Majorsilence.Forms.Gtk4 26.8.2

Majorsilence.Forms.Gtk4

A GTK 4 platform backend for Majorsilence.Forms, built on the gir.core bindings.

Majorsilence.Forms does all of its own drawing with SkiaSharp; this backend is only the host — it creates a real Gtk.Window, runs the GLib main loop, delivers input, and presents the Skia surface through a Gtk.DrawingArea.

Install

dotnet add package Majorsilence.Forms
dotnet add package Majorsilence.Forms.Gtk4

You also need GTK 4 installed on the machine (libgtk-4-1 on Debian/Ubuntu, gtk4 on Fedora/Arch, brew install gtk4 on macOS, the GTK runtime on Windows). For WebBrowser / the webview-backed compat controls, also install WebKitGTK 6.0 (libwebkitgtk-6.0-4 on Debian/Ubuntu, webkitgtk6.0 on Fedora, webkitgtk on Arch).

Use it

Unlike the default (Avalonia) backend, the GTK 4 backend is selected explicitly:

using Majorsilence.Forms;
using Majorsilence.Forms.Gtk4;

Gtk4Application.Use ();                 // installs Gtk4PlatformBackend
Application.Run (new MainForm ());      // GLib main loop

What works

• Real Gtk.Window per top-level Form, borderless windows for popups (menus, combo dropdowns).
• Skia frame rendered straight into a Cairo image surface each paint.
• Mouse (click / move / wheel), keyboard, and typed-text input via GTK event controllers.
• GLib timers back Majorsilence.Forms.Timer; Post/Invoke marshal onto the GLib loop.
• Clipboard text, multi-monitor Screen enumeration.
• Custom-chrome window move/resize drags via Gdk.Toplevel.BeginMove/BeginResize.
• ShowDialog gets a real transient-for / modal window relationship.
• NativeControlHost — a real Gtk.Widget overlaid inside an MF scene (INativeControlHostBackend). GTK 4 composites every widget into one render tree, so there is no airspace problem.
• WebBrowser / RadPdfViewer / RadRichTextEditor — IWebViewFactory backed by WebKitGTK 6.0 (GirCore.WebKit-6.0): navigation events, ExecuteScriptAsync, and a JS→host script-message bridge. Needs libwebkitgtk-6.0 installed at runtime (IsWebViewFunctional is false otherwise).

Embed in a host GTK app

The reverse direction — an existing Gtk.Application that wants to use MF objects as its own:

using Majorsilence.Forms.Gtk4;

// MF Control  → GTK widget
Gtk.Widget widget = myMfControl.ToGtkWidget ();          // or: new MajorsilenceFormsPresenter { Content = myMfControl }
someGtkBox.Append (widget);

// MF Form → Gtk.Window (created eagerly in the Form's constructor)
Gtk.Window window = myForm.ToGtkWindow ();
window.SetTransientFor (hostWindow);
window.Present ();

MajorsilenceFormsPresenter exposes a Widget property rather than deriving from a GTK widget (gir.core's GObject subclassing needs an extra integration package and a type-registration call). See samples/EmbeddingGtk4.

Known limits (v1)

• No screen-position control. GTK 4 removed client-side positioning of top-levels, so Form.Location is a stored value the window manager may ignore, and PointToScreen/PointToClient assume it.
• Topmost, ShowInTaskbar, MaximumSize round-trip as properties but GTK 4 has no API to enforce them.
• Window icons come from a themed icon name in GTK 4, so SetIcon(byte[]) is a no-op.
• File pickers (OpenFileDialog etc.) return empty — the compat dialogs fall back, as on Headless.
• Fractional display scaling uses the integer scale factor GTK reports (1 or 2); text is slightly soft at 1.25×/1.5× until fractional-scale support lands.
• Runs only where a display server (X11/Wayland) is available — use Majorsilence.Forms.Headless for offscreen/CI rendering.

Links

• Platform backends
• Repository

Licensed under the MIT License.