© 2012 Autodesk

Developing a simple Metro-style application for Windows 8Kean WalmsleySoftware Architect, Autodesk

© 2012 Autodesk

About the Presenter

Kean joined Autodesk in August 1995, and has since worked in a number of different positions and countries (UK, USA, India and Switzerland). He recently moved from the Autodesk Developer Team into the AutoCAD Engineering organisation, where he now works as a Software Architect.

Since July 2006 Kean has maintained a development-related blog at: blogs.autodesk.com/through-the-interface

Kean holds a Licence d’Informatique from l’Université de Paris-Sud and a Masters in Computer Science from the University of Kent at Canterbury.

© 2012 Autodesk

Class Summary

Covers the basic concepts around the WinRT sub-system of Windows 8, showing how to develop a simple, touch-enabled application that acts as a companion to AutoCAD.

We will look at the various contracts available to WinRT developers, and understand the limitations inherent to working inside the WinRT sandbox, including the need for asynchronous calls into many WinRT APIs.

The sample covered - while not working directly inside AutoCAD - will extract MRU information related to AutoCAD drawings in a format that can be used by our Metro-style browser application.

© 2012 Autodesk

Learning Objectives

At the end of this class, you will be able to: Extract MRU information from the Windows Registry, storing it in XML Understand the limitations imposed on applications by WinRT, including

the use of asynchronous calls Create a simple, Metro-style MRU browser application Implement contracts to enable search, sharing, settings and snapping

© 2012 Autodesk

Introducing Windows 8 and WinRT

© 2012 Autodesk

Windows 8

Latest generation of the Windows OS A critical release for Microsoft A bold departure with Windows Runtime, while focusing on legacy

Hybrid of touch-oriented and “Desktop” environments Desktop apps – such as AutoCAD – will work with modest investment More “modern” apps will work on ARM tablets such as Microsoft Surface

Easily adapted to Windows Phone 8

© 2012 Autodesk

Windows Runtime – The New Sandbox on the Block

Microsoft’s answer to the Android and iOS execution sandboxes Commonly abbreviated to WinRT

.NET was not considered the best technology for targeting mobile Technologically or politically driven?

A new layer on top of the Windows OS A set of core API services Can be used from various languages No longer required or possible to use P/Invoke

© 2012 Autodesk

WinRT – How it looks different

A whole new design language has been created Not only for Windows 8 Also found on Windows Phone, Zune, Xbox

Previously known as Metro, but has since been rebranded “Metro-style” apps became…

“Modern UI style” apps … and more recently…

“Windows Store” apps

A full-screen, touch-friendly user experience

© 2012 Autodesk

WinRT – How it looks different

Inspirations Bauhaus Swiss typography Motion Design

Design principles Pride in craftmanship Fast and fluid Authentically digital Do more with less Win as one

© 2012 Autodesk

WinRT – How it is different

The tools are familiar, but this is pretty different

Different object model for OS capabilities Asynchronous operation enforced for anything but “instant” responses Strict control over disk access Application interop only via contracts or file associations

© 2012 Autodesk

The WinRT Object Model

Let’s take a look… VS 2012 command-prompt, navigate to “c:\windows\system32\WinMetadata” ildasm.exe Windows.System.winmd

These definitions contain no code, only metadata Part of the core OS, likely to be written in native code

Useable from a variety of languages via “language projections” Available for Native (C/C++), HTML (JavaScript) & .NET (C#/VB) Use ildasm.exe /project to look at CLR projection

© 2012 Autodesk

The WinRT Object Model

But it is .NET or not? No, it isn’t, but it’s made to feel like it Underlying mechanism is actually COM WinRT and CLR type systems are distinct

Merged by metadata adapter

If coding in .NET, you target the .NETCore CLR profile Only exposes approved APIs You can try to circumvent them, but not if you want to be on the Windows Store

© 2012 Autodesk

Asynchronous operations are now the norm

Any call that might take over 50ms is now asynchronous-only Means that any “long running” call doesn’t block the UI thread Ensures a fluid UI experience (no more whitened windows)

No great coding overhead with async/await Typical code looks like this:

var file = await KnownFolders.DocumentsLibrary.GetFileAsync( “file.txt” );

© 2012 Autodesk

Restricted access to the file system

Applications can access files in a few locations Modify Package.appmanifest to request…

“Capabilities” to add/change/delete files in specific locations e.g. Documents Library, Removable Storage

“Declarations” associating the app with specific file-types Permissions get requested when installing the app

More freedom when handling a user-selected file Selection implies permissions have been granted for that file

© 2012 Autodesk

Application interop

App interop has been deliberately limited in WinRT Even if underpinnings are based on COM Imposes good behaviour on WinRT apps, but restrictive

File system and Registry isolation make it hard to share data

WinRT apps can interoperate via the Share contract Apps can be tied together at the user-level via the Share charm

e.g. a photo can be “shared” with an email client

WinRT apps can launch the desktop app associated with a file-type

© 2012 Autodesk

Additional points about WinRT apps

Really intended for lightweight, tablet-focused apps 32-bit only, implicit memory limitations Applications don’t even have a close button

Termination/resurrection is at the whim of the OS

The expectation is not that apps such as AutoCAD get ported And without a WinRT-based AutoCAD, there is no WinRT API for it

So what application possibilities are there? Especially with interop being so limited

© 2012 Autodesk

What can be done with AutoCAD?

Companion apps are an interesting possibility Windows Store apps that complement desktop apps such as AutoCAD

A fun example is to browse AutoCAD’s MRU file data Browsing data is a great use-case for WinRT

The WinRT app can launch AutoCAD with a file If AutoCAD is currently associated with the .DWG file-type If the file is located in an accessible location

© 2012 Autodesk

Implementing an AutoCAD MRU browser

© 2012 Autodesk

Browsing AutoCAD’s MRU data in WinRT

Cannot access MRU data directly from a WinRT app AutoCAD’s data is in the Registry and therefore not directly accessible

A specific export needs to be run from a desktop-hosted app Could be inside AutoCAD or otherwise Write some files that are then loadable from within WinRT

With appropriate application permissions, of course Ideally an automatic process

We’ll use a new feature in AutoCAD 2013, the Core Console…

© 2012 Autodesk

Extracting AutoCAD MRU data from the Registry

Let’s build a simple C# app that queries the Registry Writes an XML file with the MRU data Extracts thumbnails from each of the drawings Also copies the drawings to a local folder

Contrived example, but allows us to launch

The project references AcCoreMgd.dll App will be loadable in AutoCAD and the Core Console Populates a folder that’s accessible by the browser app

© 2012 Autodesk

Creating the Basic Browser

Start with the VS2012 Grid View template A very capable app for data browsing Gives a great deal of basic capabilities

From here we can add the various capabilities we need

The first step is to get the data into the browser Some work needed to manipulate the data source And then have the XAML bind to it

© 2012 Autodesk

Semantic Zoom

Pinch-zoom to see data at different levels of detail Very handy for providing a summary view of your data

Requires some work in XAML to implement SemanticZoom.ZoomedInView SemanticZoom.ZoomedOutView

If using keyboard and mouse Ctrl + mouse-wheel

© 2012 Autodesk

Contracts

Implement contracts to support Windows 8 charms Share Search Settings

All require using the static GetForCurrentView() method On a variety of different classes More on this over the coming slides

© 2012 Autodesk

Contracts – Share

Implemented by DataTransferManager.DataRequested event Add a handler when your item is created Populate the DataTarget with the data you want to provide

Warning: the Mail app is a little strange as a Share target If you add attachments it blanks the Title and Subject There’s a Share Target sample on MSDN that works more predictably

© 2012 Autodesk

Contracts – Search

Implemented by SearchPane.QuerySubmitted event Add handler when app is launched Generate a group of items that meet the search criteria Navigate to that group so they are displayed in the UI

Easy to implement using LINQ

var query = from item in Items where item.Content.Contains(queryText) select item;

© 2012 Autodesk

Contracts – Settings

Implemented by SettingsPane.CommandsRequested event Add handler when app is launched From here you register your “commands”

When your command’s event handler fires, update the settings Application.Current.RoamingSettings

Follows user between devices via Live ID Adjust the UI as appropriate to reflect changed setting

© 2012 Autodesk

Live Tile Notifications

Apps can provide notifications to the user via Start screen tiles

Tiles can be static or live Different formats to choose from

If wide, the user can also choose to make them square

Managed via Windows.UI.Notifications.TileUpdateManager Cycles through up to 5 live tiles

© 2012 Autodesk

Snapping

Two apps docked on the same screen Both WinRT apps or one can be desktop Snapped view up to 320 pixels wide Very handy for companion apps

Implemented via XAML (or HTML) Snapped visual style Contains a storyboard animating controls

© 2012 Autodesk

Launching

It’s possible to launch the application associated with a file-type

var file =await

KnownFolders.DocumentsLibrary.GetFileAsync(“A.dwg”);await Launcher.LaunchFileAsync(file);

The file needs to be in a known, application accessible folder Limits the ability to open files in arbitrary locations Why our MRU extractor makes local copies of DWGs to be browsed/opened

© 2012 Autodesk

Summary

Windows 8 is new and parts of it are very different Windows RT, the mobile-focused sub-system

Windows Store app development familiar but challenging Restrictions intended to improve trust and responsiveness Significant restrictions when looking at desktop app interop

Possible to implement interesting new capabilities for companion apps Semantic Zoom Contracts for Search, Share & Settings Live tile notifications, Snapping, Launching

© 2012 Autodesk

Autodesk, AutoCAD* [*if/when mentioned in the pertinent material, followed by an alphabetical list of all other trademarks mentioned in the material] are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders. Autodesk reserves the right to alter product and services offerings, and specifications and pricing at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document. © 2012 Autodesk, Inc. All rights reserved.