how to rotate ppimage

rbuser

how to rotate ppimage? who can help me?

nardmoseley

That is not something that is built into the TppImage class. You would need
to create a descendant of TppImage and create a custom TppDrawCommand
descendant class.


---------------------------------------
Article: Draw Command Architecture
---------------------------------------

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.


--
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--
Nard Moseley
Digital Metaphors Corporation
http://www.digital-metaphors.com