Fix getVisibleElements helper in RTL-locales

mozilla · Oct 9, 2020 · 8e43606 · 8e43606
1 parent 88f72d6
commit 8e43606
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Showing 2 changed files with 15 additions and 7 deletions.
diff --git a/web/base_viewer.js b/web/base_viewer.js
@@ -1006,6 +1006,10 @@ class BaseViewer {
       : this._scrollMode === ScrollMode.HORIZONTAL;
   }
 
+  get _isDirRtl() {
+    return this.container.ownerDocument.dir === "rtl";
+  }
+
   get isInPresentationMode() {
     return this.presentationModeState === PresentationModeState.FULLSCREEN;
   }
@@ -1055,7 +1059,8 @@ class BaseViewer {
       this.container,
       this._pages,
       true,
-      this._isScrollModeHorizontal
+      this._isScrollModeHorizontal,
+      this._isDirRtl
     );
   }
 

diff --git a/web/ui_utils.js b/web/ui_utils.js
@@ -442,7 +442,8 @@ function getVisibleElements(
   scrollEl,
   views,
   sortByVisibility = false,
-  horizontal = false
+  horizontal = false,
+  rtl = false
 ) {
   const top = scrollEl.scrollTop,
     bottom = top + scrollEl.clientHeight;
@@ -465,11 +466,11 @@ function getVisibleElements(
       element.offsetTop + element.clientTop + element.clientHeight;
     return elementBottom > top;
   }
-  function isElementRightAfterViewLeft(view) {
+  function isElementNextAfterViewHorizontally(view) {
     const element = view.div;
-    const elementRight =
-      element.offsetLeft + element.clientLeft + element.clientWidth;
-    return elementRight > left;
+    const elementLeft = element.offsetLeft + element.clientLeft;
+    const elementRight = elementLeft + element.clientWidth;
+    return rtl ? elementLeft < right : elementRight > left;
   }
 
   const visible = [],
@@ -479,7 +480,9 @@ function getVisibleElements(
       ? 0
       : binarySearchFirstItem(
           views,
-          horizontal ? isElementRightAfterViewLeft : isElementBottomAfterViewTop
+          horizontal
+            ? isElementNextAfterViewHorizontally
+            : isElementBottomAfterViewTop
         );
 
   // Please note the return value of the `binarySearchFirstItem` function when