maui-linux/Xamarin.Forms.Core/StyleSheets/StyleSheet.cs

120 строки
2.8 KiB
C#
Исходник Обычный вид История

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Xml;
using Xamarin.Forms.Xaml;
namespace Xamarin.Forms.StyleSheets
{
public sealed class StyleSheet : IStyle
{
StyleSheet()
{
}
internal IDictionary<Selector, Style> Styles { get; set; } = new Dictionary<Selector, Style>();
public static StyleSheet FromAssemblyResource(Assembly assembly, string resourceId, IXmlLineInfo lineInfo = null)
{
using (var stream = assembly.GetManifestResourceStream(resourceId)) {
if (stream == null)
throw new XamlParseException($"No resource found for '{resourceId}'.", lineInfo);
using (var reader = new StreamReader(stream)) {
return FromReader(reader);
}
}
}
//used by code generated by XamlC. Has to stay public
[EditorBrowsable(EditorBrowsableState.Never)]
public static StyleSheet FromString(string stylesheet)
{
if (stylesheet == null)
throw new ArgumentNullException(nameof(stylesheet));
using (var reader = new StringReader(stylesheet))
return FromReader(reader);
}
public static StyleSheet FromReader(TextReader reader)
{
if (reader == null)
throw new ArgumentNullException(nameof(reader));
return Parse(new CssReader(reader));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static StyleSheet Parse(CssReader reader)
{
var sheet = new StyleSheet();
Style style = null;
var selector = Selector.All;
int p;
bool inStyle = false;
reader.SkipWhiteSpaces();
while ((p = reader.Peek()) > 0) {
switch ((char)p) {
case '@':
throw new NotSupportedException("AT-rules not supported");
case '{':
reader.Read();
style = Style.Parse(reader, '}');
inStyle = true;
break;
case '}':
reader.Read();
if (!inStyle)
throw new Exception();
inStyle = false;
sheet.Styles.Add(selector, style);
style = null;
selector = Selector.All;
break;
default:
selector = Selector.Parse(reader, '{');
break;
}
}
return sheet;
}
Type IStyle.TargetType
=> typeof(VisualElement);
void IStyle.Apply(BindableObject bindable)
{
var styleable = bindable as VisualElement;
if (styleable == null)
return;
Apply(styleable);
}
void Apply(VisualElement styleable)
{
ApplyCore(styleable);
foreach (var child in styleable.LogicalChildrenInternal)
((IStyle)this).Apply(child);
}
void ApplyCore(VisualElement styleable)
{
foreach (var kvp in Styles) {
var selector = kvp.Key;
var style = kvp.Value;
if (!selector.Matches(styleable))
continue;
style.Apply(styleable);
}
}
void IStyle.UnApply(BindableObject bindable)
{
throw new NotImplementedException();
}
}
}