Add support for row-header formatting (#149)

* add row-header conditional formatting support

* move cell renderer update call for row headers to _updateGridRenderers

Author: ibdafna

src/feathergrid.ts

@@ -220,6 +220,13 @@ export class FeatherGrid extends Widget {
       verticalAlignment: 'center',
     });
 
+    this._rowHeaderRenderer = new TextRenderer({
+      textColor: Theme.getFontColor(1),
+      backgroundColor: Theme.getBackgroundColor(2),
+      horizontalAlignment: 'center',
+      verticalAlignment: 'center'
+    });
+
     const layout = (this.layout = new PanelLayout());
     layout.addWidget(this.grid);
   }
@@ -495,14 +502,6 @@ export class FeatherGrid extends Widget {
       });
     }
 
-    const rowHeaderRenderer = new TextRenderer({
-      textColor: Theme.getFontColor(1),
-      backgroundColor: Theme.getBackgroundColor(2),
-      horizontalAlignment: 'center',
-      verticalAlignment: 'center',
-    });
-    this.grid.cellRenderers.update({ 'row-header': rowHeaderRenderer });
-
     const scrollShadow = {
       size: 4,
       color1: Theme.getBorderColor(1, 1.0),
@@ -751,15 +750,19 @@ export class FeatherGrid extends Widget {
    *
    * @param config - CellConfig for the cell to be rendered.
    */
-  private _rendererResolver(config: CellRenderer.CellConfig): CellRenderer {
-    const columnName: string = config.metadata['name'];
-    return this._renderers.hasOwnProperty(columnName)
-      ? this._renderers[columnName]
-      : this._defaultRenderer;
-  }
+    private _rendererResolver(config: CellRenderer.CellConfig): CellRenderer {
+      const columnName: string = config.metadata['name'];
+      const cellRegion: string = config['region'];
+      return this._renderers.hasOwnProperty(columnName)
+        ? this._renderers[columnName]
+        : cellRegion === 'row-header'
+          ? this._rowHeaderRenderer
+          : this._defaultRenderer;
+    }
 
   private _updateGridRenderers() {
     this.grid.cellRenderers.update({ body: this._rendererResolver.bind(this) });
+    this.grid.cellRenderers.update({ 'row-header': this._rendererResolver.bind(this) });
   }
 
   private _updateColumnWidths() {
@@ -938,6 +941,7 @@ export class FeatherGrid extends Widget {
   private _editable: boolean;
   private _renderers: Dict<CellRenderer> = {};
   private _defaultRenderer: CellRenderer;
+  private _rowHeaderRenderer: CellRenderer;
   private _defaultRendererSet = false;
   private _cellClicked = new Signal<this, FeatherGrid.ICellClickedEvent>(this);
   private _columnsResized = new Signal<this, void>(this);