Events and Callbacks

A feature that notifies developers of key lifecycle moments in the close button control, such as when a form is about to close, when animations complete, or when a close operation is undone, etc.

Overview

The Events feature of the close button control exposes three primary events that enable developers to hook into important moments of the control's lifecycle. These events include notifications before the parent form is closed, when an animation sequence completes, and when a close operation is undone. By handling these events, developers can add custom logic (such as cleanup tasks, logging, or additional user prompts) to extend and tailor the control’s behavior within their applications.

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Events Summary

Event Name	Description	Triggering Action	Sample Usage Reference
BeforeFormClose	Occurs before the parent form begins its close operation, allowing cancellation if needed.	Initiated when the close button is activated and before the form closes.	closeButton.BeforeFormClose += HandlerMethod;
AnimationComplete	Raised when an animation sequence (e.g., hover, click, or transition animation) has finished.	Triggered upon completion of an animation cycle.	closeButton.AnimationComplete += HandlerMethod;
CloseUndone	Invoked when a previously initiated close operation is undone, typically in an undo-close scenario.	Occurs when the user cancels a closing operation via an undo action.	closeButton.CloseUndone += HandlerMethod;

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Code Examples

Example 1: Handling BeforeFormClose Event

In this example, a developer subscribes to the BeforeFormClose event to prompt the user for confirmation before the form is closed. The event handler uses a CancelEventArgs parameter to cancel the close operation if the user declines.

using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using SiticoneNetFrameworkUI;

public class BeforeCloseDemoForm : Form
{
    private SiticoneCloseButton closeButton;

    public BeforeCloseDemoForm()
    {
        InitializeComponents();
    }

    private void InitializeComponents()
    {
        closeButton = new SiticoneCloseButton
        {
            Location = new Point(10, 10)
        };

        // Subscribe to the BeforeFormClose event
        closeButton.BeforeFormClose += CloseButton_BeforeFormClose;

        Controls.Add(closeButton);
        Text = "BeforeFormClose Event Demo";
        Size = new Size(300, 200);
    }

    private void CloseButton_BeforeFormClose(object sender, CancelEventArgs e)
    {
        // Prompt the user for confirmation before closing
        var result = MessageBox.Show("Do you really want to close the form?", "Confirm Close", 
                                     MessageBoxButtons.YesNo, MessageBoxIcon.Question);
        if (result != DialogResult.Yes)
        {
            // Cancel the close operation if the user selects No
            e.Cancel = true;
        }
    }

    [STAThread]
    public static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new BeforeCloseDemoForm());
    }
}

Example 2: Handling AnimationComplete Event

This sample demonstrates how to handle the AnimationComplete event. In this example, after an animation finishes, a simple message is logged to the debug console.

using System;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms;
using SiticoneNetFrameworkUI;

public class AnimationDemoForm : Form
{
    private SiticoneCloseButton closeButton;

    public AnimationDemoForm()
    {
        InitializeComponents();
    }

    private void InitializeComponents()
    {
        closeButton = new SiticoneCloseButton
        {
            EnableAnimation = true,
            IconAnimation = SiticoneCloseButton.CloseIconAnimation.Rotate,
            Location = new Point(20, 20)
        };

        // Subscribe to the AnimationComplete event
        closeButton.AnimationComplete += CloseButton_AnimationComplete;

        Controls.Add(closeButton);
        Text = "AnimationComplete Event Demo";
        Size = new Size(300, 200);
    }

    private void CloseButton_AnimationComplete(object sender, EventArgs e)
    {
        // Log that the animation has completed
        Debug.WriteLine("Animation has completed.");
    }

    [STAThread]
    public static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new AnimationDemoForm());
    }
}

Example 3: Handling CloseUndone Event

This example shows how to subscribe to the CloseUndone event. When the user undoes a close operation, a custom notification is displayed to confirm that the operation has been canceled.

using System;
using System.Drawing;
using System.Windows.Forms;
using SiticoneNetFrameworkUI;

public class UndoCloseDemoForm : Form
{
    private SiticoneCloseButton closeButton;
    private Button undoButton;

    public UndoCloseDemoForm()
    {
        InitializeComponents();
    }

    private void InitializeComponents()
    {
        closeButton = new SiticoneCloseButton
        {
            EnableUndoClose = true,
            Location = new Point(10, 10)
        };

        // Subscribe to the CloseUndone event
        closeButton.CloseUndone += CloseButton_CloseUndone;

        // Additional undo button for demonstration
        undoButton = new Button
        {
            Text = "Undo Close",
            Location = new Point(10, 50)
        };

        undoButton.Click += (sender, e) => { closeButton.UndoClose(); };

        Controls.Add(closeButton);
        Controls.Add(undoButton);

        Text = "CloseUndone Event Demo";
        Size = new Size(300, 200);
    }

    private void CloseButton_CloseUndone(object sender, EventArgs e)
    {
        // Notify the user that the close operation has been undone
        MessageBox.Show("Close operation has been undone.", "Undo Close", MessageBoxButtons.OK, MessageBoxIcon.Information);
    }

    [STAThread]
    public static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new UndoCloseDemoForm());
    }
}

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Key Points

Aspect	Details
Event-Driven Design	The events provide hooks at critical points, such as before closing or after animations complete, enabling reactive programming.
Cancellation Capability	The BeforeFormClose event allows cancellation of the closing process, giving developers control over the form’s lifecycle.
Extensibility	By exposing events, the control can be integrated seamlessly into complex workflows or customized behaviors.

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Best Practices

Recommendation	Explanation
Always Validate User Intent	When using BeforeFormClose, ensure that you verify the user's intent (e.g., through confirmation dialogs) to prevent accidental closures.
Keep Event Handlers Lightweight	Ensure that event handlers do not perform heavy processing, which could delay UI feedback or interfere with animations.
Unsubscribe When Appropriate	If dynamically creating and destroying instances of the control, unsubscribe from events to avoid memory leaks and unintended behavior.

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Common Pitfalls

Pitfall	Description	Recommendation
Ignoring CancelEventArgs in BeforeFormClose	Failing to properly handle the CancelEventArgs parameter might lead to unintended form closures even when cancellation is desired.	Always check and set e.Cancel as needed in BeforeFormClose handlers.
Overcomplicating Animation Handlers	Complex logic in the AnimationComplete handler can slow down the UI or lead to hard-to-debug issues.	Keep animation event handlers simple and offload heavy tasks to asynchronous operations if necessary.
Neglecting to Inform the User for Undo Actions	Not providing clear user feedback when a close is undone might leave the user uncertain about the action taken.	Provide clear messaging or UI indications when the CloseUndone event is triggered.

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Usage Scenarios

Scenario	Description	Code Sample Integration
Preventing Accidental Closures	In applications with critical unsaved work, the BeforeFormClose event can be used to prompt for confirmation and cancel accidental closures.	See Example 1 for implementing a confirmation dialog with BeforeFormClose.
Enhancing User Feedback During Animations	For dynamic UIs, handling the AnimationComplete event can trigger subsequent actions or logging for diagnostic purposes.	See Example 2 for logging animation completion.
Enabling Safe Reversal of Close Operations	When a close operation might be mistakenly initiated, the CloseUndone event can allow the application to restore the previous state and notify the user.	See Example 3 for integrating the CloseUndone event with an Undo button.

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Review

Review Point	Consideration
Event Flexibility	The control provides well-defined events that cover critical interactions, ensuring developers can handle closing and animation states effectively.
Integration Simplicity	The events are simple to subscribe to and integrate within various application workflows, reducing the complexity of custom logic implementation.
User-Centric Behavior	By providing events that can cancel actions or notify users of undone operations, the control supports a user-friendly and error-resistant design.

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Summary

The Events feature of the close button control empowers developers to integrate custom logic at key moments in the control’s lifecycle. Through the BeforeFormClose, AnimationComplete, and CloseUndone events, developers can intercept closing actions, respond to animation completions, and handle undo operations effectively. This event-driven approach not only enhances the control's flexibility but also contributes to a more robust and interactive user experience.

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Additional Resources

Resource	Description	Link / Code Example Reference
Event Handling in WinForms	Comprehensive guide on implementing and managing events in Windows Forms applications.	MSDN documentation on C# event handling.
Debugging Best Practices	Tips and techniques for debugging event-driven applications.	Industry articles and developer blogs on debugging.
Asynchronous Programming	Guidance on offloading heavy processing in event handlers to asynchronous operations.	MSDN documentation on async and await in C#.

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By following this comprehensive documentation, developers can effectively integrate and handle the events provided by the close button control, ensuring that the application's behavior is robust, responsive, and tailored to the user’s needs.