Is the creation of a new component the best strategy for the multiple
use of such a slider input?
Not necessarily true all the time. (by my standards at least).
What is the best way to create such a new component?
I know three ways to solve your problem.
Way number 1:
create the component using the new component wizard where you create dynamically the TEdit and the TTrackBar sub components in a TGroupBox descendant.
the following is how I would do that.
unit Combindedittrack;
interface
uses
System.SysUtils,
System.Classes,
Vcl.Controls,
Vcl.comctrls,
Vcl.StdCtrls;
type
TCombindEditTrack = class(TGroupBox)
private
{ Private declarations }
FEdit: TEdit;
FTrackBar: TTrackBar;
procedure EditOnChangeProc(Sender: TObject);
procedure TrackBaroOnChangeProc(Sender: TObject);
protected
{ Protected declarations }
public
{ Public declarations }
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
{ Published declarations }
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Samples', [TCombindEditTrack]);
end;
constructor TCombindEditTrack.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
SetBounds(0, 0, 250, 50);
FEdit := TEdit.Create(Self);
with FEdit do
begin
Text := ''; //<-- you control the appearence here
Top := 10;
Left := 10;
Height := 27;
Width := 50;
Parent := Self;
OnChange := EditOnChangeProc; // your Onchange event handler for the Tedit
end;
FTrackBar := TTrackBar.Create(self);
with FTrackBar do
begin
Top := 10; //<-- you control the appearence here
Left := 60;
Height := 30;
Width := 50;
Parent := self;
Onchange := TrackBaroOnChangeProc; // your Onchange event handler for the Ttrackbar
end;
end;
destructor TCombindEditTrack.Destroy;
begin
FTrackBar.Free;
FEdit.Free;
inherited;
end;
procedure TCombindEditTrack.TrackBaroOnChangeProc(Sender: TObject);
begin
// <-- track bar onchange handling here.
end;
procedure TCombindEditTrack.EditOnChangeProc(Sender: TObject);
begin
// <-- edit onchange handling here.
end;
end.
Way number 2:
Use frames like this (I'm on delphi 10 seattle).
File-->New-->Other-->(search for frames on delphi files).
Now add the edit and the track bar and set their Onchange events.
Save the unit.
on the tool palette (the standard component section) click on the frame component.
choose the frame you just created.
You will have a replica of the frame each time you use it.
Way number 3:
Use component template like this (again I'm on delphi 10 seattle)
Select your already created and modified tedit and ttrackbar.
On the toolbar's "component" click "create component template".
Name your template and press OK.
Select the Template palette and then your template.
Now notice that even your code (events) are added as well to your project.
Finally
With the level I have on delphi and the IDE I'm really unable to give you a clear answer to which is the best way but nevertheless I have shared all what I know that could help you.
edit: Since a lot of comments are insisting that the answer should state which is the best way to do this. this is the best way based on the following.
let's put some of the key point that should be accounted for when choosing
1. Ease of modifying the combined control(s) if you wish so (by my experience you will).
2. time needed to complete this task (it means the time it will take
you to fully complete the task with minimum debugging and coding).
3. general source code readability.
4. usefulness for the future of your projects.
Now lets start criticizing the three methods based on the those criteria.
Way number 1:
C1(criteria number 1): Just modify the the source implementation of the component and each replica/use will have the same effects and properties. However this is not the case for way number 3.
C2: It depends on your knowledge of component writing but for this component it took me 5 min to create it and I'm only a beginner in delphi. For the debugging if something went wrong and the problem is in the component implementation than you just need to fix once (see C1)
C3: their is no implementation in your form(s) source code for your component just add it to your form and every thing is hidden (for example add a tedit and go to see the implementation in your forms source).
C4: You are creating a component after all this will open the door for you to create your own set of components like the Flatstyle or Indy open source components. so next time you need some thing like this you just drop it in your form designer and you are done.
Way number 2: frames
C1: It is like way number 1 because you are creating a component but it is visually this time. modifying the source frame will change the effects and properties of the replicas, also you can add extra handling to your replicas.
the event handler of the replica's Onchange event is like this
procedure TForm1.Frame2Edit1Change(Sender: TObject);
begin
Frame2.Edit1Change(Sender); //<-- this is the original onchange event you setup at the beginning
//<-- you can extra handling here if you want one of the replicas to behave differently than the original
end;
C2: same time and maybe faster than way number 1.
C3: over all, it has the same out come as way number 1.
C4: unlike way number 1 you can not use frames created in project A in project B. So your coding and debugging will stay in project A.
Way number 3: component template.
C1: you are not creating a component you are creating a repleca/macro of the exact steps you did in your last project. changing one will not change the others they are separated.
C2: same time and maybe faster than way number 1.
C3: each time you add a template to your form the events code will be added (not a good view if it is a long Onchange code).
C4: You can use templates created in project A in project B. However what you wrote in project A will be in project B (see c1) even the references of variables that don't exist in project B (this can be hard to debug and misleading, considering the period of time between each use of the template).
Conclusion: each of the ways presented will consume time to code and debug and all of them will do the task, How ever for the sake of simplicity and the reuse with minimum risks Way number 1 is the safe choice here because it will give you the chance to update and upgrade safely. also debug faster.
the good thing also about way number 1 is that after a while when you will forget the implementation and how things are working internally. The only thing that should stay in mind is the purpose of the component because it will become one of the various component you use (you don't know how Tedit is implemented and you don't need to but yet you use it in every single project you create).
based on the criteria given Way number 1 is the best.
TCustomControlandSetSubComponentfor those subcontrols. The rest would be publishing those subcontrols as properties, or publishing some basic set of properties (e.g. for value and position of those subcontrols). Another way is using frames, but there's a risk that someone moves the controls inside. – VictoriaTFrame), you or someone else will be able to move the controls within the container on each frame separately (as far as I remember). So they can break the original control layout (in the end it might be desired - depends on your needs). That's what cannot happen if you create a composite control. – VictoriaTFramefor this. Design aTFramewith a standardTEditandTTrackBarand associated event handlers, and then simply place instances of theTFramewhere needed. This can all be done visually, no need to write a custom component for it. – Remy Lebeau