maui-linux/Handlers/GtkWebViewPlatformView.cs

using System;
using Microsoft.Maui.Platform.Linux.Native;

namespace Microsoft.Maui.Platform.Linux.Handlers;

/// <summary>
/// GTK-based WebView platform view using WebKitGTK.
/// Provides web browsing capabilities within MAUI applications.
/// </summary>
public sealed class GtkWebViewPlatformView : IDisposable
{
    private IntPtr _widget;
    private bool _disposed;
    private string? _currentUri;
    private ulong _loadChangedSignalId;
    private WebKitNative.LoadChangedCallback? _loadChangedCallback;

    public IntPtr Widget => _widget;
    public string? CurrentUri => _currentUri;

    public event EventHandler<string>? NavigationStarted;
    public event EventHandler<(string Url, bool Success)>? NavigationCompleted;
    public event EventHandler<string>? TitleChanged;

    public GtkWebViewPlatformView()
    {
        if (!WebKitNative.Initialize())
        {
            throw new InvalidOperationException("Failed to initialize WebKitGTK. Is libwebkit2gtk-4.x installed?");
        }
        _widget = WebKitNative.WebViewNew();
        if (_widget == IntPtr.Zero)
        {
            throw new InvalidOperationException("Failed to create WebKitWebView widget");
        }
        WebKitNative.ConfigureSettings(_widget);
        _loadChangedCallback = OnLoadChanged;
        _loadChangedSignalId = WebKitNative.ConnectLoadChanged(_widget, _loadChangedCallback);
        Console.WriteLine("[GtkWebViewPlatformView] Created WebKitWebView widget");
    }

    private void OnLoadChanged(IntPtr webView, int loadEvent, IntPtr userData)
    {
        try
        {
            string uri = WebKitNative.GetUri(webView) ?? _currentUri ?? "";
            switch ((WebKitNative.WebKitLoadEvent)loadEvent)
            {
                case WebKitNative.WebKitLoadEvent.Started:
                    Console.WriteLine("[GtkWebViewPlatformView] Load started: " + uri);
                    NavigationStarted?.Invoke(this, uri);
                    break;
                case WebKitNative.WebKitLoadEvent.Finished:
                    _currentUri = uri;
                    Console.WriteLine("[GtkWebViewPlatformView] Load finished: " + uri);
                    NavigationCompleted?.Invoke(this, (uri, true));
                    break;
                case WebKitNative.WebKitLoadEvent.Committed:
                    _currentUri = uri;
                    Console.WriteLine("[GtkWebViewPlatformView] Load committed: " + uri);
                    break;
                case WebKitNative.WebKitLoadEvent.Redirected:
                    break;
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine("[GtkWebViewPlatformView] Error in OnLoadChanged: " + ex.Message);
            Console.WriteLine("[GtkWebViewPlatformView] Stack trace: " + ex.StackTrace);
        }
    }

    public void Navigate(string uri)
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.LoadUri(_widget, uri);
            Console.WriteLine("[GtkWebViewPlatformView] Navigate to: " + uri);
        }
    }

    public void LoadHtml(string html, string? baseUri = null)
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.LoadHtml(_widget, html, baseUri);
            Console.WriteLine("[GtkWebViewPlatformView] Load HTML content");
        }
    }

    public void GoBack()
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.GoBack(_widget);
        }
    }

    public void GoForward()
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.GoForward(_widget);
        }
    }

    public bool CanGoBack()
    {
        return _widget != IntPtr.Zero && WebKitNative.CanGoBack(_widget);
    }

    public bool CanGoForward()
    {
        return _widget != IntPtr.Zero && WebKitNative.CanGoForward(_widget);
    }

    public void Reload()
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.Reload(_widget);
        }
    }

    public void Stop()
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.StopLoading(_widget);
        }
    }

    public string? GetTitle()
    {
        return _widget == IntPtr.Zero ? null : WebKitNative.GetTitle(_widget);
    }

    public string? GetUri()
    {
        return _widget == IntPtr.Zero ? null : WebKitNative.GetUri(_widget);
    }

    public void SetJavascriptEnabled(bool enabled)
    {
        if (_widget != IntPtr.Zero)
        {
            WebKitNative.SetJavascriptEnabled(_widget, enabled);
        }
    }

    public void Dispose()
    {
        if (!_disposed)
        {
            _disposed = true;
            if (_widget != IntPtr.Zero)
            {
                WebKitNative.DisconnectLoadChanged(_widget);
            }
            _widget = IntPtr.Zero;
            _loadChangedCallback = null;
        }
    }
}