Skip fold placeholders when moving right

This relies on a new `eagerWrap` option to clipScreenPosition which
will wrap positions inside of atomic line fragments (which is what fold
placeholders are) to the end of the fragment rather than the beginning.
It also wraps positions beyond the end of a hard line to the next line,
which means Cursor.moveRight just has to increment the column, then
call clipPosition with eager wrap set to true to get all the correct
behavior.

src/atom/cursor.coffee

@@ -77,12 +77,7 @@ class Cursor extends View
 
   moveRight: ->
     { row, column } = @getScreenPosition()
-    if column < @editor.buffer.getLine(row).length
-      column++
-    else if row < @editor.buffer.numLines() - 1
-      row++
-      column = 0
-    @setScreenPosition({row, column})
+    @setScreenPosition(@editor.clipScreenPosition([row, column + 1], true))
 
   moveLeft: ->
     { row, column } = @getScreenPosition()

src/atom/editor.coffee

@@ -211,8 +211,8 @@ class Editor extends View
     else
       $(window).off 'resize', @_setMaxLineLength
 
-  clipScreenPosition: (screenPosition) ->
-    @lineWrapper.clipScreenPosition(screenPosition)
+  clipScreenPosition: (screenPosition, eagerWrap=false) ->
+    @lineWrapper.clipScreenPosition(screenPosition, eagerWrap)
 
   pixelPositionForScreenPosition: ({row, column}) ->
     { top: row * @lineHeight, left: column * @charWidth }

src/atom/line-folder.coffee

@@ -134,8 +134,8 @@ class LineFolder
   bufferPositionForScreenPosition: (screenPosition) ->
     @lineMap.bufferPositionForScreenPosition(screenPosition)
 
-  clipScreenPosition: (screenPosition) ->
-    @lineMap.clipScreenPosition(screenPosition)
+  clipScreenPosition: (screenPosition, eagerWrap=false) ->
+    @lineMap.clipScreenPosition(screenPosition, eagerWrap)
 
   screenRangeForBufferRange: (bufferRange) ->
     @lineMap.screenRangeForBufferRange(bufferRange)

src/atom/line-map.coffee

@@ -141,10 +141,9 @@ class LineMap
     end = @bufferPositionForScreenPosition(screenRange.end)
     new Range(start, end)
 
-  clipScreenPosition: (screenPosition) ->
+  clipScreenPosition: (screenPosition, eagerWrap) ->
     screenPosition = Point.fromObject(screenPosition)
 
-    debugger if screenPosition.isEqual [7,4]
     screenPosition = new Point(Math.max(0, screenPosition.row), Math.max(0, screenPosition.column))
     maxRow = @lastScreenRow()
     if screenPosition.row > maxRow
@@ -157,8 +156,17 @@ class LineMap
       break if nextDelta.isGreaterThan(screenPosition)
       screenDelta = nextDelta
 
-    maxColumn = screenDelta.column + screenLine.lengthForClipping()
-    screenDelta.column = Math.min(maxColumn, screenPosition.column)
+    if screenLine.isAtomic
+      if eagerWrap and screenPosition.column > screenDelta.column
+        screenDelta.column = screenDelta.column + screenLine.text.length
+    else
+      maxColumn = screenDelta.column + screenLine.text.length
+      if eagerWrap and screenPosition.column > maxColumn
+        screenDelta.row++
+        screenDelta.column = 0
+      else
+        screenDelta.column = Math.min(maxColumn, screenPosition.column)
+
     screenDelta
 
   logLines: (start=0, end=@screenLineCount() - 1)->

src/atom/line-wrapper.coffee

@@ -93,11 +93,15 @@ class LineWrapper
     @lineFolder.bufferRangeForScreenRange(
       @lineMap.bufferRangeForScreenRange(screenRange))
 
-  clipScreenPosition: (screenPosition) ->
+  clipScreenPosition: (screenPosition, eagerWrap=false) ->
     @lineMap.screenPositionForBufferPosition(
       @lineFolder.clipScreenPosition(
         @lineMap.bufferPositionForScreenPosition(
-          @lineMap.clipScreenPosition(screenPosition))))
+          @lineMap.clipScreenPosition(screenPosition, eagerWrap)
+        ),
+        eagerWrap
+      )
+    )
 
   lineForScreenRow: (screenRow) ->
     @linesForScreenRows(screenRow, screenRow)[0]