Files
FlaxEngine/Source/Engine/UI/GUI/Common/Dropdown.cs
2021-04-07 20:52:22 +02:00

589 lines
18 KiB
C#

// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
using System;
using System.Collections.Generic;
namespace FlaxEngine.GUI
{
/// <summary>
/// Dropdown menu control allows to choose one item from the provided collection of options.
/// </summary>
/// <seealso cref="FlaxEngine.GUI.ContainerControl" />
public class Dropdown : ContainerControl
{
/// <summary>
/// The root control used by the <see cref="Dropdown"/> to show the items collections and track item selecting event.
/// </summary>
/// <seealso cref="FlaxEngine.GUI.Panel" />
[HideInEditor]
protected class DropdownRoot : Panel
{
private bool _isMouseDown;
/// <summary>
/// Occurs when item gets clicked. Argument is item index.
/// </summary>
public Action<int> ItemClicked;
/// <summary>
/// Occurs when popup lost focus.
/// </summary>
public Action LostFocus;
/// <summary>
/// The items container control.
/// </summary>
public ContainerControl ItemsContainer;
/// <inheritdoc />
public override bool OnMouseDown(Vector2 location, MouseButton button)
{
_isMouseDown = true;
var result = base.OnMouseDown(location, button);
_isMouseDown = false;
if (!result)
return false;
var itemIndex = ItemsContainer?.GetChildIndexAt(location) ?? -1;
if (itemIndex != -1)
ItemClicked(itemIndex);
return true;
}
/// <inheritdoc />
public override void OnLostFocus()
{
base.OnLostFocus();
if (!_isMouseDown)
{
LostFocus?.Invoke();
}
}
/// <inheritdoc />
public override void OnDestroy()
{
ItemClicked = null;
LostFocus = null;
ItemsContainer = null;
base.OnDestroy();
}
}
/// <summary>
/// The items.
/// </summary>
protected List<string> _items = new List<string>();
/// <summary>
/// The popup menu. May be null if has not been used yet.
/// </summary>
protected DropdownRoot _popup;
private bool _touchDown;
/// <summary>
/// The selected index of the item (-1 for no selection).
/// </summary>
protected int _selectedIndex = -1;
/// <summary>
/// Gets or sets the items collection.
/// </summary>
[EditorOrder(1), Tooltip("The items collection.")]
public List<string> Items
{
get => _items;
set => _items = value;
}
/// <summary>
/// Gets or sets the selected item (returns <see cref="string.Empty"/> if no item is being selected).
/// </summary>
[HideInEditor, NoSerialize]
public string SelectedItem
{
get => _selectedIndex != -1 ? _items[_selectedIndex] : string.Empty;
set => SelectedIndex = _items.IndexOf(value);
}
/// <summary>
/// Gets or sets the index of the selected.
/// </summary>
[EditorOrder(2), Limit(-1), Tooltip("The index of the selected item from the list.")]
public int SelectedIndex
{
get => _selectedIndex;
set
{
value = Mathf.Min(value, _items.Count - 1);
if (value != _selectedIndex)
{
_selectedIndex = value;
OnSelectedIndexChanged();
}
}
}
/// <summary>
/// Event fired when selected index gets changed.
/// </summary>
public event Action<Dropdown> SelectedIndexChanged;
/// <summary>
/// Gets a value indicating whether this popup menu is opened.
/// </summary>
public bool IsPopupOpened => _popup != null;
/// <summary>
/// Gets or sets the font used to draw text.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000)]
public FontReference Font { get; set; }
/// <summary>
/// Gets or sets the custom material used to render the text. It must has domain set to GUI and have a public texture parameter named Font used to sample font atlas texture with font characters data.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000), Tooltip("Custom material used to render the text. It must has domain set to GUI and have a public texture parameter named Font used to sample font atlas texture with font characters data.")]
public MaterialBase FontMaterial { get; set; }
/// <summary>
/// Gets or sets the color of the text.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000)]
public Color TextColor { get; set; }
/// <summary>
/// Gets or sets the color of the border.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000)]
public Color BorderColor { get; set; }
/// <summary>
/// Gets or sets the background color when dropdown popup is opened.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2010)]
public Color BackgroundColorSelected { get; set; }
/// <summary>
/// Gets or sets the border color when dropdown popup is opened.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2020)]
public Color BorderColorSelected { get; set; }
/// <summary>
/// Gets or sets the background color when dropdown is highlighted.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000)]
public Color BackgroundColorHighlighted { get; set; }
/// <summary>
/// Gets or sets the border color when dropdown is highlighted.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000)]
public Color BorderColorHighlighted { get; set; }
/// <summary>
/// Gets or sets the image used to render dropdown drop arrow icon.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000), Tooltip("The image used to render dropdown drop arrow icon.")]
public IBrush ArrowImage { get; set; }
/// <summary>
/// Gets or sets the color used to render dropdown drop arrow icon.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000), Tooltip("The color used to render dropdown drop arrow icon.")]
public Color ArrowColor { get; set; }
/// <summary>
/// Gets or sets the color used to render dropdown drop arrow icon (menu is opened).
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000), Tooltip("The color used to render dropdown drop arrow icon (menu is opened).")]
public Color ArrowColorSelected { get; set; }
/// <summary>
/// Gets or sets the color used to render dropdown drop arrow icon (menu is highlighted).
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000), Tooltip("The color used to render dropdown drop arrow icon (menu is highlighted).")]
public Color ArrowColorHighlighted { get; set; }
/// <summary>
/// Gets or sets the image used to render dropdown checked item icon.
/// </summary>
[EditorDisplay("Style"), EditorOrder(2000), Tooltip("The image used to render dropdown checked item icon.")]
public IBrush CheckedImage { get; set; }
/// <summary>
/// Initializes a new instance of the <see cref="Dropdown"/> class.
/// </summary>
public Dropdown()
: base(0, 0, 120, 18.0f)
{
AutoFocus = false;
var style = Style.Current;
Font = new FontReference(style.FontMedium);
TextColor = style.Foreground;
BackgroundColor = style.BackgroundNormal;
BackgroundColorHighlighted = BackgroundColor;
BackgroundColorSelected = BackgroundColor;
BorderColor = style.BorderNormal;
BorderColorHighlighted = style.BorderSelected;
BorderColorSelected = BorderColorHighlighted;
ArrowImage = new SpriteBrush(style.ArrowDown);
ArrowColor = style.Foreground * 0.6f;
ArrowColorSelected = style.BackgroundSelected;
ArrowColorHighlighted = style.Foreground;
CheckedImage = new SpriteBrush(style.CheckBoxTick);
}
/// <summary>
/// Clears the items.
/// </summary>
public void ClearItems()
{
SelectedIndex = -1;
_items.Clear();
}
/// <summary>
/// Adds the item.
/// </summary>
/// <param name="item">The item.</param>
public void AddItem(string item)
{
_items.Add(item);
}
/// <summary>
/// Adds the items.
/// </summary>
/// <param name="items">The items.</param>
public void AddItems(IEnumerable<string> items)
{
_items.AddRange(items);
}
/// <summary>
/// Sets the items.
/// </summary>
/// <param name="items">The items.</param>
public void SetItems(IEnumerable<string> items)
{
SelectedIndex = -1;
_items.Clear();
_items.AddRange(items);
}
/// <summary>
/// Called when selected item index gets changed.
/// </summary>
protected virtual void OnSelectedIndexChanged()
{
SelectedIndexChanged?.Invoke(this);
}
/// <summary>
/// Called when item is clicked.
/// </summary>
/// <param name="index">The index.</param>
protected virtual void OnItemClicked(int index)
{
SelectedIndex = index;
}
/// <summary>
/// Creates the popup menu (including items collection).
/// </summary>
protected virtual DropdownRoot CreatePopup()
{
// TODO: support using templates for the items collection container panel
var popup = new DropdownRoot();
// TODO: support item templates
var container = new VerticalPanel
{
AnchorPreset = AnchorPresets.StretchAll,
BackgroundColor = BackgroundColor,
AutoSize = false,
Parent = popup,
};
var border = new Border
{
BorderColor = BorderColorHighlighted,
Width = 4.0f,
AnchorPreset = AnchorPresets.StretchAll,
Parent = popup,
};
var itemsHeight = 20.0f;
var itemsMargin = 20.0f;
/*
var itemsWidth = 40.0f;
var font = Font.GetFont();
for (int i = 0; i < _items.Count; i++)
{
itemsWidth = Mathf.Max(itemsWidth, itemsMargin + 4 + font.MeasureText(_items[i]).X);
}
*/
var itemsWidth = Width;
var height = container.Margin.Height;
for (int i = 0; i < _items.Count; i++)
{
var item = new Spacer
{
Height = itemsHeight,
Width = itemsWidth,
Parent = container,
};
var label = new Label
{
X = itemsMargin,
Size = new Vector2(itemsWidth - itemsMargin, itemsHeight),
Font = Font,
TextColor = Color.White * 0.9f,
TextColorHighlighted = Color.White,
HorizontalAlignment = TextAlignment.Near,
Text = _items[i],
Parent = item,
};
height += itemsHeight;
if (i != 0)
height += container.Spacing;
if (_selectedIndex == i)
{
var icon = new Image
{
Brush = CheckedImage,
Size = new Vector2(itemsMargin, itemsHeight),
Margin = new Margin(4.0f, 6.0f, 4.0f, 4.0f),
//AnchorPreset = AnchorPresets.VerticalStretchLeft,
Parent = item,
};
}
}
popup.Size = new Vector2(itemsWidth, height);
popup.ItemsContainer = container;
return popup;
}
/// <summary>
/// Called when popup menu gets shown.
/// </summary>
protected virtual void OnPopupShow()
{
}
/// <summary>
/// Called when popup menu gets hidden.
/// </summary>
protected virtual void OnPopupHide()
{
}
/// <summary>
/// Destroys the popup.
/// </summary>
protected virtual void DestroyPopup()
{
if (_popup != null)
{
OnPopupHide();
_popup.Dispose();
_popup = null;
}
}
/// <summary>
/// Shows the popup.
/// </summary>
public void ShowPopup()
{
var root = Root;
if (_items.Count == 0 || root == null)
return;
// Setup popup
DestroyPopup();
_popup = CreatePopup();
// Update layout
_popup.UnlockChildrenRecursive();
_popup.PerformLayout();
// Bind events
_popup.ItemClicked += index =>
{
OnItemClicked(index);
DestroyPopup();
};
_popup.LostFocus += DestroyPopup;
// Show dropdown popup
Vector2 locationRootSpace = Location + new Vector2(0, Height);
var parent = Parent;
while (parent != null && parent != Root)
{
locationRootSpace = parent.PointToParent(ref locationRootSpace);
parent = parent.Parent;
}
_popup.Location = locationRootSpace;
_popup.Parent = root;
_popup.Focus();
OnPopupShow();
}
/// <summary>
/// Hides the popup.
/// </summary>
public void HidePopup()
{
DestroyPopup();
}
/// <inheritdoc />
public override void OnDestroy()
{
DestroyPopup();
base.OnDestroy();
}
/// <inheritdoc />
public override void DrawSelf()
{
// Cache data
var clientRect = new Rectangle(Vector2.Zero, Size);
float margin = clientRect.Height * 0.2f;
float boxSize = clientRect.Height - margin * 2;
bool isOpened = IsPopupOpened;
bool enabled = EnabledInHierarchy;
Color backgroundColor = BackgroundColor;
Color borderColor = BorderColor;
Color arrowColor = ArrowColor;
if (!enabled)
{
backgroundColor *= 0.5f;
arrowColor *= 0.7f;
}
else if (isOpened || _touchDown)
{
backgroundColor = BackgroundColorSelected;
borderColor = BorderColorSelected;
arrowColor = ArrowColorSelected;
}
else if (IsMouseOver)
{
backgroundColor = BackgroundColorHighlighted;
borderColor = BorderColorHighlighted;
arrowColor = ArrowColorHighlighted;
}
// Background
Render2D.FillRectangle(clientRect, backgroundColor);
Render2D.DrawRectangle(clientRect, borderColor);
// Check if has selected item
if (_selectedIndex > -1 && _selectedIndex < _items.Count)
{
// Draw text of the selected item
var textRect = new Rectangle(margin, 0, clientRect.Width - boxSize - 2.0f * margin, clientRect.Height);
Render2D.PushClip(textRect);
var textColor = TextColor;
Render2D.DrawText(Font.GetFont(), FontMaterial, _items[_selectedIndex], textRect, enabled ? textColor : textColor * 0.5f, TextAlignment.Near, TextAlignment.Center);
Render2D.PopClip();
}
// Arrow
ArrowImage?.Draw(new Rectangle(clientRect.Width - margin - boxSize, margin, boxSize, boxSize), arrowColor);
}
/// <inheritdoc />
public override void OnLostFocus()
{
_touchDown = false;
base.OnLostFocus();
}
/// <inheritdoc />
public override void OnMouseLeave()
{
_touchDown = false;
base.OnMouseLeave();
}
/// <inheritdoc />
public override bool OnMouseDown(Vector2 location, MouseButton button)
{
if (base.OnMouseDown(location, button))
return true;
if (button == MouseButton.Left)
{
_touchDown = true;
return true;
}
return false;
}
/// <inheritdoc />
public override bool OnMouseUp(Vector2 location, MouseButton button)
{
if (_touchDown && button == MouseButton.Left)
{
_touchDown = false;
ShowPopup();
return true;
}
return base.OnMouseUp(location, button);
}
/// <inheritdoc />
public override bool OnTouchDown(Vector2 location, int pointerId)
{
if (base.OnTouchDown(location, pointerId))
return true;
_touchDown = true;
return true;
}
/// <inheritdoc />
public override bool OnTouchUp(Vector2 location, int pointerId)
{
if (base.OnTouchUp(location, pointerId))
return true;
if (_touchDown)
{
ShowPopup();
}
return true;
}
/// <inheritdoc />
public override void OnTouchLeave(int pointerId)
{
_touchDown = false;
base.OnTouchLeave(pointerId);
}
}
}