CustomFormStyler (TitleBarManager)

A lightweight helper that replaces WinForms’ classic window chrome with a flat, theme‑able title‑bar, rounded corners, and fully‑custom minimise / maximise / close buttons. Drop it into any Form, call one line of code, and instantly modernise your UI.

• It’s part of Core Keepers Workshop and is released under the GNU GPL v3.
  • Also check out the BorderlessTabControl.

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✨ Key Features

Feature	Details
Flat Title‑Bar	Removes the native chrome and draws a sleek, minimal bar that blends with your app theme.
Dark / Light Themes	One‑liner switch between dark and light palettes.
Rounded Corners	Pick any combination (Corner flag enum) and radius—independent of OS support.
Custom Buttons	Built‑in Min, Max, Close (and optional Help) buttons with glyphs you can restyle.
Border Options	Draw borders inside (Grow In) or outside (Grow Out) of the client area; choose size & colour.
Runtime Updates	Call UpdateStyle(...) to tweak theme, radius, border, etc. without recreation.
Drag Anywhere	Drag the window by the custom bar—implemented via a tiny Win32 interop helper.
Extension Helpers	Form.ApplyTheme() & RefreshAllThemes() wire everything up and keep multiple windows in sync.

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📥 Installation

1. Copy TitleBarManager.cs (or rename) into your WinForms project.
2. Change the namespace if necessary.
3. Re‑build; no designer support is needed—the styler is code‑only.

ℹ️ No NuGet package (yet) – just a single self‑contained file.

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🚀 Quick Start

public partial class MainForm : Form
{
    private CustomFormStyler _styler;

    public MainForm()
    {
        InitializeComponent();

        _styler = new CustomFormStyler(this);
        _styler.Enable(); // Apply the custom chrome.
    }
}

The One‑liner Extension

// Using the helper in FormStylingExtensions:
Load += (_, __) => this.ApplyTheme();

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🛠️ Public API (Core Class)

Member	Description
Enable() / Disable()	Replace or restore the native window chrome.
Toggle()	Convenience wrapper that flips the state.
IsEnabled	bool – current state of the styler.
UpdateStyle(...)	Change any subset of options at runtime (theme, border size, radius, etc.).
CloseButtonPressed	bool – becomes true the moment the user presses Close (handy for confirmation logic).

Style Parameters

Parameter (UpdateStyle)	Type	Notes
theme	ThemeMode	Dark / Light.
borderMode	BorderMode	GrowOut (outside) or GrowIn (inside).
roundedCorners	Corner	Flag enum (TopLeft, BottomRight, … All).
borderColor	Color?	null ➜ auto (white on dark, black on light).
titleBarHeight	int	Pixel height of the bar.
cornerRadius	int	Radius in pixels. 0 ➜ square.
borderSize	int	Stroke width in pixels. 0 ➜ no border.
showIcon	bool	Show/hide the small window icon.

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🎨 Theming & Styling Tips

• Change theme at runtime – flip a checkbox, then call RefreshAllThemes() to apply the new dark/light palette across every open window.
• Per‑window overrides – call UpdateStyle() on a specific styler to deviate from global settings.
• Help button behaviour – if your form’s HelpButton property is true and both maximise & minimise are hidden, a “?” glyph appears automatically.
• Corner selection UI – expose four checkboxes and build a Corner mask on the fly (see MainForm.SelectedCorners).
• Border insets – remember: GrowOut changes overall form size, while GrowIn eats into the client area; pick what suits your layout.

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⚙️ How It Works (Under the Hood)

1. FormBorderStyle = None – strips the OS frame so we get a blank canvas.
2. Client‑area expansion – compensates for the new title‑bar height (and optional GrowOut border) to keep your existing controls untouched.
3. Wrapper panel – all pre‑existing controls are moved into a _contentPanel so resizing the bar never upsets user content.
4. Drag support – a quick call to ReleaseCapture() + SendMessage(WM_NCLBUTTONDOWN, HTCAPTION) makes the new bar draggable.
5. Rounded corners – GraphicsPath + Region let us clip the rectangle to any combination of rounded edges.
6. Custom border paint – drawn in Form_Paint; half‑pixel offsets ensure crisp strokes at any width.

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📝 License

TitleBarManager.cs / CustomFormStyler is licensed under GNU General Public License v3.0.
See the root LICENSE file for the full text.

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🙏 Credits

Original author: RussDev7
Inspired by countless WinForms custom‑chrome experiments shared by the community.

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📷 Screenshots

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Found a bug or have an idea? Open an issue or pull request—contributions welcome!