[ADF-613] Add plain text viewer (#1873)

* add plain text viewer

* different devices optimizations

* returns types

ng2-components/ng2-alfresco-viewer/src/components/txtViewer.component.ts

@@ -0,0 +1,46 @@
+/*!
+ * @license
+ * Copyright 2016 Alfresco Software, Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { Component, Input } from '@angular/core';
+import { AlfrescoContentService } from 'ng2-alfresco-core';
+
+@Component({
+    selector: 'txt-viewer',
+    templateUrl: './txtViewer.component.html',
+    styleUrls: ['./txtViewer.component.css']
+})
+export class TxtViewerComponent {
+
+    @Input()
+    nodeId: string;
+
+    content: string;
+
+    constructor(private alfrescoContentService: AlfrescoContentService) {
+    }
+
+    ngOnChanges() {
+        this.getNodeContent(this.nodeId);
+    }
+
+    private getNodeContent(nodeId) {
+        this.alfrescoContentService.getNodeContent(nodeId).subscribe((nodeContent) => {
+            this.content = nodeContent;
+        });
+    }
+
+}