Inno Setup - Identify, what tasks correspond to the items of TaskList (to show text on mouse over for certain tasks only)

Question

So, I have these comtools tasks, which, as you can see, can have a different position in the tasks list, depending on which components were previously chosen. Moreover, they may not exist at all, if the user doesn't wish to install those components. What I need is static text shown, but only when the cursor hovers over the comtools tasks.

[Tasks]
Name: "acorig"; Description: "ac original"; GroupDescription: "Choose which version of ac to install:"; Flags: exclusive; Components: ac
Name: "acenh"; Description: "ac enhanced"; GroupDescription: "Choose which version of ac to install:"; Flags: exclusive unchecked; Components: ac
Name: "ac2comtools"; Description: "ac2"; GroupDescription: "Also install community-made tools (unsupported) for:"; Flags: unchecked; Components: ac2
Name: "bccomtools"; Description: "bc"; GroupDescription: "Also install community-made tools (unsupported) for:"; Flags: unchecked; Components: bc
Name: "bc2comtools"; Description: "bc2"; GroupDescription: "Also install community-made tools (unsupported) for:"; Flags: unchecked; Components: bc
Name: "bc3comtools"; Description: "bc3"; GroupDescription: "Also install community-made tools (unsupported) for:"; Flags: unchecked; Components: bc3
Name: "bc4comtools"; Description: "bc4"; GroupDescription: "Also install community-made tools (unsupported) for:"; Flags: unchecked; Components: bc4

Yes, I did see this, but that ties the description to index, which is not practical here. Also, that code shows description for all items in TasksList.

----Edit----

So, the only change I made to the code after Martin's answer (aside from moving everything over to the tasks page) was adding Martin's function, and editing HoverComponentChanged like this:

procedure HoverComponentChanged(Index: Integer);
var 
  Description: string;
begin
  case Index of
    -1: Description := '';
    LookupTask('ac2comtools'): Description := 'This is the description of AC2';
    LookupTask('bccomtools'): Description := 'This is the description of BC';
    LookupTask('bc2comtools'): Description := 'This is the description of BC2';
    LookupTask('bc3comtools'): Description := 'This is the description of BC3';
  else
    Description := '';
  end;
  TaskLabel.Caption := Description;
end;

-1 is a failsafe, since, when one of the components in deselected, then the index for the corresponding task is -1, which means you will see the description for the first deselected component in this list, when your cursor is outside of TasksList.

Answer 1

There's really no straightforward way to identify, what tasks correspond to the items of TaskList.

---

Quick and dirty way is to use item description.

In this case, it's better to define the description using a custom message, so that you can refer to it in the code. And it's a must anyway, if your installer is localized.

[CustomMessages]
AC2ComTools=ac2

[Tasks]
Name: "ac2comtools"; Description: {cm:AC2ComTools}

[Code]

function LookupTask(TaskCustomMessage: string): Integer;
var
  Description: string;
begin
  Description := CustomMessage(TaskCustomMessage);
  Result := WizardForm.TasksList.Items.IndexOf(Description);
  Log(Format('Index of "%s" task is %d', [Description, Result]));
end;

Use it like:

AC2ComToolsIndex := LookupTask('ac2comtools');

---

Another way is to reproduce the logic of Inno Setup for deciding, what tasks to show.

Use WizardIsComponentSelected function (IsComponentSelected before Inno Setup 6.0.2).

{ Before Inno Setup 6.0.2, use IsComponentSelected. }
if WizardIsComponentSelected('ac2') then
begin
  if WizardIsComponentSelected('ac') then AC2ComToolsIndex := 4
    else AC2ComToolsIndex := 1;
end
  else AC2ComToolsIndex := -1;

---

If you want to create a full mapping from task name to TaskList item index automatically, you can do something like this each time the task list changes, i.e. on call to CurPageChanged(wpSelectTasks):

• Remember current task state
• Check all task checkboxes
• Read WizardSelectedTasks(False) to get names of all tasks
• Generate the mapping
• Restore previous task state.

This is relatively easy, when there are only checkboxes, not radio buttons (i.e. no task with exclusive flag).

var
  Tasks: TStringList;

procedure CurPageChanged(CurPageID: Integer);
var
  TasksChecked: array of Boolean;
  I: Integer;
begin
  if CurPageID = wpSelectTasks then
  begin
    SetArrayLength(TasksChecked, WizardForm.TasksList.Items.Count);
    { Remember current task state + Check all task checkboxes }
    for I := 0 to WizardForm.TasksList.Items.Count - 1 do
    begin
      TasksChecked[I] := WizardForm.TasksList.Checked[I];
      WizardForm.TasksList.Checked[I] := True;
    end;
    Tasks := TStringList.Create;
    Tasks.CommaText := WizardSelectedTasks(False);  
    for I := 0 to WizardForm.TasksList.Items.Count - 1 do
    begin
      { Insert blank items for "group descriptions" }
      if WizardForm.TasksList.ItemObject[I] = nil then
        Tasks.Insert(I, '');
      { Restore previous task state }
      WizardForm.TasksList.Checked[I] := TasksChecked[I];
    end;
  end;
end;

Now you can use the Tasks to lookup corresponding task index:

AC2ComToolsIndex := Tasks.IndexOf('ac2comtools');

Though as you have exclusive tasks, you would need much more complicated code.