added a md file for the status bar activity API

Author: Tochibee

specs/StatusBarActivity.md

@@ -0,0 +1,119 @@
+<!-- USAGE
+  * Fill in each of the sections (like Background) below
+  * Wrap code with `single line of code` or ```code block```
+  * Before submitting, delete all <!-- TEMPLATE marked comments in this file,
+    and the following quote banner:
+-->
+# Background
+The browser has a Status bar that displays text when hovering over a link, or performing some activity. Currently, 
+Developers are able to opt in to disable showing the status bar through the browser 
+settings.
+
+Developers would also like to be able to opt in to intercept the updates which would 
+normally be displayed by the Status bar, and show it using thier own custom UI. 
+# Description
+We propose two new events for WebView2 that would allow developers to 
+listen for Status bar updates which are triggered by activity on the embedded 
+browser, and then handle those updates however they want in their applications.
+
+Developers will be able to: 
+
+1) Register an even handler for knowing when to show the status bar and what text to show
+2) Register an handler for knowing when the browser wants to dismiss the status bar
+
+
+# Examples
+## Win32 C++ Registering a listener for status bar showing
+```
+CHECK_FAILURE(m_webView->add_StatusBarShowing(
+    Callback<ICoreWebView2StatusBarShowingEventHandler>(
+        [this](ICoreWebView2* sender, ICoreWebView2StatusBarShowingEventArgs* args) -> HRESULT {
+            std::string message;
+            CHECK_FAILURE(args->get_message(&message));
+            
+            // Handle status bar text in message
+
+            return S_OK;
+        }
+    ).Get(),
+&m_statusBarShowing));
+```
+## Win32 C++ Registering a listener for status bar hiding
+```
+CHECK_FAILURE(m_webView->add_StatusBarHiding(
+    Callback<ICoreWebView2StatusBarHidingEventHandler>(
+        [this](ICoreWebView2* sender) -> HRESULT {
+            
+            // Dismiss status bar
+
+            return S_OK;
+        }
+    ).Get(),
+&m_statusBarHiding));
+```
+## C#/ .Net/ WinRT Registering a listener for status bar showing
+```
+webView.CoreWebView2.StatusBarShowing += (object sender, CoreWebView2StatusBarShowingEventArgs arg) =>
+{
+    string message = args.message;
+    // Handle status bar text in message
+};
+```
+## C#/ .Net/ WinRT Registering a listener for status bar hiding
+```
+webView.CoreWebView2.StatusBarHiding += (object sender) =>
+{
+     // Dismiss status bar
+};
+```
+# API Notes
+See [API Details](#api-details) Section below for API reference
+# API Details
+## Win32 C++
+```
+interface ICoreWebView2StatusBarShowingEventArgs : IUnknown {
+    [propget] HRESULT message([out, retval] std::string* message);
+}   
+   
+interface ICoreWebView2StatusBarShowingEventHandler : IUnknown {
+  /// Called to provide the implementer with the event args for the
+  /// corresponding event.
+  HRESULT Invoke(
+      [in] ICoreWebView2* sender,
+      [in] ICoreWebView2StatusBarShowingEventArgs* args);
+}
+
+interface ICoreWebView2StatusBarHidingEventHandler : IUnknown {
+  /// Called to provide the implementer with the event args for the
+  /// corresponding event.
+  HRESULT Invoke(
+      [in] ICoreWebView2* sender);
+}
+```
+## C#/ .Net/ WinRT
+```
+namespace Microsoft.Web.WebView2.Core {
+
+
+    runtimeclass CoreWebView2StatusBarShowingEventArgs {
+        string message {get;};
+    }
+
+    runtimeclass CoreWebView2 {
+        event Windows.Foundation.TypedEventHandler<CoreWebView2, CoreWebView2StatusBarShowingEventArgs> StatusBarShowingEvent;
+    }
+
+    runtimeclass CoreWebView2 {
+        event Windows.Foundation.TypedEventHandler<CoreWebView2> StatusBarHidingEvent;
+    }
+}
+```
+
+
+# Appendix
+<!-- TEMPLATE
+    Anything else that you want to write down for posterity, but
+    that isn't necessary to understand the purpose and usage of the API.
+    For example, implementation details or links to other resources.
+-->
+See here for more details about the Status bar: <a href="https://www.computerhope.com/jargon/s/statusbar.htm">Here</a>