Tag Archives: Windows Phone 8

Handling Input in XNA / MonoGame

This morning I didn’t have internet access and was trying to find this in my notes (which are also my blog posts), and I couldn’t; so purely for my own benefit, the following is a method of handling touch or mouse input in Monogame:

        public void HandleInput()
        {
            ProcessMouseInput();
            ProcessTouchInput();
            ProcessKeyboardInput();
        }

        private void ProcessMouseInput()
        {
            var currentMouse = Microsoft.Xna.Framework.Input.Mouse.GetState();

            if (currentMouse.LeftButton == Microsoft.Xna.Framework.Input.ButtonState.Pressed)
            {
                HandlePressed(currentMouse.Position, _controlledObject);
            }
        }

        private void ProcessTouchInput()
        {
            var currentTouch = Microsoft.Xna.Framework.Input.Touch.TouchPanel.GetState();

            foreach (var touch in currentTouch.Where(t => t.State == Microsoft.Xna.Framework.Input.Touch.TouchLocationState.Pressed))
            {
                HandlePressed(touch.Position, _controlledObject);
            }


        }

        private void ProcessKeyboardInput()
        {
            var currentKeys = Microsoft.Xna.Framework.Input.Keyboard.GetState();
            if (currentKeys.IsKeyDown(Microsoft.Xna.Framework.Input.Keys.Left))
            {
                _handler.GoLeft(_controlledObject);

By changing Pressed to Released, you can detect when the mouse button click / touch finished; however, if you hold your finger / mouse button down, it will only return a single result.

Playing Media in Windows Universal Apps

I recently had cause to write a universal app that has voice capabilities. Hopefully it will shortly be available on the Windows Store.

Adding voice synthesis, while a seemingly basic task, proved to be anything but. What follows is a series of trials and tribulations that I have overcome in order to bring this app to the public!

The Code

Here’s the basic code to get started.

                var voiceStream = await synth.SynthesizeTextToStreamAsync("Hello");
                
                MediaElement mediaElement = new MediaElement();

                mediaElement.SetSource(voiceStream, voiceStream.ContentType);
                mediaElement.AutoPlay = false;
                mediaElement.Volume = 1;
                mediaElement.IsMuted = false;

                mediaElement.Play();

Windows Phone

The first issue I encountered with Windows Phone was the volume. Having maxed out my laptop speakers, I managed get a faint whimper. What I finally deduced is that, for some reason, when the emulator starts, it starts at half volume. To increase it you have to press the phone’s volume buttons (which I initially assumed were just there for aesthetics. Clearly Microsoft haven’t entirely abandoned skeuomorphism.

Phone

The volume controls are the top right buttons (which I happened to know because I have owned a Windows Phone in the past). Once you press it then a more sensible interface appears and you can change either the ringer volume, or the game volume.

Overtalking

Although the code above does work, try calling the code in a loop (or just twice). What happens is that it doesn’t wait for itself to finish.

What I didn’t realise (until I asked this) was that there are some events which supposedly fire when the media element has finished playing.

                var voiceStream = await synth.SynthesizeTextToStreamAsync(toSay);
                
                MediaElement mediaElement = new MediaElement();

                mediaElement.Loaded += mediaElement_Loaded;
                mediaElement.MediaEnded += mediaElement_MediaEnded;
                mediaElement.MediaFailed += mediaElement_MediaFailed;

                mediaElement.SetSource(voiceStream, voiceStream.ContentType);
                mediaElement.AutoPlay = false;
                mediaElement.Volume = 1;
                mediaElement.IsMuted = false;
                
                mediaElement.Play();

I say supposedly, because when I first tried to capture the events, they did nothing. After a bit of searching, it turns out that the element needs to be part of the visual tree! Which of course makes total sense – an AUDIO media element must be part of the VISUAL tree.

In the Visual Tree

The code below now looks for the media element in the visual tree, and if it can’t find one, adds it. It also uses the TaskCompletionSource object to await the audio stream.

            using (SpeechSynthesizer synth = new SpeechSynthesizer())
            {
                var voiceStream = await synth.SynthesizeTextToStreamAsync(toSay);
                
                MediaElement mediaElement;
                
                mediaElement = this.rootControl.Children.FirstOrDefault(m => (m as MediaElement) != null) as MediaElement;
                if (mediaElement == null)
                {
                    mediaElement = new MediaElement();
                    this.rootControl.Children.Add(mediaElement);
                }
                
                mediaElement.SetSource(voiceStream, voiceStream.ContentType);                
                mediaElement.Volume = 1;
                mediaElement.IsMuted = false;

                var tcs = new TaskCompletionSource<bool>();
                mediaElement.MediaEnded += (o, e) => { tcs.TrySetResult(true); };
                mediaElement.Play();

                await tcs.Task;
                
            }

That works. At least, it works on Windows Phone. Because it uses a media element, I thought putting it on a shared XAML page would work… but it doesn’t. Windows 8.1 just sits there quietly and says nothing.

Windows Store

After much trial and error, it occurred to me (prompted by a comment on the above question) that if the problem was down to a deadlock, then destroying and recreating the control might clear this up.

Amazingly, that did seem to work; the working code is:

            using (SpeechSynthesizer synth = new SpeechSynthesizer())
            {
                var voiceStream = await synth.SynthesizeTextToStreamAsync(toSay);

                MediaElement mediaElement;

                mediaElement = rootControl.Children.FirstOrDefault(a => a as MediaElement != null) as MediaElement;
                if (mediaElement == null)
                {
                    mediaElement = new MediaElement();
                    
                    rootControl.Children.Add(mediaElement);
                }

                mediaElement.SetSource(voiceStream, voiceStream.ContentType);
                mediaElement.Volume = 1;
                mediaElement.IsMuted = false;

                var tcs = new TaskCompletionSource<bool>();                
                mediaElement.MediaEnded += (o, e) => { tcs.TrySetResult(true); };               

                mediaElement.Play();                

                await tcs.Task;

                rootControl.Children.Remove(mediaElement);

            }

And this does seem to work on both platforms.

How to Draw a Diagonal Line Using Only XAML (and no path data)

I’ve been playing around with an app to maintain a score. The first thing that I wanted to do was to split the screen, but I wanted a diagonal split; similar to this:

phonescreen

There are a number of ways that this can be achieved; however, this is a method using only XAML. The same method will (I believe) work on Windows 8, WPF and Windows Phone.

First, split the screen into three rows or columns (which depends on how you want the orientation):

        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

This needs to be an odd number of rows / columns if you want the line to be central; additionally, an increased number of rows or columns will result in a smaller incline. Next, draw a transparent rectangle across the middle grid square:

        <Rectangle Name="Placeholder" Grid.Row="1" 
                   HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
                   Opacity="0"/>

Finally, simply draw a line, binding the X2, Y2 values to the height and width of your rectangle:

        <Line Grid.Row="1" 
              X1="0" X2="{Binding ActualWidth, ElementName=Placeholder}"
              Y1="0" Y2="{Binding ActualHeight, ElementName=Placeholder}"
              StrokeThickness="2" Stroke="Blue"/>

Conclusion

I’m not saying the is the best, most efficient, or only way of doing this. However, it does mean that I can do it on both Windows Phone and Windows Store (and in WPF if I were so inclined) using a single shared project.

Adding a tile to Windows Phone (Annoying and unhelpful errors – Part 2)

Following on from this post, I encountered the following error:

Value does not fall within the expected range.

Here’s the culpable code again:

SecondaryTile tileData = new SecondaryTile()
{
    TileId = title,
    DisplayName = title,
    Arguments = arguments
};
tileData.VisualElements.Square150x150Logo = new Uri("ms-appx:///assets/TileIcon150x150.png");
tileData.VisualElements.ShowNameOnSquare150x150Logo = true;

And, as is typical with these things, it worked yesterday, when I wrote the above post. So, why now, when I run it, does it point to the instantiation of `SecondaryTile` above and cry foul?

This time, it was caused by the ID containing an invalid character (a space). Something similar to the following will fix it:

SecondaryTile tileData = new SecondaryTile()
{
    TileId = title.Replace(" ", ""),
    DisplayName = title,
    Arguments = arguments
};
tileData.VisualElements.Square150x150Logo = new Uri("ms-appx:///assets/TileIcon150x150.png");
tileData.VisualElements.ShowNameOnSquare150x150Logo = true;