Drawing Squares
/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace DrawingSquares
{
/// <summary>
/// Summary description for DrawingSquares.
/// </summary>
public class DrawingSquares : System.Windows.Forms.Form
{
internal System.Windows.Forms.ContextMenu mnuForm;
internal System.Windows.Forms.MenuItem mnuNewSquare;
internal System.Windows.Forms.ContextMenu mnuLabel;
internal System.Windows.Forms.MenuItem mnuColorChange;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public DrawingSquares()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.mnuForm = new System.Windows.Forms.ContextMenu();
this.mnuNewSquare = new System.Windows.Forms.MenuItem();
this.mnuLabel = new System.Windows.Forms.ContextMenu();
this.mnuColorChange = new System.Windows.Forms.MenuItem();
//
// mnuForm
//
this.mnuForm.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.mnuNewSquare});
//
// mnuNewSquare
//
this.mnuNewSquare.Index = 0;
this.mnuNewSquare.Text = "Create New Square";
this.mnuNewSquare.Click += new System.EventHandler(this.mnuNewSquare_Click);
//
// mnuLabel
//
this.mnuLabel.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.mnuColorChange});
//
// mnuColorChange
//
this.mnuColorChange.Index = 0;
this.mnuColorChange.Text = "Change Color";
this.mnuColorChange.Click += new System.EventHandler(this.mnuColorChange_Click);
//
// DrawingSquares
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(628, 426);
this.ContextMenu = this.mnuForm;
this.Name = "DrawingSquares";
this.Text = "DrawingSquares";
this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.DrawingSquares_MouseDown);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new DrawingSquares());
}
private void mnuNewSquare_Click(object sender, System.EventArgs e)
{
// Create and configure the "square".
Label newLabel = new Label();
newLabel.Size = new Size(40, 40);
newLabel.BorderStyle = BorderStyle.FixedSingle;
// To determine where to place the label, you need to convert the
// current screen-based mouse coordinates into relative form coordinates.
newLabel.Location = this.PointToClient(Control.MousePosition);
// Attach a context menu to the label.
newLabel.ContextMenu = mnuLabel;
// Connect the label to all its event handlers.
newLabel.MouseDown += new MouseEventHandler(lbl_MouseDown);
newLabel.MouseMove += new MouseEventHandler(lbl_MouseMove);
newLabel.MouseUp += new MouseEventHandler(lbl_MouseUp);
// Add the label to the form.
this.Controls.Add(newLabel);
}
// Keep track of when fake drag or resize mode is enabled.
private bool isDragging = false;
private bool isResizing = false;
// Store the location where the user clicked on the control.
private int clickOffsetX, clickOffsetY;
private void lbl_MouseDown(object sender,
System.Windows.Forms.MouseEventArgs e)
{
// Retrieve a reference to the active label.
Control currentCtrl;
currentCtrl = (Control)sender;
if (e.Button == MouseButtons.Right)
{
// Show the context menu.
currentCtrl.ContextMenu.Show(currentCtrl, new Point(e.X, e.Y));
}
else if (e.Button == MouseButtons.Left)
{
clickOffsetX = e.X;
clickOffsetY = e.Y;
if ((e.X + 5) > currentCtrl.Width && (e.Y + 5) > currentCtrl.Height)
{
// The mouse pointer is in the bottom right corner,
// so resizing mode is appropriate.
isResizing = true;
}
else
{
// The mouse is somewhere else, so dragging mode is
// appropriate.
isDragging = true;
}
}
}
private void lbl_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Retrieve a reference to the active label.
Control currentCtrl;
currentCtrl = (Control)sender;
if (isDragging)
{
// Move the control.
currentCtrl.Left += e.X - clickOffsetX;
currentCtrl.Top += e.Y - clickOffsetY;
}
else if (isResizing)
{
// Resize the control.
currentCtrl.Width = e.X;
currentCtrl.Height = e.Y;
}
else
{
// Change the pointer if the mouse is in the bottom corner.
if ((e.X + 5) > currentCtrl.Width && (e.Y + 5) > currentCtrl.Height)
{
currentCtrl.Cursor = Cursors.SizeNWSE;
}
else
{
currentCtrl.Cursor = Cursors.Arrow;
}
}
}
private void lbl_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
isDragging = false;
isResizing = false;
}
private void mnuColorChange_Click(object sender, System.EventArgs e)
{
// Show color dialog.
ColorDialog dlgColor = new ColorDialog();
dlgColor.ShowDialog();
// Change label background.
mnuLabel.SourceControl.BackColor = dlgColor.Color;
}
private void DrawingSquares_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
this.ContextMenu.Show(this, new Point(e.X, e.Y));
}
}
}
}
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