Fix (scrollToIfNecessary) - Moving Up Past Top Bound Issues - #4411

src/js/core/factories/Grid.js

@@ -2292,8 +2292,8 @@ angular.module('ui.grid')
 
  /*-- Get the top, left, right, and bottom "scrolled" edges of the grid --*/
 
- // The top boundary is the current Y scroll position PLUS the header height, because the header can obscure rows when the grid is scrolled downwards
- var topBound = self.renderContainers.body.prevScrollTop + self.headerHeight;
+ // The top boundary is the current top Y scroll position.
+ var topBound = self.renderContainers.body.prevScrollTop;
 
  // Don't the let top boundary be less than 0
  topBound = (topBound < 0) ? 0 : topBound;
@@ -2327,33 +2327,32 @@ angular.module('ui.grid')
  var scrollLength = (self.renderContainers.body.getCanvasHeight() - self.renderContainers.body.getViewportHeight());
 
  // Add the height of the native horizontal scrollbar to the scroll length, if it's there. Otherwise it will mask over the final row
- //if (self.horizontalScrollbarHeight && self.horizontalScrollbarHeight > 0) {
- // scrollLength = scrollLength + self.horizontalScrollbarHeight;
- //}
+ if (self.renderContainers.body.grid.scrollbarHeight && self.renderContainers.body.grid.scrollbarHeight > 0) {
+ scrollLength = scrollLength + self.renderContainers.body.grid.scrollbarHeight;
+ }
 
  // This is the minimum amount of pixels we need to scroll vertical in order to see this row.
- var pixelsToSeeRow = ((seekRowIndex + 1) * self.options.rowHeight);
+ var pixelsToSeeRow = ((seekRowIndex) * self.options.rowHeight); 
 
  // Don't let the pixels required to see the row be less than zero
  pixelsToSeeRow = (pixelsToSeeRow < 0) ? 0 : pixelsToSeeRow;
+
+ // If we are moving downwards we need to add the pixels for the entire next row. 
+ var pixelsToSeeNextRow = pixelsToSeeRow + self.options.rowHeight;
 
  var scrollPixels, percentage;
 
  // If the scroll position we need to see the row is LESS than the top boundary, i.e. obscured above the top of the self...
  if (pixelsToSeeRow < topBound) {
- // Get the different between the top boundary and the required scroll position and subtract it from the current scroll position\
- // to get the full position we need
- scrollPixels = self.renderContainers.body.prevScrollTop - (topBound - pixelsToSeeRow);
-
  // Turn the scroll position into a percentage and make it an argument for a scroll event
- percentage = scrollPixels / scrollLength;
+ percentage = pixelsToSeeRow / scrollLength;
  scrollEvent.y = { percentage: percentage };
  }
  // Otherwise if the scroll position we need to see the row is MORE than the bottom boundary, i.e. obscured below the bottom of the self...
- else if (pixelsToSeeRow > bottomBound) {
+ else if (pixelsToSeeNextRow > bottomBound) {
  // Get the different between the bottom boundary and the required scroll position and add it to the current scroll position
  // to get the full position we need
- scrollPixels = pixelsToSeeRow - bottomBound + self.renderContainers.body.prevScrollTop;
+ scrollPixels = pixelsToSeeNextRow - bottomBound + self.renderContainers.body.prevScrollTop;
 
  // Turn the scroll position into a percentage and make it an argument for a scroll event
  percentage = scrollPixels / scrollLength;