vendoring NetVips

vendor/NetVips/VipsObject.cs

@@ -0,0 +1,154 @@
+using System;
+using System.Runtime.InteropServices;
+using NetVips.Internal;
+
+namespace NetVips;
+
+/// <summary>
+/// Manage a <see cref="Internal.VipsObject"/>.
+/// </summary>
+public class VipsObject : GObject
+{
+    /// <summary>
+    /// Attach a post-close delegate. This is called on finalization.
+    /// </summary>
+    /// <remarks>
+    /// Useful for e.g. deleting the file associated with a temp image.
+    /// </remarks>
+    public event Action OnPostClose
+    {
+        add => SignalConnect("postclose", value);
+        remove => SignalHandlersDisconnectByFunc(value);
+    }
+
+    /// <inheritdoc cref="GObject"/>
+    internal VipsObject(nint pointer) : base(pointer)
+    {
+    }
+
+    /// <summary>
+    /// Print a table of all active libvips objects. Handy for debugging.
+    /// </summary>
+    internal static void PrintAll()
+    {
+        GC.Collect();
+        Internal.VipsObject.PrintAll();
+    }
+
+    /// <summary>
+    /// slow! eeeeew.
+    /// </summary>
+    /// <param name="name">Arg to fetch.</param>
+    /// <returns>The pspec for this arg.</returns>
+    private GParamSpec.Struct? GetPspec(string name)
+    {
+        var argument = Internal.VipsObject.GetArgument(this, name, out var pspec, out _, out _);
+
+        return argument != 0
+            ? default(GParamSpec.Struct?)
+            : Marshal.PtrToStructure<GParamSpec.Struct>(pspec);
+    }
+
+    /// <summary>
+    /// Get a GObject property.
+    /// </summary>
+    /// <remarks>
+    /// The value of the property is converted to a C# value.
+    /// </remarks>
+    /// <param name="name">Arg to fetch.</param>
+    /// <returns>The GObject property.</returns>
+    internal object Get(string name)
+    {
+        var pspec = GetPspec(name);
+        if (!pspec.HasValue)
+        {
+            throw new VipsException("Property not found.");
+        }
+
+        var gtype = pspec.Value.ValueType;
+        using var gv = new GValue();
+        gv.SetType(gtype);
+
+        // this will add a reference for GObject properties, that ref will be
+        // unreferenced when the GValue is finalized
+        Internal.GObject.GetProperty(this, name, ref gv.Struct);
+
+        return gv.Get();
+    }
+
+    /// <summary>
+    /// Set a GObject property. The value is converted to the property type, if possible.
+    /// </summary>
+    /// <param name="name">The name of the property to set.</param>
+    /// <param name="value">The value.</param>
+    /// <param name="gtype">The GType of the property.</param>
+    internal void Set(nint gtype, string name, object value)
+    {
+        using var gv = new GValue();
+        gv.SetType(gtype);
+        gv.Set(value);
+
+        Internal.GObject.SetProperty(this, name, in gv.Struct);
+    }
+
+    /// <summary>
+    /// Set a series of properties using a string.
+    /// </summary>
+    /// <remarks>
+    /// For example:
+    /// "fred=12, tile"
+    /// "[fred=12]"
+    /// </remarks>
+    /// <param name="stringOptions">Arguments as a string.</param>
+    /// <returns><see langword="true"/> on success; otherwise, <see langword="false"/>.</returns>
+    internal bool SetString(string stringOptions)
+    {
+        var result = Internal.VipsObject.SetFromString(this, stringOptions);
+        return result == 0;
+    }
+
+    /// <summary>
+    /// Get the GType of a GObject property.
+    /// </summary>
+    /// <param name="name">The name of the GType to get the type of.</param>
+    /// <returns>A new instance of <see langword="nint"/> initialized to the GType or
+    /// <see cref="IntPtr.Zero"/> if the property does not exist.</returns>
+    public nint GetTypeOf(string name)
+    {
+        var pspec = GetPspec(name);
+        if (!pspec.HasValue)
+        {
+            // need to clear any error, this is horrible
+            Vips.ErrorClear();
+            return IntPtr.Zero;
+        }
+
+        return pspec.Value.ValueType;
+    }
+
+    /// <summary>
+    /// Get the blurb for a GObject property.
+    /// </summary>
+    /// <param name="name">Arg to fetch.</param>
+    /// <returns>The blurb.</returns>
+    public string GetBlurb(string name)
+    {
+        var pspec = GetPspec(name);
+        if (!pspec.HasValue)
+        {
+            return null;
+        }
+
+        var pspecValue = pspec.Value;
+        return Marshal.PtrToStringAnsi(GParamSpec.GetBlurb(in pspecValue));
+    }
+
+    /// <summary>
+    /// Get the description of a GObject.
+    /// </summary>
+    /// <returns>The description of a GObject.</returns>
+    public string GetDescription()
+    {
+        return Marshal.PtrToStringAnsi(Internal.VipsObject.GetDescription(this));
+    }
+}