We help IT Professionals succeed at work.

Mouse Capture

charry
charry asked
on
Medium Priority
457 Views
Last Modified: 2010-04-04
How do I pass a message that I have capture to the object that should receive the message?  Inherited does not seem to work.  Specifically, in a component is a trackbar. I capture the mouse.  When the user first tries to reposition the trackbar, the first attempt does not work, but release the capture of the mouse, so the next attempt works normally.  How can I get the first attempt to work normally?
Comment
Watch Question

Author

Commented:
Edited text of question

Commented:
How exactly are you 'capturing' the mouse?

Author

Commented:
I am capturing the mouse by:
SetCapture(Self);

Commented:
You're going to have to explain a bit more. I assume the form is doing the capturing? What for? I can't think of a neat way to pass the message on in that case, but there may be a different approach. More info, please!!

Author

Commented:
My goal was to create a componet that included a Trackbar.  I wanted the component to have an option that the Trackbar would not be visible until the mouse was over the component.  Similarly, I wanted the Trackbar to again not be visible when the mouse moved off the component.  Geting the component to be visible was no issue using WM_MouseMove.  However, finding out when the mouse left the component has been the issue.  That is why I tried to capture the mouse.
I have worked arount this problem by using a timer and test the location of the mouse when the component is visible.  I don't like this method since I am generating many cycles that are not necessary.  

Commented:
Hi Charry,

Try the CM_MOUSEENTER and CM_MOUSELEAVE messages. I think it has to be work.

Good luck

Gabor

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts

Author

Commented:
Gabor,
I can not find any references to CM_MouseEnter/CM_MouseLeave.  Do you know where I can find information, I search MicroSoft without success. If not could you provide the syntax for these calls.
Thanks
charry

Commented:
This is a custom BORLAND message. It is sent by the form to it's controls. You can't find any references, but it works! It's defined in the CONTROLS unit.

Good luck again!

Commented:
Sorry, I forgot the 'syntax'.
You have to define a new control class. It has to have these two method:

procedure CMMouseEnter(var Msg: TMessage); message CM_MOUSEENTER;
procedure CMMouseLeave(var Msg: TMessage); message CM_MOUSELEAVE;

The Msg parameter isn't relevant, because the message is sent to the control directly. By default it sends towards to his parent.

Author

Commented:
How many hiden functions are they.  Thanks alot.  I wish I knew about these before, it would have save me much time.

Thanks
Chuck
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.