[markers] Sync problem markers with active editor

Fixes: eclipse-theia#7436

Reveals and expands the markers for the active editor.
Added a preference `problems.autoReveal` to control this behavior.

Signed-off-by: Muhammad Anas Shahid <muhammad.shahid@ericsson.com>

packages/markers/src/browser/problem/problem-preferences.ts

@@ -29,13 +29,19 @@ export const ProblemConfigSchema: PreferenceSchema = {
             'type': 'boolean',
             'description': 'Show problem decorators (diagnostic markers) in the tab bars.',
             'default': true
+        },
+        'problems.autoReveal': {
+            'type': 'boolean',
+            'description': 'Controls whether Problems view should reveal markers when file is opened.',
+            'default': true
         }
     }
 };
 
 export interface ProblemConfiguration {
     'problems.decorations.enabled': boolean,
-    'problems.decorations.tabbar.enabled': boolean
+    'problems.decorations.tabbar.enabled': boolean,
+    'problems.autoReveal': boolean
 }
 
 export const ProblemPreferences = Symbol('ProblemPreferences');

packages/markers/src/browser/problem/problem-widget.tsx

@@ -14,20 +14,33 @@
  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  ********************************************************************************/
 
-import { injectable, inject } from 'inversify';
+import { injectable, inject, postConstruct } from 'inversify';
 import { ProblemManager } from './problem-manager';
 import { ProblemMarker } from '../../common/problem-marker';
 import { ProblemTreeModel } from './problem-tree-model';
 import { MarkerInfoNode, MarkerNode, MarkerRootNode } from '../marker-tree';
-import { TreeWidget, TreeProps, ContextMenuRenderer, TreeNode, NodeProps, TreeModel } from '@theia/core/lib/browser';
+import {
+    TreeWidget, TreeProps, ContextMenuRenderer, TreeNode, NodeProps, TreeModel,
+    ApplicationShell, Navigatable, ExpandableTreeNode, SelectableTreeNode
+} from '@theia/core/lib/browser';
 import { DiagnosticSeverity } from 'vscode-languageserver-types';
 import * as React from 'react';
+import { ProblemPreferences } from './problem-preferences';
+import { DisposableCollection } from '@theia/core/lib/common/disposable';
 
 export const PROBLEMS_WIDGET_ID = 'problems';
 
 @injectable()
 export class ProblemWidget extends TreeWidget {
 
+    protected readonly toDisposeOnCurrentWidgetChanged = new DisposableCollection();
+
+    @inject(ProblemPreferences)
+    protected readonly preferences: ProblemPreferences;
+
+    @inject(ApplicationShell)
+    protected readonly shell: ApplicationShell;
+
     constructor(
         @inject(ProblemManager) protected readonly problemManager: ProblemManager,
         @inject(TreeProps) readonly treeProps: TreeProps,
@@ -46,6 +59,42 @@ export class ProblemWidget extends TreeWidget {
         this.addClipboardListener(this.node, 'copy', e => this.handleCopy(e));
     }
 
+    @postConstruct()
+    protected init(): void {
+        super.init();
+        this.updateFollowActiveEditor();
+        this.toDispose.push(this.preferences.onPreferenceChanged(e => {
+            if (e.preferenceName === 'problems.autoReveal') {
+                this.updateFollowActiveEditor();
+            }
+        }));
+    }
+
+    protected updateFollowActiveEditor(): void {
+        this.toDisposeOnCurrentWidgetChanged.dispose();
+        this.toDispose.push(this.toDisposeOnCurrentWidgetChanged);
+        if (this.preferences.get('problems.autoReveal')) {
+            this.followActiveEditor();
+        }
+    }
+
+    protected followActiveEditor(): void {
+        this.autoRevealFromActiveEditor();
+        this.toDisposeOnCurrentWidgetChanged.push(this.shell.onDidChangeCurrentWidget(() => this.autoRevealFromActiveEditor()));
+    }
+
+    protected autoRevealFromActiveEditor(): void {
+        const widget = this.shell.currentWidget;
+        if (widget && Navigatable.is(widget)) {
+            const uri = widget.getResourceUri();
+            const node = uri && this.model.getNode(uri.toString());
+            if (ExpandableTreeNode.is(node) && SelectableTreeNode.is(node)) {
+                this.model.expandNode(node);
+                this.model.selectNode(node);
+            }
+        }
+    }
+
     storeState(): object {
         // no-op
         return {};