diff --git a/src/Avalonia.Styling/ClassBindingManager.cs b/src/Avalonia.Styling/ClassBindingManager.cs new file mode 100644 index 0000000000..e8b1cc301d --- /dev/null +++ b/src/Avalonia.Styling/ClassBindingManager.cs @@ -0,0 +1,31 @@ +using System; +using System.Collections.Generic; +using Avalonia.Data; + +namespace Avalonia +{ + internal static class ClassBindingManager + { + private static readonly Dictionary s_RegisteredProperties = + new Dictionary(); + + public static IDisposable Bind(IStyledElement target, string className, IBinding source, object anchor) + { + if (!s_RegisteredProperties.TryGetValue(className, out var prop)) + s_RegisteredProperties[className] = prop = RegisterClassProxyProperty(className); + return target.Bind(prop, source, anchor); + } + + private static AvaloniaProperty RegisterClassProxyProperty(string className) + { + var prop = AvaloniaProperty.Register("__AvaloniaReserved::Classes::" + className); + prop.Changed.Subscribe(args => + { + var classes = ((IStyledElement)args.Sender).Classes; + classes.Set(className, args.NewValue.GetValueOrDefault()); + }); + + return prop; + } + } +} diff --git a/src/Avalonia.Styling/Controls/Classes.cs b/src/Avalonia.Styling/Controls/Classes.cs index 51dca57928..4e2783d4ec 100644 --- a/src/Avalonia.Styling/Controls/Classes.cs +++ b/src/Avalonia.Styling/Controls/Classes.cs @@ -265,5 +265,26 @@ namespace Avalonia.Controls $"The pseudoclass '{name}' may only be {operation} by the control itself."); } } + + /// + /// Adds a or removes a style class to/from the collection. + /// + /// The class names. + /// If true adds the class, if false, removes it. + /// + /// Only standard classes may be added or removed via this method. To add pseudoclasses (classes + /// beginning with a ':' character) use the protected + /// property. + /// + public void Set(string name, bool value) + { + if (value) + { + if (!Contains(name)) + Add(name); + } + else + Remove(name); + } } } diff --git a/src/Avalonia.Styling/StyledElementExtensions.cs b/src/Avalonia.Styling/StyledElementExtensions.cs new file mode 100644 index 0000000000..0c5a5f7438 --- /dev/null +++ b/src/Avalonia.Styling/StyledElementExtensions.cs @@ -0,0 +1,11 @@ +using System; +using Avalonia.Data; + +namespace Avalonia +{ + public static class StyledElementExtensions + { + public static IDisposable BindClass(this IStyledElement target, string className, IBinding source, object anchor) => + ClassBindingManager.Bind(target, className, source, anchor); + } +} diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs index abff763bb1..a191dc59fb 100644 --- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs +++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs @@ -41,10 +41,13 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions // Targeted InsertBefore( + new AvaloniaXamlIlResolveClassesPropertiesTransformer(), new AvaloniaXamlIlTransformInstanceAttachedProperties(), new AvaloniaXamlIlTransformSyntheticCompiledBindingMembers()); InsertAfter( - new AvaloniaXamlIlAvaloniaPropertyResolver()); + new AvaloniaXamlIlAvaloniaPropertyResolver(), + new AvaloniaXamlIlReorderClassesPropertiesTransformer() + ); InsertBefore( new AvaloniaXamlIlBindingPathParser(), diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlClassesPropertyResolver.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlClassesPropertyResolver.cs new file mode 100644 index 0000000000..23232dbcf3 --- /dev/null +++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlClassesPropertyResolver.cs @@ -0,0 +1,97 @@ +using System.Collections.Generic; +using XamlX.Ast; +using XamlX.Emit; +using XamlX.IL; +using XamlX.Transform; +using XamlX.TypeSystem; + +namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers +{ + class AvaloniaXamlIlResolveClassesPropertiesTransformer : IXamlAstTransformer + { + public IXamlAstNode Transform(AstTransformationContext context, IXamlAstNode node) + { + if (node is XamlAstNamePropertyReference prop + && prop.TargetType is XamlAstClrTypeReference targetRef + && prop.DeclaringType is XamlAstClrTypeReference declaringRef) + { + var types = context.GetAvaloniaTypes(); + if (types.StyledElement.IsAssignableFrom(targetRef.Type) + && types.Classes.Equals(declaringRef.Type)) + { + return new XamlAstClrProperty(node, "class:" + prop.Name, types.Classes, + null) + { + Setters = { new ClassValueSetter(types, prop.Name), new ClassBindingSetter(types, prop.Name) } + }; + } + } + return node; + } + + + class ClassValueSetter : IXamlEmitablePropertySetter + { + private readonly AvaloniaXamlIlWellKnownTypes _types; + private readonly string _className; + + public ClassValueSetter(AvaloniaXamlIlWellKnownTypes types, string className) + { + _types = types; + _className = className; + Parameters = new[] { types.XamlIlTypes.Boolean }; + } + + public void Emit(IXamlILEmitter emitter) + { + using (var value = emitter.LocalsPool.GetLocal(_types.XamlIlTypes.Boolean)) + { + emitter + .Stloc(value.Local) + .EmitCall(_types.StyledElementClassesProperty.Getter) + .Ldstr(_className) + .Ldloc(value.Local) + .EmitCall(_types.Classes.GetMethod(new FindMethodMethodSignature("Set", + _types.XamlIlTypes.Void, _types.XamlIlTypes.String, _types.XamlIlTypes.Boolean))); + } + } + + public IXamlType TargetType => _types.StyledElement; + + public PropertySetterBinderParameters BinderParameters { get; } = + new PropertySetterBinderParameters { AllowXNull = false }; + public IReadOnlyList Parameters { get; } + } + + class ClassBindingSetter : IXamlEmitablePropertySetter + { + private readonly AvaloniaXamlIlWellKnownTypes _types; + private readonly string _className; + + public ClassBindingSetter(AvaloniaXamlIlWellKnownTypes types, string className) + { + _types = types; + _className = className; + Parameters = new[] {types.IBinding}; + } + + public void Emit(IXamlILEmitter emitter) + { + using (var bloc = emitter.LocalsPool.GetLocal(_types.IBinding)) + emitter + .Stloc(bloc.Local) + .Ldstr(_className) + .Ldloc(bloc.Local) + // TODO: provide anchor? + .Ldnull(); + emitter.EmitCall(_types.ClassesBindMethod, true); + } + + public IXamlType TargetType => _types.StyledElement; + + public PropertySetterBinderParameters BinderParameters { get; } = + new PropertySetterBinderParameters { AllowXNull = false }; + public IReadOnlyList Parameters { get; } + } + } +} diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlReorderClassesPropertiesTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlReorderClassesPropertiesTransformer.cs new file mode 100644 index 0000000000..ae3515a6d6 --- /dev/null +++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlReorderClassesPropertiesTransformer.cs @@ -0,0 +1,40 @@ +using XamlX.Ast; +using XamlX.Transform; + +namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers +{ + class AvaloniaXamlIlReorderClassesPropertiesTransformer : IXamlAstTransformer + { + public IXamlAstNode Transform(AstTransformationContext context, IXamlAstNode node) + { + if (node is XamlAstObjectNode obj) + { + IXamlAstNode classesNode = null; + IXamlAstNode firstSingleClassNode = null; + var types = context.GetAvaloniaTypes(); + foreach (var child in obj.Children) + { + if (child is XamlAstXamlPropertyValueNode propValue + && propValue.Property is XamlAstClrProperty prop) + { + if (prop.DeclaringType.Equals(types.Classes)) + { + if (firstSingleClassNode == null) + firstSingleClassNode = child; + } + else if (prop.Name == "Classes" && prop.DeclaringType.Equals(types.StyledElement)) + classesNode = child; + } + } + + if (classesNode != null && firstSingleClassNode != null) + { + obj.Children.Remove(classesNode); + obj.Children.Insert(obj.Children.IndexOf(firstSingleClassNode), classesNode); + } + } + + return node; + } + } +} diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs index 34aae2c5ed..c4995b2de3 100644 --- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs +++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs @@ -25,6 +25,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers public IXamlType AssignBindingAttribute { get; } public IXamlType UnsetValueType { get; } public IXamlType StyledElement { get; } + public IXamlType IStyledElement { get; } public IXamlType NameScope { get; } public IXamlMethod NameScopeSetNameScope { get; } public IXamlType INameScope { get; } @@ -78,6 +79,8 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers public IXamlType ColumnDefinition { get; } public IXamlType ColumnDefinitions { get; } public IXamlType Classes { get; } + public IXamlMethod ClassesBindMethod { get; } + public IXamlProperty StyledElementClassesProperty { get; set; } public AvaloniaXamlIlWellKnownTypes(TransformerConfiguration cfg) { @@ -97,6 +100,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers IBinding, cfg.WellKnownTypes.Object); UnsetValueType = cfg.TypeSystem.GetType("Avalonia.UnsetValueType"); StyledElement = cfg.TypeSystem.GetType("Avalonia.StyledElement"); + IStyledElement = cfg.TypeSystem.GetType("Avalonia.IStyledElement"); INameScope = cfg.TypeSystem.GetType("Avalonia.Controls.INameScope"); INameScopeRegister = INameScope.GetMethod( new FindMethodMethodSignature("Register", XamlIlTypes.Void, @@ -168,6 +172,12 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers RowDefinition = cfg.TypeSystem.GetType("Avalonia.Controls.RowDefinition"); RowDefinitions = cfg.TypeSystem.GetType("Avalonia.Controls.RowDefinitions"); Classes = cfg.TypeSystem.GetType("Avalonia.Controls.Classes"); + StyledElementClassesProperty = + StyledElement.Properties.First(x => x.Name == "Classes" && x.PropertyType.Equals(Classes)); + ClassesBindMethod = cfg.TypeSystem.GetType("Avalonia.StyledElementExtensions") + .FindMethod( "BindClass", IDisposable, false, IStyledElement, + cfg.WellKnownTypes.String, + IBinding, cfg.WellKnownTypes.Object); } } diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs index 4f2b580bce..8af638c5d7 100644 --- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs +++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs @@ -377,5 +377,37 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml public string Greeting1 { get; set; } = "Hello"; public string Greeting2 { get; set; } = "World"; } + + [Fact] + public void Binding_Classes_Works() + { + using (UnitTestApplication.Start(TestServices.StyledWindow)) + { + // Note, this test also checks `Classes` reordering, so it should be kept AFTER the last single class + var xaml = @" + +