Improve company productivity with a Business Account.Sign Up

x
?
Solved

Click-through forms

Posted on 2001-08-03
4
Medium Priority
?
642 Views
Last Modified: 2010-05-18
Delphi 6 now provides the ability to create an alpha-blended (i.e. translucent) form. What I would like to do is create a form like this, with FormStyle = fsStayOnTop, as a sort of 'watermark' that always shows as a light overlay in front of whatever's on the screen. The problem, of course, is that with my form in front of whatever else is on the system, mouse clicks go to my form, not to things behind my form. So my question is, how can a Delphi form be made 'transparent' to mouse clicks - i.e. make sure all mouse clicks are routed to the window in the second-topmost position at the pixel that was clicked. Bonus points if you write the code for me. :-)
0
Comment
Question by:ghjm
  • 2
4 Comments
 
LVL 21

Expert Comment

by:gemarti
ID: 6351070
This works, but may not be what your looking for. I'm just guessing since D6 is new to me:

Create a new application.
Place a Button and a edit control on the first form (Form1)
procedure TForm1.Button1Click(Sender: TObject);
begin
  Form2.Show;
end;

Create a second form (form2)

Set AlphaBlend := true;
AlphaBlendValue := 100 (or any value from 0..255 where 255 is the least transparent)
Set TransParentColor := true;
Set TransParentColorValue := clBtnFace (or whatever color works for you)

Add these lines of code:
procedure TForm2.FormActivate(Sender: TObject);
begin
  Form1.Button1.Parent := Form2;
  Form1.Edit1.Parent := Form2;
  Form2.AlphaBlendValue := 200; //if you leave at 100 you can't see the components very well.
  Form1.Button1.GetParentComponent;
end;

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Form1.Button1.Parent := Form1;
  Form1.Edit1.Parent := Form1;
  Form2.AlphaBlendValue := 100;
end;
0
 
LVL 9

Accepted Solution

by:
ITugay earned 300 total points
ID: 6351234
Hi ghjm,

may be this code would be usefull for you.

procedure TForm1.MouseRedirect(Sender: TObject; Action: Integer; X,Y: Integer);
var
  C: TPoint;
  H: HRgn;
  L: HRgn;
begin
  C.X := X;
  C.Y := Y;
  C := TControl(Sender).ClientToScreen(C);

  // create empty region and assign it to the form to make form
  // transparent for mouse clicks
  H := CreateRectRgn(0, 0, 0, 0);
  GetWindowRgn(Handle, L);
  SetWindowRgn(Handle, H, False);
  DeleteObject(L);

  mouse_event(Action, X, Y, 0 ,0);

  // restore form region
  GetWindowRgn(Handle, L);
  SetWindowRgn(Handle, 0, False);
  DeleteObject(L);

end;

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button = mbLeft then
    MouseRedirect(Self, MOUSEEVENTF_LEFTDOWN, X, Y)
  else
    MouseRedirect(Self, MOUSEEVENTF_RIGHTDOWN, X, Y);
end;

procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button = mbLeft then
    MouseRedirect(Self, MOUSEEVENTF_LEFTUP, X, Y)
  else
    MouseRedirect(Self, MOUSEEVENTF_RIGHTUP, X, Y);
end;


Set OnMouseDown and OnMouseUp for rest of control that should be transparent for mouse clicks to the same handles (TForm1.OnMouseDown, OnMouseUp).

-----
Igor
0
 
LVL 1

Author Comment

by:ghjm
ID: 6351874
Well, I understand what you're trying to do, but I haven't been able to make it work. I'm still trying, but...I sure wish a Win32 API call existed to set the _mouse_ region without also setting the _display_ region.
0
 
LVL 1

Author Comment

by:ghjm
ID: 6351890
Okay, well I have it working, sort of. The remaining problem is that whenever a click event goes through, the transparent form disappears and reappears - even though bRedraw is set to FALSE. Any suggestions how to avoid this?
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
This is an update to some code that someone else posted on Experts Exchange. It is an alternate approach, I think a little easier to use, & makes sure that things like the Task Bar will update.
Hi, this video explains a free download that you can incorporate into your Access databases, or use stand-alone for contact management. Contacts -- Names, Addresses, Phone Numbers, eMail Addresses, Websites, Lists, Projects, Notes, Attachments…
Did you know PowerShell can save you time with SaaS platforms? Simply leverage RESTfulAPIs to build your own PowerShell modules. These will kill repetitive tickets and tabs, using the command Invoke-RestMethod. Tune into this webinar to learn how…

606 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question