowLooping}}true{{/allowLooping}}{{^allowLooping}}false{{/allowLooping}};
   </script>
 </body>
 </html>