Lazarus Framework

Overview

TeeGrid for Lazarus provides cross-platform grid components using the FreePascal compiler and LCL (Lazarus Component Library). Share the same VCL codebase across Windows, Linux, macOS, and other FreePascal-supported platforms.

Lazarus uses the same VCLTee.Grid unit as Delphi VCL, with FPC-specific conditional compilation for compatibility.

Installation

Setting Up TeeGrid in Lazarus

Clone the TeeGrid repository

git clone https://github.com/Steema/TeeGrid.git
cd TeeGrid

Open your Lazarus project

Launch Lazarus IDE and open your project or create a new application.

Add units to your uses clause

uses
  VCLTee.Grid,      // Main TTeeGrid component
  VCLTee.Control,   // Base control classes
  VCLTee.Painter,   // LCL rendering
  db;               // Database support

Configure library paths

Add TeeGrid source directories to your project search path:

Project → Project Options → Compiler Options → Paths
Add to “Other unit files”:
- TeeGrid/src/delphi/VCL
- TeeGrid/src/delphi

Platform Support

Lazarus with TeeGrid supports multiple platforms:

Windows

Win32
Win64
Full GDI support

Linux

x86_64
ARM
GTK2/GTK3/Qt5 widgets

macOS

Intel (x86_64)
Apple Silicon (AArch64)
Cocoa widget set

Additional Platforms

FreeBSD: x86_64, i386
Raspberry Pi: ARM Linux
Other Unix: Most POSIX-compatible systems

FreePascal Compatibility

Conditional Compilation

TeeGrid uses {$IFDEF FPC} directives for FreePascal compatibility:

VCLTee.Grid.pas

unit VCLTee.Grid;
{$I Tee.inc}

interface

uses
  {System.}Classes,
  
  {$IFNDEF FPC}
  {System.}Types,
  {$ENDIF}
  
  {$IFDEF MSWINDOWS}
  Windows, Messages,
  {$ENDIF}
  
  {VCL.}Controls, {VCL.}Graphics,
  
  {$IFDEF FPC}
  LCLType, LCLIntf, LMessages,
  {$ENDIF}
  
  VCLTee.Painter, VCLTee.Control;

Object Pascal Mode

Enable Object Pascal mode for Delphi compatibility:

{$mode objfpc}{$H+}

What this does:

{$mode objfpc}: Object Pascal mode (Delphi-compatible)
{$H+}: Long strings (AnsiString) by default

Architecture

Shared VCL Implementation

Lazarus uses the same classes as Delphi VCL:

TVCLTeeGrid=class(TCustomTeeGrid)
  // Same implementation as Delphi VCL
end;

TTeeGrid=class(TScrollableControl)
private
  FGrid : TVCLTeeGrid;
  FPainter : TPainter;
  
  {$IFDEF FPC}
  FParentBack : Boolean;
  {$ENDIF}
end;

LCL-Specific Members

VCLTee.Grid.pas:104

{$IFDEF FPC}
FParentBack : Boolean;
{$ENDIF}

// ...

property ParentBackground {$IFDEF FPC}:Boolean read FParentBack write FParentBack{$ENDIF};

Rendering

LCL Painter

Uses the same TGDIPainter with LCL adaptations:

VCLTee.Painter.pas

{$IFDEF FPC}
uses
  LCLType, LCLIntf, Classes;
{$ENDIF}

type
  TGDIPainter=class(TWindowsPainter)
  public
    class procedure ApplyFont(const ASource:TTeeFont; const ADest:Graphics.TFont); static;
    // ... rendering methods
  end;

Rendering features:

Native LCL canvas drawing
Platform-specific optimizations
GTK/Qt/Cocoa widget rendering

Database Integration

Supported Database Components

Lazarus TeeGrid works with various database components:

TDbf (DBF Files)
SQLdb (Built-in SQL)
ZeosLib

uses
  VCLTee.Grid, db, dbf;

type
  TForm1 = class(TForm)
    TeeGrid1: TTeeGrid;
    Dbf1: TDbf;
    DataSource1: TDataSource;
    procedure FormCreate(Sender: TObject);
  end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // Open DBF table
  Dbf1.TableName := 'disco.dbf';
  Dbf1.Open;
  
  // Bind to TeeGrid (DataSource property set at design-time)
  TeeGrid1.Selected.ScrollToView := True;
end;

uses
  VCLTee.Grid, db, sqldb, sqlite3conn;

type
  TForm1 = class(TForm)
    TeeGrid1: TTeeGrid;
    SQLQuery1: TSQLQuery;
    SQLite3Connection1: TSQLite3Connection;
    SQLTransaction1: TSQLTransaction;
    DataSource1: TDataSource;
  end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  SQLite3Connection1.DatabaseName := 'data.db';
  SQLite3Connection1.Connected := True;
  
  SQLQuery1.SQL.Text := 'SELECT * FROM Customers';
  SQLQuery1.Open;
  
  TeeGrid1.DataSource := DataSource1;
end;

uses
  VCLTee.Grid, db, ZConnection, ZDataset;

type
  TForm1 = class(TForm)
    TeeGrid1: TTeeGrid;
    ZConnection1: TZConnection;
    ZQuery1: TZQuery;
    DataSource1: TDataSource;
  end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  ZConnection1.Protocol := 'mysql';
  ZConnection1.Database := 'mydb';
  ZConnection1.Connect;
  
  ZQuery1.SQL.Text := 'SELECT * FROM Products';
  ZQuery1.Open;
  
  TeeGrid1.DataSource := DataSource1;
end;

Complete Database Example

Lazarus Database Application

unit_main.pas

unit unit_main;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs,
  ExtCtrls, StdCtrls, VCLTee.Grid, db, dbf;

type
  TForm1 = class(TForm)
    Button1: TButton;
    DataSource1: TDataSource;
    Dbf1: TDbf;
    Panel1: TPanel;
    TeeGrid1: TTeeGrid;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

uses
  VCLTee.Editor.Grid;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // DataSource property already set at design-time
  // Not necessary: TeeGrid1.Data := TVirtualDBData.From(DataSource1);
  
  // Increase scrolling speed with datasets
  TeeGrid1.Selected.ScrollToView := True;
  
  // Open DBF table
  Dbf1.TableName := 'disco.dbf';
  Dbf1.Open;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  // Launch visual editor
  TTeeGridEditor.Edit(Self, TeeGrid1);
end;

end.

Cell Editing

LCL Editor Controls

Lazarus supports standard LCL editor controls:

uses
  StdCtrls, ComCtrls, Spin;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // Assign LCL editor controls
  TeeGrid1.Columns['Date'].EditorClass := TDateEdit;
  TeeGrid1.Columns['Time'].EditorClass := TTimeEdit;
  TeeGrid1.Columns['Value'].EditorClass := TSpinEdit;
  TeeGrid1.Columns['Comment'].EditorClass := TMemo;
  TeeGrid1.Columns['Enabled'].EditorClass := TCheckBox;
  TeeGrid1.Columns['Category'].EditorClass := TComboBox;
end;

Platform-Specific Editors

Some editors may behave differently across widget sets:

Editor appearance and behavior may vary between GTK2, GTK3, Qt5, and Cocoa widget sets. Test on your target platforms.

Messages and Events

LCL Messages

Lazarus uses LCL message types:

VCLTee.Grid.pas:129

{$IFDEF FPC}
procedure WMSize(var Message: TLMSize); message LM_SIZE;
procedure MouseLeave; override;
{$ELSE}
procedure WMSize(var Message: TWMSize); message WM_SIZE;
procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
{$ENDIF}

Common LCL messages:

LM_SIZE - Component resized
LM_PAINT - Repaint needed
LM_SETFOCUS - Component gained focus
LM_KILLFOCUS - Component lost focus

Scrolling

LCL ScrollBars

Scrollbars work the same as in VCL:

TeeGrid1.ScrollBars := ssBoth;
TeeGrid1.ScrollBars := ssVertical;
TeeGrid1.ScrollBars := ssHorizontal;
TeeGrid1.ScrollBars := ssNone;

// Enable drag scrolling
TeeGrid1.Scrolling.Mode := TScrollingMode.Both;

Themes

TeeGrid adapts to the native LCL theme:

uses
  Tee.Grid.Themes;

// Apply TeeGrid themes
TGridThemes.Default.ApplyTo(TeeGrid1.Grid);
TGridThemes.iOS.ApplyTo(TeeGrid1.Grid);
TGridThemes.Android.ApplyTo(TeeGrid1.Grid);
TGridThemes.Black.ApplyTo(TeeGrid1.Grid);

Platform Native Appearance

GTK2/GTK3 (Linux)
Qt5 (Linux/Windows)
Cocoa (macOS)
Win32/Win64 (Windows)

TeeGrid automatically uses GTK theme colors and fonts.

// Follows system GTK theme
TeeGrid1.ParentFont := True;
TeeGrid1.ParentColor := True;

Uses Qt5 style sheets and colors.

// Qt5 widget appearance
TeeGrid1.Font.Name := 'Sans';  // Qt font

Native macOS appearance with Cocoa widgets.

// macOS native look
TeeGrid1.Font.Name := 'Helvetica Neue';

Standard Windows appearance.

// Windows theme support
TeeGrid1.ParentBackground := True;

Master-Detail Grids

Two-Grid Master-Detail

Master-Detail with Two TeeGrids

unit_masterdetail_twogrids.pas

unit unit_masterdetail_twogrids;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Forms, Controls, ExtCtrls,
  VCLTee.Grid, db;

type
  TFormMasterDetail = class(TForm)
    TeeGridMaster: TTeeGrid;
    TeeGridDetail: TTeeGrid;
    DataSourceMaster: TDataSource;
    DataSourceDetail: TDataSource;
    Panel1: TPanel;
    Splitter1: TSplitter;
    procedure FormCreate(Sender: TObject);
    procedure TeeGridMasterSelect(Sender: TObject);
  end;

implementation

procedure TFormMasterDetail.FormCreate(Sender: TObject);
begin
  // Bind grids to data sources
  TeeGridMaster.DataSource := DataSourceMaster;
  TeeGridDetail.DataSource := DataSourceDetail;
  
  // Enable full row selection
  TeeGridMaster.Selected.FullRow := True;
  TeeGridDetail.Selected.FullRow := True;
end;

procedure TFormMasterDetail.TeeGridMasterSelect(Sender: TObject);
begin
  // Update detail when master selection changes
  // (Automatic if DataSource.DataSet is linked via MasterSource)
end;

end.

Performance Optimization

Lazarus-Specific Tips

Widget Set Selection

Disable Visual Themes

// In project options:
// Project → Project Options → Application → Theme
// Uncheck "Use LCL platform default"

Can improve performance on some platforms.

Optimize Compiler Settings

// Project → Project Options → Compiler Options
// Optimization level: -O3
// Smart linking: Enabled

Dataset Scrolling

TeeGrid1.Selected.ScrollToView := True;

Critical for smooth scrolling with database datasets.

Common Issues

Troubleshooting

Unit not found errors

Problem: Fatal: Cannot find VCLTee.Grid used by...Solution:

Add TeeGrid source paths to Project Options → Paths
Add: TeeGrid/src/delphi/VCL and TeeGrid/src/delphi
Rebuild project

Type mismatch with TDataSource

Problem: Incompatible type for arg no. 1: Got "TDataSource", expected "TComponent"Solution:

// DataSource property accepts TComponent
TeeGrid1.DataSource := DataSource1;  // Correct

// Or use the Data property
TeeGrid1.Data := TVirtualDBData.From(DataSource1);

Access violation on Linux

Problem: Crashes on GTK2/GTK3Solution:

Check for nil objects before accessing
Use try-finally blocks for resource cleanup
Test with different widget sets (GTK2 vs GTK3)

High DPI display issues

Problem: Blurry text or small controls on HiDPI screensSolution:

// Enable HiDPI support in project
Application.Scaled := True;
TeeGrid1.Font.Height := ScaleY(12, 96);

Complete Example

Full Lazarus Application

unit_main.pas

unit unit_main;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Forms, Controls, Graphics, Dialogs,
  ExtCtrls, StdCtrls, ComCtrls, Spin,
  VCLTee.Grid, db, dbf;

type
  TForm1 = class(TForm)
    TeeGrid1: TTeeGrid;
    Dbf1: TDbf;
    DataSource1: TDataSource;
    Panel1: TPanel;
    BtnEdit: TButton;
    BtnExport: TButton;
    CheckFullRow: TCheckBox;
    procedure FormCreate(Sender: TObject);
    procedure BtnEditClick(Sender: TObject);
    procedure BtnExportClick(Sender: TObject);
    procedure CheckFullRowChange(Sender: TObject);
    procedure TeeGrid1Select(Sender: TObject);
  private
    procedure SetupGrid;
    procedure SetupDatabase;
  end;

var
  Form1: TForm1;

implementation

uses
  VCLTee.Editor.Grid, Tee.Grid.Themes;

{$R *.lfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  SetupDatabase;
  SetupGrid;
end;

procedure TForm1.SetupDatabase;
begin
  // Configure and open DBF table
  Dbf1.TableName := 'customers.dbf';
  Dbf1.Open;
end;

procedure TForm1.SetupGrid;
begin
  // Bind to database
  TeeGrid1.DataSource := DataSource1;
  
  // Performance optimization
  TeeGrid1.Selected.ScrollToView := True;
  
  // Appearance
  TeeGrid1.Rows.Height.Value := 32;
  TeeGrid1.Cells.TextAlign.Vertical := TVerticalAlign.Center;
  TeeGrid1.Selected.FullRow := True;
  
  // Theme
  TGridThemes.Default.ApplyTo(TeeGrid1.Grid);
  
  // Scrolling
  TeeGrid1.ScrollBars := ssBoth;
  TeeGrid1.Scrolling.Mode := TScrollingMode.Both;
  
  // Editing
  TeeGrid1.Editing.AutoEdit := True;
  TeeGrid1.Editing.EnterKey := TEditingEnter.NextRow;
end;

procedure TForm1.BtnEditClick(Sender: TObject);
begin
  // Launch visual editor
  TTeeGridEditor.Edit(Self, TeeGrid1);
end;

procedure TForm1.BtnExportClick(Sender: TObject);
begin
  // Export to clipboard
  TeeGrid1.Grid.Copy;
  ShowMessage('Data copied to clipboard');
end;

procedure TForm1.CheckFullRowChange(Sender: TObject);
begin
  TeeGrid1.Selected.FullRow := CheckFullRow.Checked;
end;

procedure TForm1.TeeGrid1Select(Sender: TObject);
begin
  // Handle selection change
  Caption := Format('Selected Row: %d', [TeeGrid1.Selected.Row]);
end;

end.

Deployment

Building for Distribution

Set build mode to Release

Project → Project Options → Compiler Options → Build Mode → Release

Configure optimization

Optimization level: -O3
Smart linking: Enabled
Strip symbols: Enabled (for smaller executable)

Build executable

lazbuild --build-mode=Release myproject.lpi

Include required libraries

Linux:

GTK2/GTK3 libraries (usually pre-installed)
Database client libraries if needed

macOS:

Application bundle with frameworks

Windows:

Usually no extra DLLs needed (static linking)

VCL Framework

Native Windows VCL implementation

FireMonkey Framework

Cross-platform FMX alternative

Data Binding

Connect to datasets and other data sources

Cell Editing

Editor controls and customization

Get Started

Core Concepts

Data Sources

Features

UI Customization

Framework Integration

​Overview

​Installation

​Setting Up TeeGrid in Lazarus

​Platform Support

Windows

Linux

macOS

​Additional Platforms

​FreePascal Compatibility

​Conditional Compilation

​Object Pascal Mode

​Architecture

​Shared VCL Implementation

​LCL-Specific Members

​Rendering

​LCL Painter

​Database Integration

​Supported Database Components

​Complete Database Example

​Cell Editing

​LCL Editor Controls

​Platform-Specific Editors

​Messages and Events

​LCL Messages

​Scrolling

​LCL ScrollBars

​Themes

​LCL Widget Themes

​Platform Native Appearance

​Master-Detail Grids

​Two-Grid Master-Detail

​Performance Optimization

​Lazarus-Specific Tips

​Common Issues

​Troubleshooting

​Complete Example

​Deployment

​Building for Distribution

​See Also

VCL Framework

FireMonkey Framework

Data Binding

Cell Editing

Build docs developers (and LLMs) love

Overview

Installation

Setting Up TeeGrid in Lazarus

Platform Support

Additional Platforms

FreePascal Compatibility

Conditional Compilation

Object Pascal Mode

Architecture

Shared VCL Implementation

LCL-Specific Members

Rendering

LCL Painter

Database Integration

Supported Database Components

Complete Database Example

Cell Editing

LCL Editor Controls

Platform-Specific Editors

Messages and Events

LCL Messages

Scrolling

LCL ScrollBars

Themes

LCL Widget Themes

Platform Native Appearance

Master-Detail Grids

Two-Grid Master-Detail

Performance Optimization

Lazarus-Specific Tips

Common Issues

Troubleshooting

Complete Example

Deployment

Building for Distribution

See Also