do not recalculate hidden column widths

Author: dgodinez-dh

packages/grid/src/GridMetricCalculator.ts

@@ -1710,6 +1710,13 @@ export class GridMetricCalculator {
       return columnWidth;
     }
 
+    const cachedValue = this.calculatedColumnWidths.get(modelColumn);
+
+    // Performance optimization: if the column is hidden and has a cached value, avoid recalculating until the column is shown again
+    if (cachedValue != null && this.isColumnHidden(modelColumn)) {
+      return cachedValue;
+    }
+
     const headerWidth = this.calculateColumnHeaderWidth(
       modelColumn,
       state,
@@ -1720,7 +1727,6 @@ export class GridMetricCalculator {
       state,
       maxColumnWidth
     );
-    const cachedValue = this.calculatedColumnWidths.get(modelColumn);
     let columnWidth = Math.ceil(Math.max(headerWidth, dataWidth));
     columnWidth = Math.max(minColumnWidth, columnWidth);
     columnWidth = Math.min(maxColumnWidth, columnWidth);
@@ -1741,6 +1747,21 @@ export class GridMetricCalculator {
     return columnWidth;
   }
 
+  /**
+   * Checks if a column is hidden either by a user setting the width to 0 or by initial width being 0
+   * @param modelIndex the model index of the column to check
+   * @returns true if the column is hidden, false otherwise
+   */
+  isColumnHidden(modelIndex: ModelIndex): boolean {
+    const userSetWidth = this.userColumnWidths.get(modelIndex);
+    // The column is hidden if the user set the width to 0 or if the initial width is 0 and the user hasn't set a width
+    return (
+      userSetWidth === 0 ||
+      (userSetWidth === undefined &&
+        this.initialColumnWidths.get(modelIndex) === 0)
+    );
+  }
+
   /**
    * Calculate the width of the specified column's header
    * @param modelColumn ModelIndex of the column to get the header width for