Add commands to toggle left and right panel (eclipse-theia#15041)

This was already implemented for the bottom panel, but missing for the left and right panel.
This allows the user to add keybindings to easily show/hide all panels.

Signed-off-by: Simon Graband <sgraband@eclipsesource.com>

Author: sgraband

packages/core/src/browser/common-frontend-contribution.ts

@@ -253,6 +253,16 @@ export namespace CommonCommands {
         category: VIEW_CATEGORY,
         label: 'Toggle Bottom Panel'
     }, 'theia/core/common/collapseBottomPanel', VIEW_CATEGORY_KEY);
+    export const TOGGLE_LEFT_PANEL = Command.toLocalizedCommand({
+        id: 'core.toggle.left.panel',
+        category: VIEW_CATEGORY,
+        label: 'Toggle Left Panel'
+    }, 'theia/core/common/collapseLeftPanel', VIEW_CATEGORY_KEY);
+    export const TOGGLE_RIGHT_PANEL = Command.toLocalizedCommand({
+        id: 'core.toggle.right.panel',
+        category: VIEW_CATEGORY,
+        label: 'Toggle Right Panel'
+    }, 'theia/core/common/collapseRightPanel', VIEW_CATEGORY_KEY);
     export const TOGGLE_STATUS_BAR = Command.toDefaultLocalizedCommand({
         id: 'workbench.action.toggleStatusbarVisibility',
         category: VIEW_CATEGORY,
@@ -955,6 +965,26 @@ export class CommonFrontendContribution implements FrontendApplicationContributi
                 }
             }
         });
+        commandRegistry.registerCommand(CommonCommands.TOGGLE_LEFT_PANEL, {
+            isEnabled: () => this.shell.getWidgets('left').length > 0,
+            execute: () => {
+                if (this.shell.isExpanded('left')) {
+                    this.shell.collapsePanel('left');
+                } else {
+                    this.shell.expandPanel('left');
+                }
+            }
+        });
+        commandRegistry.registerCommand(CommonCommands.TOGGLE_RIGHT_PANEL, {
+            isEnabled: () => this.shell.getWidgets('right').length > 0,
+            execute: () => {
+                if (this.shell.isExpanded('right')) {
+                    this.shell.collapsePanel('right');
+                } else {
+                    this.shell.expandPanel('right');
+                }
+            }
+        });
         commandRegistry.registerCommand(CommonCommands.TOGGLE_STATUS_BAR, {
             execute: () => this.preferenceService.updateValue('workbench.statusBar.visible', !this.preferences['workbench.statusBar.visible'])
         });