Usage of software input panel in DirectX based app

Question

I am trying to add text input functionality into existing DirectX application that was being ported to Windows Store / Phone 8.1. The problem is that I can't even get the sample code provided by microsoft in this article to compile: http://msdn.microsoft.com/en-us/library/windows/apps/jj247546%28v=vs.105%29.aspx

I am using Universal App project as a base and I have no acces to Windows::Phone::UI::Core (there is no Core namespace at all!)

I was trying to add dummy textbox and hid it somewhere but without luck as to appear the software keyboard you need to focus the textbox - the moment it receives focus it appears on the screen (we draw our own controls so I don't want the system one) despite the fact being set to Transparent, both foreground and background and width to 0.

How can I manipulate SIP to show/hide and retrieve input from the keyboard without having to hack my way through XAML and stuff?

Answer 1

On Windows Phone (but not Windows) apps can request the InputPane hide and show programmatically by calling InputPane.TryShow and TryHide.

If you want the InputPane to show automatically then you need to set focus to a control which identifies itself as a text control to the automation system (see the Touch Keyboard documentation on MSDN. Windows Phone works essentially the same as Windows 8 here).

There are two ways to do this in a DirectX app:

As the other thread describes and as you've tried, you can use a Xaml TextBox on top of your DirectX surface. This has the advantage of being easy as the Xaml controls already implement the accessibility and IME interfaces needed for full text support. It has the disadvantage of being external to the DX scene so it can require some care to place it nicely. You can't really hide the TextBox and divert the input, but need to use the TextBox for input. I prefer to do the full interactive form in Xaml rather than trying to merge a single TextBox into a full scene.

The other option is to implement a text control in DirectX. Windows uses the UI Automation API to identify and interact with text controls. If you implement the TextPattern and focus for your control within DirectX then the keyboad will automatically invoke when the user sets focus to it. There's a sample at Input: Touch keyboard sample which demonstrates the necessary interfaces within a custom Xaml control context. It won't apply directly to DX, but will give the general idea. The UI Automation Provider Programmer's Guide has more in depth information on implementing UI Automation interfaces. Again, while these docs target Windows they will also apply to Windows Phone.

I'm not sure exactly which code didn't compile for you. The linked pages are a bit out of date (SwapChainPanel is now preferred over SwapChainBackgroundPanel), but the classes and techniques involved should be valid for Windows Phone Runtime apps.