[SOLVED] Show progress on another form during data processing

[Jiří Huňáček]

Thank you Benny,

I will go through your code and try to learn something from it. It will definitely come in handy in the future. However, it doesn't solve my current problem, when the MEMO control element is needed, because the data is exported to the clipboard from another application and it probably won't work if it has to be saved in TXT before importing.

But in the end I tried an option that didn't occur to me right away and the problem is solved. As Bart wrote a bit above, you need to set the position of the ProgressBar twice, and after each setting you need to call the code from Handoko. Changed code in the PB demo project (in the attachment) - total number of lines in MEMO 139,678 converted in 5s.

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls, ComCtrls,
9.   LCLIntf, LCLType;
10.  
11. type
12.  
13.   { TfrmForm1 }
14.  
15.   TfrmForm1 = class(TForm)
16.     Button1: TButton;
17.     Label1: TLabel;
18.     Label2: TLabel;
19.     Label3: TLabel;
20.     Label4: TLabel;
21.     Label5: TLabel;
22.     Memo1: TMemo;
23.     ProgressBar1: TProgressBar;
24.     procedure Button1Click(Sender: TObject);
25.   private
26.  
27.   public
28.  
29.   end;
30.  
31. var
32.   frmForm1: TfrmForm1;
33.  
34. implementation
35.  
36. {$R *.lfm}
37.  
38. { TfrmForm1 }
39.  
40. procedure TfrmForm1.Button1Click(Sender: TObject);
41. var
42.   i: Integer;
43. begin
44.   Label5.Caption := ''; // text READY after ending the loop (visual indication only - not needed)
45.   Label5.Font.Color := clRed;
46.  
47.   Label4.Caption := FormatFloat('# ### ###', Memo1.Lines.Count);
48.   ProgressBar1.Min := 0;
49.   ProgressBar1.Max := Memo1.Lines.Count;
50.  
51.   for i := 0 to Memo1.Lines.Count - 1 do
52.   begin
53.     Label2.Caption := FormatFloat('# ### ###', i + 1);
54.  
55.     // the first setting of the ProgressBar
56.     ProgressBar1.Position := i+1;
57.     if i < (Memo1.Lines.Count-1) then
58.     begin
59.         if (i mod 50) <> 0 then Continue; // this line is for better performance
60.     end;
61.     Application.ProcessMessages;
62.  
63.     // the second ProgressBar setting
64.     ProgressBar1.Position := i;
65.     if i < (Memo1.Lines.Count-1) then
66.     begin
67.         if (i mod 50) <> 0 then Continue; // this line is for better performance
68.     end;
69.     Application.ProcessMessages;
70.  
71.     if GetKeyState(VK_ESCAPE) < 0 then Break; // Allow user cancellation
72.   end;
73.  
74.   Label5.Caption := 'Ready';
75. end;
76.  
77. end.

Thank you all for your willingness to help

[Handoko]

Thank you for reporting back.

[Jiří Huňáček]

I still tried to do the procedure to make it easier.

Code: Pascal  [Select][+][-]

1. procedure ProgressBarUpdate(pbProgressBar: TProgressBar; pbPosition: LongInt);
2. var
3.   i: Integer;
4. begin
5.   for i := 1 to 1 do
6.   begin
7.     // the first setting of the ProgressBar
8.     pbProgressBar.Position := pbPosition + 1;
9.     if pbPosition < (pbProgressBar.Max - 1) then
10.     begin
11.         if (pbPosition mod 50) <> 0 then Continue; // this line is for better performance
12.     end;
13.     Application.ProcessMessages;
14.  
15.     // the second setting of the ProgressBar
16.     pbProgressBar.Position := pbPosition;
17.     if pbPosition < (pbProgressBar.Max - 1) then
18.     begin
19.         if (pbPosition mod 50) <> 0 then Continue; // this line is for better performance
20.     end;
21.     Application.ProcessMessages;
22.   end;
23. end;

[Handoko]

I am not sure but how about this:

Code: Pascal  [Select][+][-]

1. procedure TfrmForm1.Button1Click(Sender: TObject);
2. var
3.   i: Integer;
4. begin
5.   Label5.Caption := ''; // text READY after ending the loop (visual indication only)
6.   Label5.Font.Color := clRed;
7.  
8.   Label4.Caption := FormatFloat('# ### ###', Memo1.Lines.Count);
9.   ProgressBar1.Min := 0;
10.   ProgressBar1.Max := Memo1.Lines.Count;
11.  
12.   for i := 0 to Memo1.Lines.Count - 1 do
13.   begin
14.     Label2.Caption := FormatFloat('# ### ###', i + 1);
15.  
16.     ProgressBar1.Position := i+1;
17.     if (i >= (Memo1.Lines.Count-1)) or ((i mod 50) = 0) then
18.       Application.ProcessMessages;
19.  
20.     if GetKeyState(VK_ESCAPE) < 0 then Break; // Allow user cancellation
21.   end;
22.  
23.   Label5.Caption := 'Ready';
24. end;

[Jiří Huňáček]

I tried your change but it doesn't work see screenshot. There is still a bit to touch when the value is at its maximum. Maybe it's seriously because I'm testing it on Windows 10.

But the important thing is that we have chosen a functional variant for Windows. 

[Handoko]

So, it seems the problem only happens on Windows 10 not on Linux nor Windows 7. Give me some days, I will try to find a Win10 computer to test the issue.

[Jiří Huňáček]

Thanks a lot, but I'm not sure it makes sense to pursue this further. Yesterday afternoon Bart wrote that

On Windows the progressbar lacks behind because MS made it animated.

I would see a functional solution for Windows 10 in my post a bit above, where a procedure with two settings of the ProgressBar is created. I tried it on several cases and this solution worked 100% so far, both on one form and on the original project with a separate form for information. It's possible that the simpler way won't even work, because, let's face it, Microsoft is no longer what it used to be. Unfortunately, there are people among us (like me) who have to use Windows for some reason (for example work).

[LV]

I tried your change but it doesn't work see screenshot. There is still a bit to touch when the value is at its maximum. Maybe it's seriously because I'm testing it on Windows 10.

But the important thing is that we have chosen a functional variant for Windows. 

Out of curiosity, I decided to run the program on Windows 11.

[LV]

I tested this version of the program with an execution time of 4.5 seconds

I am not sure but how about this:

Code: Pascal  [Select][+][-]

1. procedure TfrmForm1.Button1Click(Sender: TObject);
2. var
3.   i: Integer;
4. begin
5.   Label5.Caption := ''; // text READY after ending the loop (visual indication only)
6.   Label5.Font.Color := clRed;
7.  
8.   Label4.Caption := FormatFloat('# ### ###', Memo1.Lines.Count);
9.   ProgressBar1.Min := 0;
10.   ProgressBar1.Max := Memo1.Lines.Count;
11.  
12.   for i := 0 to Memo1.Lines.Count - 1 do
13.   begin
14.     Label2.Caption := FormatFloat('# ### ###', i + 1);
15.  
16.     ProgressBar1.Position := i+1;
17.     if (i >= (Memo1.Lines.Count-1)) or ((i mod 50) = 0) then
18.       Application.ProcessMessages;
19.  
20.     if GetKeyState(VK_ESCAPE) < 0 then Break; // Allow user cancellation
21.   end;
22.  
23.   Label5.Caption := 'Ready';
24. end;

I have provided my program version with an execution time of 0.25 seconds (see attachment).

[LV]

I want to share some thoughts on this topic.

The issues mentioned by the original poster (@Jiří Huňáček) can be categorized into three main points:

1. The indicator lags behind the data processing.
@Bart answered that.

2. Visuals need to be displayed without freezing.
   2.1. One approach is using `Application.ProcessMessages`, as suggested by @Jiří Huňáček and @Handoko.
   2.2. Another method is to start a worker thread for data processing, as mentioned by @cdbc and @ASerge.

You can then use `Synchronize` to update visuals without freezing.

3. Performance is another critical aspect.
I have never used `Application.ProcessMessages` for big data, only (2.2). The example provided in Adv.zip is proof of that. 

[cdbc]

Hi
@LV: Are you seriously accessing GUI-controls inside the worker thread code?!? That defeats / undermines your use of 'synchronize'!!!!!
What the H*LL?!?!

Code: Pascal  [Select][+][-]

1. procedure TThreadCalc.Execute;
2. var
3.   i: Integer;
4. begin
5.  
6.   TimeStart := Now;
7.  
8.   Form_Control.Label3.Font.Color := clRed;
9.  
10.   Form_Control.Label2.Caption := FormatFloat('# ### ###',
11.     Form_Control.Memo1.Lines.Count);
12.  
13.   Form_Control.ProgressBar1.Min := 0;
14.   Form_Control.ProgressBar1.Max := Form_Control.Memo1.Lines.Count;
15.  
16.   for i := 0 to Form_Control.Memo1.Lines.Count - 1 do
17.   begin
18.     step := i;
19.     if (i mod 50) = 0 then Synchronize(@Update);
20.   end;
21.   Synchronize(@Update);
22.   Form_Control.Label3.Caption := 'Ready';
23.   Form_Control.Label4.Caption := 'Time = ' +
24.     FormatDateTime('hh:mm:ss:zzz', Now - TimeStart);
25. end;

Tsk Tsk Tsk 
Regards Benny

[LV]

@cdbc, it's important to stay calm

syncs here

Code: Pascal  [Select][+][-]

1. for i := 0 to Form_Control.Memo1.Lines.Count - 1 do
2.   begin
3.     step := i;
4.     if (i mod 50) = 0 then Synchronize(@Update);
5.   end;
6.   Synchronize(@Update);
7.  

To maintain clean code, other chunks should be executed before and after the thread. Sorry, I was careless.

[cdbc]

Hi
Real calm here 
Especially with 'threading' code, it's crucial to show *correct* implementations, so that people who are trying to learn, get it right from the 'GetGo'. Bad habbits, they'll /learn/pickup/ all on their lonesome 
Threading is hard enough, as it is... 
Everybody knows: The LCL / VCL is NOT threadsafe! Don't access it in thread code!!!
Just saying...
Regards Benny
edit: typo

[LV]

@cdbc. Thanks.
Would this code be better?
Best regards

[cdbc]

Hi
Ahemmm... What's this?!?

Code: Pascal  [Select][+][-]

1.   for i := 0 to Form_Control.Memo1.Lines.Count - 1 do

But, Yes it's better(ish).
You have to separate the data, the thread's working on, from anything GUI!
That's why I coded my example the way I did and to avoid having 19 MB stuck into the form's streaming data...
If I didn't care about memory, I'd just copy the memo.lines into a stringlist and work on that...
Regards Benny