diff --git a/packages/plugin-ext-vscode/src/node/plugin-vscode-init.ts b/packages/plugin-ext-vscode/src/node/plugin-vscode-init.ts
index ea77f0317f461..e019af079030f 100644
--- a/packages/plugin-ext-vscode/src/node/plugin-vscode-init.ts
+++ b/packages/plugin-ext-vscode/src/node/plugin-vscode-init.ts
@@ -60,6 +60,14 @@ export const doInitialization: BackendInitializationFn = (apiFactory: PluginAPIF
             }
         });
 
+        // override postMessage method to replace vscode-resource:
+        const originalPostMessage = panel.webview.postMessage;
+        panel.webview.postMessage = (message: any): PromiseLike<boolean> => {
+            const decoded = JSON.stringify(message);
+            const newMessage = decoded.replace(new RegExp('vscode-resource:/', 'g'), '/webview/');
+            return originalPostMessage.call(panel.webview, JSON.parse(newMessage));
+        };
+
         return panel;
     };
 
diff --git a/packages/plugin-ext/src/main/browser/webview/webview.ts b/packages/plugin-ext/src/main/browser/webview/webview.ts
index 8610fe00507f7..6aa0ed3775811 100644
--- a/packages/plugin-ext/src/main/browser/webview/webview.ts
+++ b/packages/plugin-ext/src/main/browser/webview/webview.ts
@@ -35,6 +35,8 @@ export class WebviewWidget extends BaseWidget {
     private iframe: HTMLIFrameElement;
     private state: { [key: string]: any } | undefined = undefined;
     private loadTimeout: number | undefined;
+    private scrollY: number;
+    private readyToReceiveMessage: boolean = false;
 
     constructor(title: string, private options: WebviewWidgetOptions, private eventDelegate: WebviewEvents) {
         super();
@@ -43,6 +45,7 @@ export class WebviewWidget extends BaseWidget {
         this.title.closable = true;
         this.title.label = title;
         this.addClass(WebviewWidget.Styles.WEBVIEW);
+        this.scrollY = 0;
     }
 
     protected handleMessage(message: any) {
@@ -55,7 +58,9 @@ export class WebviewWidget extends BaseWidget {
         }
     }
 
-    postMessage(message: any) {
+    async postMessage(message: any): Promise<void> {
+        // wait message can be delivered
+        await this.waitReadyToReceiveMessage();
         this.iframe.contentWindow!.postMessage(message, '*');
     }
 
@@ -82,6 +87,9 @@ export class WebviewWidget extends BaseWidget {
                 a.title = a.href;
             }
         });
+        (window as any)[`postMessageExt${this.id}`] = (e: any) => {
+            this.handleMessage(e);
+        };
         this.updateApiScript(newDocument);
         const previousPendingFrame = this.iframe;
         if (previousPendingFrame) {
@@ -97,6 +105,9 @@ export class WebviewWidget extends BaseWidget {
         newFrame.contentDocument!.open('text/html', 'replace');
 
         const onLoad = (contentDocument: any, contentWindow: any) => {
+            if (newFrame && newFrame.contentDocument === contentDocument) {
+                newFrame.style.visibility = 'visible';
+            }
             if (contentDocument.body) {
                 if (this.eventDelegate && this.eventDelegate.onKeyboardEvent) {
                     const eventNames = ['keydown', 'keypress', 'click'];
@@ -110,12 +121,6 @@ export class WebviewWidget extends BaseWidget {
                     this.eventDelegate.onLoad(<Document>contentDocument);
                 }
             }
-            if (newFrame && newFrame.contentDocument === contentDocument) {
-                (<any>contentWindow).postMessageExt = (e: any) => {
-                    this.handleMessage(e);
-                };
-                newFrame.style.visibility = 'visible';
-            }
         };
 
         clearTimeout(this.loadTimeout);
@@ -141,10 +146,29 @@ export class WebviewWidget extends BaseWidget {
 
     protected onActivateRequest(msg: Message): void {
         super.onActivateRequest(msg);
+        // restore scrolling if there was one
+        if (this.scrollY > 0) {
+            this.iframe.contentWindow!.scrollTo({ top: this.scrollY });
+        }
         this.node.focus();
+        // unblock messages
+        this.readyToReceiveMessage = true;
+    }
+
+    // block messages
+    protected onBeforeShow(msg: Message): void {
+        this.readyToReceiveMessage = false;
     }
 
-    private reloadFrame() {
+    protected onBeforeHide(msg: Message): void {
+        // persist scrolling
+        if (this.iframe.contentWindow) {
+            this.scrollY = this.iframe.contentWindow.scrollY;
+        }
+        super.onBeforeHide(msg);
+    }
+
+    public reloadFrame() {
         if (!this.iframe || !this.iframe.contentDocument || !this.iframe.contentDocument.documentElement) {
             return;
         }
@@ -177,7 +201,8 @@ export class WebviewWidget extends BaseWidget {
         const codeApiScript = contentDocument.createElement('script');
         codeApiScript.id = scriptId;
         codeApiScript.textContent = `
-            const acquireVsCodeApi = (function() {
+        window.postMessageExt = window.parent['postMessageExt${this.id}'];
+        const acquireVsCodeApi = (function() {
                 let acquired = false;
                 let state = ${this.state ? `JSON.parse(${JSON.stringify(this.state)})` : undefined};
                 return () => {
@@ -234,6 +259,28 @@ export class WebviewWidget extends BaseWidget {
             parent.appendChild(codeApiScript);
         }
     }
+
+    /**
+     * Check if given object is ready to receive message and if it is ready, resolve promise
+     */
+    waitReceiveMessage(object: WebviewWidget, resolve: any) {
+        if (object.readyToReceiveMessage) {
+            resolve(true);
+        }
+    }
+
+    /**
+     * Block until we're able to receive message
+     */
+    public async waitReadyToReceiveMessage(): Promise<boolean> {
+        if (this.readyToReceiveMessage) {
+            return true;
+        }
+        return new Promise<boolean>((resolve, reject) => {
+            setTimeout(this.waitReceiveMessage, 100, this, resolve);
+        });
+    }
+
 }
 
 export namespace WebviewWidget {
diff --git a/packages/plugin-ext/src/main/browser/webviews-main.ts b/packages/plugin-ext/src/main/browser/webviews-main.ts
index d613d1a3382a0..b6424adf4424c 100644
--- a/packages/plugin-ext/src/main/browser/webviews-main.ts
+++ b/packages/plugin-ext/src/main/browser/webviews-main.ts
@@ -40,7 +40,13 @@ export class WebviewsMainImpl implements WebviewsMain {
     protected readonly updateViewOptions: () => void;
 
     private readonly views = new Map<string, WebviewWidget>();
-    private readonly viewsOptions = new Map<string, { panelOptions: WebviewPanelShowOptions; panelId: string; active: boolean; visible: boolean; }>();
+    private readonly viewsOptions = new Map<string, {
+        panelOptions: WebviewPanelShowOptions;
+        options: (WebviewPanelOptions & WebviewOptions) | undefined;
+        panelId: string;
+        active: boolean;
+        visible: boolean;
+    }>();
 
     constructor(rpc: RPCProtocol, container: interfaces.Container) {
         this.proxy = rpc.getProxy(MAIN_RPC_CONTEXT.WEBVIEWS_EXT);
@@ -102,7 +108,7 @@ export class WebviewsMainImpl implements WebviewsMain {
         });
 
         this.views.set(panelId, view);
-        this.viewsOptions.set(view.id, { panelOptions: showOptions, panelId, visible: false, active: false });
+        this.viewsOptions.set(view.id, { panelOptions: showOptions, options: options, panelId, visible: false, active: false });
         this.addOrReattachWidget(panelId, showOptions);
     }
     private addOrReattachWidget(handler: string, showOptions: WebviewPanelShowOptions) {
@@ -165,9 +171,13 @@ export class WebviewsMainImpl implements WebviewsMain {
         if (view.isDisposed) {
             return;
         }
-        if (showOptions.viewColumn !== undefined || showOptions.area !== undefined) {
+        const options = this.viewsOptions.get(view.id);
+        let retain = false;
+        if (options && options.options && options.options.retainContextWhenHidden) {
+            retain = options.options.retainContextWhenHidden;
+        }
+        if ((showOptions.viewColumn !== undefined && showOptions.viewColumn !== options!.panelOptions.viewColumn) || showOptions.area !== undefined) {
             this.viewColumnService.updateViewColumns();
-            const options = this.viewsOptions.get(view.id);
             if (!options) {
                 return;
             }
@@ -179,7 +189,11 @@ export class WebviewsMainImpl implements WebviewsMain {
                 this.updateViewOptions();
                 return;
             }
+        } else if (!retain) {
+            // reload content when revealing
+            view.reloadFrame();
         }
+
         if (showOptions.preserveFocus) {
             this.shell.revealWidget(view.id);
         } else {
diff --git a/packages/plugin-ext/src/plugin/webviews.ts b/packages/plugin-ext/src/plugin/webviews.ts
index f45094733c6bb..c9e707c41237b 100644
--- a/packages/plugin-ext/src/plugin/webviews.ts
+++ b/packages/plugin-ext/src/plugin/webviews.ts
@@ -148,7 +148,30 @@ export class WebviewImpl implements theia.Webview {
     // tslint:disable-next-line:no-any
     postMessage(message: any): PromiseLike<boolean> {
         this.checkIsDisposed();
-        return this.proxy.$postMessage(this.viewId, message);
+        // replace theia-resource: content in the given message
+        const decoded = JSON.stringify(message);
+        let newMessage = decoded.replace(new RegExp('theia-resource:/', 'g'), '/webview/');
+        if (this._options && this._options.localResourceRoots) {
+            newMessage = this.filterLocalRoots(newMessage, this._options.localResourceRoots);
+        }
+        return this.proxy.$postMessage(this.viewId, JSON.parse(newMessage));
+    }
+
+    protected filterLocalRoots(content: string, localResourceRoots: ReadonlyArray<theia.Uri>) {
+        const webViewsRegExp = /"(\/webview\/.*?)\"/g;
+        let m;
+        while ((m = webViewsRegExp.exec(content)) !== null) {
+            if (m.index === webViewsRegExp.lastIndex) {
+                webViewsRegExp.lastIndex++;
+            }
+            // take group 1 which is webview URL
+            const url = m[1];
+            const isIncluded = localResourceRoots.some((uri): boolean => url.substring('/webview'.length).startsWith(uri.fsPath));
+            if (!isIncluded) {
+                content = content.replace(url, url.replace('/webview', '/webview-disallowed-localroot'));
+            }
+        }
+        return content;
     }
 
     get options(): theia.WebviewOptions {
@@ -168,7 +191,11 @@ export class WebviewImpl implements theia.Webview {
     }
 
     set html(html: string) {
-        const newHtml = html.replace(new RegExp('theia-resource:/', 'g'), '/webview/');
+        let newHtml = html.replace(new RegExp('theia-resource:/', 'g'), '/webview/');
+        if (this._options && this._options.localResourceRoots) {
+            newHtml = this.filterLocalRoots(newHtml, this._options.localResourceRoots);
+        }
+
         this.checkIsDisposed();
         if (this._html !== newHtml) {
             this._html = newHtml;
@@ -205,6 +232,7 @@ export class WebviewPanelImpl implements theia.WebviewPanel {
         private readonly _webview: WebviewImpl
     ) {
         this._showOptions = typeof showOptions === 'object' ? showOptions : { viewColumn: showOptions as theia.ViewColumn };
+        this.setViewColumn(undefined);
     }
 
     dispose() {
@@ -267,7 +295,7 @@ export class WebviewPanelImpl implements theia.WebviewPanel {
         return this._showOptions.viewColumn;
     }
 
-    setViewColumn(value: theia.ViewColumn) {
+    setViewColumn(value: theia.ViewColumn | undefined) {
         this.checkIsDisposed();
         this._showOptions.viewColumn = value;
     }