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Terminal.Gui/Terminal.Gui/Views/ComboBox.cs
BDisp b21f203292 Fixes #820. Added HideDropdownListOnClick property. (#1983)
* Added HideDropdownListOnClick property.

* Invoking OpenSelectedItem on click.

* Added one more constructor and more unit tests.

* Added the ComboListView derived class.

* Added more features to ComboBox.

* Removes code not featured yet.

* Added HideDropdownListOnClick property to scenario.

* Ensures SetSource having the same behavior as the ListWrapper constructor.
2022-09-14 18:10:40 -07:00

876 lines
21 KiB
C#

//
// ComboBox.cs: ComboBox control
//
// Authors:
// Ross Ferguson (ross.c.ferguson@btinternet.com)
//
using System;
using System.Collections;
using System.Collections.Generic;
using NStack;
namespace Terminal.Gui {
/// <summary>
/// Provides a drop-down list of items the user can select from.
/// </summary>
public class ComboBox : View {
private class ComboListView : ListView {
private int highlighted = -1;
private bool isFocusing;
private ComboBox container;
private bool hideDropdownListOnClick;
public ComboListView (ComboBox container, bool hideDropdownListOnClick)
{
Initialize (container, hideDropdownListOnClick);
}
public ComboListView (ComboBox container, Rect rect, IList source, bool hideDropdownListOnClick) : base (rect, source)
{
Initialize (container, hideDropdownListOnClick);
}
public ComboListView (ComboBox container, IList source, bool hideDropdownListOnClick) : base (source)
{
Initialize (container, hideDropdownListOnClick);
}
private void Initialize (ComboBox container, bool hideDropdownListOnClick)
{
if (container == null)
throw new ArgumentNullException ("ComboBox container cannot be null.", nameof (container));
this.container = container;
HideDropdownListOnClick = hideDropdownListOnClick;
}
public bool HideDropdownListOnClick {
get => hideDropdownListOnClick;
set => hideDropdownListOnClick = WantContinuousButtonPressed = value;
}
public override bool MouseEvent (MouseEvent me)
{
var res = false;
var isMousePositionValid = IsMousePositionValid (me);
if (isMousePositionValid) {
res = base.MouseEvent (me);
}
if (HideDropdownListOnClick && me.Flags == MouseFlags.Button1Clicked) {
if (!isMousePositionValid && !isFocusing) {
container.isShow = false;
container.HideList ();
} else if (isMousePositionValid) {
OnOpenSelectedItem ();
} else {
isFocusing = false;
}
return true;
} else if (me.Flags == MouseFlags.ReportMousePosition && HideDropdownListOnClick) {
if (isMousePositionValid) {
highlighted = Math.Min (TopItem + me.Y, Source.Count);
SetNeedsDisplay ();
}
isFocusing = false;
return true;
}
return res;
}
private bool IsMousePositionValid (MouseEvent me)
{
if (me.X >= 0 && me.X < Frame.Width && me.Y >= 0 && me.Y < Frame.Height) {
return true;
}
return false;
}
public override void Redraw (Rect bounds)
{
var current = ColorScheme.Focus;
Driver.SetAttribute (current);
Move (0, 0);
var f = Frame;
var item = TopItem;
bool focused = HasFocus;
int col = AllowsMarking ? 2 : 0;
int start = LeftItem;
for (int row = 0; row < f.Height; row++, item++) {
bool isSelected = item == container.SelectedItem;
bool isHighlighted = hideDropdownListOnClick && item == highlighted;
Attribute newcolor;
if (isHighlighted || (isSelected && !hideDropdownListOnClick)) {
newcolor = focused ? ColorScheme.Focus : ColorScheme.HotNormal;
} else if (isSelected && hideDropdownListOnClick) {
newcolor = focused ? ColorScheme.HotFocus : ColorScheme.HotNormal;
} else {
newcolor = focused ? GetNormalColor () : GetNormalColor ();
}
if (newcolor != current) {
Driver.SetAttribute (newcolor);
current = newcolor;
}
Move (0, row);
if (Source == null || item >= Source.Count) {
for (int c = 0; c < f.Width; c++)
Driver.AddRune (' ');
} else {
var rowEventArgs = new ListViewRowEventArgs (item);
OnRowRender (rowEventArgs);
if (rowEventArgs.RowAttribute != null && current != rowEventArgs.RowAttribute) {
current = (Attribute)rowEventArgs.RowAttribute;
Driver.SetAttribute (current);
}
if (AllowsMarking) {
Driver.AddRune (Source.IsMarked (item) ? (AllowsMultipleSelection ? Driver.Checked : Driver.Selected) : (AllowsMultipleSelection ? Driver.UnChecked : Driver.UnSelected));
Driver.AddRune (' ');
}
Source.Render (this, Driver, isSelected, item, col, row, f.Width - col, start);
}
}
}
public override bool OnEnter (View view)
{
if (hideDropdownListOnClick) {
isFocusing = true;
highlighted = container.SelectedItem;
Application.GrabMouse (this);
}
return base.OnEnter (view);
}
public override bool OnLeave (View view)
{
if (hideDropdownListOnClick) {
isFocusing = false;
highlighted = container.SelectedItem;
Application.UngrabMouse ();
}
return base.OnLeave (view);
}
public override bool OnSelectedChanged ()
{
var res = base.OnSelectedChanged ();
highlighted = SelectedItem;
return res;
}
}
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;
// Only need to refresh list if its been added to a container view
if (SuperView != null && SuperView.Subviews.Contains (this)) {
SelectedItem = -1;
search.Text = "";
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 {
listview.SetSource (source);
Source = listview.Source;
}
}
/// <summary>
/// This event is raised when the selected item in the <see cref="ComboBox"/> has changed.
/// </summary>
public event Action<ListViewItemEventArgs> SelectedItemChanged;
/// <summary>
/// This event is raised when the drop-down list is expanded.
/// </summary>
public event Action Expanded;
/// <summary>
/// This event is raised when the drop-down list is collapsed.
/// </summary>
public event Action Collapsed;
/// <summary>
/// This event is raised when the user Double Clicks on an item or presses ENTER to open the selected item.
/// </summary>
public event Action<ListViewItemEventArgs> OpenSelectedItem;
readonly IList searchset = new List<object> ();
ustring text = "";
readonly TextField search;
readonly ComboListView listview;
bool autoHide = true;
int minimumHeight = 2;
/// <summary>
/// Public constructor
/// </summary>
public ComboBox () : this (string.Empty)
{
}
/// <summary>
/// Public constructor
/// </summary>
/// <param name="text"></param>
public ComboBox (ustring text) : base ()
{
search = new TextField ("");
listview = new ComboListView (this, HideDropdownListOnClick) { LayoutStyle = LayoutStyle.Computed, CanFocus = true, TabStop = false };
Initialize ();
Text = text;
}
/// <summary>
/// Public constructor
/// </summary>
/// <param name="rect"></param>
/// <param name="source"></param>
public ComboBox (Rect rect, IList source) : base (rect)
{
search = new TextField ("") { Width = rect.Width };
listview = new ComboListView (this, rect, source, HideDropdownListOnClick) { LayoutStyle = LayoutStyle.Computed, ColorScheme = Colors.Base };
Initialize ();
SetSource (source);
}
/// <summary>
/// Initialize with the source.
/// </summary>
/// <param name="source">The source.</param>
public ComboBox (IList source) : this (string.Empty)
{
search = new TextField ("");
listview = new ComboListView (this, source, HideDropdownListOnClick) { LayoutStyle = LayoutStyle.Computed, ColorScheme = Colors.Base };
Initialize ();
SetSource (source);
}
private void Initialize ()
{
if (Bounds.Height < minimumHeight && (Height == null || Height is Dim.DimAbsolute)) {
Height = minimumHeight;
}
search.TextChanged += Search_Changed;
listview.Y = Pos.Bottom (search);
listview.OpenSelectedItem += (ListViewItemEventArgs a) => Selected ();
this.Add (search, listview);
// On resize
LayoutComplete += (LayoutEventArgs a) => {
if ((!autoHide && Bounds.Width > 0 && search.Frame.Width != Bounds.Width) ||
(autoHide && Bounds.Width > 0 && search.Frame.Width != Bounds.Width - 1)) {
search.Width = listview.Width = autoHide ? Bounds.Width - 1 : Bounds.Width;
listview.Height = CalculatetHeight ();
search.SetRelativeLayout (Bounds);
listview.SetRelativeLayout (Bounds);
}
};
listview.SelectedItemChanged += (ListViewItemEventArgs e) => {
if (!HideDropdownListOnClick && searchset.Count > 0) {
SetValue (searchset [listview.SelectedItem]);
}
};
Added += (View v) => {
// Determine if this view is hosted inside a dialog and is the only control
for (View view = this.SuperView; view != null; view = view.SuperView) {
if (view is Dialog && SuperView != null && SuperView.Subviews.Count == 1 && SuperView.Subviews [0] == this) {
autoHide = false;
break;
}
}
SetNeedsLayout ();
SetNeedsDisplay ();
Search_Changed (Text);
};
// Things this view knows how to do
AddCommand (Command.Accept, () => ActivateSelected ());
AddCommand (Command.ToggleExpandCollapse, () => ExpandCollapse ());
AddCommand (Command.Expand, () => Expand ());
AddCommand (Command.Collapse, () => Collapse ());
AddCommand (Command.LineDown, () => MoveDown ());
AddCommand (Command.LineUp, () => MoveUp ());
AddCommand (Command.PageDown, () => PageDown ());
AddCommand (Command.PageUp, () => PageUp ());
AddCommand (Command.TopHome, () => MoveHome ());
AddCommand (Command.BottomEnd, () => MoveEnd ());
AddCommand (Command.Cancel, () => CancelSelected ());
AddCommand (Command.UnixEmulation, () => UnixEmulation ());
// Default keybindings for this view
AddKeyBinding (Key.Enter, Command.Accept);
AddKeyBinding (Key.F4, Command.ToggleExpandCollapse);
AddKeyBinding (Key.CursorDown, Command.LineDown);
AddKeyBinding (Key.CursorUp, Command.LineUp);
AddKeyBinding (Key.PageDown, Command.PageDown);
AddKeyBinding (Key.PageUp, Command.PageUp);
AddKeyBinding (Key.Home, Command.TopHome);
AddKeyBinding (Key.End, Command.BottomEnd);
AddKeyBinding (Key.Esc, Command.Cancel);
AddKeyBinding (Key.U | Key.CtrlMask, Command.UnixEmulation);
}
private bool isShow = false;
private int selectedItem = -1;
private int lastSelectedItem = -1;
private bool hideDropdownListOnClick;
/// <summary>
/// Gets the index of the currently selected item in the <see cref="Source"/>
/// </summary>
/// <value>The selected item or -1 none selected.</value>
public int SelectedItem {
get => selectedItem;
set {
if (selectedItem != value && (value == -1
|| (source != null && value > -1 && value < source.Count))) {
selectedItem = lastSelectedItem = value;
if (selectedItem != -1) {
SetValue (source.ToList () [selectedItem].ToString (), true);
} else {
SetValue ("", true);
}
OnSelectedChanged ();
}
}
}
/// <summary>
/// Gets the drop down list state, expanded or collapsed.
/// </summary>
public bool IsShow => isShow;
///<inheritdoc/>
public new ColorScheme ColorScheme {
get {
return base.ColorScheme;
}
set {
listview.ColorScheme = value;
base.ColorScheme = value;
SetNeedsDisplay ();
}
}
/// <summary>
///If set to true its not allow any changes in the text.
/// </summary>
public bool ReadOnly {
get => search.ReadOnly;
set {
search.ReadOnly = value;
if (search.ReadOnly) {
if (search.ColorScheme != null) {
search.ColorScheme.Normal = search.ColorScheme.Focus;
}
}
}
}
/// <summary>
/// Gets or sets if the drop-down list can be hide with a button click event.
/// </summary>
public bool HideDropdownListOnClick {
get => hideDropdownListOnClick;
set => hideDropdownListOnClick = listview.HideDropdownListOnClick = value;
}
///<inheritdoc/>
public override bool MouseEvent (MouseEvent me)
{
if (me.X == Bounds.Right - 1 && me.Y == Bounds.Top && me.Flags == MouseFlags.Button1Pressed
&& autoHide) {
if (isShow) {
isShow = false;
HideList ();
} else {
SetSearchSet ();
isShow = true;
ShowList ();
FocusSelectedItem ();
}
return true;
} else if (me.Flags == MouseFlags.Button1Pressed) {
if (!search.HasFocus) {
search.SetFocus ();
}
return true;
}
return false;
}
private void FocusSelectedItem ()
{
listview.SelectedItem = SelectedItem > -1 ? SelectedItem : 0;
listview.TabStop = true;
listview.SetFocus ();
OnExpanded ();
}
/// <summary>
/// Virtual method which invokes the <see cref="Expanded"/> event.
/// </summary>
public virtual void OnExpanded ()
{
Expanded?.Invoke ();
}
/// <summary>
/// Virtual method which invokes the <see cref="Collapsed"/> event.
/// </summary>
public virtual void OnCollapsed ()
{
Collapsed?.Invoke ();
}
///<inheritdoc/>
public override bool OnEnter (View view)
{
if (!search.HasFocus && !listview.HasFocus) {
search.SetFocus ();
}
search.CursorPosition = search.Text.RuneCount;
return base.OnEnter (view);
}
///<inheritdoc/>
public override bool OnLeave (View view)
{
if (source?.Count > 0 && selectedItem > -1 && selectedItem < source.Count - 1
&& text != source.ToList () [selectedItem].ToString ()) {
SetValue (source.ToList () [selectedItem].ToString ());
}
if (autoHide && isShow && view != this && view != search && view != listview) {
isShow = false;
HideList ();
} else if (listview.TabStop) {
listview.TabStop = false;
}
return base.OnLeave (view);
}
/// <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 (new ListViewItemEventArgs (SelectedItem, search.Text));
return true;
}
/// <summary>
/// Invokes the OnOpenSelectedItem event if it is defined.
/// </summary>
/// <returns></returns>
public virtual bool OnOpenSelectedItem ()
{
var value = search.Text;
lastSelectedItem = SelectedItem;
OpenSelectedItem?.Invoke (new ListViewItemEventArgs (SelectedItem, value));
return true;
}
///<inheritdoc/>
public override void Redraw (Rect bounds)
{
base.Redraw (bounds);
if (!autoHide) {
return;
}
Driver.SetAttribute (ColorScheme.Focus);
Move (Bounds.Right - 1, 0);
Driver.AddRune (Driver.DownArrow);
}
///<inheritdoc/>
public override bool ProcessKey (KeyEvent e)
{
var result = InvokeKeybindings (e);
if (result != null)
return (bool)result;
return base.ProcessKey (e);
}
bool UnixEmulation ()
{
// Unix emulation
Reset ();
return true;
}
bool CancelSelected ()
{
search.SetFocus ();
if (ReadOnly || HideDropdownListOnClick) {
SelectedItem = lastSelectedItem;
if (SelectedItem > -1 && listview.Source?.Count > 0) {
search.Text = text = listview.Source.ToList () [SelectedItem].ToString ();
}
} else if (!ReadOnly) {
search.Text = text = "";
selectedItem = lastSelectedItem;
OnSelectedChanged ();
}
Collapse ();
return true;
}
bool? MoveEnd ()
{
if (!isShow && search.HasFocus) {
return null;
}
if (HasItems ()) {
listview.MoveEnd ();
}
return true;
}
bool? MoveHome ()
{
if (!isShow && search.HasFocus) {
return null;
}
if (HasItems ()) {
listview.MoveHome ();
}
return true;
}
bool PageUp ()
{
if (HasItems ()) {
listview.MovePageUp ();
}
return true;
}
bool PageDown ()
{
if (HasItems ()) {
listview.MovePageDown ();
}
return true;
}
bool? MoveUp ()
{
if (search.HasFocus) { // stop odd behavior on KeyUp when search has focus
return true;
}
if (listview.HasFocus && listview.SelectedItem == 0 && searchset?.Count > 0) // jump back to search
{
search.CursorPosition = search.Text.RuneCount;
search.SetFocus ();
return true;
}
return null;
}
bool? MoveDown ()
{
if (search.HasFocus) { // jump to list
if (searchset?.Count > 0) {
listview.TabStop = true;
listview.SetFocus ();
SetValue (searchset [listview.SelectedItem]);
} else {
listview.TabStop = false;
SuperView?.FocusNext ();
}
return true;
}
return null;
}
/// <summary>
/// Toggles the expand/collapse state of the sublist in the combo box
/// </summary>
/// <returns></returns>
bool ExpandCollapse ()
{
if (search.HasFocus || listview.HasFocus) {
if (!isShow) {
return Expand ();
} else {
return Collapse ();
}
}
return false;
}
bool ActivateSelected ()
{
if (HasItems ()) {
Selected ();
return true;
}
return false;
}
bool HasItems ()
{
return Source?.Count > 0;
}
/// <summary>
/// Collapses the drop down list. Returns true if the state chagned or false
/// if it was already collapsed and no action was taken
/// </summary>
public virtual bool Collapse ()
{
if (!isShow) {
return false;
}
isShow = false;
HideList ();
return true;
}
/// <summary>
/// Expands the drop down list. Returns true if the state chagned or false
/// if it was already expanded and no action was taken
/// </summary>
public virtual bool Expand ()
{
if (isShow) {
return false;
}
SetSearchSet ();
isShow = true;
ShowList ();
FocusSelectedItem ();
return true;
}
/// <summary>
/// The currently selected list item
/// </summary>
public new ustring Text {
get {
return text;
}
set {
search.Text = text = value;
}
}
private void SetValue (object text, bool isFromSelectedItem = false)
{
search.TextChanged -= Search_Changed;
this.text = search.Text = text.ToString ();
search.CursorPosition = 0;
search.TextChanged += Search_Changed;
if (!isFromSelectedItem) {
selectedItem = GetSelectedItemFromSource (this.text);
OnSelectedChanged ();
}
}
private void Selected ()
{
isShow = false;
listview.TabStop = false;
if (listview.Source.Count == 0 || (searchset?.Count ?? 0) == 0) {
text = "";
HideList ();
return;
}
SetValue (searchset [listview.SelectedItem]);
search.CursorPosition = search.Text.RuneCount;
Search_Changed (search.Text);
OnOpenSelectedItem ();
Reset (keepSearchText: true);
HideList ();
}
private int GetSelectedItemFromSource (ustring value)
{
if (source == null) {
return -1;
}
for (int i = 0; i < source.Count; i++) {
if (source.ToList () [i].ToString () == value) {
return i;
}
}
return -1;
}
/// <summary>
/// Reset to full original list
/// </summary>
private void Reset (bool keepSearchText = false)
{
if (!keepSearchText) {
search.Text = text = "";
}
ResetSearchSet ();
listview.SetSource (searchset);
listview.Height = CalculatetHeight ();
if (Subviews.Count > 0) {
search.SetFocus ();
}
}
private void ResetSearchSet (bool noCopy = false)
{
searchset.Clear ();
if (autoHide || noCopy)
return;
SetSearchSet ();
}
private void SetSearchSet ()
{
if (Source == null) { return; }
// force deep copy
foreach (var item in Source.ToList ()) {
searchset.Add (item);
}
}
private void Search_Changed (ustring text)
{
if (source == null) { // Object initialization
return;
}
if (ustring.IsNullOrEmpty (search.Text) && ustring.IsNullOrEmpty (text)) {
ResetSearchSet ();
} else if (search.Text != text) {
isShow = true;
ResetSearchSet (noCopy: true);
foreach (var item in source.ToList ()) { // Iterate to preserver object type and force deep copy
if (item.ToString ().StartsWith (search.Text.ToString (), StringComparison.CurrentCultureIgnoreCase)) {
searchset.Add (item);
}
}
}
ShowList ();
}
/// <summary>
/// Show the search list
/// </summary>
///
/// Consider making public
private void ShowList ()
{
listview.SetSource (searchset);
listview.Clear (); // Ensure list shrinks in Dialog as you type
listview.Height = CalculatetHeight ();
this.SuperView?.BringSubviewToFront (this);
}
/// <summary>
/// Hide the search list
/// </summary>
///
/// Consider making public
private void HideList ()
{
if (lastSelectedItem != selectedItem) {
OnOpenSelectedItem ();
}
var rect = listview.ViewToScreen (listview.Bounds);
Reset (SelectedItem > -1);
listview.Clear (rect);
listview.TabStop = false;
SuperView?.SendSubviewToBack (this);
SuperView?.SetNeedsDisplay (rect);
OnCollapsed ();
}
/// <summary>
/// Internal height of dynamic search list
/// </summary>
/// <returns></returns>
private int CalculatetHeight ()
{
if (Bounds.Height == 0)
return 0;
return Math.Min (Math.Max (Bounds.Height - 1, minimumHeight - 1), searchset?.Count > 0 ? searchset.Count : isShow ? Math.Max (Bounds.Height - 1, minimumHeight - 1) : 0);
}
}
}