First draft of MDI support.

This work equates to about 3 hours of coding. Not bad I think! ;-)

The general idea is to have to new classes. The MDIWorkArea class is the
parent widget form MDI child forms. We then also have a MDIChildWindow
class which implements the outer child window - thus the one with the
titlebar and blue borders.

The end use creates a form based on TfpgFrame, not TfpgWindow. This design
might change later. The users form is then embedded inside the MDIChildWindow,
and displayed inside the bounds of the MDIWorkArea.

4 files changed, 806 insertions, 0 deletions

diff --git a/prototypes/mdi/fpg_mdi.pas b/prototypes/mdi/fpg_mdi.pas
new file mode 100644
index 00000000..2de4b642
--- /dev/null
+++ b/prototypes/mdi/fpg_mdi.pas
@@ -0,0 +1,441 @@
+unit fpg_mdi;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, fpg_base, fpg_main, fpg_widget, fpg_scrollbar, fpg_panel,
+  fpg_button;
+
+type
+	// forward declarations
+	TfpgMDIChildForm = class;
+
+
+	TfpgMDIWorkArea = class(TfpgWidget)
+	private
+		FHorBar: TfpgScrollbar;
+		FVerBar: TfpgScrollbar;
+		FList: TList;
+		FActiveWindow: TfpgMDIChildForm;
+		procedure InternalMsgFreeMe(var msg: TfpgMessageRec); message FPGM_FREEME;
+		procedure SetActiveWindow(AValue: TfpgMDIChildForm);
+		function GetChildWindowCount: integer;
+	protected
+		procedure HandlePaint; override;
+		procedure PositionScrollBars;
+	public
+		constructor Create(AOwner: TComponent); override;
+		destructor Destroy; override;
+		function AddWindow(AWindowClass: TfpgFrameClass): TfpgFrame;
+		property ActiveWindow: TfpgMDIChildForm read FActiveWindow write SetActiveWindow;
+		property ChildWindowCount: integer read GetChildWindowCount;
+	end;
+
+
+	TfpgMDIChildForm = class(TfpgWidget)
+	private
+		{@VFD_HEAD_BEGIN: MDIChildForm}
+		Panel1: TfpgPanel;
+		bevLeft: TfpgBevel;
+		Bevel2: TfpgBevel;
+		bevBottom: TfpgBevel;
+		Bevel4: TfpgBevel;
+		bevRight: TfpgBevel;
+		Button1: TfpgButton;
+		Button2: TfpgButton;
+		Button3: TfpgButton;
+		Button4: TfpgButton;
+		bvlClientArea: TfpgBevel;
+		{@VFD_HEAD_END: MDIChildForm}
+		FMDIWorkArea: TfpgMDIWorkArea;
+		FWindowTitle: TfpgString;
+		FIsMouseDown: boolean;
+		FLastPos: TPoint;
+		FActive: boolean;
+		procedure SetWindowTitle(AValue: TfpgString);
+		procedure TitleMouseMove(Sender: TObject; AShift: TShiftState; const AMousePos: TPoint);
+		procedure TitleMouseUp(Sender: TObject; AButton: TMouseButton; AShift: TShiftState; const AMousePos: TPoint);
+		procedure TitleMouseDown(Sender: TObject; AButton: TMouseButton; AShift: TShiftState; const AMousePos: TPoint);
+		procedure TitleMouseExit(Sender: TObject);
+		procedure CloseMDIWindowClicked(Sender: TObject);
+		procedure SetActive(AValue: boolean);
+	protected
+		property Active: boolean read FActive write SetActive;
+	public
+		constructor Create(AOwner: TfpgMDIWorkArea); reintroduce;
+		property WindowTitle: TfpgString read FWindowTitle write SetWindowTitle;
+		procedure SetClientFrame(AFrame: TfpgFrame);
+		procedure UpdateWindowTitle;
+		procedure Close;
+	end;
+
+implementation
+
+uses
+	dbugintf;
+
+{ TfpgMDIChildForm }
+
+procedure TfpgMDIChildForm.TitleMouseMove(Sender: TObject; AShift: TShiftState;
+	const AMousePos: TPoint);
+var
+  dx, dy: integer;
+  pt: TPoint;
+begin
+	pt := WindowToScreen(self, AMousePos);
+	if not FIsMouseDown then
+	begin
+		FLastPos := pt;
+		Exit;
+	end;
+
+	dx := pt.X - FLastPos.X;
+	dy := pt.Y - FLastPos.Y;
+	Left := Left + dx;
+	Top := Top + dy;
+	FLastPos := pt;
+	UpdateWindowPosition;
+end;
+
+procedure TfpgMDIChildForm.TitleMouseUp(Sender: TObject; AButton: TMouseButton;
+	AShift: TShiftState; const AMousePos: TPoint);
+begin
+	FIsMouseDown := False;
+	{$IFDEF MSWINDOWS}
+	ReleaseMouse;
+	{$ENDIF}
+end;
+
+procedure TfpgMDIChildForm.TitleMouseDown(Sender: TObject; AButton: TMouseButton;
+	AShift: TShiftState; const AMousePos: TPoint);
+begin
+	FMDIWorkArea.ActiveWindow := self;
+	FIsMouseDown := True;
+	FLastPos := Panel1.WindowToScreen(self, AMousePos);
+	{$IFDEF MSWINDOWS}
+	CaptureMouse;
+	{$ENDIF}
+end;
+
+procedure TfpgMDIChildForm.TitleMouseExit(Sender: TObject);
+begin
+//	FIsMouseDown := False;
+end;
+
+procedure TfpgMDIChildForm.CloseMDIWindowClicked(Sender: TObject);
+begin
+	Close;
+end;
+
+procedure TfpgMDIChildForm.SetActive(AValue: boolean);
+begin
+	if FActive = AValue then
+		Exit;
+	FActive := AValue;
+	if FActive then
+	begin
+		Panel1.BackgroundColor := clNavy;
+		bevLeft.BackgroundColor := clNavy;
+		bevBottom.BackgroundColor := clNavy;
+		bevRight.BackgroundColor := clNavy;
+		Bevel2.BackgroundColor := clNavy;
+		Bevel4.BackgroundColor := clNavy;
+	end
+	else
+	begin
+		Panel1.BackgroundColor := clMedGray;
+		bevLeft.BackgroundColor := clMedGray;
+		bevBottom.BackgroundColor := clMedGray;
+		bevRight.BackgroundColor := clMedGray;
+		Bevel2.BackgroundColor := clMedGray;
+		Bevel4.BackgroundColor := clMedGray;
+	end;
+end;
+
+procedure TfpgMDIChildForm.SetWindowTitle(AValue: TfpgString);
+begin
+	if FWindowTitle = AValue then
+		Exit;
+	FWindowTitle := AValue;
+	if not (csLoading in ComponentState) then
+		Panel1.Text := FWindowTitle;
+end;
+
+constructor TfpgMDIChildForm.Create(AOwner: TfpgMDIWorkArea);
+begin
+	inherited Create(AOwner);
+	FMDIWorkArea := AOwner;
+	FIsMouseDown := False;
+	FLastPos := Point(0,0);
+	{@VFD_BODY_BEGIN: MDIChildForm}
+	Name := 'MDIChildForm';
+	SetPosition(369, 166, 300, 250);
+	WindowTitle := 'ChildForm1';
+	Hint := '';
+
+	Panel1 := TfpgPanel.Create(self);
+	with Panel1 do
+	begin
+		Name := 'Panel1';
+		SetPosition(0, 0, 301, 24);
+		Anchors := [anLeft,anRight,anTop];
+		BackgroundColor := TfpgColor($0A0081);
+		FontDesc := '#Label2';
+		Hint := '';
+		Text := 'Window Title';
+		TextColor := TfpgColor($FFFFFF);
+		OnMouseDown := @TitleMouseDown;
+		OnMouseUp := @TitleMouseUp;
+		OnMouseMove := @TitleMouseMove;
+		OnMouseExit  := @TitleMouseExit;
+	end;
+
+	bevLeft := TfpgBevel.Create(self);
+	with bevLeft do
+	begin
+		Name := 'bevLeft';
+		SetPosition(0, 24, 3, 211);
+		Anchors := [anLeft,anTop,anBottom];
+		BackgroundColor := TfpgColor($000080);
+		Hint := '';
+		Shape := bsSpacer;
+	end;
+
+	Bevel2 := TfpgBevel.Create(self);
+	with Bevel2 do
+	begin
+		Name := 'Bevel2';
+		SetPosition(0, 235, 16, 16);
+		Anchors := [anLeft,anBottom];
+		BackgroundColor := TfpgColor($000080);
+		Hint := '';
+	end;
+
+	bevBottom := TfpgBevel.Create(self);
+	with bevBottom do
+	begin
+		Name := 'bevBottom';
+		SetPosition(16, 248, 269, 3);
+		Anchors := [anLeft,anRight,anBottom];
+		BackgroundColor := TfpgColor($000080);
+		Hint := '';
+		Shape := bsSpacer;
+	end;
+
+	Bevel4 := TfpgBevel.Create(self);
+	with Bevel4 do
+	begin
+		Name := 'Bevel4';
+		SetPosition(285, 235, 16, 16);
+		Anchors := [anRight,anBottom];
+		BackgroundColor := TfpgColor($000080);
+		Hint := '';
+	end;
+
+	bevRight := TfpgBevel.Create(self);
+	with bevRight do
+	begin
+		Name := 'bevRight';
+		SetPosition(297, 24, 3, 211);
+		Anchors := [anRight,anTop,anBottom];
+		BackgroundColor := TfpgColor($000080);
+		Hint := '';
+		Shape := bsSpacer;
+	end;
+
+	Button1 := TfpgButton.Create(Panel1);
+	with Button1 do
+	begin
+		Name := 'Button1';
+		SetPosition(3, 4, 16, 16);
+		Text := '-';
+		Embedded := True;
+		FontDesc := '#Grid';
+		Hint := '';
+		ImageName := '';
+		TabOrder := 1;
+		TextColor := TfpgColor($000000);
+	end;
+
+	Button2 := TfpgButton.Create(Panel1);
+	with Button2 do
+	begin
+		Name := 'Button2';
+		SetPosition(251, 4, 16, 16);
+		Anchors := [anRight,anTop];
+		Text := '_';
+		Embedded := True;
+		FontDesc := '#Grid';
+		Hint := '';
+		ImageName := '';
+		TabOrder := 1;
+		TextColor := TfpgColor($000000);
+	end;
+
+	Button3 := TfpgButton.Create(Panel1);
+	with Button3 do
+	begin
+		Name := 'Button3';
+		SetPosition(267, 4, 16, 16);
+		Anchors := [anRight,anTop];
+		Text := 'o';
+		Embedded := True;
+		FontDesc := '#Grid';
+		Hint := '';
+		ImageName := '';
+		TabOrder := 1;
+		TextColor := TfpgColor($000000);
+	end;
+
+	Button4 := TfpgButton.Create(Panel1);
+	with Button4 do
+	begin
+		Name := 'Button4';
+		SetPosition(283, 4, 16, 16);
+		Anchors := [anRight,anTop];
+		Text := 'X';
+		Embedded := True;
+		FontDesc := '#Grid';
+		Hint := '';
+		ImageName := '';
+		TabOrder := 1;
+		TextColor := TfpgColor($000000);
+		OnClick := @CloseMDIWindowClicked;
+	end;
+
+	bvlClientArea := TfpgBevel.Create(self);
+	with bvlClientArea do
+	begin
+		Name := 'bvlClientArea';
+		SetPosition(2, 24, 296, 224);
+		Anchors := [anLeft,anRight,anTop,anBottom];
+		Hint := '';
+		Shape := bsSpacer;
+	end;
+
+	{@VFD_BODY_END: MDIChildForm}
+	Name := 'MDIChildForm' + IntToStr(Random(MaxInt));
+end;
+
+procedure TfpgMDIChildForm.SetClientFrame(AFrame: TfpgFrame);
+begin
+//	AFrame.Owner := bvlClientArea;
+	AFrame.Align := alClient;
+	AFrame.Visible := True;
+	UpdateWindowTitle;
+end;
+
+procedure TfpgMDIChildForm.UpdateWindowTitle;
+begin
+	Panel1.Text := FWindowTitle;
+end;
+
+procedure TfpgMDIChildForm.Close;
+begin
+	// We can't free ourselves, somebody else needs to do it
+	fpgPostMessage(Self, FMDIWorkArea, FPGM_FREEME);
+end;
+
+{ TfpgMDIWorkArea }
+
+procedure TfpgMDIWorkArea.InternalMsgFreeMe(var msg: TfpgMessageRec);
+var
+	i: integer;
+begin
+	if Assigned(msg.Sender) then
+	begin
+		if csDestroying in TComponent(msg.Sender).ComponentState then
+			Exit;
+		RemoveComponent(TfpgMDIChildForm(msg.Sender));
+		i := FList.IndexOf(TfpgMDIChildForm(msg.Sender));
+		if i = -1 then
+			raise Exception.Create('Could not find MDI Child Form');
+		FList.Delete(i);
+		if FList.Count >= i+1 then
+			{ set focus to next child window after the one just deleted }
+			ActiveWidget := TfpgMDIChildForm(FList.Items[i])
+		else if FList.Count > 0 then
+			{ fallback to the first child window we created }
+			ActiveWidget := TfpgMDIChildForm(FList.Items[0])
+		else
+			{ there simply isn't any more child windows }
+			ActiveWidget := nil;
+		TfpgMDIChildForm(msg.Sender).Free;
+	end;
+end;
+
+procedure TfpgMDIWorkArea.SetActiveWindow(AValue: TfpgMDIChildForm);
+var
+  i: integer;
+  w: TfpgMDIChildForm;
+begin
+	if FActiveWindow = AValue then
+		Exit;
+	FActiveWindow := AValue;
+	ActiveWidget := FActiveWindow;
+	for i := 0 to FList.Count-1 do
+	begin
+		w := TfpgMDIChildForm(FList[i]);
+		w.Active := (w = AValue);
+	end;
+end;
+
+function TfpgMDIWorkArea.GetChildWindowCount: integer;
+begin
+	Result := FList.Count;
+end;
+
+procedure TfpgMDIWorkArea.HandlePaint;
+begin
+	inherited HandlePaint;
+	Canvas.Clear(clLtGray);
+end;
+
+procedure TfpgMDIWorkArea.PositionScrollBars;
+begin
+	FHorBar.Left := Left;
+	FHorBar.Top := Height - FHorBar.Height;
+	FHorBar.Width := Width;
+	FHorBar.Anchors := [anLeft, anBottom, anRight];
+	FVerBar.Left := Width - FVerBar.Width;
+	FVerBar.Top := 0;
+	FVerBar.Height := Height;
+	FVerBar.Anchors := [anRight, anTop, anBottom];
+end;
+
+constructor TfpgMDIWorkArea.Create(AOwner: TComponent);
+begin
+	inherited Create(AOwner);
+	FIsContainer := True;
+	FHorBar := TfpgScrollbar.Create(self);
+	FHorBar.Visible := False;
+	FHorBar.Orientation := orHorizontal;
+	FVerBar := TfpgScrollbar.Create(self);
+	FVerBar.Visible := False;
+	FVerBar.Orientation := orVertical;
+	PositionScrollBars;
+	FList := TList.Create;
+	FActiveWindow := nil;
+end;
+
+destructor TfpgMDIWorkArea.Destroy;
+begin
+	FList.Free;
+	inherited Destroy;
+end;
+
+function TfpgMDIWorkArea.AddWindow(AWindowClass: TfpgFrameClass): TfpgFrame;
+var
+	frm: TfpgMDIChildForm;
+begin
+	frm := TfpgMDIChildForm.Create(self);
+	Result := AWindowClass.Create(frm.bvlClientArea);
+	frm.SetClientFrame(Result);
+	FList.Add(frm);
+	ActiveWindow := frm;
+end;
+
+end.
+
diff --git a/prototypes/mdi/frm_child.pas b/prototypes/mdi/frm_child.pas
new file mode 100644
index 00000000..a9890a3c
--- /dev/null
+++ b/prototypes/mdi/frm_child.pas
@@ -0,0 +1,170 @@
+unit frm_child;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  SysUtils, Classes, fpg_base, fpg_main, fpg_form, fpg_button, fpg_edit,
+  fpg_checkbox, fpg_radiobutton, fpg_gauge, fpg_mdi, fpg_panel, fpg_trackbar;
+
+type
+
+	TChildForm = class(TfpgFrame)
+	private
+		{@VFD_HEAD_BEGIN: ChildForm}
+		btnClose: TfpgButton;
+		CheckBox1: TfpgCheckBox;
+		CheckBox2: TfpgCheckBox;
+		RadioButton1: TfpgRadioButton;
+		RadioButton2: TfpgRadioButton;
+		Edit1: TfpgEdit;
+		Gauge1: TfpgGauge;
+		TrackBar1: TfpgTrackBar;
+		{@VFD_HEAD_END: ChildForm}
+		FWindowTitle: TfpgString;
+		procedure btnCloseClicked(Sender: TObject);
+		procedure TrackBarChanged(Sender: TObject; APosition: integer);
+		procedure SetWindowTitle(AValue: TfpgString);
+	public
+		procedure AfterCreate; override;
+		property WindowTitle: TfpgString read FWindowTitle write SetWindowTitle;
+	end;
+
+{@VFD_NEWFORM_DECL}
+
+var
+  ChildForm: TChildForm;
+
+implementation
+
+
+{@VFD_NEWFORM_IMPL}
+
+procedure TChildForm.TrackBarChanged(Sender: TObject; APosition: integer);
+begin
+	Gauge1.Progress := APosition;
+end;
+
+procedure TChildForm.SetWindowTitle(AValue: TfpgString);
+begin
+	if FWindowTitle = AValue then
+		Exit;
+	FWindowTitle := AValue;
+	TfpgMDIChildForm(Owner.Owner).WindowTitle := FWindowTitle;
+end;
+
+procedure TChildForm.btnCloseClicked(Sender: TObject);
+begin
+	TfpgMDIChildForm(Owner).Close;
+end;
+
+procedure TChildForm.AfterCreate;
+begin
+  {%region 'Auto-generated GUI code' -fold}
+  {@VFD_BODY_BEGIN: ChildForm}
+	Name := 'ChildForm';
+	SetPosition(391, 210, 271, 150);
+//	WindowTitle := 'ChildForm';
+	Hint := '';
+
+	btnClose := TfpgButton.Create(self);
+	with btnClose do
+	begin
+		Name := 'btnClose';
+		SetPosition(180, 116, 80, 24);
+		Text := 'Close';
+		FontDesc := '#Label1';
+		Hint := '';
+		ImageName := '';
+		TabOrder := 1;
+		OnClick := @btnCloseClicked;
+	end;
+
+	CheckBox1 := TfpgCheckBox.Create(self);
+	with CheckBox1 do
+	begin
+		Name := 'CheckBox1';
+		SetPosition(164, 16, 120, 20);
+		FontDesc := '#Label1';
+		Hint := '';
+		TabOrder := 2;
+		Text := 'CheckBox';
+	end;
+
+	CheckBox2 := TfpgCheckBox.Create(self);
+	with CheckBox2 do
+	begin
+		Name := 'CheckBox2';
+		SetPosition(164, 36, 120, 20);
+		FontDesc := '#Label1';
+		Hint := '';
+		TabOrder := 3;
+		Text := 'CheckBox';
+	end;
+
+	RadioButton1 := TfpgRadioButton.Create(self);
+	with RadioButton1 do
+	begin
+		Name := 'RadioButton1';
+		SetPosition(164, 60, 120, 20);
+		FontDesc := '#Label1';
+		GroupIndex := 0;
+		Hint := '';
+		TabOrder := 4;
+		Text := 'RadioButton';
+	end;
+
+	RadioButton2 := TfpgRadioButton.Create(self);
+	with RadioButton2 do
+	begin
+		Name := 'RadioButton2';
+		SetPosition(164, 80, 120, 20);
+		FontDesc := '#Label1';
+		GroupIndex := 0;
+		Hint := '';
+		TabOrder := 5;
+		Text := 'RadioButton';
+	end;
+
+	Edit1 := TfpgEdit.Create(self);
+	with Edit1 do
+	begin
+		Name := 'Edit1';
+		SetPosition(8, 8, 120, 24);
+		ExtraHint := '';
+		FontDesc := '#Edit1';
+		Hint := '';
+		TabOrder := 6;
+		Text := '';
+	end;
+
+	Gauge1 := TfpgGauge.Create(self);
+	with Gauge1 do
+	begin
+		Name := 'Gauge1';
+		SetPosition(12, 44, 116, 25);
+		Color := TfpgColor($C4C4C4);
+		Hint := '';
+		Progress := 65;
+	end;
+
+	TrackBar1 := TfpgTrackBar.Create(self);
+	with TrackBar1 do
+	begin
+		Name := 'TrackBar1';
+		SetPosition(12, 84, 116, 30);
+		Hint := '';
+		TabOrder := 8;
+		Position := 65;
+		OnChange  := @TrackBarChanged;
+	end;
+
+	{@VFD_BODY_END: ChildForm}
+  {%endregion}
+	Name := 'ChildForm' + IntToStr(Random(MaxInt));
+
+end;
+
+
+end.
diff --git a/prototypes/mdi/project1.lpi b/prototypes/mdi/project1.lpi
new file mode 100644
index 00000000..5252f0c7
--- /dev/null
+++ b/prototypes/mdi/project1.lpi
@@ -0,0 +1,82 @@
+<?xml version="1.0"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="9"/>
+    <General>
+      <Flags>
+        <SaveOnlyProjectUnits Value="True"/>
+      </Flags>
+      <SessionStorage Value="InProjectDir"/>
+      <MainUnit Value="0"/>
+      <UseAppBundle Value="False"/>
+      <ResourceType Value="res"/>
+    </General>
+    <i18n>
+      <EnableI18N LFM="False"/>
+    </i18n>
+    <VersionInfo>
+      <StringTable ProductVersion=""/>
+    </VersionInfo>
+    <BuildModes Count="1">
+      <Item1 Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <IncludeFileFilter Value="*.(pas|pp|inc|lfm|lpr|lrs|lpi|lpk|sh|xml)"/>
+      <ExcludeFileFilter Value="*.(bak|ppu|o|so);*~;backup"/>
+    </PublishOptions>
+    <RunParams>
+      <local>
+        <FormatVersion Value="1"/>
+        <LaunchingApplication PathPlusParams="/usr/bin/xterm -T 'Lazarus Run Output' -e $(LazarusDir)/tools/runwait.sh $(TargetCmdLine)"/>
+      </local>
+    </RunParams>
+    <RequiredPackages Count="1">
+      <Item1>
+        <PackageName Value="fpgui_toolkit"/>
+      </Item1>
+    </RequiredPackages>
+    <Units Count="3">
+      <Unit0>
+        <Filename Value="project1.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="project1"/>
+      </Unit0>
+      <Unit1>
+        <Filename Value="fpg_mdi.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="fpg_mdi"/>
+      </Unit1>
+      <Unit2>
+        <Filename Value="frm_child.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="frm_child"/>
+      </Unit2>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+    </SearchPaths>
+    <Other>
+      <CompilerMessages>
+        <UseMsgFile Value="True"/>
+      </CompilerMessages>
+      <CompilerPath Value="$(CompPath)"/>
+    </Other>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions Count="3">
+      <Item1>
+        <Name Value="EAbort"/>
+      </Item1>
+      <Item2>
+        <Name Value="ECodetoolError"/>
+      </Item2>
+      <Item3>
+        <Name Value="EFOpenError"/>
+      </Item3>
+    </Exceptions>
+  </Debugging>
+</CONFIG>
diff --git a/prototypes/mdi/project1.lpr b/prototypes/mdi/project1.lpr
new file mode 100644
index 00000000..fa8a1850
--- /dev/null
+++ b/prototypes/mdi/project1.lpr
@@ -0,0 +1,113 @@
+program project1;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}{$IFDEF UseCThreads}
+  cthreads,
+  {$ENDIF}{$ENDIF}
+  Classes, SysUtils, fpg_base, fpg_main, fpg_form, fpg_mdi, frm_child,
+  fpg_menu, fpg_panel;
+
+type
+
+	TMainForm = class(TfpgForm)
+	private
+		{@VFD_HEAD_BEGIN: MainForm}
+		MainBar: TfpgMenuBar;
+		MDIWorkArea: TfpgMDIWorkArea;
+		Bevel1: TfpgBevel;
+		pmChildren: TfpgPopupMenu;
+		{@VFD_HEAD_END: MainForm}
+		procedure NewFormClicked(Sender: TObject);
+		procedure miQuitClicked(Sender: TObject);
+	public
+		procedure AfterCreate; override;
+	end;
+
+{@VFD_NEWFORM_DECL}
+
+
+
+{@VFD_NEWFORM_IMPL}
+
+procedure TMainForm.NewFormClicked(Sender: TObject);
+begin
+	ChildForm := MDIWorkArea.AddWindow(TChildForm) as TChildForm;
+	ChildForm.WindowTitle := Format('Child %d', [MDIWorkArea.ChildWindowCount]);
+end;
+
+procedure TMainForm.miQuitClicked(Sender: TObject);
+begin
+	Close;
+end;
+
+procedure TMainForm.AfterCreate;
+begin
+  {%region 'Auto-generated GUI code' -fold}
+  {@VFD_BODY_BEGIN: MainForm}
+	Name := 'MainForm';
+	SetPosition(351, 159, 555, 321);
+	WindowTitle := 'fpGUI''s MDI Demo';
+	Hint := '';
+
+	MainBar := TfpgMenuBar.Create(self);
+	with MainBar do
+	begin
+		Name := 'MainBar';
+		SetPosition(0, 0, 555, 24);
+		Anchors := [anLeft,anRight,anTop];
+	end;
+
+	MDIWorkArea := TfpgMDIWorkArea.Create(self);
+	with MDIWorkArea do
+	begin
+		Name := 'MDIWorkArea';
+		SetPosition(3, 32, 548, 264);
+		Anchors := [anLeft,anRight,anTop,anBottom];
+	end;
+
+	Bevel1 := TfpgBevel.Create(self);
+	with Bevel1 do
+	begin
+		Name := 'Bevel1';
+		SetPosition(0, 300, 555, 20);
+		Anchors := [anLeft,anRight,anBottom];
+		Hint := '';
+		Style := bsLowered;
+	end;
+
+	pmChildren := TfpgPopupMenu.Create(self);
+	with pmChildren do
+	begin
+		Name := 'pmChildren';
+		SetPosition(336, 88, 120, 20);
+		AddMenuItem('Add child', '', @NewFormClicked);
+		AddMenuItem('-', '', nil);
+		AddMenuItem('Quit', '', @miQuitClicked);
+	end;
+
+	{@VFD_BODY_END: MainForm}
+  {%endregion}
+  MainBar.AddMenuItem('Children', nil).SubMenu := pmChildren;
+end;
+
+
+procedure MainProc;
+var
+  frm: TMainForm;
+begin
+  fpgApplication.Initialize;
+  frm := TMainForm.Create(nil);
+  try
+    frm.Show;
+    fpgApplication.Run;
+  finally
+    frm.Free;
+  end;
+end;
+
+begin
+  MainProc;
+end.
+