From 425b1e86047b9adb7f7f8383b345ecaa519f0cfb Mon Sep 17 00:00:00 2001
From: Colin Grant <colin.grant@ericsson.com>
Date: Wed, 1 Dec 2021 01:01:19 +0100
Subject: [PATCH] update UI if user cancels

---
 .../abstract-resource-preference-provider.ts     | 16 +++++++++++-----
 .../views/components/preference-node-renderer.ts | 14 +++++++++++++-
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/packages/preferences/src/browser/abstract-resource-preference-provider.ts b/packages/preferences/src/browser/abstract-resource-preference-provider.ts
index 2e2637412e09a..3ab08079a4b6d 100644
--- a/packages/preferences/src/browser/abstract-resource-preference-provider.ts
+++ b/packages/preferences/src/browser/abstract-resource-preference-provider.ts
@@ -30,7 +30,7 @@ import { MonacoEditorModel } from '@theia/monaco/lib/browser/monaco-editor-model
 import { MonacoWorkspace } from '@theia/monaco/lib/browser/monaco-workspace';
 import { Deferred } from '@theia/core/lib/common/promise-util';
 import { FileService } from '@theia/filesystem/lib/browser/file-service';
-import { nls } from '@theia/core';
+import { CancellationError, nls } from '@theia/core';
 import { EditorManager } from '@theia/editor/lib/browser';
 
 export interface FilePreferenceProviderLocks {
@@ -141,14 +141,14 @@ export abstract class AbstractResourcePreferenceProvider extends PreferenceProvi
                 return false;
             }
             if (!locks) { // Action cancelled by user. Consider it complete.
-                return true;
+                throw new CancellationError();
             }
             if (shouldSave) {
                 if (this.model.dirty) {
                     shouldSave = await this.handleDirtyEditor();
                 }
-                if (!shouldSave) { // Action cancelled by user. Consider it complete.
-                    return true;
+                if (!shouldSave) {
+                    throw new CancellationError();
                 }
             }
             const editOperations = this.getEditOperations(path, value);
@@ -157,6 +157,9 @@ export abstract class AbstractResourcePreferenceProvider extends PreferenceProvi
             }
             return this.pendingTransaction.promise;
         } catch (e) {
+            if (e instanceof CancellationError) {
+                throw e;
+            }
             const message = `Failed to update the value of '${key}' in '${this.getUri()}'.`;
             this.messageService.error(`${message} Please check if it is corrupted.`);
             console.error(`${message}`, e);
@@ -203,6 +206,7 @@ export abstract class AbstractResourcePreferenceProvider extends PreferenceProvi
             } else { // User cancelled the operation.
                 this.singleChangeLock.cancel();
                 locks.releaseTransaction!();
+                this.pendingTransaction.resolve(false);
             }
         }
         locks?.releaseChange();
@@ -342,7 +346,9 @@ export abstract class AbstractResourcePreferenceProvider extends PreferenceProvi
         const saveAndRetry = nls.localizeByDefault('Save and Retry');
         const open = nls.localizeByDefault('Open File');
         const msg = await this.messageService.error(
-            nls.localizeByDefault('Unable to write preference change because the settings file is dirty. Please save the file and try again.'),
+            nls.localizeByDefault('Unable to write into {0} settings because the file has unsaved changes. Please save the {0} settings file first and then try again.',
+                nls.localizeByDefault(PreferenceScope[this.getScope()].toLocaleLowerCase())
+            ),
             saveAndRetry, open);
 
         if (this.model) {
diff --git a/packages/preferences/src/browser/views/components/preference-node-renderer.ts b/packages/preferences/src/browser/views/components/preference-node-renderer.ts
index 46453e91448b4..9c3e821da5ab5 100644
--- a/packages/preferences/src/browser/views/components/preference-node-renderer.ts
+++ b/packages/preferences/src/browser/views/components/preference-node-renderer.ts
@@ -403,7 +403,8 @@ export abstract class PreferenceLeafNodeRenderer<ValueType extends JSONValue, In
     protected setPreferenceWithDebounce = debounce(this.setPreferenceImmediately.bind(this), 500, { leading: false, trailing: true });
 
     protected setPreferenceImmediately(value: ValueType | undefined): Promise<void> {
-        return this.preferenceService.set(this.id, value, this.scopeTracker.currentScope.scope, this.scopeTracker.currentScope.uri);
+        return this.preferenceService.set(this.id, value, this.scopeTracker.currentScope.scope, this.scopeTracker.currentScope.uri)
+            .catch(() => this.handleValueChange());
     }
 
     handleSearchChange(isFiltered = this.model.isFiltered): void {
@@ -420,7 +421,18 @@ export abstract class PreferenceLeafNodeRenderer<ValueType extends JSONValue, In
         this.updateHeadline();
     }
 
+    /**
+     * Should create an HTML element that the user can interact with to change the value of the preference.
+     * @param container the parent element for the interactable. This method is responsible for adding the new element to its parent.
+     */
     protected abstract createInteractable(container: HTMLElement): void;
+    /**
+     * @returns a fallback default value for a preference of the type implemented by a concrete leaf renderer
+     * This function is only called if the default value for a given preference is not specified in its schema.
+     */
     protected abstract getFallbackValue(): ValueType;
+    /**
+     * This function is responsible for reconciling the display of the preference value with the value reported by the PreferenceService.
+     */
     protected abstract doHandleValueChange(): void;
 }