feat: support keyboard shortcuts for all rows selection (#44)

Allows user to select all rows with keyboard `meta+a` or `ctrl+a`. This only selects rows which are currently available to the datatable and will not select rows which get loaded from server in future by user actions like scrolling/paging

Author: chintankavathia

projects/ngx-datatable/src/lib/components/body/body-row.component.ts

@@ -229,7 +229,9 @@ export class DataTableBodyRowComponent implements DoCheck {
       keyCode === Keys.left ||
       keyCode === Keys.right;
 
-    if (isAction && isTargetRow) {
+    const isCtrlA = event.key === 'a' && (event.ctrlKey || event.metaKey);
+
+    if ((isAction && isTargetRow) || isCtrlA) {
       event.preventDefault();
       event.stopPropagation();
 

projects/ngx-datatable/src/lib/components/body/selection.component.ts

@@ -42,6 +42,9 @@ export class DataTableSelectionComponent {
     if (multi || chkbox || multiClick) {
       if (event.shiftKey) {
         selected = selectRowsBetween([], this.rows, index, this.prevIndex, this.getRowSelectedIdx.bind(this));
+      } else if ((event as KeyboardEvent).key === 'a' && (event.ctrlKey || event.metaKey)) {
+        // select all rows except dummy rows which are added for ghostloader in case of virtual scroll
+        selected = this.rows.filter(rowItem => !!rowItem);
       } else if (event.ctrlKey || event.metaKey || multiClick || chkbox) {
         selected = selectRows([...this.selected], row, this.getRowSelectedIdx.bind(this));
       } else {
@@ -79,6 +82,8 @@ export class DataTableSelectionComponent {
     } else if (type === 'keydown') {
       if ((event as KeyboardEvent).keyCode === Keys.return) {
         this.selectRow(event, index, row);
+      } else if ((event as KeyboardEvent).key === 'a' && (event.ctrlKey || event.metaKey)) {
+        this.selectRow(event, 0, this.rows[this.rows.length - 1]);
       } else {
         this.onKeyboardFocus(model);
       }