MosaicUIWpf 2026.6.20.1

<span><img src="./docs/images/collage-48.png" alt="Mosaic Icon" height="48" style="vertical-align: middle;"> Mosaic UI for WPF</span>

Mosaic UI for WPF is a control library that seeks to provide compartmentalized controls that if needed could be easily extracted from this project and included in your own.

Almost every WPF UI kit contains a way to theme that's custom and unique to their framework, it makes mixing and matching controls sometimes cumbersome. This project is trying to provide enough themeing options that you could use it by itself but not tether all of the controls to it so you could include it, or parts of it in other projects that use other UI libraries. I'll also be providing basic examples of how to use each control so you've got a copy/paste reference to start from and a working demo app to quickly browse and try out controls.

WPF is a great, mature technology that will be with us for a long time now that's part of .NET Core. WPF's current and future longevity are one of its strengths. If you're writing a hobby project you want to be around in 10 years, WPF is a great choice. Credit to the dotnet developer team for bringing it the modern .NET stack.

If you find this project interesting or useful, please give it a star.

Note: Expect frequent updates to the styling system during the early stages of this project. I’m currently exploring various theming patterns through a process of experimentation. I've concluded that customizing the default control templates for native WPF controls is necessary; these will be provided in a separate ResourceDictionary. Previously, I overrode SystemColors, but this approach proved too invasive—particularly for applications aiming to coexist with other UI frameworks without conflict. Also, there are many stock controls that use static resources or hard coded colors so SystemColors gets you some of the way there, but not all of the way

A final note, if you have a useful reusable (mostly) compartmentalized control you want to share and be creditted for, feel free to put in a pull request and I'll look at it.

Getting Started

Install the NuGet Package

Install the package from NuGet using the .NET CLI:

dotnet add package MosaicUIWpf

Or search for MosaicUIWpf in the Visual Studio NuGet Package Manager.

Set Up Your Application

1. Update App.xaml to use MosaicApp and merge ThemeManager into your application resources:

<wpf:MosaicApp
    x:Class="YourApp.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mosaic="http://schemas.apexgate.net/wpf/mosaic-ui"
    xmlns:vm="clr-namespace:YourApp.Common"
    xmlns:wpf="clr-namespace:Mosaic.UI.Wpf;assembly=Mosaic.UI.Wpf"
    x:TypeArguments="vm:AppSettings, vm:AppViewModel"
    StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <mosaic:ThemeManager
                    Native="True"
                    SystemColors="True"
                    Theme="Dark" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</wpf:MosaicApp>

Set Theme to "Light", "Dark", or "HighContrast". Set Native="True" to restyle built-in WPF controls. Set SystemColors="True" to integrate with the OS accent color.

2. Update MainWindow.xaml to apply the window chrome behavior and Mosaic theme brushes:

<Window
    x:Class="YourApp.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mosaic="clr-namespace:Mosaic.UI.Wpf.Controls;assembly=Mosaic.UI.Wpf"
    xmlns:theme="http://schemas.apexgate.net/wpf/mosaic-ui"
    theme:WindowChromeBehavior.CaptionHeight="0"
    theme:WindowChromeBehavior.CornerRadius="10"
    theme:WindowChromeBehavior.IsEnabled="True"
    theme:WindowChromeBehavior.ResizeBorderThickness="5"
    Background="{DynamicResource {x:Static theme:MosaicTheme.WindowBackgroundBrush}}"
    Foreground="{DynamicResource {x:Static theme:MosaicTheme.WindowForegroundBrush}}">

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="35" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <mosaic:WindowTitleBar Grid.Row="0" IconSource="/Assets/icon.png" />

        
    </Grid>
</Window>

3. Use controls anywhere in your XAML with the mosaic namespace (http://schemas.apexgate.net/wpf/mosaic-ui):

xmlns:mosaic="http://schemas.apexgate.net/wpf/mosaic-ui"

For a complete wiring example, see MosaicTemplateApp in the repository.

Dark Theme

Light Theme

Architecture Blueprint

See docs/ARCHITECTURE_BLUEPRINT.md for the control-library architecture, theming model, interoperability rules, accessibility baseline, and DX guidelines.

Solution Projects

Included Controls

The following table lists the controls found in src/Mosaic.UI.Wpf/Controls and their class descriptions (from XML comments).

Included Behaviors

The following table lists the behaviors found in src/Mosaic.UI.Wpf/Behaviors.