Merge pull request #100 from readium/feature/prev-next-button-visibil…

…ity-lars Split apart @larsvoigt's work that adds support for next/previous button...
readium · Aug 27, 2014 · f7eace5 · danielweck · Sep 1, 2014 · danielweck
2 parents a592f34 + efe8414
commit f7eace5
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Showing 4 changed files with 45 additions and 6 deletions.
diff --git a/js/models/current_pages_info.js b/js/models/current_pages_info.js
@@ -30,17 +30,17 @@ Used to report pagination state back to the host application
 
 @constructor
 
-@param {Number} spineItemCount Number of spine items
+@param {ReadiumSDK.Models.Spine} spine
 @param {boolean} isFixedLayout is fixed or reflowable spine item
 @param {string} pageProgressionDirection ltr | rtl
 */
 
-ReadiumSDK.Models.CurrentPagesInfo = function(spineItemCount, isFixedLayout, pageProgressionDirection) {
+ReadiumSDK.Models.CurrentPagesInfo = function(spine, isFixedLayout) {
 
 
-    this.pageProgressionDirection = pageProgressionDirection;
+    this.isRightToLeft = spine.direction == "rtl";
     this.isFixedLayout = isFixedLayout;
-    this.spineItemCount = spineItemCount;
+    this.spineItemCount = spine.items.length
     this.openPages = [];
 
     this.addOpenPage = function(spineItemPageIndex, spineItemPageCount, idref, spineItemIndex) {
@@ -49,6 +49,40 @@ ReadiumSDK.Models.CurrentPagesInfo = function(spineItemCount, isFixedLayout, pag
         this.sort();
     };
 
+    this.canGoLeft = function () {
+        return this.isRightToLeft ? this.canGoNext() : this.canGoPrev();
+    };
+
+    this.canGoRight = function () {
+        return this.isRightToLeft ? this.canGoPrev() : this.canGoNext();
+    };
+
+    this.canGoNext = function() {
+
+        if(this.openPages.length == 0)
+            return false;
+
+        var lastOpenPage = this.openPages[this.openPages.length - 1];
+
+        if(!spine.isValidLinearItem(lastOpenPage.spineItemIndex))
+            return false;
+
+        return lastOpenPage.spineItemIndex < spine.last().index || lastOpenPage.spineItemPageIndex < lastOpenPage.spineItemPageCount - 1;
+    };
+
+    this.canGoPrev = function() {
+
+        if(this.openPages.length == 0)
+            return false;
+
+        var firstOpenPage = this.openPages[0];
+
+        if(!spine.isValidLinearItem(firstOpenPage.spineItemIndex))
+            return false;
+
+        return spine.first().index < firstOpenPage.spineItemIndex || 0 < firstOpenPage.spineItemPageIndex;
+    };
+
     this.sort = function() {
 
         this.openPages.sort(function(a, b) {

diff --git a/js/models/spine.js b/js/models/spine.js
@@ -64,6 +64,11 @@ ReadiumSDK.Models.Spine = function(epubPackage, spineDTO) {
         return !_handleLinear || item.linear !== "no";
     }
 
+
+    this.isValidLinearItem = function(index) {
+        return isValidLinearItem(this.item(index));
+    };
+
     this.prevItem = function(item) {
 
         return lookForPrevValidItem(item.index - 1);

diff --git a/js/views/fixed_view.js b/js/views/fixed_view.js
@@ -519,7 +519,7 @@ ReadiumSDK.Views.FixedView = function(options, reader){
 
     this.getPaginationInfo = function() {
 
-        var paginationInfo = new ReadiumSDK.Models.CurrentPagesInfo(_spine.items.length, true, _spine.direction);
+        var paginationInfo = new ReadiumSDK.Models.CurrentPagesInfo(_spine, true);
 
         var spreadItems = [_spread.leftItem, _spread.rightItem, _spread.centerItem];
 

diff --git a/js/views/reflowable_view.js b/js/views/reflowable_view.js
@@ -701,7 +701,7 @@ ReadiumSDK.Views.ReflowableView = function(options, reader){
 
     this.getPaginationInfo = function() {
 
-        var paginationInfo = new ReadiumSDK.Models.CurrentPagesInfo(_spine.items.length, false, _spine.direction);
+        var paginationInfo = new ReadiumSDK.Models.CurrentPagesInfo(_spine, false);
 
         if(!_currentSpineItem) {
             return paginationInfo;