This project is based on a post I wrote a long time ago for my blog.
The .NET MAUI library has been separated into its own repository. If you are looking for the library for .NET MAUI, please go here.
If you are looking for Xamarin library, keep on this current repo.
OnScreenSizeMarkup is XAML markup extension for controlliing UI elements depending on the device screen size category.
OnScreenSizeMarkup is currently compatible with:
- Xamarin.Forms
- MAUI
It works exactly as other markup extensions such as OnPlatform or OnIdiom, allowing you to control UI views accordding to the screen sizes category a device fits in.
The screen sizes are grouped into six categories:
ExtraSmall- Tiny devices as an Apple Watch.Small- Small devices, such as a Google Pixel 5.Medium- Medium devices such as IPhone 12.Large- Large devices such as an IPhone 13 Pro Max.ExtraLarge- Extra large devices such as tablets.
For each category we define specific value when using the markup on XAML.
There is also a DefaultSize category that should be used when only few category options are used in the markup properties, in this case a value defined in the DefaultSize property will be applied for the missing options.
Using the markup is very straight foward, you can apply it to most UI View elements, such as Labels, Grids, Buttons, ImageButtons, and etc.
<ContentPage
xmlns:markups="clr-namespace:OnScreenSizeMarkup.Forms;assembly=OnScreenSizeMarkup.Forms">
<ContentPage.Content>
<Grid RowDefinitions="{markups:OnScreenSize Large='200, *, 200',
ExtraLarge='300, *, 300',
DefaultSize='100, *, 100'}">
<Label
Padding="{markups:OnScreenSize
Medium='15, 15, 0, 0',
Large='20, 20, 0, 0',
DefaultSize='10, 10, 0, 0'}"
Text="Hello" TextColor="White" />
</Grid>
</ContentPage.Content>
</ContentPage> In the above example we are defining a Grid with 3 rows, with different values for RowDefinitions depending on the category of the screen fits in.
We are also defining a Label and setting it's padding to vary also depending on the screen's category.
Note You can use the markup for most View's properties, not limited to RowDefinitions or Paddings.
You can also use a similar mechanism from code-behind:
using OnScreenSizeMarkup.Forms;
public MainPage()
{
Grid grid = new Grid
{
RowDefinitions =
{
//first row
Markup.OnScreenSize(defaultSize: new RowDefinition { Height = new GridLength(100) },
large: new RowDefinition { Height = new GridLength(200) },
extraLarge: new RowDefinition { Height = new GridLength(300) }),
//second row
new RowDefinition(),
//third row
Markup.OnScreenSize(defaultSize: new RowDefinition { Height = new GridLength(100) },
large: new RowDefinition { Height = new GridLength(200) },
extraLarge: new RowDefinition { Height = new GridLength(300) }),
}
};
grid.Children.Add(new Label
{
Text = "Hello",
Padding = Markup.OnScreenSize(defaultSize: new Thickness(10, 10, 0, 0),
medium: new Thickness(15, 15, 0, 0),
large: new Thickness(20, 20, 0, 0))
});
Content = grid;
}
}; Most of the time you don't need do implement anything in order to categorize the screen sizes, as the markup is backed by a DefaultFallbackHandler instance class, but there may be times you may need to override/customize the screen size categorization with your own rules, thats when the Category Fallback Handlers comes to the rescue.
A category fallback handler is a class that implements ICategoryFallbackHandler interface composed of two methods which returns a ScreenCategories Enum (ExtraSmall, Small, Medium, Large, ExtraLarge) based on device's model, or device's physical screen size (Width/Height):
TryGetCategoryByDeviceModel- Returns a screen category by the device-model.TryGetCategoryByPhysicalSize- Returns a screen category by screen measures (width/height).
Due to some incorrect screen size info returned by some iOS simulator devices during development and tests, it was not possible to depend only on the screen size measures for categorize screens, and in order to fix that, it was intruduced TryGetCategoryByDeviceModel method, which based on the device's model we can confidently categorize a device.
The Markup first attempts to execute TryGetCategoryByDeviceModel by passing the device's model, and in case it returns false, it tries to execute TryGetCategoryByPhysicalSize by passing a device screen size (Width/Height).
Note: For getting either the device model or the device size I use Xamarin.Essentials.
If you need to implement your own handler you MUST set its instance during the app initialization as follow:
OnScreenSizeMarkup.Core.Manager.Current.Handler = new MyNewFallBackHandlerClass();The markup comes with a DefaultFallbackHandler class which maps most iOS devices models and screens sizes (for android devices).
Here is dictionary's items of the device models and it's categories mappings we currently have:
{ "iPhone1_1", ScreenCategories.Small },
{ "iPhone1,2", ScreenCategories.Small },
{ "iPhone2,1", ScreenCategories.Small },
{ "iPhone3,1", ScreenCategories.Small },
{ "iPhone3,2", ScreenCategories.Small },
{ "iPhone3,3", ScreenCategories.Small },
{ "iPhone4,1", ScreenCategories.Small },
{ "iPhone5,1", ScreenCategories.Small },
{ "iPhone5,2", ScreenCategories.Small },
{ "iPhone5,3", ScreenCategories.Small },
{ "iPhone5,4", ScreenCategories.Small },
{ "iPhone6,1", ScreenCategories.Small},
{ "iPhone6,2", ScreenCategories.Small },
{ "iPhone7,1", ScreenCategories.Large },
{ "iPhone7,2", ScreenCategories.Medium },
{ "iPhone8,1", ScreenCategories.Medium },
{ "iPhone8,2", ScreenCategories.Large },
{ "iPhone8,4", ScreenCategories.Medium },
{ "iPhone9,1", ScreenCategories.Medium },
{ "iPhone9,2", ScreenCategories.Large },
{ "iPhone9,3", ScreenCategories.Medium },
{ "iPhone9,4", ScreenCategories.Large },
{ "iPhone10,1", ScreenCategories.Medium },
{ "iPhone10,2", ScreenCategories.Large },
{ "iPhone10,3", ScreenCategories.Medium },
{ "iPhone10,4", ScreenCategories.Medium },
{ "iPhone10,5", ScreenCategories.Large },
{ "iPhone10,6", ScreenCategories.Medium },
{ "iPhone11,2", ScreenCategories.Medium },
{ "iPhone11,4", ScreenCategories.Large },
{ "iPhone11,6", ScreenCategories.Large },
{ "iPhone11,8", ScreenCategories.Medium },
{ "iPhone12,1", ScreenCategories.Medium },
{ "iPhone12,3", ScreenCategories.Medium },
{ "iPhone12,5", ScreenCategories.Large },
{ "iPhone12,8", ScreenCategories.Medium },
{ "iPhone13,1", ScreenCategories.Medium },
{ "iPhone13,2", ScreenCategories.Medium },
{ "iPhone13,3", ScreenCategories.Medium },
{ "iPhone13,4", ScreenCategories.Large },
{ "iPhone14,2", ScreenCategories.Medium },
{ "iPhone14,3", ScreenCategories.Large },
{ "iPhone14,4", ScreenCategories.Medium },
{ "iPhone14,5", ScreenCategories.Medium },
{ "Pad12,2", ScreenCategories.ExtraLarge },
{ "iPad_9th_Gen", ScreenCategories.ExtraLarge },
{ "iPad1,2", ScreenCategories.ExtraLarge },
{ "iPad2,1", ScreenCategories.ExtraLarge },
{ "iPad2,2", ScreenCategories.ExtraLarge },
{ "iPad2,3", ScreenCategories.ExtraLarge },
{ "iPad2,4", ScreenCategories.ExtraLarge },
{ "iPad2,5", ScreenCategories.ExtraLarge },
{ "iPad2,6", ScreenCategories.ExtraLarge },
{ "iPad2,7", ScreenCategories.ExtraLarge },
{ "iPad3,1", ScreenCategories.ExtraLarge },
{ "iPad3,2", ScreenCategories.ExtraLarge },
{ "iPad3,3", ScreenCategories.ExtraLarge },
{ "iPad3,4", ScreenCategories.ExtraLarge },
{ "iPad3,5", ScreenCategories.ExtraLarge },
{ "iPad3,6", ScreenCategories.ExtraLarge },
{ "iPad4,1", ScreenCategories.ExtraLarge },
{ "iPad4,2", ScreenCategories.ExtraLarge },
{ "iPad4,3", ScreenCategories.ExtraLarge },
{ "iPad4,4", ScreenCategories.ExtraLarge },
{ "iPad4,5", ScreenCategories.ExtraLarge },
{ "iPad4,6", ScreenCategories.ExtraLarge },
{ "iPad4,7", ScreenCategories.ExtraLarge },
{ "iPad4,8", ScreenCategories.ExtraLarge },
{ "iPad4,9", ScreenCategories.ExtraLarge },
{ "iPad5,1", ScreenCategories.ExtraLarge },
{ "iPad5,2", ScreenCategories.ExtraLarge },
{ "iPad5,3", ScreenCategories.ExtraLarge },
{ "iPad5,4", ScreenCategories.ExtraLarge },
{ "iPad6,4", ScreenCategories.ExtraLarge },
{ "iPad6,7",ScreenCategories.ExtraLarge },
{ "iPad6,8", ScreenCategories.ExtraLarge },
{ "iPad6,11", ScreenCategories.ExtraLarge },
{ "iPad6,12", ScreenCategories.ExtraLarge },
{ "iPad7,1", ScreenCategories.ExtraLarge },
{ "iPad7,2", ScreenCategories.ExtraLarge },
{ "iPad7,3", ScreenCategories.ExtraLarge },
{ "iPad7,4", ScreenCategories.ExtraLarge },
{ "iPad7,5", ScreenCategories.ExtraLarge },
{ "iPad7,6", ScreenCategories.ExtraLarge },
{ "iPad7,11", ScreenCategories.ExtraLarge },
{ "iPad7,12", ScreenCategories.ExtraLarge },
{ "iPad8,1", ScreenCategories.ExtraLarge },
{ "iPad8,2", ScreenCategories.ExtraLarge },
{ "iPad8,3", ScreenCategories.ExtraLarge },
{ "iPad8,4", ScreenCategories.ExtraLarge},
{ "iPad8,5", ScreenCategories.ExtraLarge },
{ "iPad8,6", ScreenCategories.ExtraLarge },
{ "iPad8,7", ScreenCategories.ExtraLarge },
{ "iPad8,8", ScreenCategories.ExtraLarge },
{ "iPad8,9", ScreenCategories.ExtraLarge },
{ "iPad8,10", ScreenCategories.ExtraLarge },
{ "iPad8,11", ScreenCategories.ExtraLarge },
{ "iPad8,12", ScreenCategories.ExtraLarge },
{ "iPad11,1", ScreenCategories.ExtraLarge },
{ "iPad11,2", ScreenCategories.ExtraLarge },
{ "iPad11,3", ScreenCategories.ExtraLarge },
{ "iPad11,4", ScreenCategories.ExtraLarge },
{ "iPad11,6", ScreenCategories.ExtraLarge },
{ "iPad11,7", ScreenCategories.ExtraLarge },
{ "iPad12,1", ScreenCategories.ExtraLarge },
{ "iPad12,2", ScreenCategories.ExtraLarge },
{ "iPad13,1", ScreenCategories.ExtraLarge },
{ "iPad13,2", ScreenCategories.ExtraLarge },
{ "iPad13,4", ScreenCategories.ExtraLarge },
{ "iPad13,5", ScreenCategories.ExtraLarge },
{ "iPad13,6", ScreenCategories.ExtraLarge },
{ "iPad13,7", ScreenCategories.ExtraLarge },
{ "iPad13,8", ScreenCategories.ExtraLarge },
{ "iPad13,9", ScreenCategories.ExtraLarge },
{ "iPad13,10", ScreenCategories.ExtraLarge },
{ "iPad13,11", ScreenCategories.ExtraLarge },
{ "iPad14,1", ScreenCategories.ExtraLarge },
{ "iPad14,2", ScreenCategories.ExtraLarge },Also, for other screens sizes such as Android devices, here is the mapping based on the screen size:
private static ScreenSizeInfo[] screenSizeCategories = new ScreenSizeInfo[]
{
new ScreenSizeInfo(480,800, ScreenCategories.ExtraSmall),
new ScreenSizeInfo(720,1280, ScreenCategories.Small),
new ScreenSizeInfo(750,1334, ScreenCategories.Medium),
new ScreenSizeInfo(1125,2436, ScreenCategories.Medium),
new ScreenSizeInfo(828,1792, ScreenCategories.Medium),
new ScreenSizeInfo(1080,1920, ScreenCategories.Large),
new ScreenSizeInfo(1242,2688, ScreenCategories.Large),
new ScreenSizeInfo(1284,2778, ScreenCategories.Large),
new ScreenSizeInfo(1440,3200, ScreenCategories.ExtraLarge),
new ScreenSizeInfo(2732,2048, ScreenCategories.ExtraLarge),
};There are some custom Xamarin.Forms types such as Xamarin.Forms.Color in which it's value conversion are not currently supported which leads the markup to handle incorrectly these types.
I intent to implement these value conversions along the time.