chore(*): Adjust some styles for row selection.

Author: MKirova

projects/igniteui-angular/src/lib/core/styles/components/grid/_grid-theme.scss

@@ -1825,6 +1825,20 @@
         color: var-get($theme, 'row-selected-text-color');
         background: var-get($theme, 'row-selected-background');
 
+        &%grid-row--mrl {
+            background: transparent;
+            %grid-mrl-block {
+                color: var-get($theme, 'row-selected-text-color');
+                background: var-get($theme, 'row-selected-background');
+                %igx-grid__td--merged {
+                    color: var-get($theme, 'row-selected-text-color');
+                    background: var-get($theme, 'row-selected-background');
+                }
+            }
+        }
+
+
+
         %grid-cell--selected,
         %grid-cell--pinned-selected {
             color: var-get($theme, 'cell-selected-within-text-color');

src/app/grid-cellMerging/grid-cellMerging.component.html

@@ -1,5 +1,5 @@
 <h4 class="sample-title">Grid with cell merge</h4>
-<igx-grid [data]="data" width="800px" height="550px" [primaryKey]="'ProductID'" [moving]="true" [cellMergeMode]="'always'" >
+<igx-grid [data]="data" width="800px" height="550px" [primaryKey]="'ProductID'" [moving]="true" [cellMergeMode]="'always'" [rowSelection]="'single'" >
     <igx-column field="ProductID" header="Product ID" width="200px">
         <ng-template igxCell let-cell="cell" let-val>
         <div>