Link to home
Start Free TrialLog in
Avatar of vanchai
vanchai

asked on

Howto redraw text at any point on screen?

i want redraw text output on screen by the word. i can redraw a line of text in window but can't redraw the word in window. please show some source code.
Avatar of kretzschmar
kretzschmar
Flag of Germany image

?
Avatar of vanchai
vanchai

ASKER

i can use ddihook for hook ExtTextOut function. i can redraw a line of text but i can't force to redraw only one word in a line.
Hello vanchai,

can you post you code here...

cause i tried the api function and it works

procedure TForm1.Button1Click(Sender: TObject);
VAR
  R : TRect;
begin
 R := Rect ( 50,50,200,100);
 ExtTextOut(
    self.Canvas.Handle,   // handle to device context
    50,                   // x-coordinate of reference point
    50,                   // y-coordinate of reference point
    ETO_CLIPPED,          // text will be clipped
    @R,                   // optional clipping and/or opaquing rectangle
    pChar('hello'),       // points to string
    5,                   // number of characters in string
    NIL
   );

end;


Best Regards

Cesario
If you know where the word is I should expect that you could try somthing like:

var
 dc : HDC;
begin
 dc := getDC(getDesktopWindow);
 invalidateRect(dc,some_rect,true);
 releaseDC(getDesktopWindow,dc);
end;

GL
Mike
the easiest way may  be to call upon any wincontrol that have a canvas like a form with the simple line

TWincontrol(Sender).Canvas.
  TextOut(Mouse.x, Mouse.y, 'word to Write');

I hope this helps

Manata
Avatar of vanchai

ASKER

hello all experts,
:-)

Cesario,
i use Win32 Hooks to hook mouse button, when i click on screen i can retrieve point and some handle window by code.
...
procedure MyRedrawText(Wnd: HWND; P: TPoint);
var
    ClientPoint: TPoint;
    R: TRect;
begin
        ClientPoint:= P;
        MapWindowPoints(0, Wnd, ClientPoint, 1);
        GetClientRect(Wnd, R);
        R.Top:= ClientPoint.y;
        R.Bottom:= ClientPoint.y+1;
        SetMyDDIHook;
        RedrawWindow(Wnd, @R, 0, RDW_FRAME or RDW_INVALIDATE or RDW_UPDATENOW or RDW_NOCHILDREN);
        DeleteMyDDIHook;
end;

.
.
.

 GetCursorPos(P);
 Wnd:= WindowFromPoint(P);
 MyRedrawText(Wnd,P);

...
this code can redraw a line in control window such as notepad, title bar, button ... but in IE i can not redraw. why?

To edey,
'If you know where the word is '. this is very big problem for me. i don't know RECT structure of the word.

see more information about ddihook here.-> https://www.experts-exchange.com/jsp/qShow.jsp?ta=delphi&qid=11622218
To only redraw the word, can't you add:

  R.Left := ClientPoint.x;
  R.Right := ClientPoint.x+1;

? Just a thought. But maybe this way only the current CHARACTER is redrawn, don't know...

About IE: Maybe IE caches the current visible screen in a bitmap (some of my own controls do that to boost up the speed, too). In that case, if you invalidate a rect, IE only uses BitBlt to repaint the rect instead of (Ext)TextOutA/W. If that is the case, I have no idea about how to force IE to redraw the text with (Ext)TextOutA/W...  :-(

Regards, Madshi.
Just out of curiosity, why do you need to repaint just one word?  Perhaps if we knew more about -what_ you're trying to accomlish we could give a better solution.

GL
Mike
Avatar of vanchai

ASKER

"R.Left := ClientPoint.x;
 R.Right := ClientPoint.x+1;"
Thank you Madshi, i just try but the method not work. its worked in some control.

eday,
I want to know RECT of the word. If i know, i can implement application for disabled or can write program like babylon for people in my country(thai). In text editor, word processing or viewer application, when double-click, one word is selected. How to? I have idia to implement by send WM_LBUTTONDOWN and WM_LBUTTONUP message to application for repaint word but it not work for all case. e.g. hyper-link in IE.

Regard, vanchai.
I would be tempted to sugest that you could use IE's DOM to get/set text in the webBrowser - unfortunatly I don't know if it's possible to get a refrence to explorer's document from it's HWND.

GL
Mike
Please update the expert here who have so willingly stepped in to help you, since much time has passed since your last comments, and Email notifications may not have been generated to the participating experts here due to some problems at that time.  If you've been helped, accept the respective question by that expert to grade and close it.

Somewhat off-topic, but important.

****************************** ALERT********************************
WindowsUpdate - Critical Update alert March 28, 2002 from Microsoft
http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/ms02-015.asp
Synopsis:
Microsoft Security Bulletin MS02-015  
28 March 2002 Cumulative Patch for Internet Explorer
Originally posted: March 28, 2002
Summary
Who should read this bulletin: Customers using Microsoft® Internet Explorer
Impact of vulnerability: Two vulnerabilities, the most serious of which would allow script to run in the Local Computer Zone.
Maximum Severity Rating: Critical
Recommendation: Consumers using the affected version of IE should install the patch immediately.
Affected Software:
Microsoft Internet Explorer 5.01
Microsoft Internet Explorer 5.5
Microsoft Internet Explorer 6.0

Thought you'd appreciate knowing this.
":0)
Asta
No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

To be PAQ/Refund

Please leave any comments here within the next seven days.
 
PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!
 
Thank you,
Russell

EE Cleanup Volunteer
ASKER CERTIFIED SOLUTION
Avatar of PashaMod
PashaMod

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial