Printing

Print trees with page support, preview, and printer configuration

Overview

TeeTree includes comprehensive printing support with multi-page capability, print preview, page borders, and full printer integration. The TTreePage class manages page layout and dimensions.

Printing features are built into the core TeeTree.pas unit. The TreeEd.pas editor provides a complete print preview implementation.

Quick Start

Simple Printing

Print the tree directly to the default printer:

begin
  // Print to default printer
  Tree1.Print;
end;

Print Preview

Show preview dialog before printing:

uses
  TreeEd;  // For TreePreview function

begin
  // Show print preview dialog
  TreePreview(Self, Tree1);
  
  // Or include panel background
  TreePreview(Self, Tree1, True);  // PrintPanel = True
end;

From TreeEd.pas (lines 1057-1087):

procedure TreePreview(AOwner: TComponent; 
                      Tree: TCustomTree; 
                      PrintPanel: Boolean = False);
var
  OldPrintTeePanel: Boolean;
  OldChange: Boolean;
  OldPage: Integer;
begin
  OldPrintTeePanel := PrintTeePanel;
  PrintTeePanel := PrintPanel;
  OldChange := TeeChangePaperOrientation;
  OldPage := Tree.Page.Page;
  
  TeeChangePaperOrientation := False;
  try
    with TChartPreview.Create(AOwner) do
    try
      PageNavigatorClass := TTreePageNavigator;
      TeePreviewPanel1.Panel := Tree;
      Tree.Page.Refresh;
      ShowModal;
    finally
      Free;
      Tree.Page.Page := OldPage;
      Tree.Invalidate;
    end;
  finally
    TeeChangePaperOrientation := OldChange;
    PrintTeePanel := OldPrintTeePanel;
  end;
end;

Page Configuration

Page Size

Configure page dimensions:

with Tree1.Page do
begin
  // Use printer page size (default)
  UsePrinter := True;
  
  // Or set custom page size (in pixels)
  UsePrinter := False;
  Width := 800;   // Custom width
  Height := 1000; // Custom height
  
  // Access calculated page count
  ShowMessage(Format('Total pages: %d', [Count]));
end;

From TeeTree.pas, the TTreePage class:

TTreePage = class(TPersistent)
private
  FBorder: TTreePageBorder;
  FPage: Integer;
  FUsePrinter: Boolean;
published
  property Page: Integer read FPage write SetPage default 1;
  property Border: TTreePageBorder read FBorder write SetBorder;
  property UsePrinter: Boolean read FUsePrinter 
                               write SetUsePrinter default True;
end;

Page Borders

Show/hide page boundaries:

with Tree1.Page.Border do
begin
  // Show page borders on screen
  Visible := True;
  
  // Also print the borders
  Print := True;
  
  // Customize border appearance
  Color := clGray;
  Style := psDot;
  Width := 1;
end;

From TeeTree.pas:

TTreePageBorder = class(TTreePen)
private
  FPrint: Boolean;
published
  property Print: Boolean read FPrint 
                          write FPrint default False;
end;

Current Page

Navigate between pages:

with Tree1.Page do
begin
  // Go to specific page
  Page := 1;  // First page
  
  // Navigate pages
  if Page < Count then
    Page := Page + 1;  // Next page
  
  if Page > 1 then
    Page := Page - 1;  // Previous page
  
  // Refresh page layout
  Refresh;
end;

Multi-Page Trees

1. Enable Page Support

   Configure tree for multi-page layout:

   with Tree1 do
   begin
     // Use printer page size
     Page.UsePrinter := True;
     
     // Show page borders during design
     Page.Border.Visible := True;
     Page.Border.Print := False;  // Don't print borders
     
     // Tree will automatically calculate page count
     // based on node positions and page size
   end;
   
2. Calculate Page Bounds

   The tree automatically calculates pages:

   procedure CalculatePageBounds;  // From TeeTree.pas
   var
     tmpBounds: TRect;
     PageWidth, PageHeight: Integer;
   begin
     tmpBounds := GetNodesRect;  // Get bounds of all nodes
     
     if Page.UsePrinter then
     begin
       PageWidth := Printer.PageWidth;
       PageHeight := Printer.PageHeight;
     end
     else
     begin
       PageWidth := Page.Width;
       PageHeight := Page.Height;
     end;
     
     // Calculate number of pages needed
     Page.FCount := CalculatePageCount(tmpBounds, 
                                       PageWidth, 
                                       PageHeight);
   end;
   
3. Print All Pages

   Print entire multi-page tree:

   procedure PrintAllPages;
   var
     i: Integer;
   begin
     for i := 1 to Tree1.Page.Count do
     begin
       Tree1.Page.Page := i;
       Tree1.Print;  // Print current page
     end;
     
     // Reset to first page
     Tree1.Page.Page := 1;
   end;
   

Printer Settings

Accessing Printer Properties

uses
  Printers;

procedure ConfigurePrinter;
begin
  with Printer do
  begin
    // Set orientation
    Orientation := poLandscape;  // or poPortrait
    
    // Get page dimensions (in device units)
    ShowMessage(Format(
      'Page size: %d x %d pixels',
      [PageWidth, PageHeight]
    ));
    
    // Select printer
    if PrintDialog1.Execute then
    begin
      PrinterIndex := PrintDialog1.PrinterIndex;
    end;
  end;
end;

Print with Custom Settings

procedure PrintWithSettings;
var
  OldOrientation: TPrinterOrientation;
begin
  OldOrientation := Printer.Orientation;
  try
    // Temporarily change orientation
    Printer.Orientation := poLandscape;
    
    // Print
    Tree1.Print;
  finally
    // Restore original orientation
    Printer.Orientation := OldOrientation;
  end;
end;

Page Navigator

The editor includes a page navigation control:

From TreeEd.pas (line 1071):

PageNavigatorClass := TTreePageNavigator;

You can use the navigator in your own preview:

var
  Navigator: TTreePageNavigator;
begin
  Navigator := TTreePageNavigator.Create(Self);
  Navigator.Parent := Panel1;
  Navigator.Tree := Tree1;
  
  // User can now navigate pages with navigator buttons
end;

Custom Page Size

Setting Exact Dimensions

A4 Portrait

with Tree1.Page do
begin
  UsePrinter := False;
  
  // A4 at 96 DPI: 794 x 1123 pixels
  Width := 794;
  Height := 1123;
end;

Print Quality Settings

From TreeEd.pas TabSheet1 (Print settings):

with Tree1 do
begin
  // Print panel background
  CBPrintPanel.Checked := PrintPanel;
  
  // Print page borders
  Page.Border.Print := CBPrintPageBorder.Checked;
  
  // Use printer defaults
  Page.UsePrinter := CBPrinterDefault.Checked;
  
  // Custom page dimensions (when not using printer)
  if not Page.UsePrinter then
  begin
    Page.Width := StrToInt(EPageWidth.Text);
    Page.Height := StrToInt(EPageHeight.Text);
  end;
end;

Scrollbars and Page Size

From TeeTree.pas, scrollbars use page size:

procedure TTeeScrollBar.SetPageSize(Value: Integer);
begin
  if FPageSize <> Value then
  begin
    FPageSize := Value;
    // Update scrollbar page size for smoother scrolling
    ScrollInfo.nPage := Value;
  end;
end;

Events During Printing

Detecting Print Mode

Check if tree is currently printing:

procedure TForm1.Tree1AfterDraw(Sender: TObject);
begin
  if Tree1.Printing then
  begin
    // Skip drawing interactive elements when printing
    Exit;
  end;
  
  // Draw selection handles, etc. (screen only)
  DrawSelectionHandles;
end;

From TeeTree.pas (line 10608):

if Selected and (not Tree.Printing) then
begin
  // Don't draw selection handles when printing
end;

Print Dialog Integration

Standard Print Dialog

procedure TForm1.ButtonPrintClick(Sender: TObject);
begin
  if PrintDialog1.Execute then
  begin
    // User confirmed print settings
    Tree1.Print;
  end;
end;

Page Setup Dialog

procedure TForm1.ButtonPageSetupClick(Sender: TObject);
begin
  if PageSetupDialog1.Execute then
  begin
    // User changed margins, orientation, etc.
    Tree1.Page.Refresh;
    Tree1.Invalidate;
  end;
end;

Print with Progress

procedure TForm1.PrintWithProgress;
var
  i: Integer;
begin
  ProgressBar1.Max := Tree1.Page.Count;
  ProgressBar1.Position := 0;
  
  Printer.BeginDoc;
  try
    for i := 1 to Tree1.Page.Count do
    begin
      Tree1.Page.Page := i;
      Tree1.Print;  // Print current page
      
      ProgressBar1.Position := i;
      Application.ProcessMessages;
      
      if i < Tree1.Page.Count then
        Printer.NewPage;
    end;
  finally
    Printer.EndDoc;
    Tree1.Page.Page := 1;
  end;
end;

Advanced: Custom Print Rendering

Override the default print behavior:

type
  TMyTree = class(TTree)
  protected
    procedure Print; override;
  end;

procedure TMyTree.Print;
begin
  // Add custom header/footer
  with Printer.Canvas do
  begin
    Font.Size := 10;
    TextOut(50, 50, 'Company Name - Tree Diagram');
    TextOut(50, Printer.PageHeight - 100, 
            Format('Page %d of %d', [Page.Page, Page.Count]));
  end;
  
  // Call default printing
  inherited Print;
end;

Printing Best Practices

Test Print Preview

Always use print preview before printing to avoid wasted paper.

Page Borders

Show page borders during design to visualize print layout.

Landscape for Wide Trees

Use landscape orientation for horizontally-oriented trees.

UsePrinter = True

Let the printer define page size for best results.

Export as Alternative

For sharing without printing, consider export formats:

uses
  TreeExport;

begin
  // Show export dialog (see Import/Export guide)
  ShowTreeExport(Self, Tree1);
end;

See the Import/Export guide for saving trees to PDF, images, and other formats.

Print Settings in Editor

From TreeEd.pas TabSheet1 settings:

• Printer Default - Use printer page size (UsePrinter)
• Page Width/Height - Custom page dimensions in pixels
• Print Page Border - Include page borders in printout
• Print Panel - Include panel background color

These settings are accessible via the editor’s “Print” tab.