As someone who has a daily job  as a Delphi developer, it’s almost always the case that I am missing many features without noticing. In my case I actually noticed what I was missing when I installed the MMX Code Explorer. But what actually is the MMX Code Explorer? In short it doesn’t give you many revolutionary things, but that’s fine. It rather gives you improved (or rather working) tools you almost already know from the Delphi IDE.

MMX Code Explorer


  • A Code Browser
  • A structured Class Editor
  • Class Refactoring
  • Editor Refactoring
  • Entity Insight bar
  • Live Documentation
  • Advanced code sorting (read more)
  • other nice little features


It’s available for Delphi 7, 2007-2010, XE – XE8, Delphi 10 – 10.2 Tokyo (as of time of writing).


Not much to do here. Just install it and you are ready to go.

You can find the newest version at



Try the MMX Code Explorer. You won’t be disappointed 😉

When defining parameters it’s possible to define them either as default (none), var, out or const. The difference between all these is the way the value is committed to the called function. The cue’s for this are:

– Call-by-reference
– Call-by-value

The above mentioned keywords (none, var, out, const) define the way variables are called:

// Call-by-value
procedure ParamDefault(AValue: Integer);

// Call-by-reference
procedure ParamVar(var AValue: Integer);
procedure ParamOut(out AValue: Integer);
procedure ParamConst(const AValue: Integer);

But why bothering defining parameters as call-by-reference?
By defining a parameter as call-by-reference it’s not the value that is committed, but the address of the value. This can be extremely useful, when the value itself is many times bigger than the pointer (pointer-sizes depend on the architecture).

So let’s look at an example using an Integer-parameter:

{ Call-by-value

Size of Integer is 32-Bit }
procedure CallByValue(AValue: Integer);

{ Call-by-reference

Size of Integer is:
 - 32-Bit system: 32-Bit
 - 64-Bit system: 64-Bit }
procedure CallByReference(const AValue: Integer);

In this example we can see that defining the parameter as call-by-reference it gets even worse. But when we take a type whose size is bigger it quickly becomes clear, why it’s sometimes better to use call-by-reference.

// Size of TSize = 96-Bit
TSize = record
  FWidth: Integer; // 32-Bit
  FHeight: Integer; // 32-Bit
  FDepth: Integer; // 32-Bit

// Size of Sizes = 288-Bit (96-Bit * 3)
  Sizes: Array[0..2] of TSize;

Types like records (depending on the fields) and arrays can use quite a big amount of memory where it’s more efficient to use call-by-reference.

The same goes for String. String essentially is an object, but when you commit it to a function as parameter you don’t commit the address like with every other object. Instead it creates a copy of the String in the memory and commits the address.

So a general recommendation is, to use call-by-reference (var, out, const) for record-, array- and String-parameter whenever it’s possible to save memory and performance.



Use const/var/out parameters for Arrays, Records and Strings whenever it’s possible.

Ever wondered why your exe-File got so big after all the time you worked on it? Well, for that reason the map-file actually exists, but it’s not really easy to understand. Lines and lines of non-human-readable lines of debug text…
Wouldn’t it be great if there was a tool to parse it? That was at least what I was thinking. After searching and not finding anything the answer either was “There is not tool” or “You don’t know how to search”. Positively thinking it was the first I started making my own parser for map-files, so here’s the result of my short work to quickly find unnecessary units in my application.


The tool (called DSMapParser) is quite simple in what it’s doing. You compile your project with a map file and open the map-file in the Map Parser.
The parser than (surprise!) parses the map-file and groups every file by its namespace. The result is a quite nice overview of all the units that bloat your application.



  1. Grab the latest release from the github repository:
  2. Extract it and use it! That simple!


Using it

Before you can actually use the map-parser you probably need to adjust some settings in your project to generate a map-file:

  1. Go to your project options: Project > Options
  2. Navigate to “Delphi-Compiler > Linking”
  3. Change the setting “Map-File” to “Segments”

Ensure that you have changed the options in your corresponding release-configuration.

After changing these settings your compiler creates beside your .exe-file also a .map-file, which can be used by the Map-Parser.



Parse your Map-File with the DSMapParser to find out why your application is so bloated.

The try-finally block is awesome. Especially for creating and freeing objects. But what do you all do when you want to create multiple objects in a row? Create a nested try-finally for ever object you create?

Object1 := TObject.Create;
  Object2 := TObject.Create;

This is obviously quite an overhead when having multiple objects. So let’s create every object at the beginning and free all in the finally-block, right? Hypothetically asking for if it is right should already give you the hint that this is obviously wrong or rather even more bad.
For understanding purposes have an example:

Object1 := TObject.Create;
Object2 := TObject.Create;

At first this looks like a good idea. We have only one try-finally for as many objects we want to create, but here hides a possible memory leak.
Consider this; the first object got created successfully, but the second one raised an exception while creating. At this point we still are outside the try-finally-statement so we aren’t going to free the object that was previously successfully created.
Have this kind of bug a dozen times and you can say goodbye to your memory or even to your application because the memory ran out for it.

So lets just move the creation of the objects inside the try-finally! Well, that idea would be even more bad.
Variables aren’t initialized so we can assume that the objects point to some garbage. Now one of the objects can’t be created and an exception is raised, but the finally-block gets executed. That’s what we want! But then suddenly we get an access violation because of an object pointing to garbage…

And here comes the final necessary part for creating multiple objects with one try-finally. We just initialize it as nil, because the .Free method checks if the object is <> nil so we can execute this without worrying about errors.

Object1 := nil;
Object2 := nil;
  Object1 := TObject.Create;
  Object2 := TObject.Create;

With this method of writing one try-finally-statement for multiple objects you can have less overhead, because of no more nested try-finally-statements, and have a better overview of your objects.

Hint: Free the objects at reversed order to minimize bugs because of dependencies between the objects.


Use one try-finally for multiple objects by initializing every object with nil and creating them within the try-block.

As a Delphi developer, you don’t get around objects. Creating and freeing them is an essential part of every Object Pascal based application. But now here comes a random guy telling you that you made your whole life a serious mistake at object management! Unbelievable, but hear me out, because you are going to thank me later on.

As you probably already know an object variable is essentially a pointer to the address where the memory for your instance is reserved. So creating an object returns the address and freeing an object marks the reserved memory as “not in use anymore”, but the object variable still contains the address to where the object originally was. And here comes the horror of object management in Delphi!
When you forget to nil the variable after freeing than you don’t know if it’s still valid, but that’s not even the worst that could happen. Imagine you have a business application where it’s critical that everything runs perfectly, but then out of nowhere your objects returns a number you can’t explain. It’s nothing you have ever seen and no one in your company can help you. Even worse; you can’t replicate the bug, but your customer/the user still gets this bug from time to time corrupting his data. I will leave it to your imagination what can happen when you have a 1 instead of a 0 in an application that decides between life and death.
But why can something like that happen just because I forgot to nil an object after freeing it?

The thing is that your program doesn’t care if the reserved memory of your object is valid or not. When it’s able to get what it wants, then it’s happy even if the memory got reserved and overridden by another instance.
This typically results in the well known access violation of reading/writing at address 80070010 (or something similar) and when you see something like this you really should freak out! This is obviously a bug where the application tries to access the memory of an object that got freed and it’s a miracle you accidentally found this because it’s completely random (well, not really random, but depending on your application you can interpret it as random) if this access violation happens.

Hint: An easy way to differentiate between a null-pointer access violation and an access violation because of freed memory is by looking at the address. When the address is a really small number (something like 00000004) then it’s a null-pointer access violation. Otherwise, it’s an access violation because of freed memory.

But how can I fix this memory madness?!
— Random stranger on the Internet

Forget the idea of using .Free! Yeah, it’s the time of object oriented programming, but no one wants bugs or write two lines of code when they can just write one.
So instead of writing

Object := nil; // <- considering you even wrote this line

Just write



The thing is that FreeAndNil does nothing more than checking if your object is <> nil and if it is it calls .Free and sets it := nil.


So here is my advice; use FreeAndNil all the times when it’s possible. It’s not going to change the logic but help you find bugs before you deliver them out.



Use FreeAndNil(Object) instead of Object.Free to prevent data corruption and bugs that are gonna break your mind!

Ever wanted to use some fancy Unicode emotes in your Delphi application? Well good luck with that, because the RichEdit controls are using a library that’s so old it even supports Windows 95! An OS that had no support for more than 16 years (support ended December 31, 2001)!

So why isn’t embarcadero also dropping support for that and use a library for at least Windows XP (let’s be serious, enough people are still using it). The reason probably would be because either way embarcadero want’s to still support it (like Windows 3.11) or because Microsoft doesn’t offer really good alternatives.

So let’s look at the possibilities Microsoft gives us here; Looking at the MSDN-Page about the RichEdit-Control ( we can see that it’s documented from version 1.0 (Windows 95) up to 4.1 (Windows XP), but aren’t there any other versions? I mean Microsoft can’t seriously not have updated their RichEdit-Control since Windows XP, right? They have! But not for everyone! If you want to use a version higher than 4.1 you would need Microsoft Office.

This is obviously not a solution having Microsoft Office as requirement for your application and embarcadero probably thinks the same way. So what are your solutions? Use the latest version you can use without worrying about too much! In this case it would be version 4.1 which also supports Unicode.

Getting RichEdit 4.1

To enable support for RichEdit 4.1 in your RichEdit-controls you need to load the library and tell your control to use another version:

unit UnicodeRichEdit;


  Vcl.Controls, Vcl.ComCtrls;

  TUnicodeRichEdit = class(TRichEdit)
    procedure CreateParams(var Params: TCreateParams); override;



procedure TDSUnicodeRichEdit.CreateParams(var Params: TCreateParams);
  // Tell the RichEdit control to use 4.1
  CreateSubClass(Params, 'RICHEDIT50W');

  FRichEditUnicodeModule: HMODULE;

  // Load the library
  FRichEditUnicodeModule := LoadLibrary('MSFTEDIT.DLL');
  if FRichEditUnicodeModule &amp;lt;= HINSTANCE_ERROR then
    raise Exception.Create('Could not load library "MSFTEDIT.DLL"!');

  // Free the library
  if FRichEditUnicodeModule &amp;lt;&amp;gt; 0 then



A complete package ready to install is also available at GitHub:

  1. Download the latest version from
  2. Open the project-file “src/DSUnicodeRichEdit.dpk”
  3. Install it (right click on the project in the project overview and “Install”)
  4. Go to Tools > Options > Delphi Options > Library
  5. Add the path to the src folder to the Library-Path (repeat this step for every platform you want to use this component with)


It’s a bit tricky but with a small amount of code you can have Unicode emotes in your RichEdit control and also enjoy the old new features of version 4.1. If you are concerned about reliability then don’t worry; After a long period of use in a production environment I had no single error. You only have to consider that you need to have at least Windows XP otherwise it won’t run.



Have RichEdit-controls with Unicode support by using the DSUnicodeRichEdit package.

Wouldn’t it be nice if you could just make your Delphi IDE a bit more nice to look at? Well, when working with Delphi every day you really need something to get your thoughts of the frustration. So here is my recommendation for you!

The Ita-IDE plugin gives you the ability to set a custom background in the editor, so you have always something nice to look at.




You need to have at least Delphi XE2 to install it without modifying the source code.

It’s compatible with the newest version (at the time of writing) Delphi 10.2 Tokyo.


  1. Grab a copy of the source from
  2. Open the project and install it as a plugin
  3. Done!


To personalize the background just go to the settings at “Tools > Ita IDE Options”. There you can set your own image (better use one with a transparent background otherwise it will look weird), set the size, position and transparency.



Set a custom background with the Ita-IDE plugin.