wxPrintout - Functions for wxPrintout class
Please see following description for synopsis
wxPrintout(3) Erlang Module Definition wxPrintout(3)
NAME
wxPrintout - Functions for wxPrintout class
DESCRIPTION
This class encapsulates the functionality of printing out an applica-
tion document.
A new class must be derived and members overridden to respond to calls
such as OnPrintPage() (not implemented in wx) and HasPage() (not imple-
mented in wx) and to render the print image onto an associated wxDC.
Instances of this class are passed to wxPrinter:print/4 or to a
wxPrintPreview object to initiate printing or previewing.
Your derived wxPrintout is responsible for drawing both the preview
image and the printed page. If your windows' drawing routines accept an
arbitrary DC as an argument, you can re-use those routines within your
wxPrintout subclass to draw the printout image. You may also add addi-
tional drawing elements within your wxPrintout subclass, like headers,
footers, and/or page numbers. However, the image on the printed page
will often differ from the image drawn on the screen, as will the print
preview image - not just in the presence of headers and footers, but
typically in scale. A high-resolution printer presents a much larger
drawing surface (i.e., a higher-resolution DC); a zoomed-out preview
image presents a much smaller drawing surface (lower-resolution DC). By
using the routines FitThisSizeToXXX() and/or MapScreenSizeToXXX()
within your wxPrintout subclass to set the user scale and origin of the
associated DC, you can easily use a single drawing routine to draw on
your application's windows, to create the print preview image, and to
create the printed paper image, and achieve a common appearance to the
preview image and the printed page.
See: Overview printing, wxPrinterDC (not implemented in wx), wxPrintDi-
alog, wxPageSetupDialog, wxPrinter, wxPrintPreview
wxWidgets docs: wxPrintout
DATA TYPES
wxPrintout() = wx:wx_object()
EXPORTS
new(Title :: string(), OnPrintPage, Opts :: [Option]) ->
wxPrintout:wxPrintout()
Types:
OnPrintPage =
fun((wxPrintout(), Page :: integer()) -> boolean())
Option =
{onPreparePrinting, fun((wxPrintout()) -> ok)} |
{onBeginPrinting, fun((wxPrintout()) -> ok)} |
{onEndPrinting, fun((wxPrintout()) -> ok)} |
{onBeginDocument,
fun((wxPrintout(),
StartPage :: integer(),
EndPage :: integer()) ->
boolean())} |
{onEndDocument, fun((wxPrintout()) -> ok)} |
{hasPage, fun((wxPrintout(), Page :: integer()) -> ok)} |
{getPageInfo,
fun((wxPrintout()) ->
{MinPage :: integer(),
MaxPage :: integer(),
PageFrom :: integer(),
PageTo :: integer()})}
Constructor.
Creates a wxPrintout object with a callback fun and optionally
other callback funs. The This argument is the wxPrintout object
reference to this object
Notice: The callbacks may not call other processes.
destroy(This :: wxPrintout()) -> ok
Destructor.
getDC(This) -> wxDC:wxDC()
Types:
This = wxPrintout()
Returns the device context associated with the printout (given
to the printout at start of printing or previewing).
The application can use getDC/1 to obtain a device context to
draw on.
This will be a wxPrinterDC (not implemented in wx) if printing
under Windows or Mac, a wxPostScriptDC if printing on other
platforms, and a wxMemoryDC if previewing.
getPageSizeMM(This) -> {W :: integer(), H :: integer()}
Types:
This = wxPrintout()
Returns the size of the printer page in millimetres.
getPageSizePixels(This) -> {W :: integer(), H :: integer()}
Types:
This = wxPrintout()
Returns the size of the printer page in pixels, called the page
rectangle.
The page rectangle has a top left corner at (0,0) and a bottom
right corner at (w,h). These values may not be the same as the
values returned from wxDC:getSize/1; if the printout is being
used for previewing, a memory device context is used, which uses
a bitmap size reflecting the current preview zoom. The applica-
tion must take this discrepancy into account if previewing is to
be supported.
getPaperRectPixels(This) ->
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
Types:
This = wxPrintout()
Returns the rectangle that corresponds to the entire paper in
pixels, called the paper rectangle.
This distinction between paper rectangle and page rectangle
reflects the fact that most printers cannot print all the way to
the edge of the paper. The page rectangle is a rectangle whose
top left corner is at (0,0) and whose width and height are given
by wxDC::GetPageSizePixels().
On MSW and Mac, the page rectangle gives the printable area of
the paper, while the paper rectangle represents the entire
paper, including non-printable borders. Thus, the rectangle
returned by wxDC::GetPaperRectPixels() will have a top left cor-
ner whose coordinates are small negative numbers and the bottom
right corner will have values somewhat larger than the width and
height given by wxDC::GetPageSizePixels().
On other platforms and for PostScript printing, the paper is
treated as if its entire area were printable, so this function
will return the same rectangle as the page rectangle.
getPPIPrinter(This) -> {W :: integer(), H :: integer()}
Types:
This = wxPrintout()
Returns the number of pixels per logical inch of the printer
device context.
Dividing the printer PPI by the screen PPI can give a suitable
scaling factor for drawing text onto the printer.
Remember to multiply this by a scaling factor to take the pre-
view DC size into account. Or you can just use the FitThisSize-
ToXXX() and MapScreenSizeToXXX routines below, which do most of
the scaling calculations for you.
getPPIScreen(This) -> {W :: integer(), H :: integer()}
Types:
This = wxPrintout()
Returns the number of pixels per logical inch of the screen
device context.
Dividing the printer PPI by the screen PPI can give a suitable
scaling factor for drawing text onto the printer.
If you are doing your own scaling, remember to multiply this by
a scaling factor to take the preview DC size into account.
getTitle(This) -> unicode:charlist()
Types:
This = wxPrintout()
Returns the title of the printout.
isPreview(This) -> boolean()
Types:
This = wxPrintout()
Returns true if the printout is currently being used for pre-
viewing.
See: GetPreview() (not implemented in wx)
fitThisSizeToPaper(This, ImageSize) -> ok
Types:
This = wxPrintout()
ImageSize = {W :: integer(), H :: integer()}
Set the user scale and device origin of the wxDC associated with
this wxPrintout so that the given image size fits entirely
within the paper and the origin is at the top left corner of the
paper.
Use this if you're managing your own page margins.
Note: With most printers, the region around the edges of the
paper are not printable so that the edges of the image could be
cut off.
fitThisSizeToPage(This, ImageSize) -> ok
Types:
This = wxPrintout()
ImageSize = {W :: integer(), H :: integer()}
Set the user scale and device origin of the wxDC associated with
this wxPrintout so that the given image size fits entirely
within the page rectangle and the origin is at the top left cor-
ner of the page rectangle.
On MSW and Mac, the page rectangle is the printable area of the
page. On other platforms and PostScript printing, the page rec-
tangle is the entire paper.
Use this if you want your printed image as large as possible,
but with the caveat that on some platforms, portions of the
image might be cut off at the edges.
fitThisSizeToPageMargins(This, ImageSize, PageSetupData) -> ok
Types:
This = wxPrintout()
ImageSize = {W :: integer(), H :: integer()}
PageSetupData = wxPageSetupDialogData:wxPageSetupDialogData()
Set the user scale and device origin of the wxDC associated with
this wxPrintout so that the given image size fits entirely
within the page margins set in the given wxPageSetupDialogData
object.
This function provides the greatest consistency across all plat-
forms because it does not depend on having access to the print-
able area of the paper.
Remark: On Mac, the native wxPageSetupDialog does not let you
set the page margins; you'll have to provide your own mechanism,
or you can use the Mac-only class wxMacPageMarginsDialog.
mapScreenSizeToPaper(This) -> ok
Types:
This = wxPrintout()
Set the user scale and device origin of the wxDC associated with
this wxPrintout so that the printed page matches the screen size
as closely as possible and the logical origin is in the top left
corner of the paper rectangle.
That is, a 100-pixel object on screen should appear at the same
size on the printed page. (It will, of course, be larger or
smaller in the preview image, depending on the zoom factor.)
Use this if you want WYSIWYG behaviour, e.g., in a text editor.
mapScreenSizeToPage(This) -> ok
Types:
This = wxPrintout()
This sets the user scale of the wxDC associated with this
wxPrintout to the same scale as mapScreenSizeToPaper/1 but sets
the logical origin to the top left corner of the page rectangle.
mapScreenSizeToPageMargins(This, PageSetupData) -> ok
Types:
This = wxPrintout()
PageSetupData = wxPageSetupDialogData:wxPageSetupDialogData()
This sets the user scale of the wxDC associated with this
wxPrintout to the same scale as mapScreenSizeToPageMargins/2 but
sets the logical origin to the top left corner of the page mar-
gins specified by the given wxPageSetupDialogData object.
mapScreenSizeToDevice(This) -> ok
Types:
This = wxPrintout()
Set the user scale and device origin of the wxDC associated with
this wxPrintout so that one screen pixel maps to one device
pixel on the DC.
That is, the user scale is set to (1,1) and the device origin is
set to (0,0).
Use this if you want to do your own scaling prior to calling
wxDC drawing calls, for example, if your underlying model is
floating-point and you want to achieve maximum drawing precision
on high-resolution printers.
You can use the GetLogicalXXXRect() routines below to obtain the
paper rectangle, page rectangle, or page margins rectangle to
perform your own scaling.
Note: While the underlying drawing model of macOS is floating-
point, wxWidgets's drawing model scales from integer coordi-
nates.
getLogicalPaperRect(This) ->
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
Types:
This = wxPrintout()
Return the rectangle corresponding to the paper in the associ-
ated wxDC 's logical coordinates for the current user scale and
device origin.
getLogicalPageRect(This) ->
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
Types:
This = wxPrintout()
Return the rectangle corresponding to the page in the associated
wxDC 's logical coordinates for the current user scale and
device origin.
On MSW and Mac, this will be the printable area of the paper. On
other platforms and PostScript printing, this will be the full
paper rectangle.
getLogicalPageMarginsRect(This, PageSetupData) ->
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
Types:
This = wxPrintout()
PageSetupData = wxPageSetupDialogData:wxPageSetupDialogData()
Return the rectangle corresponding to the page margins specified
by the given wxPageSetupDialogData object in the associated
wxDC's logical coordinates for the current user scale and device
origin.
The page margins are specified with respect to the edges of the
paper on all platforms.
setLogicalOrigin(This, X, Y) -> ok
Types:
This = wxPrintout()
X = Y = integer()
Set the device origin of the associated wxDC so that the current
logical point becomes the new logical origin.
offsetLogicalOrigin(This, Xoff, Yoff) -> ok
Types:
This = wxPrintout()
Xoff = Yoff = integer()
Shift the device origin by an amount specified in logical coor-
dinates.
wxWidgets team. wx 2.1.1 wxPrintout(3)