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Strange behavior of TPageControl

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gouyon:
Hi every body

TPageControl as a strange behaviour on linux  :-[. I have made a small application with a Form on which I have put a TPageControl with three TTabSheet (Page1,Page2 et Page3). On each page there is a button. A click on these buttons hide all the pages except one.
Here is how it works
Page1->Page2 no problem Page1 disappear and Page2 is showing
Page2->Page1 no problem Page2 disappear and Page1 is showing
Page2->Page3 no problem Page2 disappear and Page3 is showing
Page3->Page2 problem Page3 disappear and Page1 is not showing


--- Code: ---unit Unit1;
 
{$mode objfpc}{$H+}
 
interface
 
uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, ComCtrls,
  StdCtrls;
 
type
 
  { TForm1 }
 
  TForm1 = class(TForm)
    Btnpg2: TButton;
    Btnpg1: TButton;
    Btnpg3: TButton;
    Btnpg32: TButton;
    LesPages: TPageControl;
    Page1: TTabSheet;
    Page2: TTabSheet;
    Page3: TTabSheet;
    procedure Btnpg1Click(Sender: TObject);
    procedure Btnpg2Click(Sender: TObject);
    procedure Btnpg32Click(Sender: TObject);
    procedure Btnpg3Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { private declarations }
    procedure AffichePage(LaPage: TTabSheet);
  public
    { public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.lfm}
 
{ TForm1 }
 
 
procedure TForm1.AffichePage(LaPage: TTabSheet);
var
  i: integer;
begin
  LesPages.ActivePage := LaPage;
  for i := 0 to LesPages.PageCount - 1 do
  begin
    if LesPages.Pages[i] = LaPage then
      LesPages.Pages[i].TabVisible := True
    else
      LesPages.Pages[i].TabVisible := False;
  end;
end;
 
procedure TForm1.Btnpg2Click(Sender: TObject);
 
begin
  AffichePage(Page2);
end;
 
procedure TForm1.Btnpg32Click(Sender: TObject);
begin
  AffichePage(Page2);
end;
 
procedure TForm1.Btnpg3Click(Sender: TObject);
begin
  AffichePage(Page3);
end;
 
procedure TForm1.Btnpg1Click(Sender: TObject);
begin
  AffichePage(Page1);
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  AffichePage(Page1);
end;
 
end.

--- End code ---

This problem does not show on Windows.
I use Lazarus v 0.930 with fpc 2.4.2 on Ubuntu v10.10

 

Blaazen:
I assume Button1 is on the Page1 etc.
Is your problem related to Button32?


--- Code: ---procedure TForm1.AffichePage(LaPage: TTabSheet);
var
  i: integer;
begin
  LesPages.ActivePage := LaPage;
  for i := 0 to LesPages.PageCount - 1 do
  begin
    if LesPages.Pages[i] = LaPage then
      LesPages.Pages[i].TabVisible := True
    else
      LesPages.Pages[i].TabVisible := False;
  end;
end;
--- End code ---

This procedure seems to make visible LaPage and make invisible the others. Button32 sends AffichePage(Page2) so Page1 is not shown.

EDIT: Maybe problem is that you can sometimes do Active an invisible page. Try to change order in your procedure like this:


--- Code: ---procedure TForm1.AffichePage(LaPage: TTabSheet);
var
  i: integer;
begin
  for i := 0 to LesPages.PageCount - 1 do
  begin
    if LesPages.Pages[i] = LaPage then
      LesPages.Pages[i].TabVisible := True
    else
      LesPages.Pages[i].TabVisible := False;
  end;
   LesPages.ActivePage := LaPage;
end;
--- End code ---

gouyon:

--- Quote ---I assume Button1 is on the Page1 etc.
Is your problem related to Button32?

--- End quote ---
Yes that's it
I have tried your solution but it does not work.

Blaazen:
This works here:

--- Code: ---procedure TForm1.Button1Click(Sender: TObject);
begin
  SwapPages(TabSheet2);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  SwapPages(TabSheet3);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  SwapPages(TabSheet1);
end;

procedure TForm1.SwapPages(LaPage: TTabSheet);
var i: LongInt;
begin
  for i := 0 to LesPages.PageCount - 1 do
    LesPages.Pages[i].TabVisible := (LesPages.Pages[i] = LaPage);
  LesPages.ActivePage := LaPage;        
end;

--- End code ---
Note:
  Button1 is on TabSheet1 and swaps to TabSheet2
  Button2 is on TabSheet2 and swaps to TabSheet3
  Button3 is on TabSheet3 and swaps to TabSheet1
  Inintial state is TabSheet1.TabVisible=True, the others are hidden.

EDIT: I am on Linux (SVN 30480) + Qt 4.7.1

gouyon:
It's not working but this one works

--- Code: ---procedure TForm1.AffichePage(LaPage: TTabSheet);
var
  i: integer;
begin

{this part solve the problem}

  LesPages.Pages[0].TabVisible := True;
  for i := 1 to LesPages.PageCount - 1 do
    LesPages.Pages[i].TabVisible := False;

{I dont know why}

  for i := 0 to LesPages.PageCount - 1 do
  begin
    if LesPages.Pages[i] = LaPage then
      LesPages.Pages[i].TabVisible := True
    else
      LesPages.Pages[i].TabVisible := False;
  end;
  LesPages.ActivePage := LaPage;
end;

--- End code ---

My system is Ubuntu 11.04 and Lazarus is 0.930

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