You'll need to create a draw command in the Report.OnEndPageEvent.
In the AfterPrint event of the last band printed (which could be a detail band, group footer, or summary band) you'll want to get the printing position right after it has printed.
Report.Engine.PrintPosRect.Bottom which will give you thousandths of millimeters from the top of the page. There is a demo which does something similar- it creates draw line commands that occupy the empty space on a page below the last band printed.
When a report prints it generates Page objects. Each Page object contains an array of DrawCommand objects (Page.DrawCommands[]) that describe what needs to be rendered for the page.
Each TppComponent generates a DrawCommand object each time it prints on a page. For example if the component is a TppLabel and prints at the top of the page - one draw command object will be created for each page. If the Label is in the detail band, many draw commands will be created for each page.
A DrawCommand contains a complete description of the location and content to draw. See ppDrwCmd.pas for the existing DrawCommand class descendants (DrawText, DrawImage, etc.)
Some of the basic DrawCommand classes such as DrawImage and DrawText, rely on the ScreenDevice and PrinterDevice classes to render their content. Other DrawCommand classes such as TppDrawBarCode and TppDrawRichText render themselves to the appropriate device canvas directly.
Each component has an associated DrawCommand class that is is the value of its DrawCommandClass property. For a Label, the DrawCommandClass is TppDrawText. This value is normally set in the constructor. Examples of the common components are located in ppCtrls.pas.
constructor TmyComponent.Create(AOwner: TComponent); begin
inherited Create(AOwner);
DrawCommandClass := TppDrawText;
end;
Each time the component prints, a DrawCommand object of the designated DrawCommand class will automatically be created and the components PropertiesToDrawCommand method will be called. You override this method to transfer the appropriate property values from the component to the drawcommand object.
When you create a descendant component you can either use an existing draw command class or create a new one. For the TeeChart wrapper components, we chose to use the existing DrawImage class to specify the TeeChart as a metafile image. So it is not always necessary to create a draw command class.
Examples of DrawCommand classes are located in ppDrwCmd.pas. A drawcommand will contain published properties that contain a complete description of the location and content to be rendered.
DrawCommand classes must be registered - see the initization and finalization sections at the bottom of the ppDrwCmd.pas unit for an example.
DrawCommand classes should publish all properties used to describe the object.
DrawCommand classes must implment the Assign method to assign the values of all published properties from one draw command to another.
Comments
In the AfterPrint event of the last band printed (which could be a detail
band, group footer, or summary band) you'll want to get the printing
position right after it has printed.
Report.Engine.PrintPosRect.Bottom which will give you thousandths of
millimeters from the top of the page. There is a demo which does something
similar- it creates draw line commands that occupy the empty space on a page
below the last band printed.
http://www.digital-metaphors.com/tips/FillPageWithLines.zip
From the tech-tips NG on draw commands:
Page Objects
-------------
When a report prints it generates Page objects. Each Page object
contains an array of DrawCommand objects (Page.DrawCommands[]) that
describe what needs to be rendered for the page.
Report --> Pages.DrawCommands[] ---> Device (Printer, Screen, ..) -->
final output
DrawCommands Objects
--------------------
Component --> DrawCommand
Each TppComponent generates a DrawCommand object each time
it prints on a page. For example if the component is a TppLabel and
prints at the top of the page - one draw command object will be created
for each page. If the Label is in the detail band, many draw commands
will be created for each page.
A DrawCommand contains a complete description of the location and
content to draw. See ppDrwCmd.pas for the existing DrawCommand class
descendants (DrawText, DrawImage, etc.)
Some of the basic DrawCommand classes such as DrawImage and DrawText,
rely on the ScreenDevice and PrinterDevice classes to render their
content. Other DrawCommand classes such as TppDrawBarCode and
TppDrawRichText render themselves to the appropriate device canvas
directly.
Creating Custom Components
--------------------------
Each component has an associated DrawCommand class that is
is the value of its DrawCommandClass property. For a Label,
the DrawCommandClass is TppDrawText. This value is normally
set in the constructor. Examples of the common components
are located in ppCtrls.pas.
constructor TmyComponent.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
DrawCommandClass := TppDrawText;
end;
Each time the component prints, a DrawCommand object of
the designated DrawCommand class will automatically be
created and the components PropertiesToDrawCommand method
will be called. You override this method to transfer the
appropriate property values from the component to
the drawcommand object.
{-----------------------------------------------------------------------
-}
{ TmyComponent.PropertiesToDrawCommand }
procedure TmyComponent.PropertiesToDrawCommand(aDrawCommand:
TppDrawCommand);
var
lWrappedText: TStrings;
lTextBuf: PChar;
lPrinter: TObject;
lDrawText: TppDrawText;
llCharPos: Longint;
begin
inherited PropertiesToDrawCommand(aDrawCommand);
if not(aDrawCommand is TppDrawText) then Exit;
lDrawText := TppDrawText(aDrawCommand);
{set properties here}
lDrawText.Alignment := Alignment;
lDrawText.AutoSize := AutoSize;
lDrawText.Color := Color;
lDrawText.Left := PrintPosRect.Left;
lDrawText.Top := PrintPosRect.Top;
lDrawText.Height := PrintPosRect.Bottom - PrintPosRect.Top;
lDrawText.Width := PrintPosRect.Right - PrintPosRect.Left;
lDrawText.Text := Text;
lDrawText.Transparent := Transparent;
lDrawText.WordWrap := WordWrap;
lDrawText.Font := Font;
end;
Creating Custom DrawCommands
----------------------------
When you create a descendant component you can either
use an existing draw command class or create a new one.
For the TeeChart wrapper components, we chose to use
the existing DrawImage class to specify the TeeChart
as a metafile image. So it is not always necessary to
create a draw command class.
Examples of DrawCommand classes are located in ppDrwCmd.pas.
A drawcommand will contain published properties that
contain a complete description of the location and
content to be rendered.
DrawCommand classes must be registered - see the
initization and finalization sections at the bottom
of the ppDrwCmd.pas unit for an example.
DrawCommand classes should publish all properties
used to describe the object.
DrawCommand classes must implment the Assign
method to assign the values of all published
properties from one draw command to another.
Cheers,
Jim Bennett
Digital Metaphors
http://www.digital-metaphors.com
info@digital-metaphors.com