mosaic-setup-project

name	mosaic-setup-project
description	Wire Mosaic UI into a WPF project. Converts App.xaml/App.xaml.cs to MosaicApp, adds ThemeManager to resources, replaces any hand-rolled title bar with mosaic:WindowTitleBar, applies WindowChromeBehavior and MosaicTheme brushes to MainWindow, and creates Common/AppSettings.cs + Common/AppViewModel.cs if they do not exist.
argument-hint	Root namespace of the target WPF project (e.g. 'MyApp'). Defaults to the assembly name.

Mosaic Setup Project

Wires Mosaic UI for WPF into an existing WPF application. The skill touches four files and optionally creates two:

1. App.xaml — change root element to wpf:MosaicApp, add ThemeManager to resources
2. App.xaml.cs — inherit from MosaicApp<AppSettings, AppViewModel>, call base.OnStartup / base.OnExit
3. MainWindow.xaml — add WindowChromeBehavior attached properties, Mosaic background/foreground brushes, and replace any hand-rolled title bar with mosaic:WindowTitleBar
4. MainWindow.xaml.cs — keep only MainWindow_OnLoaded and ButtonToggleTheme_OnClick; remove all chrome helpers that WindowTitleBar now owns
5. Common/AppSettings.cs (create if missing)
6. Common/AppViewModel.cs (create if missing)

---

Step 1 — Gather Information

Before editing anything:

• Root namespace — read App.xaml (x:Class prefix) or ask the user. All generated namespace declarations must match.
• Assembly name — read the .csproj (<AssemblyName> or project file name stem). Used for the xmlns:wpf and xmlns:mosaic assembly references. If the assembly name differs from the root namespace, note it.
• Existing Common/AppSettings.cs and Common/AppViewModel.cs — check with Glob. If they already exist, skip Steps 6 and 7 but still verify they implement IAppSettings (AppSettings) and extend ObservableObject (AppViewModel).
• Existing window chrome or title bar — read MainWindow.xaml. Any existing hand-rolled <Border>/<DockPanel> title bar should be replaced with mosaic:WindowTitleBar. If a mosaic:WindowTitleBar is already present, preserve it and only add missing attributes.

---

Step 2 — Update App.xaml

Replace the root element from <Application ...> to <wpf:MosaicApp ...> and add the required namespaces and ThemeManager. The final file must look like this (substitute {RootNamespace} and {AssemblyName}):

<wpf:MosaicApp
    x:Class="{RootNamespace}.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:{RootNamespace}.Common"
    xmlns:wpf="clr-namespace:Mosaic.UI.Wpf;assembly={AssemblyName}"
    x:TypeArguments="vm:AppSettings, vm:AppViewModel"
    Exit="App_OnExit"
    Startup="App_OnStartup"
    StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <mosaic:ThemeManager
                    Native="True"
                    SystemColors="True"
                    Theme="Dark" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</wpf:MosaicApp>

If App.xaml already has a <ResourceDictionary.MergedDictionaries> block, insert the <mosaic:ThemeManager ... /> entry into it rather than replacing the whole block.

---

Step 3 — Update App.xaml.cs

Replace the class declaration so App inherits MosaicApp<AppSettings, AppViewModel> and calls the base lifecycle methods:

using Mosaic.UI.Wpf;
using {RootNamespace}.Common;
using System.Windows;

namespace {RootNamespace}
{
    public partial class App : MosaicApp<AppSettings, AppViewModel>
    {
        private void App_OnStartup(object sender, StartupEventArgs e)
        {
            base.OnStartup(e);
        }

        private void App_OnExit(object sender, ExitEventArgs e)
        {
            base.OnExit(e);
        }
    }
}

Preserve any existing using directives and event handlers that are not replaced above.

---

Step 4 — Update MainWindow.xaml

Window element attributes

Add (or update) the following on the <Window> root element. Do not duplicate attributes that are already present:

xmlns:mosaic="clr-namespace:Mosaic.UI.Wpf.Controls;assembly={AssemblyName}"
xmlns:theme="http://schemas.apexgate.net/wpf/mosaic-ui"
Background="{DynamicResource {x:Static theme:MosaicTheme.WindowBackgroundBrush}}"
Foreground="{DynamicResource {x:Static theme:MosaicTheme.WindowForegroundBrush}}"
theme:WindowChromeBehavior.CaptionHeight="0"
theme:WindowChromeBehavior.CornerRadius="10"
theme:WindowChromeBehavior.GlassFrameThickness="0"
theme:WindowChromeBehavior.IsEnabled="True"
theme:WindowChromeBehavior.ResizeBorderThickness="5"
theme:WindowChromeBehavior.UseAeroCaptionButtons="True"
Loaded="MainWindow_OnLoaded"

Remove xmlns:d, xmlns:mc, and mc:Ignorable="d" if d: prefixed attributes are not used anywhere in the file.

Title bar — replace with mosaic:WindowTitleBar

Replace any hand-rolled <Border>/<DockPanel> title bar (or any earlier manual chrome) in Row 0 of the root <Grid> with the mosaic:WindowTitleBar control. The control handles drag-to-move, double-click maximize/restore, and the minimize/maximize/close buttons internally — no code-behind is required for those actions.

<!--  Title Bar  -->
<mosaic:WindowTitleBar
    Grid.Row="0"
    Grid.Column="0"
    Grid.ColumnSpan="2"
    IconSource="/Assets/collage-48.png">
    <mosaic:WindowTitleBar.RightContent>
        <!--  Toggle Theme Button  -->
        <Button
            Width="48"
            Click="ButtonToggleTheme_OnClick"
            Style="{DynamicResource {x:Static theme:MosaicTheme.WindowTitleBarButtonStyle}}"
            ToolTip="Toggle Theme">
            <Button.ContentTemplate>
                <DataTemplate>
                    <Viewbox Width="16" Height="16">
                        <Canvas Width="512" Height="512">
                            <Path
                                Data="M8 256c0 137 111 248 248 248s248-111 248-248S393 8 256 8 8 119 8 256zm248 184V72c101.7 0 184 82.3 184 184 0 101.7-82.3 184-184 184z"
                                Fill="{DynamicResource {x:Static theme:MosaicTheme.WindowForegroundBrush}}" />
                        </Canvas>
                    </Viewbox>
                </DataTemplate>
            </Button.ContentTemplate>
        </Button>
    </mosaic:WindowTitleBar.RightContent>
</mosaic:WindowTitleBar>

mosaic:WindowTitleBar key properties:

Property	Purpose
IconSource	Path to the 16/48 px app icon
TitleText	Static title string. Omit (or leave empty) to auto-bind to Window.Title
TitleAlignment	HorizontalAlignment of the title text (default Left)
ShowIcon / ShowMinimizeButton / ShowMaxRestoreButton / ShowCloseButton	bool visibility toggles
RightContent	Content slot shown left of the system buttons (theme toggle, settings, etc.)
LeftContent	Content slot shown right of the app icon (breadcrumbs, search, etc.)

---

Step 5 — Update MainWindow.xaml.cs

Because mosaic:WindowTitleBar owns all chrome behaviour internally, the code-behind only needs the startup handler and the theme-toggle handler. Remove TitleBar_MouseLeftButtonDown, Minimize_Click, MaximizeRestore_Click, Close_Click, ToggleMaximize, UpdateMaximizeIcon, and the OnStateChanged override. Also remove using System.Windows.Input if it is no longer referenced.

using System.Windows;
using Argus.Memory;
using Mosaic.UI.Wpf.Themes;

namespace {RootNamespace}
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
        {
        }

        private void ButtonToggleTheme_OnClick(object sender, RoutedEventArgs e)
        {
            var theme = AppServices.GetRequiredService<ThemeManager>();
            theme.ToggleTheme();
        }
    }
}

---

Step 6 — Create Common/AppSettings.cs (if missing)

Path: Common/AppSettings.cs relative to the project root.

using CommunityToolkit.Mvvm.ComponentModel;
using Mosaic.UI.Wpf;
using Mosaic.UI.Wpf.Common;
using Mosaic.UI.Wpf.Interfaces;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Text.Json.Serialization;

namespace {RootNamespace}.Common
{
    public partial class AppSettings : ObservableObject, IAppSettings
    {
        [property: Category("File System")]
        [property: DisplayName("Application Data Folder")]
        [property: Description("The application data folder.")]
        [property: ReadOnly(true)]
        [ObservableProperty]
        private string? _applicationDataFolder;

        [property: Category("File System")]
        [property: DisplayName("Client Settings")]
        [JsonIgnore]
        [ObservableProperty]
        private LocalSettings? _clientSettings = new();

        [property: Category("UI")]
        [property: DisplayName("Theme")]
        [property: Browsable(false)]
        [ObservableProperty]
        private MosaicThemeMode _theme = MosaicThemeMode.Light;

        [property: Category("UI")]
        [property: DisplayName("Font Size")]
        [ObservableProperty]
        private double _fontSize = 12.0;

        [property: Category("UI")]
        [property: DisplayName("Window View States")]
        [ObservableProperty]
        private ObservableCollection<WindowViewState> _windowViewStates = new();
    }
}

---

Step 7 — Create Common/AppViewModel.cs (if missing)

using CommunityToolkit.Mvvm.ComponentModel;

namespace {RootNamespace}.Common
{
    public partial class AppViewModel : ObservableObject
    {
        [ObservableProperty]
        private AppSettings _appSettings = new();

        [ObservableProperty]
        private string _title = "{RootNamespace}";
    }
}

---

Step 8 — Verify

Run:

dotnet build <path-to-csproj> -c Debug

Confirm 0 errors. Common issues:

Symptom	Fix
MosaicApp not found	Verify xmlns:wpf uses the correct assembly name in App.xaml
AppSettings/AppViewModel type not found	Check namespace matches root namespace; ensure x:TypeArguments values match
WindowChromeBehavior XAML parse error	Ensure xmlns:theme="http://schemas.apexgate.net/wpf/mosaic-ui" is on the <Window> element
ButtonToggleTheme_OnClick not found	The handler must exist in MainWindow.xaml.cs
AppServices not found	Add using Argus.Memory; — it comes from the Argus.Core NuGet package

---

Quick Checklist

• App.xaml root element is wpf:MosaicApp with x:TypeArguments
• ThemeManager is in Application.Resources > MergedDictionaries
• App.xaml.cs inherits MosaicApp<AppSettings, AppViewModel> and calls base.OnStartup / base.OnExit
• MainWindow.xaml has WindowChromeBehavior attributes and Mosaic Background/Foreground brushes
• MainWindow.xaml title bar uses mosaic:WindowTitleBar (no hand-rolled <Border>/<DockPanel> chrome)
• MainWindow.xaml.cs contains only MainWindow_OnLoaded and ButtonToggleTheme_OnClick (all chrome helpers removed)
• Common/AppSettings.cs exists and implements IAppSettings
• Common/AppViewModel.cs exists
• Build passes with 0 errors