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IDE Development

This page contains notes for lazarus core developers about ongoing development.

Note: This paragraph is referenced by

Multi form properties / using DataModules from other forms in the designer

Short Description

This feature allows to use components of other designer forms. A common example is to use the TDataSource on a DataModule for the DataSource property of a db control. Designer forms can only reference each other if they have a CreateForm statement in the lpr file (Project Options / Forms).

Working

Manual referencing via source code works.
TPersistentPropertyEditor.GetValues - List all possible values. Check for class compatibility and if the target form is listed in the CreateForm statements of the lpr file and if the target unit does not belong to a package that will conflict if used.
TPersistentPropertyEditor.GetValue - Show component path
TPersistentPropertyEditor.SetValue - search the component via the given path
When component is deleted, the property must be set to nil - This is not the job of the IDE, but should be achieved by the normal TComponent FreeNotification feature. Maybe eventually a check could be added, if this is implemented properly and force a nil on error.
When a component is renamed the property does not need to be updated, because the form is open and use the pointer not the name. But the designer must be flagged 'modified', because the lfm has changed. See below.
When reference form is opened, then target forms are opened too.
When target form is closed, then only the designer is closed. The component is kept hidden.
When all referring forms are closed/hidden, the hidden component will be automatically freed.
Circle dependencies are allowed.
When referenced component is renamed, the using units must be set modified.
When referenced component is deleted, the using units must be set modified.
Opening a unit now checks if designer is already created
Reopen/Revert a form - all connected forms are now closed

ToDo

Allow to connect to forms, that are used in the uses section. Technically there is no connection between the uses section and the form streaming, because form streaming uses global variables. But the IDE must somehow find the referenced form. Without the uses section the IDE must in worst case search and read every reachable lfm file on disk. So the uses section is a good compromise between speed and flexibility.

Translations, i18n, lrt files, po files

Short Description

This feature automatically creates and updates .po files for packages and projects.

Working

Dialog options for project/package to enable i18n
Collect TTranslateStrings from RTTI while designer form writing and writing them to lrt file.
Copying new strings from rst and lrt files to a single .po file for each project
load the .po files
Delete unused strings from the .po file of package/projects
Update translated .po files, similar to the updatepofiles tool.

ToDo

Copying new strings from rst and lrt files to a single .po file for each package (implemented, need dialog option to change po filename or need agreedment to use same name of package)
Collect all .po files of project and all used packages into a directory. This directory can then be used by the project to load the strings at runtime. And installers can copy the content.
standardize filenames and path, so that loading the translations at runtime is possible without writing code.

Frames

Short Description

Frames are special child forms. The goal is to edit them like forms in the IDE designer, and to use them as components on designer forms.

Working

compile lazarus clean with passing -dEnableTFrame (not necessary starting from svn release 16909)

Manually creating via source
gtk1, gtk2, qt, win32/win64
Create a new frame
Open a frame in the designer
Save a frame
Close a frame
Revert a frame
Design a frame (adding, selecting, moving controls, ...)
Opening a nested frame
Opening a nested frame with ancestors
Support for the inline keyword for lfm and lrs streams.
Add a frame to a form, add unit to uses section, package to project dependencies
- Auto opening frame if not yet loaded
Close a frame that is currently used by a nested frame
Close a form with an embedded frame
Save a form with an embedded frame
Delete a frame embedded in a form
Inherited nested Components (Components with the frame as Owner and not the Form)
- Show inherited nested components properties in OI
- Forbid deleting nested inherited components
- Forbid renaming nested inherited components
- Show inherited nested components events in OI as ClassName.MethodName
- When dblclick on inherited nested components events in OI create an event with the following code: Frame1.FrameResize(Sender);
- When Ctrl+Click on inherited nested components events in OI jump to inherited code.
- show nested components in OI component tree
- Write nested component to stream
Forbid putting a component onto a nested frame, because TWriter does not support that.
Revert a form with an embedded frame

ToDo

Propagate changes of ancestor to nested controls
Tutorial
Documentation
Update

VFI - Visual Form Inheritance

Short Description

Forms can inherit from other forms. The .lfm streams of ancestors are read/applied before the current lfm. The .lfm of the descendant is the difference between ancestor and current state. The IDE allows to open and edit inherited forms. VFI does not only apply to TForm, but TDataModule, TFrame and any registered base designer class. For the full features compile with -dEnableTFrame.

Working

find ancestor unit, lfm and class
automatically open ancestor form hidden in background
open descendant and read ancestor lfm first
show hidden ancestor form
hide ancestor form
automatically close hidden ancestor form if not needed anymore
create new ancestor form via 'File / New ... / Inherited Items'
forbid deleting inherited components
forbid renaming inherited components

ToDo

inherited events (partially working)
apply changes of ancestor to descendants when both are open
Tutorial
Documentation

The jedi code formatter

Short Description

Working

Pressing ctrl+D will format your source file
Settings are stored and read by IDE from JCFSettings.cfg file
port the jcf option dialogs

ToDo

use jcf for indentation

Debugger

Please see: Debugger Status

Short Description

Working

show breakpoints etc in asm window
implement/design interface on debugger class to show/handle threads
attach to process

ToDo

implement/design interface on debuggerclass to handle os exceptions
implement/design interface on debugger class to show messages
implement/design interface on debugger class to show loaded modules
implement debugging of forked processes
implement launching process on xterm (mainly for console apps)
find include files in fpc sources

Release Notes

From the Free Pascal wiki, page "IDE Development", as it stood on 2019-12-09 after a change by Martin, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.

Revision 3, last changed by WikiArchive 11-4-2026.