Every once in a while, I run into one of those small Delphi features that makes me wonder, “Why haven't I been using this more?”
Code folding is one of those features.
I was reminded of this during
a recent ChatGPT coding session
It does not make your code run faster. It does not fix bad logic. It does not magically turn a messy unit into clean architecture. But it does make the Delphi editor easier to work in, and when you spend a lot of time moving around in the source code, that matters.
I was reminded of this during a recent ChatGPT coding session while working in Delphi 13.1.
We were not doing anything glamorous. We were not building some grand framework or rewriting the whole application. We were doing the kind of careful work real programmers do all the time: find this section of code, replace it with that section of code, compile, test, and move on to the next small change.
In other words, it was surgical coding.
ChatGPT would tell me something like, “Find this method,” or “Replace this block,” or “Add this procedure right below that one.” That works fine when the unit is small. But once the source file starts growing, finding the right place in the code can turn into a scroll hunt. You move up, move down, pass the section you were looking for, scroll back, and hope you do not paste the new code in the wrong place.
That is when folding code started looking a lot less like an editor gimmick and a lot more like a practical navigation tool.
I created a simple test form with one button so I could slow down and look at how Delphi handles folded regions and folded methods. Nothing fancy. Just a small, controlled example where I could see what happens when the editor shows the code as an outline instead of one long strip of source code.
The lesson was simple: when you are making careful, targeted edits, folded code helps you find the right operating table before you pick up the scalpel.
unit Unit1;
interface
{$REGION 'Interface Comments'}
// ============================================================================
// Interface comments go here
// ============================================================================
//
//
// ============================================================================
{$ENDREGION}
uses
System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
FMX.Controls.Presentation, FMX.StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$REGION 'Implementation Comments'}
// ============================================================================
// Implementation comments go here
// ============================================================================
//
//
// ============================================================================
{$ENDREGION}
{$R *.fmx}
procedure TForm1.Button1Click(Sender: TObject);
begin
//
// Button1 Click Code Goes Here
//
end;
end.
What Is a Delphi Region?
A Delphi region starts with {$REGION ...} and ends with {$ENDREGION}.
For example:
{$REGION 'Interface Comments'}
// code or comments go here
{$ENDREGION}
The text inside the quotes becomes the folded label in the editor. In this example, Delphi shows the folded section as Interface Comments.
That may not seem like much in a small unit, but once a source file grows, these regions can act like road signs. Instead of scrolling through everything line by line, you can collapse the sections you do not need and keep the overall structure visible.
The Before Picture
 |
| Nothing Folded |
This first screenshot shows the unit with nothing folded.
In a tiny example like this, it is not a big deal. Everything fits on the screen, and there is not much to hunt for. But that is not how real Delphi projects usually stay. A form starts simple, then a few more event handlers get added. Then a few helper methods show up. Then some temporary test code appears. Before long, you are scrolling through the file trying to find the one method you need.
That is where folding starts to earn its keep.
Folding the Regions
 |
Regions Folded
|
In the second screenshot, the two comment regions are folded.
The code is still there. Nothing has been removed. Delphi simply collapses those sections so they take up less room in the editor.
This is one of the things I like about folding code. It lets me get things out of the way without deleting anything. Sometimes I want those big comment blocks. Sometimes they are helpful. But when I am working on a method, I do not always need to see them.
Folding lets me say, “Not now. Stay there, but get out of my way.”
That is useful.
Folding Regions and Methods
 |
| Regions & Methods Folded |
The third screenshot shows both the regions and the method body folded.
At this point, the source file starts to look more like an outline. You can see the major parts of the unit without seeing every line inside each part.
That is probably my favorite use of folding. It helps me move around in the source file without getting pulled into the details too soon. When everything is expanded, every line competes for attention. When sections are folded, I can scan the shape of the unit first, then open only the part I need.
For someone like me, that matters. I do not “picture” the code in my mind. I work better when the structure is visible on the screen. Folding code gives me a simple way to make the editor show the structure instead of forcing me to mentally hold it all together.
Customizing the Folded Code Color
Delphi also lets you customize the way folded code looks in the editor.
You can find this under:
Tools > Options > Editor > Color
Then scroll down to the Folded code element.
 |
| Delphi 13.1 Editor Color settings |
I usually work in the Light theme, so I changed my folded code colors to something I could spot quickly without making the editor look like a warning sign.
My settings are:
That is just my personal preference. You may like something different. The important thing is that folded code should be easy to recognize. I want it to stand out, but I do not want it shouting at me all day.
Palevioletred on Mistyrose works for me. It is visible, but not obnoxious.
At least in my humble opinion.
Why This Helps
The real benefit of folding code is navigation.
When I am working in a source file, I do not always need to see everything. Sometimes I only need the interface section. Sometimes I only need the implementation section. Sometimes I want to hide temporary test methods so I can focus on the production code. Sometimes I want to collapse a group of helper methods because they are not the thing I am working on right now.
That is where regions can be helpful.
For example, you might use:
{$REGION 'Helper Methods'}
or
{$REGION 'Temporary Sample/Test Methods'}
or
{$REGION 'Initialization Code'}
The region names become little signposts inside the editor. When they are folded, they help you move around the unit faster.
Used carefully, code folding reduces visual clutter. Used carelessly, it can become clutter of its own. I would not wrap every tiny thing in a region just because Delphi lets me do it. But for logical sections of code, longer comment blocks, temporary test code, or helper methods, regions can make a unit easier to live in.
Final Thought
Code folding is a small feature, but it solves a real problem.
It helps you move around inside your code without scrolling through every line. It lets you collapse the parts you do not need right now. It turns a long source file into something closer to an outline.
And when you can see the outline, it is easier to find your way.
Sometimes the best productivity improvement is not a new tool. Sometimes it is just making the tool you already use a little easier to work with.
Share Your Colors With a Comment
Please share the foreground and background colors you are using for your Folded Code in the comments.
Enjoy!
Semper Fi
Gunny Mike
https://zilchworks.com
https://debtblaster.com
GOTCHAS!
As pointed out by SilverWarrior in the comments. Code errors lead to unfolded code from the error point on. There are two very quick ways to re-fold all the methods instead of toggling the ( - ) or ( + ) in the left margin.
Method Folding quick Steps
Mouse: Right Click > Fold > Methods
Keyboard: [ Ctrl ] + [ Shift ] (keep held down) press K then press M
