C# Rect Tracker

• Download source code - 18.7 Kb

Introduction

Ever tried to find that object that allows Visual studio to move and resize controls? Well, I didn't find it in C# but in C++. Well, here it is in C# :)

Background

The project I was working on required me to create forms in run-time, so I needed something to edit controls - RectTracker.

In C++ there is an object called CRectTracker, but in C# there isn't, so I tried to clone it, it doesn't do what the Visual Studio Tracker does, but it does the job on resizing and moving controls on a form.

Methodology

It's made of a UserControl because doing it using the form graphics object creates ordering problems (a control is "above" the tracker), so making it a control itself, allows me to play with Z-Order and set the control to front.

I used Region Transparenting to create a place for the Control I want to move/resize.

Using The Code

SomeControl.BringToFront();
SomeControl.Capture = false;
if(this.Controls.Contains(CSharpTracker))
  this.Controls.Remove(CSharpTracker);
CSharpTracker = new RectTracker(SomeControl);

this.Controls.Add(CSharpTracker);
CSharpTracker.BringToFront();
CSharpTracker.Draw();

Control Moving

public void Mouse_Move(object sender,System.Windows.Forms.MouseEventArgs e)
    {
//minimum size for the control is 8x8
if (currentControl.Height < 8)
{
  currentControl.Height = 8;
  return;
}
else if (currentControl.Width < 8)
{
  currentControl.Width = 8;
  return;
}
    
switch(this.CurrBorder)
{
  case RESIZE_BORDER.RB_TOP:
    currentControl.Height = currentControl.Height - e.Y + prevLeftClick.Y;
    if (currentControl.Height > 8)
    currentControl.Top = currentControl.Top + e.Y - prevLeftClick.Y;    
    break;
  case RESIZE_BORDER.RB_TOPLEFT:
    currentControl.Height = currentControl.Height - e.Y + prevLeftClick.Y;
    if (currentControl.Height > 8)
    currentControl.Top =currentControl.Top + e.Y - prevLeftClick.Y;
    currentControl.Width = currentControl.Width - e.X + prevLeftClick.X;
    if (currentControl.Width > 8)
    currentControl.Left =currentControl.Left + e.X - prevLeftClick.X;
    break;
  case RESIZE_BORDER.RB_TOPRIGHT:
    currentControl.Height = currentControl.Height - e.Y + prevLeftClick.Y;
    if (currentControl.Height > 8)
    currentControl.Top = currentControl.Top + e.Y - prevLeftClick.Y;
    currentControl.Width = currentControl.Width + e.X - prevLeftClick.X;
    break;
  case RESIZE_BORDER.RB_RIGHT:
    currentControl.Width = currentControl.Width + e.X - prevLeftClick.X;
    break;
  case RESIZE_BORDER.RB_BOTTOM:
    currentControl.Height = currentControl.Height + e.Y - prevLeftClick.Y;
    break;
  case RESIZE_BORDER.RB_BOTTOMLEFT:
    currentControl.Height = currentControl.Height + e.Y - prevLeftClick.Y;
    currentControl.Width = currentControl.Width - e.X + prevLeftClick.X;
    if (currentControl.Width > 8)
currentControl.Left = currentControl.Left + e.X - prevLeftClick.X;
    break;
  case RESIZE_BORDER.RB_BOTTOMRIGHT:
    currentControl.Height = currentControl.Height + e.Y - prevLeftClick.Y;
    currentControl.Width = currentControl.Width + e.X - prevLeftClick.X;
    break;
  case RESIZE_BORDER.RB_LEFT:
    currentControl.Width = currentControl.Width - e.X + prevLeftClick.X;
    if (currentControl.Width > 8)
    currentControl.Left = currentControl.Left + e.X - prevLeftClick.X;
    break;
  case RESIZE_BORDER.RB_NONE:
    currentControl.Location = new Point(currentControl.Location.X + e.X - 
    prevLeftClick.X, currentControl.Location.Y + e.Y - prevLeftClick.Y);
    break;
  
}

}

Conclusion

This SharpRectTracker control is a clone of the CRectTracker, and it allows a user to Move and Resize form objects (control) in run-time, this control can be further enhanced to allow multiple object move/resize (using selection) and to do selectable Resize (for an object that only the width can be changed).