Re: Duplicated items in watch window ? - C# Discussion Boards

10-Dec-04 15:19

hello i am having tons of trouble moving a child window where i want if the user click within that child i want to keep the cursor at the same location on the child however i want to be able to drag the child around basicly i want to keep the mouse at the same position on the child and be able to move the child relative to the form

here is the code im working with

<br />
	private void gripper1_Click(object sender, System.Windows.Forms.MouseEventArgs e)<br />
	{<br />
		dragging = true;<br />
		this.Dock = System.Windows.Forms.DockStyle.None;<br />
			<br />
		Point p1, p2;<br />
		p1 = PointToClient(new Point(e.X, e.Y));<br />
		p2 = PointToClient(Location);<br />
		diff = new Point(p2.X + p1.X, p2.Y+p1.Y);<br />
	}<br />
		<br />
	private void gripper1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)<br />
	{<br />
		if(dragging)<br />
		{<br />
			this.Location = PointToScreen(new Point(e.X + diff.X, e.Y + diff.Y));<br />
		}<br />
	}<br />

i have tried every combination of adding and subtracting and PointToScreen and PointToClient
however none work this is the closest it sometimes keeps the pointer within the child but it seems inconsistant please help this is my 3rd post and none of the solutions that have been offered actualy work. PLEASE PLEASE PLEASE HELP ME!

Skynyrd10-Dec-04 16:28

10-Dec-04 16:28

No need to fumble with Screen or Client coordinates. Its all a question of relative distances so your absolute zero really doesnt matter.

See if this works any better. Haven't tested it, but logic says it should work :p (Contrary to what I said above the code includes some Screen / Client coordinates but its not strictly necessary. The sole purpose is to make everything a little fancier detecting when ur trying to move the child form out of it's parent window)

Point mouseDownPos;

protected override void OnMouseDown(MouseEventArgs e)
{
mouseDownPos=Cursor.Position;
Cursor.Clip=new Rectangle(this.MdiParent.PointToScreen(this.MdiParent.ClientRectangle.Location),this.MdiParent.ClientRectangle.Size);
this.Capture=true;
}

protected override void OnMouseMove(MouseEventArgs e)
{
if (this.Capture)
{
Point mousePos=Cursor.Position;
Rectangle rec=this.MdiParent.ClientRectangle;
int cx=mousePos.X-mouseDownPos.X;
int cy=mousePos.Y-mouseDownPos.Y;
this.Location=new Point(this.Left+cx,this.Top+cy);
mouseDownPos=Cursor.Position;
}
}

protected override void OnMouseUp(MouseEventArgs e)
{
Cursor.Clip=new Rectangle(0,0,0,0);
base.OnMouseUp (e);
}

Hope it helps

Tyrus18210-Dec-04 17:03

10-Dec-04 17:03

i tried your code but nothing act6ualy happens

Skynyrd10-Dec-04 17:07

10-Dec-04 17:07

I just tried it and apart from making a small change to make the cursor clipping a little better everything works fine.

P.D. The code is supposed to be implemented in the child form, not in the parent. And of course, I've tested it with an empty form, if ur form has controls, then it wont pick up the mouse events and the code wont do anything. U seem to link the mouse events to an object called gripper. Link the your gripper mouse events instead of the Form's overrides if your form isnt picking up the mouse events.

Tyrus18210-Dec-04 17:15

10-Dec-04 17:15

read my previous response please

Tyrus18210-Dec-04 17:14

10-Dec-04 17:14

actualy i just changed capture to my dragging and it worked however the mouse position does move slightly in relation to the form when i drag it around alot but for the most part it works how i want it to any ideas how to prevent the mouse from drifting off?

Skynyrd10-Dec-04 17:17

10-Dec-04 17:17

I'm not experiencing any mouse drif but I'm testing this with an empty form. If your form has controls that could intercept mouse events and therefore not reaching the form hanlders, it could be cause of a small drift. I'm not too sure about it though.

Check that, I dont think that could be the cause. The only sympton would be that depending where u click, the form would capture the mousedown and move or it wouldn't do anything.

What is ur form's control layout if any?

Tyrus18210-Dec-04 17:29

10-Dec-04 17:29

atm it the form inherats a base class that is a form with a custom gripper control the gripper is the thing actualy is reciving my mouse click and mouse move message the mouse seems to drift when i move the mouse really fast or when i move the window beyond the edge of the visible screen and yes i do have docked control in my parent

what i am trying to do is create my own docking windows so far its going well except for this mouse positon stuff :p

Tyrus18210-Dec-04 17:44

10-Dec-04 17:44

hey on a similar topic how would i determine whether or not my child is at or beyond the parents rectangle
if(this.ClientRectangle.Top <= this.MdiParent.ClientRectangle.Top)
MessageBox.Show("Hi");

i tried this but it always message boxs me no matter where i drop the form

Skynyrd10-Dec-04 19:10

10-Dec-04 19:10

Check my original post. I modified the post and implemented a mouse clipping that prevents u from moving the mouse outside the parentform if a child form is captured.

This only prevents ur mouse exiting the parent form when moving a child. If u want to detect when the child form begins to go past the parent window I would work with screen coordinates similar to what I did with the mouse clipping.

For example: The parent client rectangle in Screen coord would be:

clientRec = new Rectangle(this.MdiParent.PointToScreen(this.MdiParent.ClientRectangle.Location),this.MdiParent.ClientRectangle.Size);

Your child form rectangle (including none client areas) would be:
childRec=new Rectangle(this.PointToScreen(this.Bounds.Location),this.Bounds.Size);

Then it would be a matter of comparing when one crosses over the other. Top, Bottom, Left and Right.

There could be a problem with the parent's client rectangle. Its not always the same size as the MdiChildContainerWindow. Some docked controls like a StatusBar shorten the MdiChildrenWindow but dont afect the form's clientSize.

A way to get around this is to iterate through the control collection of ur parent form until u find the one with the type 'System.Windows.Forms.MdiClient' (You tipically do this after the InitializeComponents method in your constructor and store the MdiClient control in a private class member that u can access whenever u want without having to search through the control collection again and again). This control is automatically added when u set ur form as a MdiContainer. U can then base ur calculations on the MdiClient control's true size and location instead of using the forms ClientRectangle.

Tyrus18210-Dec-04 19:54