gui-cs.Terminal.Gui/Terminal.Gui/View/ViewMouse.cs

using System;

namespace Terminal.Gui; 

public partial class View {

	/// <summary>
	/// Gets or sets a value indicating whether this <see cref="View"/> wants mouse position reports.
	/// </summary>
	/// <value><see langword="true"/> if want mouse position reports; otherwise, <see langword="false"/>.</value>
	public virtual bool WantMousePositionReports { get; set; }

	/// <summary>
	/// Gets or sets a value indicating whether this <see cref="View"/> want continuous button pressed event.
	/// </summary>
	public virtual bool WantContinuousButtonPressed { get; set; }

	/// <summary>
	/// Event fired when the view receives the mouse event for the first time.
	/// </summary>
	public event EventHandler<MouseEventEventArgs> MouseEnter;

	/// <summary>
	/// Event fired when the view receives a mouse event for the last time.
	/// </summary>
	public event EventHandler<MouseEventEventArgs> MouseLeave;

	/// <summary>
	/// Event fired when a mouse event is generated.
	/// </summary>
	public event EventHandler<MouseEventEventArgs> MouseClick;

	/// <inheritdoc/>
	public override bool OnMouseEnter (MouseEvent mouseEvent)
	{
		if (!Enabled) {
			return true;
		}

		if (!CanBeVisible (this)) {
			return false;
		}

		var args = new MouseEventEventArgs (mouseEvent);
		MouseEnter?.Invoke (this, args);

		return args.Handled || base.OnMouseEnter (mouseEvent);
	}

	/// <inheritdoc/>
	public override bool OnMouseLeave (MouseEvent mouseEvent)
	{
		if (!Enabled) {
			return true;
		}

		if (!CanBeVisible (this)) {
			return false;
		}

		var args = new MouseEventEventArgs (mouseEvent);
		MouseLeave?.Invoke (this, args);

		return args.Handled || base.OnMouseLeave (mouseEvent);
	}

	/// <summary>
	/// Method invoked when a mouse event is generated
	/// </summary>
	/// <param name="mouseEvent"></param>
	/// <returns><see langword="true"/>, if the event was handled, <see langword="false"/> otherwise.</returns>
	public virtual bool OnMouseEvent (MouseEvent mouseEvent)
	{
		if (!Enabled) {
			return true;
		}

		if (!CanBeVisible (this)) {
			return false;
		}

		var args = new MouseEventEventArgs (mouseEvent);
		if (MouseEvent (mouseEvent)) {
			return true;
		}

		if (mouseEvent.Flags == MouseFlags.Button1Clicked) {
			if (CanFocus && !HasFocus && SuperView != null) {
				SuperView.SetFocus (this);
				SetNeedsDisplay ();
			}

			return OnMouseClick (args);
		}
		if (mouseEvent.Flags == MouseFlags.Button2Clicked) {
			return OnMouseClick (args);
		}
		if (mouseEvent.Flags == MouseFlags.Button3Clicked) {
			return OnMouseClick (args);
		}
		if (mouseEvent.Flags == MouseFlags.Button4Clicked) {
			return OnMouseClick (args);
		}

		return false;
	}

	/// <summary>
	/// Invokes the MouseClick event.
	/// </summary>
	protected bool OnMouseClick (MouseEventEventArgs args)
	{
		if (!Enabled) {
			return true;
		}

		MouseClick?.Invoke (this, args);
		return args.Handled;
	}
}