Files
Terminal.Gui/Terminal.Gui/Views/ComboBox.cs
2020-06-20 18:28:59 +01:00

358 lines
8.2 KiB
C#

//
// ComboBox.cs: ComboBox control
//
// Authors:
// Ross Ferguson (ross.c.ferguson@btinternet.com)
//
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using NStack;
namespace Terminal.Gui {
/// <summary>
/// ComboBox control
/// </summary>
public class ComboBox : View {
IListDataSource source;
/// <summary>
/// Gets or sets the <see cref="IListDataSource"/> backing this <see cref="ComboBox"/>, enabling custom rendering.
/// </summary>
/// <value>The source.</value>
/// <remarks>
/// Use <see cref="SetSource"/> to set a new <see cref="IList"/> source.
/// </remarks>
public IListDataSource Source {
get => source;
set {
source = value;
Search_Changed ("");
SetNeedsDisplay ();
}
}
/// <summary>
/// Sets the source of the <see cref="ComboBox"/> to an <see cref="IList"/>.
/// </summary>
/// <value>An object implementing the IList interface.</value>
/// <remarks>
/// Use the <see cref="Source"/> property to set a new <see cref="IListDataSource"/> source and use custome rendering.
/// </remarks>
public void SetSource (IList source)
{
if (source == null)
Source = null;
else {
Source = MakeWrapper (source);
}
}
/// <summary>
/// Changed event, raised when the selection has been confirmed.
/// </summary>
/// <remarks>
/// Client code can hook up to this event, it is
/// raised when the selection has been confirmed.
/// </remarks>
public event EventHandler<ustring> SelectedItemChanged;
IList searchset;
ustring text = "";
readonly TextField search;
readonly ListView listview;
int height;
int width;
bool autoHide = true;
/// <summary>
/// Public constructor
/// </summary>
public ComboBox () : base()
{
search = new TextField ("");
listview = new ListView () { LayoutStyle = LayoutStyle.Computed, CanFocus = true };
Initialize ();
}
/// <summary>
/// Public constructor
/// </summary>
/// <param name="text"></param>
public ComboBox (ustring text) : base ()
{
search = new TextField ("");
listview = new ListView () { LayoutStyle = LayoutStyle.Computed, CanFocus = true };
Initialize ();
Text = text;
}
/// <summary>
/// Public constructor
/// </summary>
/// <param name="rect"></param>
/// <param name="source"></param>
public ComboBox (Rect rect, IList source) : base (rect)
{
this.height = rect.Height;
this.width = rect.Width;
search = new TextField ("") { Width = width };
listview = new ListView (rect, source) { LayoutStyle = LayoutStyle.Computed };
Initialize ();
SetSource (source);
}
static IListDataSource MakeWrapper (IList source)
{
return new ListWrapper (source);
}
private void Initialize()
{
ColorScheme = Colors.Base;
search.TextChanged += Search_Changed;
listview.OpenSelectedItem += (ListViewItemEventArgs a) => Selected();
// On resize
LayoutComplete += (LayoutEventArgs a) => {
search.Width = Bounds.Width;
listview.Width = autoHide ? Bounds.Width - 1 : Bounds.Width;
listview.Height = CalculatetHeight ();
};
listview.SelectedItemChanged += (ListViewItemEventArgs e) => {
if(searchset.Count > 0)
SetValue ((string)searchset [listview.SelectedItem]);
};
Application.Loaded += (Application.ResizedEventArgs a) => {
// Determine if this view is hosted inside a dialog
for (View view = this.SuperView; view != null; view = view.SuperView) {
if (view is Dialog) {
autoHide = false;
break;
}
}
ResetSearchSet ();
ColorScheme = autoHide ? Colors.Base : ColorScheme = null;
listview.Y = Pos.Bottom (search);
if (Width != null && width == 0) // new ComboBox() { Width =
width = Bounds.Width;
search.Width = width;
listview.Width = CalculateWidth ();
if (Height != null && height == 0) // new ComboBox() { Height =
height = Bounds.Height;
listview.Height = CalculatetHeight ();
SetNeedsLayout ();
if (this.Text != null)
Search_Changed (Text);
if (autoHide)
listview.ColorScheme = Colors.Menu;
else
search.ColorScheme = Colors.Menu;
};
search.MouseClick += Search_MouseClick;
this.Add(listview, search);
this.SetFocus(search);
}
private void Search_MouseClick (MouseEventArgs e)
{
if (e.MouseEvent.Flags != MouseFlags.Button1Clicked)
return;
SuperView.SetFocus (search);
}
///<inheritdoc/>
public override bool OnEnter ()
{
if (!search.HasFocus)
this.SetFocus (search);
search.CursorPosition = search.Text.Length;
return true;
}
/// <summary>
/// Invokes the SelectedChanged event if it is defined.
/// </summary>
/// <returns></returns>
public virtual bool OnSelectedChanged ()
{
// Note: Cannot rely on "listview.SelectedItem != lastSelectedItem" because the list is dynamic.
// So we cannot optimize. Ie: Don't call if not changed
SelectedItemChanged?.Invoke (this, search.Text);
return true;
}
///<inheritdoc/>
public override bool ProcessKey(KeyEvent e)
{
if (e.Key == Key.Tab) {
base.ProcessKey(e);
return false; // allow tab-out to next control
}
if (e.Key == Key.Enter && listview.HasFocus) {
Selected ();
return true;
}
if (e.Key == Key.CursorDown && search.HasFocus && listview.SelectedItem == 0 && searchset.Count > 0) { // jump to list
this.SetFocus (listview);
SetValue ((string)searchset [listview.SelectedItem]);
return true;
}
if (e.Key == Key.CursorUp && search.HasFocus) // stop odd behavior on KeyUp when search has focus
return true;
if (e.Key == Key.CursorUp && listview.HasFocus && listview.SelectedItem == 0 && searchset.Count > 0) // jump back to search
{
search.CursorPosition = search.Text.Length;
this.SetFocus (search);
return true;
}
if (e.Key == Key.Esc) {
this.SetFocus (search);
search.Text = text = "";
OnSelectedChanged ();
return true;
}
// Unix emulation
if (e.Key == Key.ControlU)
{
Reset();
return true;
}
return base.ProcessKey(e);
}
/// <summary>
/// The currently selected list item
/// </summary>
public ustring Text
{
get
{
return text;
}
set {
search.Text = text = value;
}
}
private void SetValue(ustring text)
{
search.TextChanged -= Search_Changed;
this.text = search.Text = text;
search.CursorPosition = 0;
search.TextChanged += Search_Changed;
}
private void Selected()
{
if (listview.Source.Count == 0 || searchset.Count == 0) {
text = "";
return;
}
SetValue ((string)searchset [listview.SelectedItem]);
search.CursorPosition = search.Text.Length;
Search_Changed (search.Text);
Reset (keepSearchText: true);
}
/// <summary>
/// Reset to full original list
/// </summary>
private void Reset(bool keepSearchText = false)
{
if(!keepSearchText)
search.Text = text = "";
OnSelectedChanged ();
ResetSearchSet ();
listview.SetSource(searchset);
listview.Height = CalculatetHeight ();
this.SetFocus(search);
}
private void ResetSearchSet()
{
if (autoHide) {
if (searchset == null)
searchset = new List<string> ();
else
searchset.Clear ();
} else
searchset = source.ToList ();
}
private void Search_Changed (ustring text)
{
if (source == null) // Object initialization
return;
if (string.IsNullOrEmpty (search.Text.ToString ()))
ResetSearchSet ();
else
searchset = source.ToList().Cast<string>().Where (x => x.StartsWith (search.Text.ToString (), StringComparison.CurrentCultureIgnoreCase)).ToList();
listview.SetSource (searchset);
listview.Height = CalculatetHeight ();
listview.Redraw (new Rect (0, 0, width, height)); // for any view behind this
this.SuperView?.BringSubviewToFront (this);
}
/// <summary>
/// Internal width of search list
/// </summary>
/// <returns></returns>
private int CalculateWidth ()
{
return autoHide ? Math.Max (1, width - 1) : width;
}
/// <summary>
/// Internal height of dynamic search list
/// </summary>
/// <returns></returns>
private int CalculatetHeight ()
{
var h = (Height is Dim.DimAbsolute) ? height : Bounds.Height;
return Math.Min (Math.Max (0, h - 1), searchset?.Count ?? 0);
}
}
}