Inno Setup - Conditionally hide/show static text based on task selection

Question

[Components]
Name: "Slasher"; Description: "Dagon Slasher"; Types: Slasher Full
Name: "Frankenstein"; Description: "Dagon Frankenstein"; Types: Frankenstein Full

[Types]
Name: "Full"; Description: "Dagon Video Tools"
Name: "Slasher"; Description: "Dagon Slasher"
Name: "Frankenstein"; Description: "Dagon FrankenStein"

[Tasks]
Name: "Debug"; Description: "Nothing"; Components: not Slasher
Name: "Vid"; Description: "Install Extra Codecs for Frankenstein"; Flags: unchecked; Components: not Slasher

[Code]
var
  Warning: TNewStaticText;

procedure InitializeWizard;
begin
  Warning := TNewStaticText.Create(WizardForm);
  Warning.Parent := WizardForm.SelectTasksPage;
  Warning.Visible := False;
  Warning.AutoSize := False;
  Warning.SetBounds(
    WizardForm.TasksList.Left,
    WizardForm.TasksList.Top + WizardForm.TasksList.Height,
    WizardForm.TasksList.Width,
    50
  );
  Warning.Font.Color := clRed;
  Warning.Caption := 'Warning: This will result in a non-functional "Join in FrankenStein" button in the Tools Menu.';
end;

I used yet another amazing piece of code by TLama. The problem is I need the note to be visible when the user selects the task, and be hidden otherwise (while on the same page).

Answer 1

You have to handle WizardForm.TasksList.OnClickCheck event and update the Warning label visibility accordingly.

var
  Warning: TNewStaticText;

procedure TasksListClickCheck(Sender: TObject);
begin
  Warning.Visible :=
    { This (and the task index below)  has to be kept in sync with the expression }
    { in "Components" parameter of the respective task. }
    { Though note that in your specific case the test }
    { is redundant as when "Slasher" is selected, you have no tasks, }
    { and the "Tasks" page is completely skipped, so you do not even get here. }
    (not IsComponentSelected('Slasher')) and
    WizardForm.TasksList.Checked[0]; { You can also use WizardIsTaskSelected }
end;

procedure InitializeWizard;
begin
  Warning := TNewStaticText.Create(WizardForm);
  ...
  { Update Warning label visibility on task selection change }
  WizardForm.TasksList.OnClickCheck := @TasksListClickCheck
end;

procedure CurPageChanged(CurPageID: Integer);
begin
  if CurPageID = wpSelectTasks then
  begin
    { Update initial visibility }
    TasksListClickCheck(WizardForm.TasksList);
  end;
end;

---

Side notes:

• Do not hard code the height to fixed 50. Scale it with DPI instead: ScaleY(50).
• You should set Warning.WordWrap := True as the caption does not fit page width.
• You should shrink TasksList's height as the label does not fit below the list. You are missing the WizardForm.TasksList.Height := WizardForm.TasksList.Height - NoteHeight; from @TLama's code. Again note that he is missing the scaling of the NoteHeight.

const
  NoteHeight = 50;

procedure InitializeWizard;
begin
  WizardForm.TasksList.Height := WizardForm.TasksList.Height - ScaleY(NoteHeight);

  Warning := TNewStaticText.Create(WizardForm);
  Warning.Parent := WizardForm.SelectTasksPage;
  Warning.AutoSize := False;
  Warning.WordWrap := True;
  Warning.SetBounds(
    WizardForm.TasksList.Left,
    WizardForm.TasksList.Top + WizardForm.TasksList.Height,
    WizardForm.TasksList.Width,
    ScaleY(NoteHeight)
  );
  Warning.Font.Color := clRed;
  { Update Warning label visibility on task selection change }
  WizardForm.TasksList.OnClickCheck := @TasksListClickCheck
  Warning.Caption :=
    'Warning: This will result in a non-functional "Join in FrankenStein" button ' +
    'in the Tools Menu.';
end;