TStringList image view[SOLVED]

[Pe3s]

Hello, how can I improve the code so that it loads the next and previous images after clicking the buttons?
Regards

[paweld]

Code: Pascal  [Select][+][-]

1. procedure TForm1.FormCreate(Sender: TObject);
2. begin
3.    FImages := TStringList.Create;
4. end;
5.  
6. procedure TForm1.FormDestroy(Sender: TObject);
7. begin
8.   FImages.Free;
9. end;
10.  
11. procedure TForm1.SpeedButton1Click(Sender: TObject);
12. begin
13.   if OpenPictureDialog1.Execute then
14.   begin
15.     FImages.Clear;  //clear images list
16.     try
17.       FindAllFiles(FImages, ExtractFileDir(OpenPictureDialog1.FileName) + PathDelim, '*.jpg; *.jpeg', True);
18.       Form1.Caption := IntToStr(FImages.IndexOf(OpenPictureDialog1.FileName)) +' / '+ IntToStr(FImages.Count);
19.       //Image1.Picture.LoadFromFile(FImages[FImages.IndexOf(OpenPictureDialog1.FileName)]);
20.       FIIndex := FImages.IndexOf(OpenPictureDialog1.FileName);
21.       if FIIndex < 0 then  //if the selected file is not found (is not JPG) then select the first one in the list
22.         FIIndex := 0;
23.  
24.       NextImage;
25.     finally
26.  
27.     end;
28.   end;
29. end;
30.  
31. procedure TForm1.ShowImage(Sender: TObject);
32.  var
33.   ImageIndex: integer;
34. begin
35.   if FImages.Count = 0 then //protect from an empty list
36.     exit;
37.   ImageIndex := FIIndex;
38.   FIIndex := (FIIndex + 1) mod FImages.Count;
39.   Image1.Picture.LoadFromFile(FImages[ImageIndex]);
40. end;      
41.  

[Pe3s]

Thank you 

[Pe3s]

Hello, what do I need to correct to make the program count the number of images correctly, to count from 1 and not from zero?

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   FileUtil, Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ComCtrls,
9.   ExtCtrls, Buttons, ExtDlgs, GR32_Image;
10.  
11. type
12.  
13.   { TForm1 }
14.  
15.   TForm1 = class(TForm)
16.     ImageList1: TImageList;
17.     ImgView32_1: TImgView32;
18.     OpenPictureDialog1: TOpenPictureDialog;
19.     StatusBar1: TStatusBar;
20.     ToolBar1: TToolBar;
21.     ToolButton1: TToolButton;
22.     ToolButton2: TToolButton;
23.     ToolButton3: TToolButton;
24.     ToolButton4: TToolButton;
25.     procedure FormCreate(Sender: TObject);
26.     procedure FormDestroy(Sender: TObject);
27.     procedure ToolButton1Click(Sender: TObject);
28.     procedure ToolButton3Click(Sender: TObject);
29.     procedure ToolButton4Click(Sender: TObject);
30.   private
31.     FImages: TStringList;
32.     FCurrentIndex: Integer;
33.     procedure LoadImage(const APrev: Boolean);
34.  
35.   public
36.  
37.   end;
38.  
39. var
40.   Form1: TForm1;
41.  
42. implementation
43.  
44. {$R *.lfm}
45.  
46. { TForm1 }
47.  
48. procedure TForm1.FormCreate(Sender: TObject);
49. begin
50.   FImages := TStringList.Create;
51. end;
52.  
53. procedure TForm1.FormDestroy(Sender: TObject);
54. begin
55.   FImages.Free;
56. end;
57.  
58. procedure TForm1.ToolButton1Click(Sender: TObject);
59. begin
60.   if OpenPictureDialog1.Execute then
61.   begin
62.       FImages.Clear;
63.       FindAllFiles(FImages, ExtractFileDir(OpenPictureDialog1.FileName) + PathDelim, '*.jpg; *.jpeg', True);
64.       FCurrentIndex := FImages.IndexOf(OpenPictureDialog1.FileName);
65.  
66.      LoadImage(False);
67.   end;
68. end;
69.  
70. procedure TForm1.ToolButton3Click(Sender: TObject);
71. begin
72.   LoadImage(True);
73. end;
74.  
75. procedure TForm1.ToolButton4Click(Sender: TObject);
76. begin
77.   LoadImage(False);
78. end;
79.  
80. procedure TForm1.LoadImage(const APrev: Boolean);
81. var
82.   ImageIndex: Integer;
83. begin
84.   ImageIndex := FCurrentIndex;
85.  
86.   if APrev then
87.   begin
88.      if FCurrentIndex > 0 then
89.     Dec(FCurrentIndex)
90.   end else
91.   begin
92.     if FCurrentIndex < FImages.Count -1 then
93.     Inc(FCurrentIndex);
94.   end;
95.  
96.   ImgView32_1.Bitmap.LoadFromFile(FImages[ImageIndex]);
97.  
98.   Form1.Caption := ExtractFileName(FImages[ImageIndex]);
99.   StatusBar1.Panels[0].Text := IntToStr(ImgView32_1.Bitmap.Width) +'x'+ IntToStr(ImgView32_1.Bitmap.Height);
100.   StatusBar1.Panels[1].Text := IntToStr(FCurrentIndex) +' / '+ IntToStr(FImages.Count);
101. end;
102.  
103. end.
104.  
105.  

[alpine]

Code: Pascal  [Select][+][-]

1. StatusBar1.Panels[1].Text := IntToStr(FCurrentIndex + 1) +' / '+ IntToStr(FImages.Count);

?

[Pe3s]

Now he counts from 2

[alpine]

Now he counts from 2

It does not.

[paweld]

@alpine provided the correct code, but it is misplaced in your procedure code. Since you immediately change the current index when you press the button, you need to place this line of code at the beginning of the procedure.

Code: Pascal  [Select][+][-]

1. procedure TForm1.LoadImage(const APrev: Boolean);
2. var
3.   ImageIndex: Integer;
4. begin
5.   ImageIndex := FCurrentIndex;
6.   StatusBar1.Panels[1].Text := IntToStr(FCurrentIndex + 1) +' / '+ IntToStr(FImages.Count);
7.  
8.   if APrev then
9.   begin
10.      if FCurrentIndex > 0 then
11.     Dec(FCurrentIndex)
12.   end else
13.   begin
14.     if FCurrentIndex < FImages.Count -1 then
15.     Inc(FCurrentIndex);
16.   end;
17.  
18.   ImgView32_1.Bitmap.LoadFromFile(FImages[ImageIndex]);
19.  
20.   Form1.Caption := ExtractFileName(FImages[ImageIndex]);
21.   StatusBar1.Panels[0].Text := IntToStr(ImgView32_1.Bitmap.Width) +'x'+ IntToStr(ImgView32_1.Bitmap.Height);
22. end;

[alpine]

And I bet there will be a little surprise when the direction is changed 

Edit: To be a bit more clear - modifying FCurrentIndex after the loading of the image file will have the (unexpected) effect of showing the result of the previous movement.

[Pe3s]

exactly the other way around doesn't work

[alpine]

exactly the other way around doesn't work

I don't know what do you mean by "the other way around", perhaps it is changing FCurrentIndex before the loading, but actually that's the way it should work if you don't want your current picture to lag one step behind.
One simple way to do it:

Code: Pascal  [Select][+][-]

1. procedure TForm1.LoadImage(const AInc: Integer);
2. var
3.   ImageIndex: Integer;
4. begin
5.   ImageIndex := FCurrentIndex + AInc;
6.   if (ImageIndex < 0) or (ImageIndex >= FImages.Count) then
7.     Exit;
8.   ImgView32_1.Bitmap.LoadFromFile(FImages[ImageIndex]);
9.   Form1.Caption := ExtractFileName(FImages[ImageIndex]);
10.   StatusBar1.Panels[0].Text := IntToStr(ImgView32_1.Bitmap.Width) +'x'+ IntToStr(ImgView32_1.Bitmap.Height);
11.   StatusBar1.Panels[1].Text := IntToStr(ImageIndex + 1) +' / '+ IntToStr(FImages.Count);
12.   FCurrentIndex := ImageIndex;
13. end;

Then call LoadImage(0) on initial loading, call LoadImage(1) when 'Next' clicked and call LoadImage(-1) when 'Prev' clicked.

Another way would be not to modify FCurrentIndex into the LoadImage(), i.e. just load and show texts, and to do incrementing/decrementing into Next/Prev handlers.

It's pretty trivial and I don't know why you expect someone to do it for you.

[Pe3s]

Thank you