fix: 🐛 ensure viewport height cannot be negative

Closes: #3034

Author: marcelo-portugal

packages/cellnav/test/uiGridCellNavService.spec.js

@@ -201,7 +201,7 @@ describe('ui.grid.edit uiGridCellNavService', function() {
 $timeout.flush();
 
 expect(args.grid).toEqual(grid);
-expect(Math.round(args.y.percentage * 10) / 10).toBe(0.4);
+expect(Math.round(args.y.percentage * 10) / 10).toBe(0.5);
 expect(isNaN(args.x.percentage)).toEqual(true);
 });
 
@@ -233,7 +233,7 @@ describe('ui.grid.edit uiGridCellNavService', function() {
 });
 $timeout.flush();
 
-expect(Math.round(args.y.percentage * 10) / 10).toEqual(0.5);
+expect(Math.round(args.y.percentage * 10) / 10).toEqual(0.6);
 expect(args.x).toBe(null);
 });
 

packages/core/src/js/factories/Grid.js

@@ -1685,7 +1685,7 @@ angular.module('ui.grid')
 
  // gridUtil.logDebug('viewPortHeight', viewPortHeight);
 
- return viewPortHeight;
+ return viewPortHeight > 0 ? viewPortHeight : 0;
  };
 
  Grid.prototype.getViewportWidth = function getViewportWidth() {

packages/core/src/js/factories/GridRenderContainer.js

@@ -229,7 +229,7 @@ angular.module('ui.grid')
 
  viewPortHeight = viewPortHeight + adjustment.height;
 
- return viewPortHeight;
+ return viewPortHeight > 0 ? viewPortHeight : 0;
  };
 
  GridRenderContainer.prototype.getViewportWidth = function getViewportWidth() {