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Dragging a Timage in scrollBox

Posted on 1998-08-22
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Medium Priority
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Last Modified: 2010-04-04
Sorry for my bad English...
I would like to move at runtime an image with the mouse, inside a scrollbox like in PaintShop Pro or others graphic programs.
I need this when the Image is greater than the scrollbox dimensions.I have tried some solutions but when I move the image, I get Flickering.
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Question by:1bdev
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9 Comments
 
LVL 10

Expert Comment

by:viktornet
ID: 1337439
Try this .....

inOnMouseMove of the Image....

if ssleft in shift then
begin
     releasecapture;
     Image1.perform(WM_SYSCOMMAND, $F012, 0);
end;

Hope this helps....You can also assign OnDragDrop, and OnDropOver...

Regards,
Viktor Ivanov
0
 

Author Comment

by:1bdev
ID: 1337440
Hi Viktor,
thank you for your answer but it is not the answser that I am waiting.
Due to my very bad english, my question is not so clear.
It's not the Image I want to move but the scrollbars of the scrollBox.
For example :
I have an image 640x480 pixels inside a scrollbox 100x100 pixels.
My users needs to see the invisibles portions of this image by dragging
the image with the mouse. Like in PaintShop Pro

Best regards
Bernard Deveza
bdeveza@hol.fr

Here is a code I used but it is not good :

public
    mousedown:boolean;
    currentx:longint;
    currenty:longint;
    { Public declarations }
  end;

procedure Tframeview.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if button=mbleft then
   begin
     mousedown:=true;
     currentx:=x;
     currenty:=y;
   end;
end;

procedure Tframeview.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if (image1.Width>frameview.width) or (image1.height>frameview.height) then
    if mousedown then
      begin
        if horzscrollbar.position<horzscrollbar.range then
          horzscrollbar.position:=horzscrollbar.position+(currentx-x);
        if vertscrollbar.position<vertscrollbar.range then
          vertscrollbar.position:=vertscrollbar.position+(currenty-y);
        currentx:=x;
        currenty:=y;
      end;
end;

procedure Tframeview.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  mousedown:=false;
  currentx:=x;
  currenty:=y;
end;
0
 
LVL 10

Accepted Solution

by:
viktornet earned 200 total points
ID: 1337441
Here is something that I just whiped together

var
  PT : TPoint;
procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if ssLeft in Shift then
  begin
    if pt.x > x then
      SB.ScrollBy(1, 0)
    else if pt.x < x then
      SB.ScrollBy(-1, 0);
    if pt.y > y then
      SB.ScrollBy(0, 1)
    else if pt.y < y then
      SB.ScrollBy(0, -1);
  end;
end;

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  GetCursorPos(PT);
end;

procedure TForm1.IMMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  GetCursorPos(pt);
end;

Hope this works...

Regards,
Viktor Ivanov
0
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LVL 10

Expert Comment

by:viktornet
ID: 1337442
SB is the scroll box, and the OnMouseDown, OnMouseUp, and OnMouseMove are part of Image's events not the form's or the scrollbox's events....

Regards,
Viktor Ivanov
0
 

Author Comment

by:1bdev
ID: 1337443
Thank you Viktor, I'm trying your solution... and it seems a good solution. I come back to you quickly.
0
 
LVL 10

Expert Comment

by:viktornet
ID: 1337444
Is it working for you that way??? =)

Regards,
Viktor Ivanov
0
 

Author Comment

by:1bdev
ID: 1337445
Yes it globally work for me but with some imperfections I am working on. I have made a little program based on your example. Is it possible to email it to you because It is difficult for me to explain correctly the problems encountered.
Best regards
Bernard
bdeveza@hol.fr
0
 
LVL 10

Expert Comment

by:viktornet
ID: 1337446
Sorry for so late reply but I was out of town....so here I am again =)
Of course send it to me...My e-mail is viktor@megsinet.net

0
 

Expert Comment

by:perkley
ID: 2621233
Will you post what you have found, I have the same problem that you have, will you post how you achieved your end result?
0

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