Add support for signal handling

+ update CHANGELOG.md and add CHANGELOG.native.md (for the changes to the pre-compiled binaries of libvips).

CHANGELOG.md

@@ -1,25 +1,25 @@
 # Changelog
-All notable changes to this project will be documented in this file.
+All notable changes to NetVips will be documented in this file. See [here](CHANGELOG.native.md) for the changes to the [pre-compiled binaries of libvips](https://www.nuget.org/packages/NetVips.Native/).
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.1.0] - ???
+## [1.1.0] - Unreleased
 ### Added
-- Pre-compiled libvips binaries for a few distros ([#21](https://github.com/kleisauke/net-vips/issues/21)):
-  - [NetVips.Native.linux-x64](https://www.nuget.org/packages/NetVips.Native.linux-x64) - Linux x64 glibc (Ubuntu, Debian, etc).
-  - [NetVips.Native.linux-musl-x64](https://www.nuget.org/packages/NetVips.Native.linux-musl-x64) - Linux x64 musl (Alpine, Gentoo Linux, etc).
-  - [NetVips.Native.osx-x64](https://www.nuget.org/packages/NetVips.Native.osx-x64) - macOS x64.
+- A new [NetVips.Native](https://www.nuget.org/packages/NetVips.Native/) package containing the pre-compiled libvips binaries for Linux, macOS and Windows ([#21](https://github.com/kleisauke/net-vips/issues/21)).
+  - Changes to the [NetVips.Native.*](https://www.nuget.org/packages?q=id%3ANetVips.Native) packages will be documented [here](CHANGELOG.native.md).
+- Add `Base.GetSuffixes()` to get a list of all the filename suffixes supported by libvips ([libvips/ruby-vips#186](https://github.com/libvips/ruby-vips/issues/186)).
+- Add support for progress feedback (`image.SetProgress()`) and signal handling (`image.SignalConnect()`) ([#31](https://github.com/kleisauke/net-vips/issues/31)).
+- Add `image.SetKill()` and `image.IsKilled()` ([#31](https://github.com/kleisauke/net-vips/issues/31), [libvips/libvips@91d0e7e](https://github.com/libvips/libvips/commit/91d0e7e3d06fe6293f8e7513f30fd21585ea4305)).
 
 ### Changed
 - Improve memory management ([#26](https://github.com/kleisauke/net-vips/issues/26)).
-- The bundled libvips Windows binaries were split into different NuGet packages:
-  - [NetVips.Native.win-x64](https://www.nuget.org/packages/NetVips.Native.win-x64) - Windows 64-bit.
-  - [NetVips.Native.win-x86](https://www.nuget.org/packages/NetVips.Native.win-x86) - Windows 32-bit.
+- The bundled libvips Windows binaries were moved to the [NetVips.Native](https://www.nuget.org/packages/NetVips.Native/) package. 
 - Update the [NetVips.Benchmarks](https://github.com/kleisauke/net-vips/tree/master/tests/NetVips.Benchmarks).
-- A statically linked libvips binary is build for Windows. This reduces the number of DLLs from 37 to 3 ([libvips/build-win64#21](https://github.com/libvips/build-win64/issues/21#issuecomment-458112440)).
+- The overloadable operators `==` and `!=` have been changed to `Equal` and `NotEqual` to avoid conflicts with `null` checks.
+- Some methods are overloaded instead of defining the parameters as `object` type.
 
 ### Removed
-- The `UseGlobalLibvips` property since the bundled libvips binaries are split into different NuGet packages.
+- The `UseGlobalLibvips` property since the bundled libvips binaries were moved to the [NetVips.Native](https://www.nuget.org/packages/NetVips.Native/) package.
 
 ## [1.0.7] - 2019-01-18
 ### Changed
@@ -85,7 +85,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Added
 - First release!
 
-[1.1.0]: https://github.com/kleisauke/net-vips/compare/v1.0.7...v1.1.0
+[1.1.0]: https://github.com/kleisauke/net-vips/compare/v1.0.7...1.1.0
 [1.0.7]: https://github.com/kleisauke/net-vips/compare/v1.0.6...v1.0.7
 [1.0.6]: https://github.com/kleisauke/net-vips/compare/v1.0.5...v1.0.6
 [1.0.5]: https://github.com/kleisauke/net-vips/compare/v1.0.4...v1.0.5

CHANGELOG.native.md

@@ -0,0 +1,33 @@
+# Changelog
+All notable changes to the pre-compiled binaries of libvips will be documented in this file. The version number of these NuGet packages is in sync with libvips' version number.
+The changes of libvips are documented [here](https://github.com/libvips/libvips/blob/master/ChangeLog).
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [8.8.0] - Unreleased
+### Note
+If you would like to see a complete list of all the new features, changes and bug fixes, please visit the the release notes of libvips:
+https://github.com/libvips/libvips/releases
+
+## [8.7.4] - 2019-04-10
+### Added
+- A [NetVips.Native](https://www.nuget.org/packages/NetVips.Native/) package which depends on the other [NetVips.Native.*](https://www.nuget.org/packages?q=id%3ANetVips.Native) packages. 
+
+### Changed
+- The OS X binaries are now distributed with [`jpeg-turbo`](https://github.com/libjpeg-turbo/libjpeg-turbo) instead than [`jpeg`](https://www.ijg.org/) ([lovell/package-libvips-darwin#3](https://github.com/lovell/package-libvips-darwin/pull/3)).
+
+## [8.7.4 beta 1] - 2019-02-25
+### Added
+- Pre-compiled libvips binaries for a few distros ([#21](https://github.com/kleisauke/net-vips/issues/21)):
+  - [NetVips.Native.linux-x64](https://www.nuget.org/packages/NetVips.Native.linux-x64) - Linux x64 glibc (Ubuntu, Debian, etc).
+  - [NetVips.Native.linux-musl-x64](https://www.nuget.org/packages/NetVips.Native.linux-musl-x64) - Linux x64 musl (Alpine, Gentoo Linux, etc).
+  - [NetVips.Native.osx-x64](https://www.nuget.org/packages/NetVips.Native.osx-x64) - macOS x64.
+  - [NetVips.Native.win-x64](https://www.nuget.org/packages/NetVips.Native.win-x64) - Windows 64-bit.
+  - [NetVips.Native.win-x86](https://www.nuget.org/packages/NetVips.Native.win-x86) - Windows 32-bit.
+
+### Changed
+- A statically linked libvips binary is build for Windows. This reduces the number of DLLs from 37 to 3 ([libvips/build-win64#21](https://github.com/libvips/build-win64/issues/21#issuecomment-458112440)).
+
+[8.8.0]: https://github.com/kleisauke/libvips-packaging/compare/v8.7.4...HEAD
+[8.7.4]: https://github.com/kleisauke/libvips-packaging/compare/v8.7.4-beta1...v8.7.4
+[8.7.4 beta 1]: https://github.com/kleisauke/libvips-packaging/releases/tag/v8.7.4-beta1

documentation/docfx.json

@@ -30,6 +30,10 @@
         "files": "CHANGELOG.md",
         "src": ".."
       },
+      {
+        "files": "CHANGELOG.native.md",
+        "src": ".."
+      },
       {
         "files": [
           "tutorial/**/*.{md,yml}",

src/NetVips/ExtensionMethods.cs

@@ -252,28 +252,5 @@ internal static string ToReadableBytes(this ulong value)
 
             return $"{dValue:n2} {sizeSuffixes[i]}";
         }
-
-        /// <summary>
-        /// Connects a callback function (<see cref="GCallback"/>)
-        /// to a signal for a particular <see cref="GObject"/>.
-        /// </summary>
-        /// <param name="instance">The instance to connect to.</param>
-        /// <param name="detailedSignal">A string of the form "signal-name::detail".</param>
-        /// <param name="callback">The <see cref="GCallback"/> to connect.</param>
-        /// <param name="data">Data to pass to handler calls.</param>
-        /// <returns>The handler id.</returns>
-        /// <exception cref="T:System.Exception">If it failed to connect the signal.</exception>
-        internal static uint Connect(this GObject instance, string detailedSignal, GCallback callback,
-            IntPtr data = default)
-        {
-            var ret = GSignal.ConnectData(instance, detailedSignal, callback, data, null, default);
-
-            if (ret == 0)
-            {
-                throw new Exception("Failed to connect signal.");
-            }
-
-            return ret;
-        }
     }
 }

src/NetVips/GObject.cs

@@ -2,6 +2,8 @@ namespace NetVips
 {
     using System;
     using System.Runtime.InteropServices;
+    using System.Collections.Generic;
+    using NetVips.Internal;
 
     /// <summary>
     /// Manage <see cref="Internal.GObject"/> lifetime.
@@ -10,6 +12,12 @@ public class GObject : SafeHandle
     {
         // private static Logger logger = LogManager.GetCurrentClassLogger();
 
+        /// <summary>
+        /// We have to record all of the <see cref="SignalConnect"/> delegates to
+        /// prevent them from being re-located or disposed of by the garbage collector.
+        /// </summary>
+        private readonly List<GCHandle> _handles = new List<GCHandle>();
+
         // Handy for debugging
         // public static int NObjects;
 
@@ -32,6 +40,35 @@ internal GObject(IntPtr pointer)
             // logger.Debug($"GObject = {pointer}");
         }
 
+        /// <summary>
+        /// Connects a callback function (<paramref name="callback"/>) to a signal on this object.
+        /// </summary>
+        /// <remarks>
+        /// The callback will be triggered every time this signal is issued on this instance.
+        /// </remarks>
+        /// <param name="detailedSignal">A string of the form "signal-name::detail".</param>
+        /// <param name="callback">The callback to connect.</param>
+        /// <param name="data">Data to pass to handler calls.</param>
+        /// <returns>The handler id.</returns>
+        /// <exception cref="T:System.Exception">If it failed to connect the signal.</exception>
+        public uint SignalConnect(string detailedSignal, Delegate callback, IntPtr data = default)
+        {
+            // prevent the delegate from being re-located or disposed of by the garbage collector
+            var delegateHandle = GCHandle.Alloc(callback);
+            _handles.Add(delegateHandle);
+
+            // get the pointer for the delegate which can be passed to the native code
+            var callbackPtr = Marshal.GetFunctionPointerForDelegate(callback);
+            var ret = GSignal.ConnectData(this, detailedSignal, callbackPtr, data, null, default);
+
+            if (ret == 0)
+            {
+                throw new Exception("Failed to connect signal.");
+            }
+
+            return ret;
+        }
+
         /// <summary>
         /// Decreases the reference count of object.
         /// When its reference count drops to 0, the object is finalized (i.e. its memory is freed).
@@ -44,6 +81,14 @@ protected override bool ReleaseHandle()
             if (!IsInvalid)
             {
                 Internal.GObject.Unref(handle);
+
+                // release all handles recorded by this object
+                foreach (var gcHandle in _handles)
+                {
+                    gcHandle.Free();
+                }
+
+                _handles.Clear();
             }
             // NObjects--;
 

src/NetVips/Image.cs

@@ -21,11 +21,6 @@ public sealed partial class Image : VipsObject
         /// </summary>
         private GCHandle _dataHandle;
 
-        /// <summary>
-        /// Ref for <see cref="SetProgress" />.
-        /// </summary>
-        private GCHandle _progressHandle;
-
         /// <inheritdoc cref="VipsObject"/>
         internal Image(IntPtr pointer)
             : base(pointer)
@@ -1426,7 +1421,7 @@ public void SetKill(bool kill)
                 return;
             }
 
-           VipsImage.SetKill(this, kill ? 1 : 0);
+            VipsImage.SetKill(this, kill ? 1 : 0);
         }
 
         /// <summary>
@@ -1456,11 +1451,15 @@ public void SetKill(bool kill)
         public void SetProgress(IProgress<int> progress, CancellationToken token = default)
         {
             VipsImage.SetProgress(this, progress == null ? 0 : 1);
+            if (progress == null)
+            {
+                return;
+            }
 
             var lastPercent = 0;
             var isKilled = false;
 
-            GCallback evalCallback = (imagePtr, progressPtr, userDataPtr) =>
+            EvalCallback evalCallback = (imagePtr, progressPtr, userDataPtr) =>
             {
                 // Block evaluation on this image if a cancellation
                 // has been requested for this token.
@@ -1483,15 +1482,12 @@ public void SetProgress(IProgress<int> progress, CancellationToken token = defau
                 var progressStruct = progressPtr.Dereference<VipsProgress.Struct>();
                 if (progressStruct.Percent != lastPercent)
                 {
-                    progress?.Report(progressStruct.Percent);
+                    progress.Report(progressStruct.Percent);
                     lastPercent = progressStruct.Percent;
                 }
             };
 
-            // prevent it from being re-located or disposed of by the garbage collector
-            _progressHandle = GCHandle.Alloc(evalCallback);
-
-            this.Connect(Internal.Enums.VipsEvaluation.Eval, evalCallback);
+            SignalConnect(Internal.Enums.VipsEvaluation.Eval, evalCallback);
         }
 
         #endregion
@@ -1630,17 +1626,12 @@ public override int GetHashCode()
         /// <inheritdoc />
         protected override void Dispose(bool disposing)
         {
-            // release references to delegates / data objects
+            // release reference to our secret ref
             if (_dataHandle.IsAllocated)
             {
                 _dataHandle.Free();
             }
 
-            if (_progressHandle.IsAllocated)
-            {
-                _progressHandle.Free();
-            }
-
             // Call our base Dispose method
             base.Dispose(disposing);
         }

src/NetVips/Internal/GObject.cs

@@ -163,16 +163,13 @@ internal struct Struct
     [SuppressUnmanagedCodeSecurity, UnmanagedFunctionPointer(CallingConvention.Cdecl)]
     internal delegate void GClosureNotify(IntPtr data, IntPtr closure);
 
-    [SuppressUnmanagedCodeSecurity, UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-    internal delegate void GCallback(IntPtr gobjectPtr, IntPtr pspecPtr, IntPtr userDataPtr);
-
     internal static class GSignal
     {
         [SuppressUnmanagedCodeSecurity]
         [DllImport(Libraries.GObject, CallingConvention = CallingConvention.Cdecl,
             EntryPoint = "g_signal_connect_data")]
         internal static extern uint ConnectData(NetVips.GObject instance,
-            [MarshalAs(UnmanagedType.LPStr)] string detailedSignal, GCallback cHandler, IntPtr data,
+            [MarshalAs(UnmanagedType.LPStr)] string detailedSignal, IntPtr cHandler, IntPtr data,
             GClosureNotify destroyData, Enums.GConnectFlags connectFlags);
     }
 }

src/NetVips/Internal/Vips.cs

@@ -295,6 +295,9 @@ internal static extern void SetArrayInt(ref GValue.Struct value,
         internal static extern void SetArrayImage(ref GValue.Struct value, int n);
     }
 
+    [SuppressUnmanagedCodeSecurity, UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+    internal delegate void EvalCallback(IntPtr imagePtr, IntPtr progressPtr, IntPtr userDataPtr);
+
     internal static class VipsImage
     {
         [SuppressUnmanagedCodeSecurity]

tests/NetVips.Tests/IoFuncsTests.cs

@@ -162,15 +162,13 @@ public void TestSetProgress()
 
             var progress = new Progress<int>(percent =>
             {
-                // Tests whether the actual percentage is higher 
-                // than the last percentage received.
-                Assert.True(percent > lastPercent);
                 lastPercent = percent;
             });
             im.SetProgress(progress);
 
             var buf = im.DzsaveBuffer("image-pyramid");
             Assert.True(buf.Length > 0);
+            Assert.True(lastPercent <= 100);
         }
 
         [Fact]