diff --git a/packages/core/src/browser/common-frontend-contribution.ts b/packages/core/src/browser/common-frontend-contribution.ts
index c020f63682288..bdff121311e0c 100644
--- a/packages/core/src/browser/common-frontend-contribution.ts
+++ b/packages/core/src/browser/common-frontend-contribution.ts
@@ -30,6 +30,8 @@ import * as browser from './browser';
 import URI from '../common/uri';
 import { ContextKeyService } from './context-key-service';
 import { OS } from '../common/os';
+import { ResourceContextKey } from './resource-context-key';
+import { UriSelection } from '../common/selection';
 
 export namespace CommonMenus {
 
@@ -203,11 +205,25 @@ export class CommonFrontendContribution implements FrontendApplicationContributi
     @inject(ContextKeyService)
     protected readonly contextKeyService: ContextKeyService;
 
+    @inject(ResourceContextKey)
+    protected readonly resourceContextKey: ResourceContextKey;
+
     @postConstruct()
     protected init(): void {
         this.contextKeyService.createKey<boolean>('isLinux', OS.type() === OS.Type.Linux);
         this.contextKeyService.createKey<boolean>('isMac', OS.type() === OS.Type.OSX);
         this.contextKeyService.createKey<boolean>('isWindows', OS.type() === OS.Type.Windows);
+
+        this.initResourceContextKeys();
+    }
+
+    protected initResourceContextKeys(): void {
+        const updateContextKeys = () => {
+            const resourceUri = UriSelection.getUri(this.selectionService.selection);
+            this.resourceContextKey.set(resourceUri);
+        };
+        updateContextKeys();
+        this.selectionService.onSelectionChanged(updateContextKeys);
     }
 
     registerMenus(registry: MenuModelRegistry): void {
diff --git a/packages/core/src/browser/frontend-application-module.ts b/packages/core/src/browser/frontend-application-module.ts
index 4edb14bf7517f..052e5f74e7e91 100644
--- a/packages/core/src/browser/frontend-application-module.ts
+++ b/packages/core/src/browser/frontend-application-module.ts
@@ -68,6 +68,7 @@ import { bindCorePreferences } from './core-preferences';
 import { QuickPickServiceImpl } from './quick-open/quick-pick-service-impl';
 import { QuickPickService, quickPickServicePath } from '../common/quick-pick-service';
 import { ContextKeyService } from './context-key-service';
+import { ResourceContextKey } from './resource-context-key';
 
 export const frontendApplicationModule = new ContainerModule((bind, unbind, isBound, rebind) => {
     const themeService = ThemeService.get();
@@ -152,6 +153,7 @@ export const frontendApplicationModule = new ContainerModule((bind, unbind, isBo
         return messages;
     });
 
+    bind(ResourceContextKey).toSelf().inSingletonScope();
     bind(CommonFrontendContribution).toSelf().inSingletonScope();
     [FrontendApplicationContribution, CommandContribution, KeybindingContribution, MenuContribution].forEach(serviceIdentifier =>
         bind(serviceIdentifier).toService(CommonFrontendContribution)
diff --git a/packages/core/src/browser/resource-context-key.ts b/packages/core/src/browser/resource-context-key.ts
new file mode 100644
index 0000000000000..9440eff0edb7e
--- /dev/null
+++ b/packages/core/src/browser/resource-context-key.ts
@@ -0,0 +1,52 @@
+/********************************************************************************
+ * Copyright (C) 2019 TypeFox and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { injectable, inject, postConstruct } from 'inversify';
+import URI from '../common/uri';
+import { ContextKeyService, ContextKey } from './context-key-service';
+
+@injectable()
+export class ResourceContextKey {
+
+    @inject(ContextKeyService)
+    protected readonly contextKeyService: ContextKeyService;
+
+    protected resourceSchemeKey: ContextKey<string>;
+    protected resourceFileName: ContextKey<string>;
+    protected resourceExtname: ContextKey<string>;
+    protected resourceLangId: ContextKey<string>;
+
+    @postConstruct()
+    protected init(): void {
+        this.resourceSchemeKey = this.contextKeyService.createKey<string>('resourceScheme', undefined);
+        this.resourceFileName = this.contextKeyService.createKey<string>('resourceFilename', undefined);
+        this.resourceExtname = this.contextKeyService.createKey<string>('resourceExtname', undefined);
+        this.resourceLangId = this.contextKeyService.createKey<string>('resourceLangId', undefined);
+    }
+
+    set(resourceUri: URI | undefined): void {
+        this.resourceSchemeKey.set(resourceUri && resourceUri.scheme);
+        this.resourceFileName.set(resourceUri && resourceUri.path.base);
+        this.resourceExtname.set(resourceUri && resourceUri.path.ext);
+        this.resourceLangId.set(resourceUri && this.getLanguageId(resourceUri));
+    }
+
+    /** should be implemented by subclasses */
+    protected getLanguageId(uri: URI | undefined): string | undefined {
+        return undefined;
+    }
+
+}
diff --git a/packages/editor/src/browser/editor-contribution.ts b/packages/editor/src/browser/editor-contribution.ts
index 0bfdf17b9e26a..d1156e1e92f6b 100644
--- a/packages/editor/src/browser/editor-contribution.ts
+++ b/packages/editor/src/browser/editor-contribution.ts
@@ -36,29 +36,16 @@ export class EditorContribution implements FrontendApplicationContribution {
     protected readonly contextKeyService: ContextKeyService;
 
     onStart(): void {
-        this.initResourceContextKeys();
         this.initEditorContextKeys();
 
         this.updateStatusBar();
         this.editorManager.onCurrentEditorChanged(() => this.updateStatusBar());
     }
 
+    /** @default since 0.5.0 - will be removed in farther releases */
     protected initResourceContextKeys(): void {
-        const resourceSchemeKey = this.contextKeyService.createKey<string>('resourceScheme', undefined);
-        const resourceFileName = this.contextKeyService.createKey<string>('resourceFilename', undefined);
-        const resourceExtname = this.contextKeyService.createKey<string>('resourceExtname', undefined);
-        const resourceLangId = this.contextKeyService.createKey<string>('resourceLangId', undefined);
-        const updateContextKeys = () => {
-            const editor = this.editorManager.currentEditor;
-            const resourceUri = editor && editor.getResourceUri();
-            resourceSchemeKey.set(resourceUri && resourceUri.scheme);
-            resourceFileName.set(resourceUri && resourceUri.path.base);
-            resourceExtname.set(resourceUri && resourceUri.path.ext);
-            resourceLangId.set(this.getLanguageId(resourceUri));
-        };
-        updateContextKeys();
-        this.editorManager.onCurrentEditorChanged(updateContextKeys);
     }
+    /** @default since 0.5.0 - will be removed in farther releases */
     protected getLanguageId(uri: URI | undefined): string | undefined {
         const { languages } = this.languages;
         if (uri && languages) {
diff --git a/packages/editor/src/browser/editor-widget.ts b/packages/editor/src/browser/editor-widget.ts
index 4981ad4778685..9bb2d7385ae78 100644
--- a/packages/editor/src/browser/editor-widget.ts
+++ b/packages/editor/src/browser/editor-widget.ts
@@ -14,7 +14,7 @@
  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  ********************************************************************************/
 
-import { SelectionService } from '@theia/core/lib/common';
+import { Disposable, SelectionService } from '@theia/core/lib/common';
 import { Widget, BaseWidget, Message, Saveable, SaveableSource, Navigatable, StatefulWidget, DiffUris } from '@theia/core/lib/browser';
 import URI from '@theia/core/lib/common/uri';
 import { TextEditor } from './editor';
@@ -32,6 +32,11 @@ export class EditorWidget extends BaseWidget implements SaveableSource, Navigata
                 this.selectionService.selection = this.editor;
             }
         }));
+        this.toDispose.push(Disposable.create(() => {
+            if (this.selectionService.selection === this.editor) {
+                this.selectionService.selection = undefined;
+            }
+        }));
     }
 
     get saveable(): Saveable {
diff --git a/packages/languages/src/browser/language-resource-context-key.ts b/packages/languages/src/browser/language-resource-context-key.ts
new file mode 100644
index 0000000000000..826f851d8a141
--- /dev/null
+++ b/packages/languages/src/browser/language-resource-context-key.ts
@@ -0,0 +1,40 @@
+/********************************************************************************
+ * Copyright (C) 2019 TypeFox and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { injectable, inject } from 'inversify';
+import URI from '@theia/core/lib/common/uri';
+import { ResourceContextKey } from '@theia/core/lib/browser/resource-context-key';
+import { Languages } from './language-client-services';
+
+@injectable()
+export class LanguageResourceContextKey extends ResourceContextKey {
+
+    @inject(Languages)
+    protected readonly languages: Languages;
+
+    protected getLanguageId(uri: URI | undefined): string | undefined {
+        const { languages } = this.languages;
+        if (uri && languages) {
+            for (const language of languages) {
+                if (language.extensions.has(uri.path.ext)) {
+                    return language.id;
+                }
+            }
+        }
+        return undefined;
+    }
+
+}
diff --git a/packages/languages/src/browser/languages-frontend-module.ts b/packages/languages/src/browser/languages-frontend-module.ts
index 0409a73d9afa2..d1ea33fec38fa 100644
--- a/packages/languages/src/browser/languages-frontend-module.ts
+++ b/packages/languages/src/browser/languages-frontend-module.ts
@@ -16,6 +16,7 @@
 
 import { ContainerModule } from 'inversify';
 import { bindContributionProvider, CommandContribution } from '@theia/core/lib/common';
+import { ResourceContextKey } from '@theia/core/lib/browser/resource-context-key';
 import { FrontendApplicationContribution, KeybindingContribution, QuickOpenContribution, WebSocketConnectionProvider } from '@theia/core/lib/browser';
 import { Window } from './language-client-services';
 import { WindowImpl } from './window-impl';
@@ -26,8 +27,9 @@ import { WorkspaceSymbolCommand } from './workspace-symbols';
 import { LanguageClientProvider } from './language-client-provider';
 import { LanguageClientProviderImpl } from './language-client-provider-impl';
 import { LanguageContribution } from '../common';
+import { LanguageResourceContextKey } from './language-resource-context-key';
 
-export default new ContainerModule(bind => {
+export default new ContainerModule((bind, unbind, isBound, rebind) => {
     bind(Window).to(WindowImpl).inSingletonScope();
 
     bind(LanguageClientFactory).toSelf().inSingletonScope();
@@ -47,4 +49,7 @@ export default new ContainerModule(bind => {
 
     bind(LanguageClientProviderImpl).toSelf().inSingletonScope();
     bind(LanguageClientProvider).toService(LanguageClientProviderImpl);
+
+    bind(LanguageResourceContextKey).toSelf().inSingletonScope();
+    rebind(ResourceContextKey).to(LanguageResourceContextKey).inSingletonScope();
 });
diff --git a/packages/navigator/src/browser/navigator-widget.tsx b/packages/navigator/src/browser/navigator-widget.tsx
index 52dc894b69008..4f3f8f824c230 100644
--- a/packages/navigator/src/browser/navigator-widget.tsx
+++ b/packages/navigator/src/browser/navigator-widget.tsx
@@ -17,7 +17,7 @@
 import { injectable, inject, postConstruct } from 'inversify';
 import { Message } from '@phosphor/messaging';
 import URI from '@theia/core/lib/common/uri';
-import { CommandService, SelectionService } from '@theia/core/lib/common';
+import { CommandService, SelectionService, Disposable } from '@theia/core/lib/common';
 import { CommonCommands, CorePreferences } from '@theia/core/lib/browser';
 import {
     ContextMenuRenderer, ExpandableTreeNode,
@@ -83,6 +83,11 @@ export class FileNavigatorWidget extends FileTreeWidget {
                         this.model.expandNode(child);
                     }
                 }
+            }),
+            Disposable.create(() => {
+                if (this.selectionService.selection === this) {
+                    this.selectionService.selection = undefined;
+                }
             })
         ]);
     }