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#nullable disable
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using Microsoft.Maui.Controls.Internals;
using Microsoft.Maui.Controls.Xaml;
using Microsoft.Maui.Graphics;
namespace Microsoft.Maui.Controls
{
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="Type[@FullName='Microsoft.Maui.Controls.Picker']/Docs/*" />
public partial class Picker : View, IFontElement, ITextElement, ITextAlignmentElement, IElementConfiguration<Picker>, IPicker
{
/// <summary>Bindable property for <see cref="TextColor"/>.</summary>
public static readonly BindableProperty TextColorProperty = TextElement.TextColorProperty;
/// <summary>Bindable property for <see cref="CharacterSpacing"/>.</summary>
public static readonly BindableProperty CharacterSpacingProperty = TextElement.CharacterSpacingProperty;
/// <summary>Bindable property for <see cref="Title"/>.</summary>
public static readonly BindableProperty TitleProperty =
BindableProperty.Create(nameof(Title), typeof(string), typeof(Picker), default(string));
/// <summary>Bindable property for <see cref="TitleColor"/>.</summary>
public static readonly BindableProperty TitleColorProperty =
BindableProperty.Create(nameof(TitleColor), typeof(Color), typeof(Picker), default(Color));
/// <summary>Bindable property for <see cref="SelectedIndex"/>.</summary>
public static readonly BindableProperty SelectedIndexProperty =
BindableProperty.Create(nameof(SelectedIndex), typeof(int), typeof(Picker), -1, BindingMode.TwoWay,
propertyChanged: OnSelectedIndexChanged, coerceValue: CoerceSelectedIndex);
/// <summary>Bindable property for <see cref="ItemsSource"/>.</summary>
public static readonly BindableProperty ItemsSourceProperty =
BindableProperty.Create(nameof(ItemsSource), typeof(IList), typeof(Picker), default(IList),
propertyChanged: OnItemsSourceChanged);
/// <summary>Bindable property for <see cref="SelectedItem"/>.</summary>
public static readonly BindableProperty SelectedItemProperty =
BindableProperty.Create(nameof(SelectedItem), typeof(object), typeof(Picker), null, BindingMode.TwoWay,
propertyChanged: OnSelectedItemChanged);
/// <summary>Bindable property for <see cref="FontFamily"/>.</summary>
public static readonly BindableProperty FontFamilyProperty = FontElement.FontFamilyProperty;
/// <summary>Bindable property for <see cref="FontSize"/>.</summary>
public static readonly BindableProperty FontSizeProperty = FontElement.FontSizeProperty;
/// <summary>Bindable property for <see cref="FontAttributes"/>.</summary>
public static readonly BindableProperty FontAttributesProperty = FontElement.FontAttributesProperty;
/// <summary>Bindable property for <see cref="FontAutoScalingEnabled"/>.</summary>
public static readonly BindableProperty FontAutoScalingEnabledProperty = FontElement.FontAutoScalingEnabledProperty;
/// <summary>Bindable property for <see cref="HorizontalTextAlignment"/>.</summary>
public static readonly BindableProperty HorizontalTextAlignmentProperty = TextAlignmentElement.HorizontalTextAlignmentProperty;
/// <summary>Bindable property for <see cref="VerticalTextAlignment"/>.</summary>
public static readonly BindableProperty VerticalTextAlignmentProperty = TextAlignmentElement.VerticalTextAlignmentProperty;
readonly Lazy<PlatformConfigurationRegistry<Picker>> _platformConfigurationRegistry;
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='.ctor']/Docs/*" />
public Picker()
{
((INotifyCollectionChanged)Items).CollectionChanged += OnItemsCollectionChanged;
_platformConfigurationRegistry = new Lazy<PlatformConfigurationRegistry<Picker>>(() => new PlatformConfigurationRegistry<Picker>(this));
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='FontAttributes']/Docs/*" />
public FontAttributes FontAttributes
{
get { return (FontAttributes)GetValue(FontAttributesProperty); }
set { SetValue(FontAttributesProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='FontFamily']/Docs/*" />
public string FontFamily
{
get { return (string)GetValue(FontFamilyProperty); }
set { SetValue(FontFamilyProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='FontSize']/Docs/*" />
[System.ComponentModel.TypeConverter(typeof(FontSizeConverter))]
public double FontSize
{
get { return (double)GetValue(FontSizeProperty); }
set { SetValue(FontSizeProperty, value); }
}
public bool FontAutoScalingEnabled
{
get => (bool)GetValue(FontAutoScalingEnabledProperty);
set => SetValue(FontAutoScalingEnabledProperty, value);
}
TextTransform ITextElement.TextTransform
{
get => TextTransform.Default;
set { }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='UpdateFormsText']/Docs/*" />
public virtual string UpdateFormsText(string source, TextTransform textTransform)
=> TextTransformUtilites.GetTransformedText(source, textTransform);
void IFontElement.OnFontFamilyChanged(string oldValue, string newValue) =>
HandleFontChanged();
void IFontElement.OnFontSizeChanged(double oldValue, double newValue) =>
HandleFontChanged();
double IFontElement.FontSizeDefaultValueCreator() =>
this.GetDefaultFontSize();
void IFontElement.OnFontAttributesChanged(FontAttributes oldValue, FontAttributes newValue) =>
HandleFontChanged();
void IFontElement.OnFontAutoScalingEnabledChanged(bool oldValue, bool newValue) =>
HandleFontChanged();
void HandleFontChanged()
{
Handler?.UpdateValue(nameof(ITextStyle.Font));
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
}
void ITextElement.OnTextTransformChanged(TextTransform oldValue, TextTransform newValue) =>
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='Items']/Docs/*" />
public IList<string> Items { get; } = new LockableObservableListWrapper();
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='ItemsSource']/Docs/*" />
public IList ItemsSource
{
get { return (IList)GetValue(ItemsSourceProperty); }
set { SetValue(ItemsSourceProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='SelectedIndex']/Docs/*" />
public int SelectedIndex
{
get { return (int)GetValue(SelectedIndexProperty); }
set { SetValue(SelectedIndexProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='SelectedItem']/Docs/*" />
public object SelectedItem
{
get { return GetValue(SelectedItemProperty); }
set { SetValue(SelectedItemProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='TextColor']/Docs/*" />
public Color TextColor
{
get { return (Color)GetValue(TextElement.TextColorProperty); }
set { SetValue(TextElement.TextColorProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='CharacterSpacing']/Docs/*" />
public double CharacterSpacing
{
get { return (double)GetValue(TextElement.CharacterSpacingProperty); }
set { SetValue(TextElement.CharacterSpacingProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='Title']/Docs/*" />
public string Title
{
get { return (string)GetValue(TitleProperty); }
set { SetValue(TitleProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='TitleColor']/Docs/*" />
public Color TitleColor
{
get { return (Color)GetValue(TitleColorProperty); }
set { SetValue(TitleColorProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='HorizontalTextAlignment']/Docs/*" />
public TextAlignment HorizontalTextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentElement.HorizontalTextAlignmentProperty); }
set { SetValue(TextAlignmentElement.HorizontalTextAlignmentProperty, value); }
}
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='VerticalTextAlignment']/Docs/*" />
public TextAlignment VerticalTextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentElement.VerticalTextAlignmentProperty); }
set { SetValue(TextAlignmentElement.VerticalTextAlignmentProperty, value); }
}
BindingBase _itemDisplayBinding;
/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='ItemDisplayBinding']/Docs/*" />
[DoesNotInheritDataType]
public BindingBase ItemDisplayBinding
{
get { return _itemDisplayBinding; }
set
{
if (_itemDisplayBinding == value)
return;
OnPropertyChanging();
var oldValue = value;
_itemDisplayBinding = value;
OnItemDisplayBindingChanged(oldValue, _itemDisplayBinding);
OnPropertyChanged();
}
}
public event EventHandler SelectedIndexChanged;
static readonly BindableProperty s_displayProperty =
BindableProperty.Create("Display", typeof(string), typeof(Picker), default(string));
string GetDisplayMember(object item)
{
if (ItemDisplayBinding == null)
return item == null ? string.Empty : item.ToString();
ItemDisplayBinding.Apply(item, this, s_displayProperty, false, SetterSpecificity.FromBinding);
ItemDisplayBinding.Unapply();
return (string)GetValue(s_displayProperty);
}
static object CoerceSelectedIndex(BindableObject bindable, object value)
{
var picker = (Picker)bindable;
return picker.Items == null ? -1 : ((int)value).Clamp(-1, picker.Items.Count - 1);
}
void OnItemDisplayBindingChanged(BindingBase oldValue, BindingBase newValue)
{
ResetItems();
}
void OnItemsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
// Do not execute when Items is locked because updates to ItemsSource will
// take care of it
if (((LockableObservableListWrapper)Items).IsLocked)
return;
ClampSelectedIndex();
Handler?.UpdateValue(nameof(IPicker.Items));
}
static void OnItemsSourceChanged(BindableObject bindable, object oldValue, object newValue)
{
((Picker)bindable).OnItemsSourceChanged((IList)oldValue, (IList)newValue);
}
void OnItemsSourceChanged(IList oldValue, IList newValue)
{
var oldObservable = oldValue as INotifyCollectionChanged;
if (oldObservable != null)
oldObservable.CollectionChanged -= CollectionChanged;
var newObservable = newValue as INotifyCollectionChanged;
if (newObservable != null)
{
newObservable.CollectionChanged += CollectionChanged;
}
if (newValue != null)
{
((LockableObservableListWrapper)Items).IsLocked = true;
ResetItems();
}
else
{
// Unlock, then clear, so OnItemsCollectionChanged executes
((LockableObservableListWrapper)Items).IsLocked = false;
((LockableObservableListWrapper)Items).InternalClear();
}
}
void CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
AddItems(e);
break;
case NotifyCollectionChangedAction.Remove:
RemoveItems(e);
break;
default: //Move, Replace, Reset
ResetItems();
break;
}
Handler?.UpdateValue(nameof(IPicker.Items));
}
void AddItems(NotifyCollectionChangedEventArgs e)
{
int insertIndex = e.NewStartingIndex < 0 ? Items.Count : e.NewStartingIndex;
int index = insertIndex;
foreach (object newItem in e.NewItems)
((LockableObservableListWrapper)Items).InternalInsert(index++, GetDisplayMember(newItem));
if (insertIndex <= SelectedIndex)
UpdateSelectedItem(SelectedIndex);
}
void RemoveItems(NotifyCollectionChangedEventArgs e)
{
int removeStart;
// Items are removed in reverse order, so index starts at the index of the last item to remove
int index;
if (e.OldStartingIndex < Items.Count)
{
// Remove e.OldItems.Count items starting at e.OldStartingIndex
removeStart = e.OldStartingIndex;
index = e.OldStartingIndex + e.OldItems.Count - 1;
}
else
{
// Remove e.OldItems.Count items at the end when e.OldStartingIndex is past the end of the Items collection
removeStart = Items.Count - e.OldItems.Count;
index = Items.Count - 1;
}
foreach (object _ in e.OldItems)
((LockableObservableListWrapper)Items).InternalRemoveAt(index--);
if (removeStart <= SelectedIndex)
{
ClampSelectedIndex();
}
}
void ResetItems()
{
if (ItemsSource == null)
return;
((LockableObservableListWrapper)Items).InternalClear();
foreach (object item in ItemsSource)
((LockableObservableListWrapper)Items).InternalAdd(GetDisplayMember(item));
Handler?.UpdateValue(nameof(IPicker.Items));
ClampSelectedIndex();
}
static void OnSelectedIndexChanged(object bindable, object oldValue, object newValue)
{
var picker = (Picker)bindable;
picker.UpdateSelectedItem(picker.SelectedIndex);
picker.SelectedIndexChanged?.Invoke(bindable, EventArgs.Empty);
}
static void OnSelectedItemChanged(BindableObject bindable, object oldValue, object newValue)
{
var picker = (Picker)bindable;
picker.UpdateSelectedIndex(newValue);
}
void ClampSelectedIndex()
{
var oldIndex = SelectedIndex;
var newIndex = SelectedIndex.Clamp(-1, Items.Count - 1);
//FIXME use the specificity of the caller
SetValue(SelectedIndexProperty, newIndex, SetterSpecificity.FromHandler);
// If the index has not changed, still need to change the selected item
if (newIndex == oldIndex)
UpdateSelectedItem(newIndex);
}
void UpdateSelectedIndex(object selectedItem)
{
//FIXME use the specificity of the caller
if (ItemsSource != null)
{
SetValue(SelectedIndexProperty, ItemsSource.IndexOf(selectedItem), SetterSpecificity.FromHandler);
return;
}
SetValue(SelectedIndexProperty, Items.IndexOf(selectedItem), SetterSpecificity.FromHandler);
}
void UpdateSelectedItem(int index)
{
//FIXME use the specificity of the caller
if (index == -1)
{
SetValue(SelectedItemProperty, null, SetterSpecificity.FromHandler);
return;
}
if (ItemsSource != null)
{
var item = index < ItemsSource.Count ? ItemsSource[index] : null;
SetValue(SelectedItemProperty, item, SetterSpecificity.FromHandler);
return;
}
SetValue(SelectedItemProperty, Items[index], SetterSpecificity.FromHandler);
}
/// <inheritdoc/>
public IPlatformElementConfiguration<T, Picker> On<T>() where T : IConfigPlatform
{
return _platformConfigurationRegistry.Value.On<T>();
}
void ITextElement.OnTextColorPropertyChanged(Color oldValue, Color newValue)
{
}
void ITextElement.OnCharacterSpacingPropertyChanged(double oldValue, double newValue)
{
InvalidateMeasure();
}
void ITextAlignmentElement.OnHorizontalTextAlignmentPropertyChanged(TextAlignment oldValue, TextAlignment newValue)
{
}
Font ITextStyle.Font => this.ToFont();
IList<string> IPicker.Items => Items;
int IPicker.SelectedIndex
{
get => SelectedIndex;
set => SetValue(SelectedIndexProperty, value, SetterSpecificity.FromHandler);
}
int IItemDelegate<string>.GetCount() => Items?.Count ?? ItemsSource?.Count ?? 0;
string IItemDelegate<string>.GetItem(int index)
{
if (index < 0)
return string.Empty;
if (index < Items?.Count)
return GetItem(index);
if (index < ItemsSource?.Count)
return GetDisplayMember(ItemsSource[index]);
return string.Empty;
}
string GetItem(int index)
{
if (index < Items?.Count)
{
var item = Items[index];
return item ?? string.Empty;
}
return string.Empty;
}
}
}
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