Make scrollable elements selectable with hints.

Fixes #425.

Conflicts:
	content_scripts/scroller.coffee

2 files changed, 26 insertions, 12 deletions

diff --git a/content_scripts/link_hints.coffee b/content_scripts/link_hints.coffee
index 3088812b..994d99b5 100644
--- a/content_scripts/link_hints.coffee
+++ b/content_scripts/link_hints.coffee
@@ -190,6 +190,7 @@ LocalHints =
     isClickable = false
     onlyHasTabIndex = false
     visibleElements = []
+    reason = null
 
     # Insert area elements that provide click functionality to an img.
     if tagName == "img"
@@ -254,8 +255,15 @@ LocalHints =
       when "label"
         isClickable ||= element.control? and (@getVisibleClickable element.control).length == 0
       when "body"
-        isClickable ||= element == document.body and not document.hasFocus() and
-          window.innerWidth > 3 and window.innerHeight > 3
+        isClickable ||=
+          if element == document.body and not document.hasFocus() and
+              window.innerWidth > 3 and window.innerHeight > 3 and
+              document.body?.tagName.toLowerCase() != "frameset"
+            reason = "Frame."
+      when "div", "ol", "ul"
+        isClickable ||=
+          if Scroller.isScrollableElement element
+            reason = "Scroll."
 
     # Elements with tabindex are sometimes useful, but usually not. We can treat them as second class
     # citizens when it improves UX, so take special note of them.
@@ -267,7 +275,7 @@ LocalHints =
     if isClickable
       clientRect = DomUtils.getVisibleClientRect element, true
       if clientRect != null
-        visibleElements.push {element: element, rect: clientRect, secondClassCitizen: onlyHasTabIndex}
+        visibleElements.push {element: element, rect: clientRect, secondClassCitizen: onlyHasTabIndex, reason}
 
     visibleElements
 
@@ -313,7 +321,7 @@ LocalHints =
         # Subtract negativeRect from every rect in rects, and concatenate the arrays of rects that result.
         rects = [].concat (rects.map (rect) -> Rect.subtract rect, negativeRect)...
       if rects.length > 0
-        nonOverlappingElements.push {element: visibleElement.element, rect: rects[0]}
+        nonOverlappingElements.push extend visibleElement, rect: rects[0]
       else
         # Every part of the element is covered by some other element, so just insert the whole element's
         # rect. Except for elements with tabIndex set (second class citizens); these are often more trouble
@@ -325,7 +333,7 @@ LocalHints =
     hint.hasHref = hint.element.href? for hint in localHints
     if Settings.get "filterLinkHints"
       @withLabelMap (labelMap) =>
-        extend hint, @generateLinkText labelMap, hint.element for hint in localHints
+        extend hint, @generateLinkText labelMap, hint for hint in localHints
     localHints
 
   # Generate a map of input element => label text, call a callback with it.
@@ -342,7 +350,8 @@ LocalHints =
         labelMap[forElement] = labelText
     callback labelMap
 
-  generateLinkText: (labelMap, element) ->
+  generateLinkText: (labelMap, hint) ->
+    element = hint.element
     linkText = ""
     showLinkText = false
     # toLowerCase is necessary as html documents return "IMG" and xhtml documents return "img"
@@ -362,8 +371,8 @@ LocalHints =
         element.firstElementChild.nodeName.toLowerCase() == "img"
       linkText = element.firstElementChild.alt || element.firstElementChild.title
       showLinkText = true if linkText
-    else if element == document.body
-      linkText = "Frame."
+    else if hint.reason?
+      linkText = hint.reason
       showLinkText = true
     else
       linkText = (element.textContent.trim() || element.innerHTML.trim())[...512]
diff --git a/content_scripts/scroller.coffee b/content_scripts/scroller.coffee
index f83d0e87..7b46bab0 100644
--- a/content_scripts/scroller.coffee
+++ b/content_scripts/scroller.coffee
@@ -77,12 +77,14 @@ doesScroll = (element, direction, amount, factor) ->
   delta = getSign delta # 1 or -1
   performScroll(element, direction, delta) and performScroll(element, direction, -delta)
 
+isScrollableElement = (element, direction = "y", amount = 1, factor = 1) ->
+  doesScroll(element, direction, amount, factor) and shouldScroll element, direction
+
 # From element and its parents, find the first which we should scroll and which does scroll.
 findScrollableElement = (element, direction, amount, factor) ->
-  while element != document.body and
-    not (doesScroll(element, direction, amount, factor) and shouldScroll(element, direction))
-      element = (DomUtils.getContainingElement element) ? document.body
-  if element == document.body then firstScrollableElement element else element
+  while element != document.body and not isScrollableElement element, direction, amount, factor
+    element = DomUtils.getContainingElement(element) ? document.body
+  element
 
 # On some pages, document.body is not scrollable.  Here, we search the document for the largest visible
 # element which does scroll vertically. This is used to initialize activatedElement. See #1358.
@@ -257,6 +259,9 @@ Scroller =
     amount = getDimension(element,direction,pos) - element[scrollProperties[direction].axisName]
     CoreScroller.scroll element, direction, amount
 
+  isScrollableElement: (element) ->
+    isScrollableElement element
+
   # Scroll the top, bottom, left and right of element into view.  The is used by visual mode to ensure the
   # focus remains visible.
   scrollIntoView: (element) ->