Files
Terminal.Gui/Terminal.Gui/Views/Shortcut.cs
2024-10-19 17:37:55 -06:00

840 lines
26 KiB
C#

#nullable enable
using System.ComponentModel;
namespace Terminal.Gui;
/// <summary>
/// Displays a command, help text, and a key binding. When the key specified by <see cref="Key"/> is pressed, the
/// command will be invoked. Useful for
/// displaying a command in <see cref="Bar"/> such as a
/// menu, toolbar, or status bar.
/// </summary>
/// <remarks>
/// <para>
/// The following user actions will invoke the <see cref="Command.Accept"/>, causing the
/// <see cref="View.Accepting"/> event to be fired:
/// - Clicking on the <see cref="Shortcut"/>.
/// - Pressing the key specified by <see cref="Key"/>.
/// - Pressing the HotKey specified by <see cref="CommandView"/>.
/// </para>
/// <para>
/// If <see cref="KeyBindingScope"/> is <see cref="KeyBindingScope.Application"/>, <see cref="Key"/> will invoke
/// <see cref="Command.Accept"/>
/// regardless of what View has focus, enabling an application-wide keyboard shortcut.
/// </para>
/// <para>
/// By default, a Shortcut displays the command text on the left side, the help text in the middle, and the key
/// binding on the
/// right side. Set <see cref="AlignmentModes"/> to <see cref="AlignmentModes.EndToStart"/> to reverse the order.
/// </para>
/// <para>
/// The command text can be set by setting the <see cref="CommandView"/>'s Text property or by setting
/// <see cref="View.Title"/>.
/// </para>
/// <para>
/// The help text can be set by setting the <see cref="HelpText"/> property or by setting <see cref="View.Text"/>.
/// </para>
/// <para>
/// The key text is set by setting the <see cref="Key"/> property.
/// If the <see cref="Key"/> is <see cref="Key.Empty"/>, the <see cref="Key"/> text is not displayed.
/// </para>
/// </remarks>
public class Shortcut : View, IOrientation, IDesignable
{
/// <summary>
/// Creates a new instance of <see cref="Shortcut"/>.
/// </summary>
public Shortcut () : this (Key.Empty, null, null, null) { }
/// <summary>
/// Creates a new instance of <see cref="Shortcut"/>, binding it to <paramref name="targetView"/> and
/// <paramref name="command"/>. The Key <paramref name="targetView"/>
/// has bound to <paramref name="command"/> will be used as <see cref="Key"/>.
/// </summary>
/// <remarks>
/// <para>
/// This is a helper API that simplifies creation of multiple Shortcuts when adding them to <see cref="Bar"/>-based
/// objects, like <see cref="MenuBarv2"/>.
/// </para>
/// </remarks>
/// <param name="targetView">
/// The View that <paramref name="command"/> will be invoked on when user does something that causes the Shortcut's Accept
/// event to be raised.
/// </param>
/// <param name="command">
/// The Command to invoke on <paramref name="targetView"/>. The Key <paramref name="targetView"/>
/// has bound to <paramref name="command"/> will be used as <see cref="Key"/>
/// </param>
/// <param name="commandText">The text to display for the command.</param>
/// <param name="helpText">The help text to display.</param>
public Shortcut (View targetView, Command command, string commandText, string helpText)
: this (
targetView?.KeyBindings.GetKeyFromCommands (command)!,
commandText,
null,
helpText)
{
_targetView = targetView;
_command = command;
}
/// <summary>
/// Creates a new instance of <see cref="Shortcut"/>.
/// </summary>
/// <remarks>
/// <para>
/// This is a helper API that mimics the V1 API for creating StatusItems.
/// </para>
/// </remarks>
/// <param name="key"></param>
/// <param name="commandText">The text to display for the command.</param>
/// <param name="action"></param>
/// <param name="helpText">The help text to display.</param>
public Shortcut (Key key, string? commandText, Action? action, string? helpText = null)
{
Id = "_shortcut";
HighlightStyle = HighlightStyle.None;
CanFocus = true;
Width = GetWidthDimAuto ();
Height = Dim.Auto (DimAutoStyle.Content, 1);
_orientationHelper = new (this);
_orientationHelper.OrientationChanging += (sender, e) => OrientationChanging?.Invoke (this, e);
_orientationHelper.OrientationChanged += (sender, e) => OrientationChanged?.Invoke (this, e);
AddCommands ();
TitleChanged += Shortcut_TitleChanged; // This needs to be set before CommandView is set
CommandView = new ()
{
Id = "CommandView",
Width = Dim.Auto (),
Height = Dim.Auto (DimAutoStyle.Auto, 1)
};
HelpView.Id = "_helpView";
HelpView.CanFocus = false;
HelpView.Text = helpText ?? string.Empty;
KeyView.Id = "_keyView";
KeyView.CanFocus = false;
LayoutStarted += OnLayoutStarted;
key ??= Key.Empty;
Key = key;
Title = commandText ?? string.Empty;
Action = action;
}
// Helper to set Width consistently
private Dim GetWidthDimAuto ()
{
// TODO: PosAlign.CalculateMinDimension is a hack. Need to figure out a better way of doing this.
return Dim.Auto (
DimAutoStyle.Content,
Dim.Func (() =>
{
return PosAlign.CalculateMinDimension (0, Subviews, Dimension.Width);
}),
Dim.Func (() =>
{
return PosAlign.CalculateMinDimension (0, Subviews, Dimension.Width);
}))!;
}
/// <inheritdoc />
public override void EndInit ()
{
base.EndInit ();
SuperViewRendersLineCanvas = true;
Border.Settings &= ~BorderSettings.Title;
ShowHide ();
// Force Width to DimAuto to calculate natural width and then set it back
Dim? savedDim = Width;
Width = GetWidthDimAuto ();
// Force a SRL)
SetRelativeLayout (Application.Screen.Size);
_minimumNatrualWidth = Frame.Width;
Width = savedDim;
SetCommandViewDefaultLayout ();
SetHelpViewDefaultLayout ();
SetKeyViewDefaultLayout ();
SetColors ();
}
private AlignmentModes _alignmentModes = AlignmentModes.StartToEnd | AlignmentModes.IgnoreFirstOrLast;
// This is used to calculate the minimum width of the Shortcut when the width is NOT Dim.Auto
// It is calculated by setting Width to DimAuto temporarily and forcing layout
private int? _minimumNatrualWidth;
/// <inheritdoc/>
protected override bool OnHighlight (CancelEventArgs<HighlightStyle> args)
{
if (args.NewValue.HasFlag (HighlightStyle.Hover))
{
HasFocus = true;
}
return true;
}
/// <summary>
/// Gets or sets the <see cref="AlignmentModes"/> for this <see cref="Shortcut"/>.
/// </summary>
/// <remarks>
/// <para>
/// The default is <see cref="AlignmentModes.StartToEnd"/>. This means that the CommandView will be on the left,
/// HelpView in the middle, and KeyView on the right.
/// </para>
/// </remarks>
public AlignmentModes AlignmentModes
{
get => _alignmentModes;
set
{
_alignmentModes = value;
SetCommandViewDefaultLayout ();
SetHelpViewDefaultLayout ();
SetKeyViewDefaultLayout ();
}
}
// When one of the subviews is "empty" we don't want to show it. So we
// Use Add/Remove. We need to be careful to add them in the right order
// so Pos.Align works correctly.
internal void ShowHide ()
{
RemoveAll ();
if (CommandView.Visible)
{
Add (CommandView);
}
if (HelpView.Visible && !string.IsNullOrEmpty (HelpView.Text))
{
Add (HelpView);
}
if (KeyView.Visible && Key != Key.Empty)
{
Add (KeyView);
}
}
private Thickness GetMarginThickness ()
{
if (Orientation == Orientation.Vertical)
{
return new (1, 0, 1, 0);
}
return new (1, 0, 1, 0);
}
// When layout starts, we need to adjust the layout of the HelpView and KeyView
private void OnLayoutStarted (object? sender, LayoutEventArgs e)
{
if (Width is DimAuto widthAuto)
{
_minimumNatrualWidth = Frame.Width;
}
else
{
if (string.IsNullOrEmpty (HelpView.Text))
{
return;
}
int currentWidth = Frame.Width;
// If our width is smaller than the natural width then reduce width of HelpView first.
// Then KeyView.
// Don't ever reduce CommandView (it should spill).
// When Horizontal, Key is first, then Help, then Command.
// When Vertical, Command is first, then Help, then Key.
// BUGBUG: This does not do what the above says.
// TODO: Add Unit tests for this.
if (currentWidth < _minimumNatrualWidth)
{
int delta = _minimumNatrualWidth.Value - currentWidth;
int maxHelpWidth = int.Max (0, HelpView.Text.GetColumns () + Margin.Thickness.Horizontal - delta);
switch (maxHelpWidth)
{
case 0:
// Hide HelpView
HelpView.Visible = false;
HelpView.X = 0;
break;
case 1:
// Scrunch it by removing margins
HelpView.Margin.Thickness = new (0, 0, 0, 0);
break;
case 2:
// Scrunch just the right margin
Thickness t = GetMarginThickness ();
HelpView.Margin.Thickness = new (t.Right, t.Top, t.Left - 1, t.Bottom);
break;
default:
// Default margin
HelpView.Margin.Thickness = GetMarginThickness ();
break;
}
if (maxHelpWidth > 0)
{
HelpView.X = Pos.Align (Alignment.End, AlignmentModes);
// Leverage Dim.Auto's max:
HelpView.Width = Dim.Auto (DimAutoStyle.Text, maximumContentDim: maxHelpWidth);
HelpView.Visible = true;
}
}
else
{
// Reset to default
SetHelpViewDefaultLayout ();
}
}
}
#region Accept/Select/HotKey Command Handling
private readonly View? _targetView; // If set, _command will be invoked
private readonly Command _command; // Used when _targetView is set
private void AddCommands ()
{
// Accept (Enter key) -
AddCommand (Command.Accept, DispatchCommand);
// Hotkey -
AddCommand (Command.HotKey, DispatchCommand);
// Select (Space key or click) -
AddCommand (Command.Select, DispatchCommand);
}
private bool? DispatchCommand (CommandContext ctx)
{
if (ctx.Data != this)
{
// Invoke Select on the command view to cause it to change state if it wants to
// If this causes CommandView to raise Accept, we eat it
ctx.Data = this;
CommandView.InvokeCommand (Command.Select, ctx);
}
if (RaiseSelecting (ctx) is true)
{
return true;
}
// The default HotKey handler sets Focus
SetFocus ();
var cancel = false;
cancel = RaiseAccepting (ctx) is true;
if (cancel)
{
return true;
}
if (Action is { })
{
Action.Invoke ();
// Assume if there's a subscriber to Action, it's handled.
cancel = true;
}
if (_targetView is { })
{
_targetView.InvokeCommand (_command);
}
return cancel;
}
/// <summary>
/// Gets or sets the action to be invoked when the shortcut key is pressed or the shortcut is clicked on with the
/// mouse.
/// </summary>
/// <remarks>
/// Note, the <see cref="View.Accepting"/> event is fired first, and if cancelled, the event will not be invoked.
/// </remarks>
public Action? Action { get; set; }
#endregion Accept/Select/HotKey Command Handling
#region IOrientation members
private readonly OrientationHelper _orientationHelper;
/// <summary>
/// Gets or sets the <see cref="Orientation"/> for this <see cref="Bar"/>. The default is
/// <see cref="Orientation.Horizontal"/>.
/// </summary>
/// <remarks>
/// <para>
/// Horizontal orientation arranges the command, help, and key parts of each <see cref="Shortcut"/>s from right to
/// left
/// Vertical orientation arranges the command, help, and key parts of each <see cref="Shortcut"/>s from left to
/// right.
/// </para>
/// </remarks>
public Orientation Orientation
{
get => _orientationHelper.Orientation;
set => _orientationHelper.Orientation = value;
}
/// <inheritdoc/>
public event EventHandler<CancelEventArgs<Orientation>>? OrientationChanging;
/// <inheritdoc/>
public event EventHandler<EventArgs<Orientation>>? OrientationChanged;
/// <summary>Called when <see cref="Orientation"/> has changed.</summary>
/// <param name="newOrientation"></param>
public void OnOrientationChanged (Orientation newOrientation)
{
// TODO: Determine what, if anything, is opinionated about the orientation.
SetLayoutNeeded ();
}
#endregion
#region Command
private View _commandView = new ();
/// <summary>
/// Gets or sets the View that displays the command text and hotkey.
/// </summary>
/// <exception cref="ArgumentNullException"></exception>
/// <remarks>
/// <para>
/// By default, the <see cref="View.Title"/> of the <see cref="CommandView"/> is displayed as the Shortcut's
/// command text.
/// </para>
/// <para>
/// By default, the CommandView is a <see cref="View"/> with <see cref="View.CanFocus"/> set to
/// <see langword="false"/>.
/// </para>
/// <para>
/// Setting the <see cref="CommandView"/> will add it to the <see cref="Shortcut"/> and remove any existing
/// <see cref="CommandView"/>.
/// </para>
/// </remarks>
/// <example>
/// <para>
/// This example illustrates how to add a <see cref="Shortcut"/> to a <see cref="StatusBar"/> that toggles the
/// <see cref="Application.Force16Colors"/> property.
/// </para>
/// <code>
/// var force16ColorsShortcut = new Shortcut
/// {
/// Key = Key.F6,
/// KeyBindingScope = KeyBindingScope.HotKey,
/// CommandView = new CheckBox { Text = "Force 16 Colors" }
/// };
/// var cb = force16ColorsShortcut.CommandView as CheckBox;
/// cb.Checked = Application.Force16Colors;
///
/// cb.Toggled += (s, e) =>
/// {
/// var cb = s as CheckBox;
/// Application.Force16Colors = cb!.Checked == true;
/// Application.Refresh();
/// };
/// StatusBar.Add(force16ColorsShortcut);
/// </code>
/// </example>
public View CommandView
{
get => _commandView;
set
{
ArgumentNullException.ThrowIfNull (value);
if (value == null)
{
throw new ArgumentNullException ();
}
// Clean up old
_commandView.Selecting -= CommandViewOnSelecting;
_commandView.Accepting -= CommandViewOnAccepted;
Remove (_commandView);
_commandView?.Dispose ();
// Set new
_commandView = value;
_commandView.Id = "_commandView";
// The default behavior is for CommandView to not get focus. I
// If you want it to get focus, you need to set it.
_commandView.CanFocus = false;
_commandView.HotKeyChanged += (s, e) =>
{
if (e.NewKey != Key.Empty)
{
// Add it
AddKeyBindingsForHotKey (e.OldKey, e.NewKey);
}
};
_commandView.HotKeySpecifier = new ('_');
Title = _commandView.Text;
_commandView.Selecting += CommandViewOnSelecting;
_commandView.Accepting += CommandViewOnAccepted;
SetCommandViewDefaultLayout ();
SetHelpViewDefaultLayout ();
SetKeyViewDefaultLayout ();
ShowHide ();
UpdateKeyBindings (Key.Empty);
return;
void CommandViewOnAccepted (object? sender, CommandEventArgs e)
{
// Always eat CommandView.Accept
e.Cancel = true;
}
void CommandViewOnSelecting (object? sender, CommandEventArgs e)
{
if (e.Context.Data != this)
{
// Forward command to ourselves
InvokeCommand (Command.Select, new (Command.Select, null, null, this));
}
e.Cancel = true;
}
}
}
private void SetCommandViewDefaultLayout ()
{
CommandView.Margin.Thickness = GetMarginThickness ();
CommandView.X = Pos.Align (Alignment.End, AlignmentModes);
CommandView.Y = 0; //Pos.Center ();
HelpView.HighlightStyle = HighlightStyle.None;
}
private void Shortcut_TitleChanged (object? sender, EventArgs<string> e)
{
// If the Title changes, update the CommandView text.
// This is a helper to make it easier to set the CommandView text.
// CommandView is public and replaceable, but this is a convenience.
_commandView.Text = Title;
}
#endregion Command
#region Help
/// <summary>
/// The subview that displays the help text for the command. Internal for unit testing.
/// </summary>
internal View HelpView { get; } = new ();
private void SetHelpViewDefaultLayout ()
{
HelpView.Margin.Thickness = GetMarginThickness ();
HelpView.X = Pos.Align (Alignment.End, AlignmentModes);
HelpView.Y = 0; //Pos.Center ();
HelpView.Width = Dim.Auto (DimAutoStyle.Text);
HelpView.Height = CommandView?.Visible == true ? Dim.Height (CommandView) : 1;
HelpView.Visible = true;
HelpView.VerticalTextAlignment = Alignment.Center;
HelpView.HighlightStyle = HighlightStyle.None;
}
/// <summary>
/// Gets or sets the help text displayed in the middle of the Shortcut. Identical in function to <see cref="HelpText"/>
/// .
/// </summary>
public override string Text
{
get => HelpView.Text;
set
{
HelpView.Text = value;
ShowHide ();
}
}
/// <summary>
/// Gets or sets the help text displayed in the middle of the Shortcut.
/// </summary>
public string HelpText
{
get => HelpView.Text;
set
{
HelpView.Text = value;
ShowHide ();
}
}
#endregion Help
#region Key
private Key _key = Key.Empty;
/// <summary>
/// Gets or sets the <see cref="Key"/> that will be bound to the <see cref="Command.Accept"/> command.
/// </summary>
public Key Key
{
get => _key;
set
{
ArgumentNullException.ThrowIfNull (value);
Key oldKey = _key;
_key = value;
UpdateKeyBindings (oldKey);
KeyView.Text = Key == Key.Empty ? string.Empty : $"{Key}";
ShowHide ();
}
}
private KeyBindingScope _keyBindingScope = KeyBindingScope.HotKey;
/// <summary>
/// Gets or sets the scope for the key binding for how <see cref="Key"/> is bound to <see cref="Command"/>.
/// </summary>
public KeyBindingScope KeyBindingScope
{
get => _keyBindingScope;
set
{
if (value == _keyBindingScope)
{
return;
}
if (_keyBindingScope == KeyBindingScope.Application)
{
Application.KeyBindings.Remove (Key);
}
if (_keyBindingScope is KeyBindingScope.HotKey or KeyBindingScope.Focused)
{
KeyBindings.Remove (Key);
}
_keyBindingScope = value;
UpdateKeyBindings (Key.Empty);
}
}
/// <summary>
/// Gets the subview that displays the key. Internal for unit testing.
/// </summary>
internal View KeyView { get; } = new ();
private int _minimumKeyTextSize;
/// <summary>
/// Gets or sets the minimum size of the key text. Useful for aligning the key text with other <see cref="Shortcut"/>s.
/// </summary>
public int MinimumKeyTextSize
{
get => _minimumKeyTextSize;
set
{
if (value == _minimumKeyTextSize)
{
//return;
}
_minimumKeyTextSize = value;
SetKeyViewDefaultLayout ();
CommandView.SetLayoutNeeded ();
HelpView.SetLayoutNeeded ();
KeyView.SetLayoutNeeded ();
SetSubViewNeedsDisplay ();
}
}
private int GetMinimumKeyViewSize () { return MinimumKeyTextSize; }
private void SetKeyViewDefaultLayout ()
{
KeyView.Margin.Thickness = GetMarginThickness ();
KeyView.X = Pos.Align (Alignment.End, AlignmentModes);
KeyView.Y = 0;
KeyView.Width = Dim.Auto (DimAutoStyle.Text, Dim.Func (GetMinimumKeyViewSize));
KeyView.Height = CommandView?.Visible == true ? Dim.Height (CommandView) : 1;
KeyView.Visible = true;
// Right align the text in the keyview
KeyView.TextAlignment = Alignment.End;
KeyView.VerticalTextAlignment = Alignment.Center;
KeyView.KeyBindings.Clear ();
HelpView.HighlightStyle = HighlightStyle.None;
}
private void UpdateKeyBindings (Key oldKey)
{
if (Key.IsValid)
{
if (KeyBindingScope.FastHasFlags (KeyBindingScope.Application))
{
if (oldKey != Key.Empty)
{
Application.KeyBindings.Remove (oldKey);
}
Application.KeyBindings.Remove (Key);
Application.KeyBindings.Add (Key, this, Command.HotKey);
}
else
{
if (oldKey != Key.Empty)
{
KeyBindings.Remove (oldKey);
}
KeyBindings.Remove (Key);
KeyBindings.Add (Key, KeyBindingScope | KeyBindingScope.HotKey, Command.HotKey);
}
}
}
#endregion Key
#region Focus
/// <inheritdoc/>
public override ColorScheme? ColorScheme
{
get => base.ColorScheme;
set
{
base.ColorScheme = value;
SetColors ();
}
}
/// <summary>
/// </summary>
internal void SetColors (bool highlight = false)
{
// Border should match superview.
if (Border is { })
{
Border.ColorScheme = SuperView?.ColorScheme;
}
if (HasFocus || highlight)
{
base.ColorScheme ??= new (Attribute.Default);
// When we have focus, we invert the colors
base.ColorScheme = new (base.ColorScheme)
{
Normal = base.ColorScheme.Focus,
HotNormal = base.ColorScheme.HotFocus,
HotFocus = base.ColorScheme.HotNormal,
Focus = base.ColorScheme.Normal
};
}
else
{
base.ColorScheme = SuperView?.ColorScheme ?? base.ColorScheme;
}
// Set KeyView's colors to show "hot"
if (IsInitialized && base.ColorScheme is { })
{
var cs = new ColorScheme (base.ColorScheme)
{
Normal = base.ColorScheme.HotNormal,
HotNormal = base.ColorScheme.Normal
};
KeyView.ColorScheme = cs;
}
}
/// <inheritdoc/>
protected override void OnHasFocusChanged (bool newHasFocus, View? previousFocusedView, View? view) { SetColors (); }
#endregion Focus
/// <inheritdoc/>
public bool EnableForDesign ()
{
Title = "_Shortcut";
HelpText = "Shortcut help";
Key = Key.F1;
return true;
}
/// <inheritdoc/>
protected override void Dispose (bool disposing)
{
if (disposing)
{
TitleChanged -= Shortcut_TitleChanged;
if (CommandView?.IsAdded == false)
{
CommandView.Dispose ();
}
if (HelpView?.IsAdded == false)
{
HelpView.Dispose ();
}
if (KeyView?.IsAdded == false)
{
KeyView.Dispose ();
}
}
base.Dispose (disposing);
}
}