Intellisense for Google Maps API in Visual Studio

If you wish to incorporate Intellisense for the Google Maps JavaScript API in Visual Studio you can use the following open-source project for version 3: http://gmapvsdoc.codeplex.com/. For version 2 of the API, you can use the following project: http://gmapjs.codeplex.com/. [Quick start guide and documentation is available in each link.]

It’s not just doing it again and again!

I’d like to quote some lines from Peter Norvig’s masterpiece: Learn Programming in 10 Years:

The key is deliberative practice: not just doing it again and again, but challenging yourself with a task that is just beyond your current ability, trying it, analyzing your performance while and after doing it, and correcting any mistakes. Then repeat. And repeat again.

And…

In any case, book learning alone won’t be enough. “Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter” says Eric Raymond, author of The New Hacker’s Dictionary.

Also another amazing article that you’ll like to check is Herbert Klaeren’s Epigrams on Programming.

Using Video Markers in Silverlight

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Definition

Markers are text annotations embedded at certain points in a media file. They help you in several cases. For example, you might use markers to set captions or subtitles for a video file, or maybe you use it to identify particular points in a media file so you can play the media starting at particular points.

 

Marker Support

Silverlight has native support for video markers, you can subscribe to the MarkerReached event of MediaElement control to get notified whenever you reach a marker. However, in order to use video markers you need to encode them in the video file. The best application that you can use to encode markers in a video file for Silverlight is Microsoft Expression Encoder.

 

Marker Encoding

After you have your video file added to Expression Encoder, you can use the timeline to set the markers at the desired locations. You can add a marker by moving to the position where you want to set the marker at, then right-clicking the timeline and selecting Add Marker to add a new marker.

You then go to the Markers window where you can set marker text (value) and manage existing markers.

Notice that every marker is identified on the timeline by a symbol like diamond (♦). You can change marker position by moving this symbol, and you can remove it by right-clicking it and choosing Remove (you can also use the Markers window.)

Now encode the video and prepare it to be used in Silverlight.

 

Code

After you have created your MediaElement and prepared it with the video, you can then subscribe to the MarkerReached event and handle the marker when the video reaches it. An example of handling markers is to display the marker text on the screen if, for example, it is a caption/subtitle for the video:

void theMedia_MarkerReached(object sender, TimelineMarkerRoutedEventArgs e)
{
    theTextBlock.Text = e.Marker.Text;
}

And you can also load the markers to a list box (for example) and let the user moves to the position of the markers he chooses (worth mentioning that markers are only available after MediaOpened event is raised):

void theList_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (this.theList.SelectedIndex > -1)
        theMedia.Position = theMedia.Markers[theList.SelectedIndex].Time;
}

Makes sense?

What’s New in Silverlight 5? – Performance and Other Improvements

What’s New in Silverlight 5?

شاهد كورس كامل سيلفرلايت 5 مجانا هنا.

This content is based on Beta release, expect many changes in the final release.

Read What’s New in Silverlight 5 series here.

 

 

Introduction

In this article, we’ll have a brief discussion of the performance, networking, and other improvements in Silverlight 5.

 

Performance

Performance has been improved in Silverlight 5 in a number of ways:

  • Significant improvement in performance through the entire product
  • Startup performance has been improved using a multi-core background JIT compiler
  • XAML parsing time has been improved especially for UserControl and ResourceDictionary
  • Added 64-bit runtime version. Not in beta
  • Hardware accelerated rendering in Internet Explorer 9 in windowless mode

 

Networking

And networking has its share of improvements:

  • Network latency has been improved significantly
  • 90% performance improvements in ClientHttpWebRequest scenarios

 

Services

Added support for WS-Trust in WCF. (WS-Trust is a specification aimed to improve security and validation.)

 

Profiling and Testing

  • Automated UI testing
  • Improved profiling support:
    • Memory
    • CPU
    • Thread contention

 

Other

  • Support for Windows Azure
  • In-Browser HTML support
  • Many more fixes and improvements throughout the product

 

Now, check out other What’s New in Silverlight 5? articles.

What’s New in Silverlight 5? – Elevated-Trust Changes

What’s New in Silverlight 5?

شاهد كورس كامل سيلفرلايت 5 مجانا هنا.

This content is based on Beta release, expect many changes in the final release.

Read What’s New in Silverlight 5 series here.

Download Sample Code

 

Introduction

In this article, we’ll have a brief discussion of the new features in elevated-trust applications in Silverlight 5.

 

Overview

Elevated-trust applications have undergone few changes in Silverlight 5:

  • In-Browser Support
  • Multiple Windows Support
  • File System Access
  • Platform Invocation

Let’s see those changes in details.

 

In-Browser Support

Unlike previous versions, in Silverlight 5 you don’t have to run your application as OOB to get elevated-trust features, you can now run elevated-trust applications in the browser and get all the features you need.

There’re two security considerations to be taken in order to run your elevated-trust application in browser:

  1. You must enable running your application in browser via either the Client Access Policy file or the Windows Registry. Using the policy file allows your application to run in a private network. Using the Windows Registry approach allows your application to run on a single machine. In either approaches, you cannot deploy in-browser elevated-trust applications to everyone on the web.
  2. In addition, your XAP must be signed with a trusted certificate e.g. X.509 certificate) available in the Trusted Publisher Certificate store.

Without any of those requirements, you won’t be able to run your elevated-trust application in browser. But wait, there’s a catch!

In your development machine you can run elevated-trust applications in browser only on whitelisted domains. For example, by default, localhost is whitelisted, so you can easily run an elevated-trust application in the browser in localhost. If you change to another domain, ensure that you add this name to the whitelist, or you won’t be able to run the application. More comes about this later.

The last thing to keep in mind is that in the Beta version, in-browser elevated-trust applications are supported in Windows only. Other platforms are going to be available in the final version.

Client Access Policy Approach

If you want your application to be available in a private network, you need to do some changes to the client access policy file in order to allow it to run in browser as elevated-trust. The changes are as the following; just set the ElevatedPermissions property of SecuritySettings to Required:

<Deployment.OutOfBrowserSettings>
  ...
  <OutOfBrowserSettings.SecuritySettings>
    <SecuritySettings ElevatedPermissions="Required" />
  <OutOfBrowserSettings.SecuritySettings>
  ...
</Deployment.OutOfBrowserSettings>

Windows Registry Approach

The other approach you have is to use the Windows Registry to enable in-browser elevated-trust applications to run on a particular machine. To do this, go to HKEY_LOCAL_MACHINESOFTWAREMicrosoftSilverlight. In this registry key, you have several values related to elevated-trust applications:

  • AllowElevatedTrustAppsInBrowser:
    Set to TRUE (0x00000001) to enable running elevated-trust applications in browser.
  • AllowInstallOfElevatedTrustApps:
    Set to TRUE to enable installation of elevated-trust applications to the PC (i.e. OOB.)
  • AllowLaunchOfElevatedTrustApps:
    Set to TRUE to enable launching elevated-trust applications (in-browser or OOB.)

Example

To run an elevated-trust application in browser you need first to enable OOB and elevated-trust features from project properties. After that, create a Web application and link it to the Silverlight application to host it. If you didn’t do this, your Silverlight application will run as OOB. Your application is able now to run as elevated-trust in browser. To ensure this, you can check for the Application.HasElevatedPermissions property:

  theTextBlock.Text = "Is Elevated-Trust: " +
    Application.Current.HasElevatedPermissions.ToString();

Now try something more interesting. Try reading a file in the file system that only elevated-trust applications have access to:

theTextBlock.Text =
        File.ReadAllText(@"C:WindowsSystem32Driversetchosts");

As you see, the application works as expected, and has all the elevated-trust features as OOB applications.

Now let’s try changing the domain from localhost to another domain. Go to Web application project properties, switch to the Web tab, then go to Server settings and change the server from Visual Studio Development Server to Local IIS Web Server and use your machine name as the domain and save the settings. (You might be asked to confirm virtual directory creation, it’s because you have changed to another domain and used another virtual directory.)

Now try to run the application. The application won’t be able to run and you’ll get a security exception, that’s because the new domain is not whitelisted like localhost.

 

Multiple Windows Support

Multiple Windows Support or Ad-hoc Windows is a feature that enables elevated-trust OOB applications in Silverlight 5 to have windows other than the main window. The feature is available through the Window class which is now instantiable. You use the Window class to create another window and set its contents through the Content property and show it using the Visibility property.

The following code creates a Window that’s 400 pixels wide and 300 pixels long, and has just a button in the interface:

    Window wnd = new Window();
    wnd.Width = 400;
    wnd.Height = 300;
    wnd.Content = new Button { Content = "Say Hello" };
    wnd.Visibility = System.Windows.Visibility.Visible;

Notice that you can end the application by closing the main window; it doesn’t matter if you close any other window.

You’re not limited to just a button or a single object in the window contents. You can create another page (i.e. user control) and set it to be the content of the window:

    Window wnd = new Window();
    wnd.Width = 400;
    wnd.Height = 300;
    wnd.Content = new MyOtherPage();
    wnd.Visibility = System.Windows.Visibility.Visible;

And you can also create windows with custom chrome by removing the toolbar and borders and create them yourself via code:

    Window wnd = new Window();
    wnd.Width = 400;
    wnd.Height = 300;
    wnd.Content = new MyOtherPageWithCustomChrome();
    wnd.WindowStyle = WindowStyle.None;
    wnd.Visibility = System.Windows.Visibility.Visible;

Notice that if you don’t have elevated-trust features, you won’t be able to spawn other windows. And if you tried to, you’ll get a security exception.

 

File System Access

Unlike elevated-trust applications in Silverlight 4 which have access to only My Documents folder, Silverlight 5 elevated-trust applications (in-browser and out-of-browser) have full access to the file system. But keep in mind that although you have full access to the file system, you still restricted by the rights of the user running your application. If the user doesn’t have access to a specific file or folder, then you don’t have access to that file or folder.

To test this feature, try reading contents from a file in the system folder (for instance):

theTextBlock.Text =
        File.ReadAllText(@"C:WindowsSystem32Driversetchosts");

As you see, you have access to that file.

By default, if you’re running Windows Vista or Windows 7, your user wouldn’t have administrator privileges as long as he doesn’t launch Visual Studio (or your application) in elevated mode. So if you don’t have admin privileges and tries to gain the write access to the same file your application would fail, that’s because your application is restricted by user rights and the user don’t have write access to that file:

    File.AppendAllText
      (@"C:WindowsSystem32Driversetchosts",
      "nfoo");

Same results when trying to write to the system drive without elevated permissions for the user:

    File.WriteAllText(@"C:test.txt", "Foo");

 

Platform Invocation

Silverlight 4 has introduced support for automation and COM components. Silverlight 5 has added support for Platform Invocation (or P/Invoke.) Platform Invocation allows you to call native code (e.g. DLLs and Windows API) from your Silverlight application. This is a great improvement of course. It uses the same mechanism as other WinForms applications. Unfortunately, this feature is currently not available in the Beta.

 

Summary

The following changes have been happened to elevated-trust applications in Silverlight 5:

  • In-Browser Support:
    You can now run elevated-trust applications in Silverlight 5 in browser. Must be enabled via client access policy file or Windows Registry, and XAP must be signed with a trusted certificate.
  • Multiple Windows Support:
    Allows elevated-trust OOB applications to span windows other than the main window.
  • File System Access:
    Allows you to have full access to the file system with the rights of the current user.
  • Platform Invocation:
    Allows you to call native code like DLLs and Windows API from your Silverlight application. Not available in Beta.

Now, check out other What’s New in Silverlight 5? articles.

What’s New in Silverlight 5? – Media Changes

What’s New in Silverlight 5?

شاهد كورس كامل سيلفرلايت 5 مجانا هنا.

This content is based on Beta release, expect many changes in the final release.

Read What’s New in Silverlight 5 series here.

Download Sample Code

 

Introduction

In this article, we’ll have a brief discussion of the new features in media stack in Silverlight 5.

 

Overview

Silverlight 5 has undergone few changes in the media stack:

  • Better Battery Management:
    Less battery when playing media. Plus, no screensaver in the full-screen mode.
  • Remote Control Support:
    Now you can control the media being played in Silverlight 5 using a remote control. This feature is currently not available in the Beta.
  • Hardware Decoding; More GPU Support:
    For better performance, Silverlight 5 depends more on the GPU for media decoding especially for the high definition H.264 formats. In Beta, no DRM or Mac support.
  • 1080p Support:
    Combined with hardware decoding, user can now watch high definition 1080p media on a Netbook or Tablet.
  • IIS Media Services 4:
    Support for media streaming using IIS Media Services 4 has been added.

And two more features require more details:

  • Speed Control; Trick Play:
    Allows you to control playing speed, and to play the media forward or backward.
  • Low-Latency Sounds:
    Silverlight 5 has added native support for raw wave files.

 

Speed Control; Trick Play

This feature allows you to control playing speed, to speed-up or slow-down the media. The ability to change playing speed is called, Trick Play. This feature is available in the MediaElement control through a new property called PlaybackRate. This property takes a decimal value ranges from -8, -4, -2, … to …, 0.5, 1.2, 1.4, 2, 4, 8, and the default is 1. The downside of the Beta version is that it doesn’t have a pitch correction, means that when you change the rate to a value other than the default (1) you wouldn’t have any sound. And because of a bug found in the Beta version, you must set this property in code, if you set it in XAML will reset at application start to the default value.

The following are three examples of changing the playing speed of a media element:

    // Normal Speed
    media.PlaybackRate = 1.0;
    // Fast
    media.PlaybackRate = 4.0;
    // Slow
    media.PlaybackRate = -2.0;

 

Low-Latency Sounds

In the past, you had to create a wave file parser that reads file headers to determine if this is a wave file, and after recognizing a wave file, the parser reads file contents and encode them in order for your application to be able to play it. That changed completely in Silverlight 5. Today, you have native support for raw sounds data (i.e. low-latency sounds.) You can now play wave files and wave data directly in your application without the need to encode them.

This feature is available through a new API based on the XNA Framework. It uses the same classes and functions available in XNA. The main class you have is SoundEffect (Microsoft.Xna.Framework.Audio) that you can use it to play wave files and raw data. You have all the control over the media played; you can set volume, pitch, and stereo space. And you can create a more sophisticated class of SoundEffect called SoundEffectInstance that represents an instance of that sound file. This instance can be played repeatedly, and allows you to have all the control like SoundEffect and more, as we’ll see in the examples.

Finally, keep in mind that Silverlight 5 has the same limitations as XNA; it allows only for 8/16bit PCM, mono/stereo, 22.5/44.1/48khz wave files.

The following code loads the SoundEffect class with a wave file available in application resources:

    var resource = Application.GetResourceStream(
      new Uri("MediaLowLatency;component/tada.wav",
        UriKind.RelativeOrAbsolute));

    SoundEffect effect = SoundEffect.FromStream(resource.Stream);

After you have the SoundEffect at your hands, you can call the Play() method to play it. This method have two overrides, one can accept no parameters in which it plays the media normally with the default volume and no changes in the pitch or the stereo space. The other override accepts three values:

  1. volume:
    Ranges from 0.0f to 1.0f.
  2. pitch:
    Ranges from -1.0f to 1.0f. Default is 0f.
  3. pan:
    Controls the stereo space. Ranges from -1.0f to 1.0f. Default is 0f.

The following are some examples of playing sound files using SoundEffect:

    // Normal
    effect.Play();
    // Normal (default values)
    effect.Play(1.0f, 0f, 0f);
    // Faster
    effect.Play(1.0f, 1.0f, 0f);
    // Slower
    effect.Play(1.0f, -1.0f, 0f);

And finally you can use the SoundEffectInstance to create multiple instances of the same audio, or to play it repeatedly (Volume, Pitch, and Pan values are available through properties):

    SoundEffectInstance instance = effect.CreateInstance();

    instance.IsLooped = true;
    instance.Play();

 

Summary

While Silverlight 5 manages battery better, it also has improved media performance by depending more on the GPU for media decoding. And it allows now for high definition 1080p and H.264 videos. In addition, Silverlight 5 has introduced remote control support. And finally, the greatest features are its support for raw wave files and the ability to control playing speed.

Now, check out other What’s New in Silverlight 5? articles.

What’s New in Silverlight 5? – Graphics Changes

What’s New in Silverlight 5?

شاهد كورس كامل سيلفرلايت 5 مجانا هنا.

This content is based on Beta release, expect many changes in the final release.

Read What’s New in Silverlight 5 series here.

 

Introduction

In this article, we’ll have a brief discussion of the new features in graphics stack in Silverlight 5.

 

Overview

Silverlight 5 has undergone few changes in the graphics stack:

  • Improved Performance and Rendering:
    Performance has been improved dramatically by using lessons learned from Windows Phone 7. More comes later in this article.
  • Hardware Acceleration:
    Silverlight 5 now depends more on GPU for graphics processing. This frees CPU from much work, and as a result, improves performance.
  • New 3D API:
    The most exciting feature yet. Silverlight 5 now supports native 3D API. More comes later.
  • Vector Printing:
    Very useful for certain cases, not available in the Beta.
  • Print Preview:
    The long-waited printing feature. Silverlight 5 now allows you to show the user a preview of what he is going to print. Yet not available in the Beta.

Now let’s look at the currently available features in details.

 

Performance Improvements

To improve rendering performance, Silverlight 5 uses the composition model available in Windows Phone 7. This model implies using a separate, dedicated thread for graphics rendering instead of using the UI thread. This helps freeing the UI thread from graphics work, and thus improves the performance of rendering UI elements and reduces flickers and glitchy animations happen when UI thread was interrupted.

In addition, moving the graphics rendering to another thread adds support for independent animations and helps with immediate-mode rendering on the GPU (in which graphics are sent directly and being rendered on the display.)

 

3D API

Silverlight 5 now supports natively a 3D API. This API is based on the XNA API; you have the same classes and the same code, however, the 3D API is Silverlight is not game-loop based.

While it’s so amazing to have a 3D API natively supported in Silverlight, things are not as good as they seem. The 3D API of Silverlight 5 is very low-level, means that you have access to the GPU, vertex shaders, and other 3D primitives. It’s not as easy as it should be; it requires that you have a solid understanding of low-level graphics and game development to be able to interact with this API. However, the good news is that community will likely wrap this low-level API into simpler components.

Technically, to draw graphics on the screen you need to use the new control DrawingSurface where all the rendering and graphics go on. This control offers a Draw event that you can use to supply your drawing calls. The calls are carried to a GraphicsDevice object and then be processed and carried to the display.

Because of the complexities in this low-level API, and because we assume that you are a business developer, we won’t discuss the 3D API. Instead, we’ll have a brief look at two of the great samples of this API.

Cube Sample

The cube sample (download from http://bit.ly/sl5-cubesample, colored, non-textured) demonstrates how to create and rotate a 3D cube in Silverlight 5. Here’s a screenshot of this sample:

Looking at the Solution Explorer at project files, we can see that the project contains some pixel shader (PS) and vertex shader (VS) files. Those files besides the HLSL files contain the code (in the HLSL language) for the effects required to render the cube.

Moving to MainPage.xaml you can see the DrawingSurface object used to display the graphics and drawings.

<DrawingSurface Draw="OnDraw" SizeChanged="OnSizeChanged" />

Looking at the code behind at the Draw event handler, we can see that the sample has encapsulated all the code required for drawing the cube and rotating it into a new class called Scene. The Draw event passes the GraphicsDevice object to the Scene to have it draw the cube and other graphics into the device:

// init the 3D scene
Scene scene = new Scene();

public MainPage()
{
    InitializeComponent();
}

void OnDraw(object sender, DrawEventArgs args)
{
    // draw 3D scene
    scene.Draw(args.GraphicsDevice, args.TotalTime);

    // invalidate to get a callback next frame
    args.InvalidateSurface();
}

Moving to the Scene class, we can see that it creates another class that handles drawing the Cube, and has configured the view and camera position and completes the drawing in the Draw() function by clearing the screen and calling the Draw() function of the cube.

public class Scene
{
    Matrix view; // The view or camera transform
    Matrix projection;

    // The single Cube at the root of the scene
    Cube Cube = new Cube();

    public Scene()
    {
        // the camera's position
        Vector3 cameraPosition = new Vector3(0, 0, 5.0f);
        // the place the camera is looking (towards world origin)
        Vector3 cameraTarget = Vector3.Zero;

        // the transform representing a camera at a position looking at a target
        view = Matrix.CreateLookAt(cameraPosition, cameraTarget, Vector3.Up);
    }

    ...

    public void Draw(GraphicsDevice graphicsDevice, TimeSpan totalTime)
    {
        // clear the existing render target
        graphicsDevice.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, 
            Color.Transparent, 1.0f, 0);

        // draw the Cube
        Cube.Draw(graphicsDevice, totalTime, view * projection);
    }
}

Finally, the Cube class completes all the drawing by loading the vertex and pixel shaders in its constructor, configuring cube surfaces and surface colors in the CreateCube() function, and then performs the drawing and handling the animation in the Draw() function.

public class Cube
{
    // the device to use when creating resources
    static readonly GraphicsDevice resourceDevice 
        = GraphicsDeviceManager.Current.GraphicsDevice;

    // resources
    VertexShader vertexShader;
    PixelShader pixelShader;

    public Cube()
    {
        // Initialize resources required to draw the Cube
        vertexBuffer = CreateCube();

        Stream shaderStream = Application.GetResourceStream(
            new Uri(@"CubeSample;component/Cube.vs", UriKind.Relative)).Stream;
        vertexShader = VertexShader.FromStream(resourceDevice, shaderStream);

        shaderStream = Application.GetResourceStream(...);
        ,,,
    }

    VertexBuffer CreateCube()
    {
        // cube vertices
        var cube = new VertexPositionColor[36];

        // face coordinates
        Vector3 topLeftFront = new Vector3(-1.0f, 1.0f, 1.0f);
        Vector3 bottomLeftFront = new Vector3(-1.0f, -1.0f, 1.0f);
        ...

        return vb;
    }

    public void Draw(GraphicsDevice graphicsDevice, ...)
    {
        // update cube transform
        Matrix position = Matrix.Identity; // origin
        Matrix scale = Matrix.CreateScale(1.0f); // no scale modifier

        ...

        // setup pixel pipeline
        graphicsDevice.SetPixelShader(pixelShader);

        // draw using the configured pipeline
        graphicsDevice.DrawPrimitives(PrimitiveType.TriangleList, 0, 12);
    }
}

Lengthy, isn’t it? Now, let’s have a look at another example.

Solar Wind

The Solar Wind 3D sample (download from http://bit.ly/sl5-solarwind) uses the new 3D features of Silverlight 5 to draw the Earth with day and night transitions, atmosphere layers, and population density overlays. It demonstrates advanced concepts and it’s very cool that you’ll like to run and play with it.

Babylon3D

The most amazing sample yet (download from http://bit.ly/sl5-babylon3d), it shows a full 3D realtime engine with some advanced features and an integrated collisions system.

 

Summary

Silverlight 5 has got few improvements in the graphics stack:

  • Improved performance:
    Uses the composition model of Windows Phone 7; a separate, dedicated thread for graphics and drawing.
  • Hardware Acceleration:
    Depending more on GPU for graphics processing. Frees CPU from much work, and as a result, improves performance.
  • New 3D API:
    A low-level 3D API based on XNA Framework. Difficult to work with. Community will likely wrap to simplify use.
  • Vector Printing:
    Very useful for certain cases, not available in the Beta.
  • Print Preview:
    Allows for print previews. Not in Beta.

Now, check out other What’s New in Silverlight 5? articles.

What’s New in Silverlight 5? – Control and Text Improvements

What’s New in Silverlight 5?

شاهد كورس كامل سيلفرلايت 5 مجانا هنا.

This content is based on Beta release, expect many changes in the final release.

Read What’s New in Silverlight 5 series here.

Download Sample Code

 

Introduction

In this article, we’ll have a brief discussion of the new features of controls and text in Silverlight 5.

 

Overview

Silverlight 5 has undergone few improvements in controls and text; new added features for controls, and rendering and performance enhancements for text.

The following are the new features of controls in Silverlight 5:

  • Text tracking and leading control
  • Text overflow
  • Multi-click support
  • Type-ahead text searching
  • SaveFileDialog DefaultFilename
  • DataContextChanged event (not in Beta)

And text has been improved in in a few ways:

  • Rendering is now better
  • Performance of text layout has been improved
  • Text clarity is improved with Pixel Snapping
  • OpenType support has been enhanced

As improvements in text were all about rendering and performance, we won’t talk more about the text improvements. Instead, we’ll focus in this article on control stack and cover the changes that happened to it in details.

 

Text Tracking and Leading Control

Silverlight 5 has added three features to text controls (TextBlock, TextBox, and RichTextBox) to allow you to control precisely text tracking and leading space for characters and lines:

  • Character Spacing
  • Line Height
  • Line Stacking Strategy

Character Spacing

This feature allows you to precisely set how far apart each character is. This feature is available in all text controls through a property called CharacterSpacing that specifies the distance between characters. This distance is measured by 1000th of the current font size, means that for instance if you set the font size to 20px and character spacing to 500, then the distance will be 10px between each character (since 20 * 500 / 1000 = 10px.)

Here’s an example of a TextBlock that uses the character spacing feature to put 10px between each character:

<TextBlock FontSize="20" CharacterSpacing="500">
  Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</TextBlock>

Line Height

This feature allows you to set precisely the height of each line of the content in a text controls. It’s available in all text controls through a property called LineHeight and, unlike CharacterSpacing, it’s measured in pixels.

The following code sets the height of each line in the text to 50px:

<TextBlock Margin="5" LineHeight="50">
  Lorem ipsum dolor sit amet, consectetur adipiscing elit.
  <LineBreak />
  Lorem ipsum dolor sit amet, consectetur adipiscing elit.
  <LineBreak />
  Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</TextBlock>

Line Stacking Strategy

This feature allows you to specify how each line box is determined. For example, if you’re in a scenario like the following where you have some text larger than other text, what will you do?  Would you increase the height for each line to accommodate the size for the larger text and allow the text to be readable?  Or would you leave the text as it as if there wasn’t any text with different font size? That’s what the stacking strategy is all about.

<TextBlock Margin="25" FontSize="12">
  Lorem ipsum <Span FontSize="20">dolor sit amet</Span>, ...
  <LineBreak />
  Proin aliquam augue quis ipsum <Span FontSize="38">rhoncus</Span> ...
  <LineBreak />
  Quisque eleifend ante vitae velit vehicula luctus. ...
</TextBlock>

The stacking strategy is available to your code through a new property called LineStackingStrategy. This property takes one value of three:

  • MaxHeight (default):
    Increases the size of each line’s box enough to hold its content. If LineHeight is set, adds the value of LineHeight to the determined value of the height of line’s box.
  • BlockLineHeight:
    Uses value from LineHeight if specified. Otherwise, increases the size for each line’s box to hold its various font sizes content.
  • BaselineToBaseline:
    Uses value from LineHeight if sepified. Otherwise, uses the default line height that doesn’t care about whether the content has larger text or not.

The following figure compares between the three stacking strategies while setting LineHeight and while not setting it.

Makes sense?

 

Text Overflow

This feature allows for multi-column and free-form text layouts. It’s available for RichTextBoxes only. You set a RichTextBox as the master element, and link it to the new RichTextBoxOverflow to capture extra text that doesn’t fit in the master RichTextBox. You can also continue the chain and link another RichTextBoxOverflow to the previous one to capture extra text that doesn’t fit there and so on. To link an overflow control to another one, you use the new OverflowContentTarget property available in the previous control to bind to the next overflow control.

The following figure shows how you can use overflow controls to create multi-column text:

And the following shows an example of a free-form text where the text wraps around an object in the center:

The following example creates a multi-column text:

<Grid.ColumnDefinitions>
  <ColumnDefinition />
  <ColumnDefinition />
  <ColumnDefinition />
</Grid.ColumnDefinitions>

<RichTextBox OverflowContentTarget="{Binding ElementName=firstOverflow}" />

<RichTextBoxOverflow x:Name="firstOverflow" Grid.Column="1"
  OverflowContentTarget="{Binding ElementName=secondOverflow}"/>

<RichTextBoxOverflow x:Name="secondOverflow" Grid.Column="2" />

 

Multi-Click Support

Silverlight 5 now allows you to capture multi-clicks in controls. It can capture any n-clicks, but most of the time you’ll capture double-clicks and sometimes triple clicks. This feature is available through a property called ClickCount available in MouseButtonEventArgs. While MouseButtonEventArgs is available in ButtonDown and ButtonUp events, ClickCount is only valid on MouseLeftButtonDown and MouseRightButtonDown, it always return 1 from ButtonUp events.

The following code shows how you can capture multiple clicks in a TextBlock, it updates the TextBlock for each click:

private void theTextBlock_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
  if (e.ClickCount == 1)
    theTextBlock.Text += "Single-clickn";
  else if (e.ClickCount == 2)
    theTextBlock.Text += "Double-clicksn";
  else if (e.ClickCount == 3)
    theTextBlock.Text += "Triple-clicksn";
  else
    theTextBlock.Text += e.ClickCount.ToString() + "n";
}

 

Type-Ahead Text Searching

Type-ahead text searching capability in Silverlight 5 allows you to search in a collection control (e.g. ComboBox, ListBox, etc.) using keyboard; you reach the desired item by typing the first letters of its content.

The content that the control searches in must be specified in DisplayMemberPath. For example, in our books scenario to search in book titles you must set DisplayMemberPath to the Title field. This leads up to another problem, if you have set a data template, you cannot set DisplayMemberPath along with it. This problem can be solved by using the new Silverlight 5 XAML feature, implicit data templates, which has been covered earlier in the previous article.

In our books scenario, we have the following ComboBox that has an implicit data template applied:

<ComboBox x:Name="books" />

And we have also the following code that populates the ComboBox and sets the DisplayMemberPath to allow searching using keyboard:

books.ItemsSource = new BookData().OrderBy(b => b.Title);
books.DisplayMemberPath = "Title";

The application works perfectly now. But if you convert the data template to an explicit data template like the following:

<ComboBox x:Name="books>
  <ComboBox.ItemTemplate>
    <DataTemplate>
      <StackPanel>
        <TextBlock Text="{Binding Title}" FontWeight="Bold" />
        <TextBlock Text="{Binding Author}" />
        <TextBlock Text="{Binding Price, StringFormat='C'}" />
      </StackPanel>
    </DataTemplate>
  </ComboBox.ItemTemplate>
</ComboBox>

You receive the following error, because DisplayMemberPath cannot be set while setting an ItemTemplate:

 

SaveFileDialog DefaultFilename

Now in Silverlight 5 you can set the default filename in SaveFileDialog (using the new DefaultFileName property) that will show in the file name box when you launch the dialog:

SaveFileDialog dialog = new SaveFileDialog();
dialog.DefaultFileName = "Foo";
dialog.ShowDialog();

 

DataContextChanged Event

This feature is currently not available in Beta; it should be available in the final version. It occurs when the DataContext object for a control changes.

 

Summary

For controls in Silverlight 5, we have the following improvements:

  • Text tracking and leading control:
    Allows you to set character spacing, line height, and line stacking strategy for a text control.
  • Text overflow:
    Available for RichTextBoxes. Allows for multi-column and free-form text layouts.
  • Multi-click support:
    Allows you to capture any n-clicks.
  • Type-ahead text searching:
    Allows searching in a collection control using keyboard.
  • SaveFileDialog DefaultFilename:
    Allows you to set the default file name for SaveFileDialog.
  • DataContextChanged event:
    Not in beta. Occurs when the DataContext object for a control changes.

And in the text stack, there were some improvements related to performance and rendering:

  • Rendering is now better
  • Performance of text layout has been improved
  • Text clarity is improved with Pixel Snapping
  • OpenType support has been enhanced

Now, check out other What’s New in Silverlight 5? articles.