Examples: Add text editor sample project. Add more comments to the Laz_Hello demo project. MR !454 by Aruna Hewapathirane.

examples/examples.txt

@@ -207,3 +207,4 @@
 ./examples/canvas_test/canvas_test.ex-meta
 ./examples/cleandir/cleandir.ex-meta
 ./examples/fontenum/fontenum.ex-meta
+./examples/texteditor/texteditor.ex-meta

examples/laz_hello/Laz_Hello.lpi

@@ -41,6 +41,7 @@
         <Filename Value="unit1.pas"/>
         <IsPartOfProject Value="True"/>
         <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
         <ResourceBaseClass Value="Form"/>
         <UnitName Value="Unit1"/>
       </Unit1>
@@ -56,6 +57,9 @@
       <UnitOutputDirectory Value="lib/$(TargetCPU)-$(TargetOS)"/>
     </SearchPaths>
     <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
       <Options>
         <Win32>
           <GraphicApplication Value="True"/>

examples/laz_hello/laz_hello.ex-meta

@@ -1,5 +1,5 @@
 { "Laz_Hello" : {
    "Category" : "Beginner",
    "Keywords" : ["Lazarus","Hello World","TButton","TMemo"],
-   "Description" : "This might be your first Lazarus project, its the traditional Hello World.  Two buttons have been dropped on the form, renamed and their captions set. A memo was then added and each button was double clicked and what they are expected to do was set."}
+   "Description" : "This might be your first Lazarus project, its the traditional 'Hello World' project.\n\nTwo buttons have been dropped on the form, renamed and their captions set. A memo was then added and each button was double clicked and what they are expected to do was set.\n\nMany comments are provided to explain the instructions used."}
 }

examples/laz_hello/unit1.lfm

@@ -6,15 +6,15 @@ object Form1: TForm1
   Caption = 'Form1'
   ClientHeight = 226
   ClientWidth = 467
-  LCLVersion = '2.3.0.0'
+  LCLVersion = '4.99.0.0'
   object ButtonHello: TButton
     Left = 40
     Height = 41
     Top = 160
     Width = 103
     Caption = 'Say Hello'
-    OnClick = ButtonHelloClick
     TabOrder = 0
+    OnClick = ButtonHelloClick
   end
   object ButtonClose: TButton
     Left = 272
@@ -22,8 +22,8 @@ object Form1: TForm1
     Top = 160
     Width = 91
     Caption = 'Close'
-    OnClick = ButtonCloseClick
     TabOrder = 1
+    OnClick = ButtonCloseClick
   end
   object Memo1: TMemo
     Left = 24

examples/laz_hello/unit1.pas

@@ -1,45 +1,60 @@
-unit Unit1;
+unit Unit1;          // Declares the unit name. Each Pascal unit must have a unique name.
 
-{$mode objfpc}{$H+}
+{$mode objfpc}{$H+}  // Use the Free Pascal Object Pascal syntax and enable long strings (AnsiString).
 
-interface
+interface            // Start of the interface section — defines what’s visible to other units.
 
 uses
-    Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls;
+            // These are standard units that provide core functionality:
+  Classes,  // - Classes & SysUtils: core data types and utilities.
+  SysUtils,
+  Forms,    // - Forms: GUI form definitions.
+  Controls, // - Controls: inner functionality of controls
+  Graphics, // - Graphics: drawing and colors.
+  Dialogs,  // - Dialogs: message dialogs.
+  StdCtrls; // - StdCtrls: standard controls like TButton, TMemo, TLabel.
 
 type
 
     { TForm1 }
 
-    TForm1 = class(TForm)
-        ButtonHello: TButton;
-        ButtonClose: TButton;
-        Memo1: TMemo;
-        procedure ButtonCloseClick(Sender: TObject);
-        procedure ButtonHelloClick(Sender: TObject);
+    TForm1 = class(TForm)      // This declares a form class named TForm1, inheriting from TForm (a window).
+        ButtonHello: TButton;  // A button named ButtonHello — clicking this will show “Hello World” in the memo.
+        ButtonClose: TButton;  // A button named ButtonClose — clicking this will close the form.
+        Memo1: TMemo;          // A TMemo component named Memo1 — used to display and edit multiple lines of text.
+        procedure ButtonCloseClick(Sender: TObject);  // This procedure handles clicks on the Close button.
+        procedure ButtonHelloClick(Sender: TObject);  // This procedure handles clicks on the Hello button.
+
     private
+        // Private section for internal fields or methods (not used here).
 
     public
+        // Public section for fields/methods accessible by other units (not used here).
 
     end;
 
 var
-    Form1: TForm1;
+    Form1: TForm1;    // This declares the global instance of the form.
 
-implementation
+implementation        // Implementation section starts here — contains the actual code of the methods.
 
-{$R *.lfm}
+{$R *.lfm}            // This links the form's design file (.lfm) into the unit at compile time.
 
-{ TForm1 }
+{ TForm1 }            // This just tells you: "Hey! The following procedures belong to the TForm1 form."
 
+// This is the handler of the OnClick event of the ButtonHello.
+// "Event handler" means: The associated code is executed whenever the
+// corresponding "event" is triggered, in this case, when the button is clicked.
 procedure TForm1.ButtonHelloClick(Sender: TObject);
 begin
-    Memo1.Append('Hello World');
+    Memo1.Append('Hello World');                    // Appends the string 'Hello World' as a new line at the end of the memo.
 end;
 
+// This is the handler of the OnClick event of the ButtonClose.
+// The event fires when the ButtonClose is clicked.
 procedure TForm1.ButtonCloseClick(Sender: TObject);
 begin
-    close;
+    Close;    // Closes the form (and ends the application if it's the main form).
 end;
 
 end.

examples/texteditor/project1.lpi

@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <General>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="project1"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+    </General>
+    <BuildModes>
+      <Item Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <UseFileFilters Value="True"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+    </RunParams>
+    <RequiredPackages>
+      <Item>
+        <PackageName Value="LCL"/>
+      </Item>
+    </RequiredPackages>
+    <Units>
+      <Unit>
+        <Filename Value="project1.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="unit1.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Unit1"/>
+      </Unit>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <Target>
+      <Filename Value="project1"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib/$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions>
+      <Item>
+        <Name Value="EAbort"/>
+      </Item>
+      <Item>
+        <Name Value="ECodetoolError"/>
+      </Item>
+      <Item>
+        <Name Value="EFOpenError"/>
+      </Item>
+    </Exceptions>
+  </Debugging>
+</CONFIG>

examples/texteditor/project1.lpr

@@ -0,0 +1,24 @@
+program project1;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}
+  cthreads,
+  {$ENDIF}
+  {$IFDEF HASAMIGA}
+  athreads,
+  {$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, Unit1;
+
+{$R *.res}
+
+begin
+  RequireDerivedFormResource:=True;
+  Application.Scaled:=True;
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+

examples/texteditor/texteditor.ex-meta

@@ -0,0 +1,5 @@
+{ "texteditor" : {
+   "Category" : "Beginner",
+   "Keywords" : ["TMemo", "editor"],
+   "Description" : "Text editor example with TMemo and basic file menu operations (New, Open, Save, Exit)" }
+}

examples/texteditor/unit1.lfm

@@ -0,0 +1,56 @@
+object Form1: TForm1
+  Left = 467
+  Height = 600
+  Top = 256
+  Width = 800
+  Caption = 'Lazarus Text Editor'
+  ClientHeight = 600
+  ClientWidth = 800
+  Menu = MainMenu1
+  LCLVersion = '4.99.0.0'
+  OnCreate = FormCreate
+  object Memo1: TMemo
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 800
+    Align = alClient
+    Font.Height = -13
+    Font.Name = 'Noto Sans Mono'
+    ParentFont = False
+    ScrollBars = ssAutoBoth
+    TabOrder = 0
+    WordWrap = False
+  end
+  object MainMenu1: TMainMenu
+    Left = 24
+    Top = 14
+    object MenuItemFile: TMenuItem
+      Caption = 'File'
+      object MenuItemNew: TMenuItem
+        Caption = 'New'
+        OnClick = MenuItemNewClick
+      end
+      object MenuItemOpen: TMenuItem
+        Caption = 'Open'
+        OnClick = MenuItemOpenClick
+      end
+      object MenuItemSave: TMenuItem
+        Caption = 'Save'
+        OnClick = MenuItemSaveClick
+      end
+      object MenuItemExit: TMenuItem
+        Caption = 'Exit'
+        OnClick = MenuItemExitClick
+      end
+    end
+  end
+  object OpenDialog1: TOpenDialog
+    Left = 368
+    Top = 58
+  end
+  object SaveDialog1: TSaveDialog
+    Left = 503
+    Top = 58
+  end
+end

examples/texteditor/unit1.pas

@@ -0,0 +1,97 @@
+unit Unit1;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, Menus, StdCtrls;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    Memo1: TMemo;                 // Text editing area
+    MainMenu1: TMainMenu;         // Main menu bar
+    MenuItemFile: TMenuItem;      // 'File' menu
+    MenuItemNew: TMenuItem;       // 'New' file
+    MenuItemOpen: TMenuItem;      // 'Open' file
+    MenuItemSave: TMenuItem;      // 'Save' file
+    MenuItemExit: TMenuItem;      // 'Exit' application
+    OpenDialog1: TOpenDialog;     // Dialog to select the file to be opened
+    SaveDialog1: TSaveDialog;     // Dialog to select the file name for saving
+    procedure FormCreate(Sender: TObject);
+    procedure MenuItemFileClick(Sender: TObject);
+
+    procedure MenuItemExitClick(Sender: TObject);
+    procedure MenuItemNewClick(Sender: TObject);
+    procedure MenuItemOpenClick(Sender: TObject);
+    procedure MenuItemSaveClick(Sender: TObject);
+  private
+
+  public
+
+  end;
+
+var
+  Form1: TForm1;
+
+implementation
+
+{$R *.lfm} // Links the .lfm form file
+
+{ TForm1 }
+
+procedure TForm1.FormCreate(Sender: TObject);
+begin
+  // Optional: Set dialog filters and default file extensions
+  OpenDialog1.Filter := 'Text files (*.txt)|*.txt|All files (*.*)|*.*';
+  SaveDialog1.Filter := 'Text files (*.txt)|*.txt|All files (*.*)|*.*';
+end;
+
+
+procedure TForm1.MenuItemExitClick(Sender: TObject);
+begin
+  // Closes the application
+  Close;
+end;
+
+procedure TForm1.MenuItemFileClick(Sender: TObject);
+begin
+  // Shows the file open dialog
+   if OpenDialog1.Execute then
+   begin
+     // Loads file contents into the memo
+     Memo1.Lines.LoadFromFile(OpenDialog1.FileName);
+   end;
+end;
+
+procedure TForm1.MenuItemNewClick(Sender: TObject);
+begin
+  // Clears the text editor for a new file
+  Memo1.Clear;
+end;
+
+procedure TForm1.MenuItemOpenClick(Sender: TObject);
+begin
+  // Shows the file open dialog
+  if OpenDialog1.Execute then
+  begin
+    // Loads file contents into the memo
+    Memo1.Lines.LoadFromFile(OpenDialog1.FileName);
+  end;
+end;
+
+procedure TForm1.MenuItemSaveClick(Sender: TObject);
+begin
+  // Shows the file save dialog
+  if SaveDialog1.Execute then
+  begin
+    // Saves memo contents to the selected file
+    Memo1.Lines.SaveToFile(SaveDialog1.FileName);
+  end;
+end;
+
+end.
+