Do not dispose dialogs on close

CHANGELOG.md

@@ -5,6 +5,8 @@
 - [Previous Changelogs](https://github.com/eclipse-theia/theia/tree/master/doc/changelogs/)
 
 <!-- ## 1.56.0 - not yet released -->
+<a name="breaking_changes_1.56.0">[Breaking Changes:](#breaking_changes_1.56.0)</a>
+- [core] Do not dispose dialogs on close - [#14456](https://github.com/eclipse-theia/theia/pull/14456) - Contributed on behalf of STMicroelectronics 
 
 ## 1.55.0 - 10/31/2024
 

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

@@ -1199,7 +1199,7 @@ export class CommonFrontendContribution implements FrontendApplicationContributi
     }
 
     protected async openAbout(): Promise<void> {
-        this.aboutDialog.open();
+        this.aboutDialog.open(false);
     }
 
     protected shouldPreventClose = false;

packages/core/src/browser/dialogs.ts

@@ -258,13 +258,15 @@ export abstract class AbstractDialog<T> extends BaseWidget {
         }
     }
 
-    open(): Promise<T | undefined> {
+    open(disposeOnResolve: boolean = true): Promise<T | undefined> {
         if (this.resolve) {
             return Promise.reject(new Error('The dialog is already opened.'));
         }
         this.activeElement = this.node.ownerDocument.activeElement as HTMLElement;
         return new Promise<T | undefined>((resolve, reject) => {
-            this.resolve = resolve;
+            this.resolve = value => {
+                resolve(value);
+            };
             this.reject = reject;
             this.toDisposeOnDetach.push(Disposable.create(() => {
                 this.resolve = undefined;
@@ -273,9 +275,23 @@ export abstract class AbstractDialog<T> extends BaseWidget {
 
             Widget.attach(this, this.node.ownerDocument.body);
             this.activate();
+        }).finally(() => {
+            if (disposeOnResolve) {
+                this.dispose();
+            }
         });
     }
 
+    protected override onCloseRequest(msg: Message): void {
+        // super.onCloseRequest() would automatically dispose the dialog, which we don't want because we're reusing it
+        if (this.parent) {
+            // eslint-disable-next-line no-null/no-null
+            this.parent = null;
+        } else if (this.isAttached) {
+            Widget.detach(this);
+        }
+    }
+
     override close(): void {
         if (this.resolve) {
             if (this.activeElement) {