Droid ValueConverter for LinearLayout Gravity

Question

I'm developing an application that contains a ListView. The items on the ListView should be either on the left or on the right of the screen depending on the item's content. So i created a converter to check the item and set a LinearLayout gravity. The converter is being called and it's returning right or left "correctly", but the LinearLayout is not being set. The Linear Layout is the following:

<LinearLayout
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="5dp"
    android:layout_marginBottom="5dp"
    android:background="#FFFFFF"
    local:MvxBind="Gravity Content, Converter=MessageAlign">

The converter I tried it in 2 different ways, one using GravityFlags and the other strings:

public class MessageAlignConverter : MvxValueConverter<string, GravityFlags>
{
    protected override GravityFlags Convert(string value, Type targetType, object parameter, CultureInfo culture)
    {
        if (My Test)
        {
            return GravityFlags.Right;
        }
        return GravityFlags.Left;
    }
}

public class MessageAlignConverter : MvxValueConverter<string, string>
{
    protected override string Convert(string value, Type targetType, object parameter, CultureInfo culture)
    {
        if (My Test)
        {
            return "right";
        }
        return "left";
    }
}

Neither one of them worked, so i checked the LinkerPleaseInclude. I tried adding in the LinkerPleaseInclude but i cannot get the current gravity, for a button (as example) i would do:

public void Include(Button button)
    {
        button.Click += (s,e) => button.Text = button.Text + "";
    }

So i imagined something like this for the LinearLayout:

public void Include(LinearLayout linearLayout)
    {
        linearLayout.SetGravity(linearLayout.Gravity?);
    }

Any ideas on how to do this?

Forgot to mention the output:

MvxBind:Warning:  6.00 Failed to create target binding for binding Gravity for Content
[0:] MvxBind:Warning:  6.00 Failed to create target binding for binding Gravity for Content
10-26 15:43:51.796 I/mono-stdout(11936): MvxBind:Warning:  6.00 Failed to create target binding for binding Gravity for Content

Thanks!

I don't know this API, but if there is no `set` for the C# property `Gravity`, then you'll need to make a custom binding which calls `SetGravity`. Custom bindings are easy to do - see the samples in the N+1 tutorial — Stuart, Oct 26 '14 at 16:24

score 2 · Accepted Answer · edited May 23 '17 at 12:11

2

First, I think you should use the first version of the value converter (the one returning GravityFlags)

Second, in the application output, do you see any debug text saying that it couldn't bind to Content? If you don't, then there's no reason to think about LinkerPleaseInclude.

Third, you didn't show how you define the ListView in AXML, so make sure you don't have any issues with the UI. If you replace the Mvx.Bind binding with harcoding the android:gravity to a value, is the item displayed correctly?

EDIT: Use define your own binding to set Gravity: In MvvmCross how do I do custom bind properties

edited May 23 '17 at 12:11

Community

1
1

answered Oct 25 '14 at 23:26

WriteEatSleepRepeat

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I checked the list it's working correctly, i tried hardcoding the gravity and it worked. I forgot to add there in the question the output, it has one, that's why I imagined it had a relation with the LinkerPleaseInclude, the output is the following: (I'm gonna add it in the question as well) MvxBind:Warning: 6.00 Failed to create target binding for binding Gravity for Content [0:] MvxBind:Warning: 6.00 Failed to create target binding for binding Gravity for Content 10-26 15:43:51.796 I/mono-stdout(11936): MvxBind:Warning: 6.00 Failed to create target binding for binding Gravity for Content – Daniel Oct 26 '14 at 17:46
binding works with properties. There's no 'Gravity' property on the LinearLayout so that's why it doesn't work – WriteEatSleepRepeat Oct 26 '14 at 19:04

Droid ValueConverter for LinearLayout Gravity

1 Answers1