eXept Software AG Logo

Smalltalk/X Webserver

Documentation of class 'Form':

Home

Documentation
www.exept.de
Everywhere
for:
[back]

Class: Form


Inheritance:

   Object
   |
   +--GraphicsMedium
      |
      +--Form
         |
         +--Form::ImageForm
         |
         +--Pixmap

Package:
stx:libview
Category:
Compatibility-ST80-Graphics-Display Objects
Version:
rev: 1.173 date: 2018/05/06 15:46:59
user: cg
file: Form.st directory: libview
module: stx stc-classLibrary: libview
Author:
Claus Gittinger

Description:


NOTICE:
    Not for public use.

    the Form class is a historic leftover and now only used for real
    device forms (i.e. on devices which support downloading bitmaps).

    In your application, you should always use Image, both for compatibility
    with ST-80 and for device independence, since not all Form depths are supported
    by all devices, whereas Image contains all the required code to convert as
    required.


Instances of this class represent forms (i.e. bit- and pixmaps)
which are present on a drawing device.

In X, these are XPixmaps; on Windows, these are bitmaps.

WARNING:
    Forms created on some device may not be recreatable, when an
    image is restarted on a display with different display capabilities.
    For example, a 24bit truecolor form will be lost when the image is
    saved and restarted in an 8bit or monochrome display.
    Worse: the information is completely lost.

    With images, the original information is always preserved, although
    the display may be with less resolution, dithered or otherwise
    approximated.


Related information:

    Image
    DeviceDrawable

Class protocol:

Compatibility-ST80
o  and
return a constant usable as bitblt-combinationrule.
In ST-80rel2.x, these used to be numeric constants; in ST/X,
these are symbolic.

o  black
ST80 compatibility;
In old st80, you could use `Form black' for drawing
- here we return the black color.

o  darkGray
ST80 compatibility;
In old st80, you could use `Form darkGray' for drawing
- here we return the darkGray color.

o  darkGrey
ST80 compatibility;
In old st80, you could use `Form darkGrey' for drawing
- here we return the darkGrey color.

o  gray
ST80 compatibility;
In old st80, you could use `Form gray' for drawing
- here we return the grey color.

o  grey
ST80 compatibility;
In old st80, you could use `Form grey' for drawing
- here we return the grey color.

o  lightGray
ST80 compatibility;
In old st80, you could use `Form lightGray' for drawing
- here we return the lightGray color.

o  lightGrey
ST80 compatibility;
In old st80, you could use `Form lightGray' for drawing
- here we return the lightGray color.

o  over
return a constant usable as bitblt-combinationrule.
In ST-80rel2.x, these used to be numeric constants; in ST/X,
these are symbolic.

o  paint
return a constant usable as bitblt-combinationrule.
In ST-80rel2.x, these used to be numeric constants; in ST/X,
these are symbolic.

o  reverse
return a constant usable as bitblt-combinationrule.
In ST-80rel2.x, these used to be numeric constants; in ST/X,
these are symbolic.

o  under
return a constant usable as bitblt-combinationrule.
In ST-80rel2.x, these used to be numeric constants; in ST/X,
these are symbolic.

o  white
ST80rel2.x compatibility;
In old st80, you could use `Form white' for drawing
- here we return the white color.

Compatibility-Squeak
o  extent: ext depth: d bits: data

o  extent: ext depth: d fromArray: data offset: offs

o  fromUser
Delay waitForSeconds:1.
Form fromUser inspect.
Delay waitForSeconds:1.

accessing private classes
o  imageForm

cleanup
o  lowSpaceCleanup
cleanup in low-memory situations

file search
o  findBitmapFile: fileName
find the bitmap file in one of the standard places;
return the pathName or nil

** This is an obsolete interface - do not use it (it may vanish in future versions) **

initialization
o  initialize
initialize set of dictionaries to look for bitmaps

o  reinitializeAllOn: aDevice
recreate all forms on aDevice; called by Workstation after snapIn, to
have all background bitmaps at hand, when views are restored

o  update: something with: aParameter from: changedObject
sent just before snapOut and just after a snapIn

instance creation
o  dotOfSize: size
create and return a form which contains a dot (filled circle)
of the given size.
usage example(s):
     (Form dotOfSize:8) inspect
     (Form dotOfSize:20) inspect

o  extent: ext
create a new, cleared form, take dimensions from ext.
Smalltalk-80 compatibility

o  extent: ext depth: d
create a new, cleared form.
Smalltalk-80 compatibility

o  extent: ext depth: d onDevice: aDevice
create a new form on device, aDevice; depth is what device likes most

o  extent: ext fromArray: data
create a new form, take dimensions from ext, bits from data.
Smalltalk-80 compatibility.

o  extent: ext fromArray: data offset: offs
create a new form, take dimensions from ext, bits from data.
Smalltalk-80 compatibility.

o  extent: ext fromArray: data offset: offs onDevice: aDevice
create a new form, take dimensions from ext, bits from data.

o  extent: ext fromArray: data onDevice: aDevice
create a new form, take dimensions from ext, bits from data.

o  extent: ext offset: anOffset
create a new, cleared form, take dimensions from ext.
Smalltalk-80 compatibility

o  extent: ext onDevice: aDevice
create a new form on device, aDevice; depth is what device likes most

o  width: w height: h
create a new form on the default device

o  width: w height: h depth: d
create a new form on the default device

o  width: w height: h depth: d onDevice: aDevice
create a new form with depth d on device, aDevice

o  width: w height: h fromArray: anArray
create a new form on the default device

o  width: w height: h fromArray: anArray onDevice: aDevice
create a new form on device, aDevice and
initialize the pixels from anArray

o  width: w height: h offset: offs fromArray: anArray
create a new form on the default device

o  width: w height: h offset: offs fromArray: anArray onDevice: aDevice
create a new form on the default device

o  width: w height: h onDevice: aDevice
create a new form on device, aDevice; depth is what device likes most

obsolete instance creation
o  darkGreyFormOn: aDevice
return a darkGrey form

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  extent: ext depth: d on: aDevice
create a new form on device, aDevice; depth is what device likes most

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  extent: ext fromArray: data offset: offs on: aDevice
create a new form, take dimensions from ext, bits from data.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  extent: ext fromArray: data on: aDevice
create a new form, take dimensions from ext, bits from data.

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  extent: ext on: aDevice
create a new form on device, aDevice; depth is what device likes most

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  grey: percent on: aDevice
return a form for dithering

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  lightGreyFormOn: aDevice
return a lightGrey form

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  mediumGreyFormOn: aDevice
return a grey form

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  veryDarkGreyFormOn: aDevice
return a veryDarkGrey form

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  veryLightGreyFormOn: aDevice
return a veryLightGrey form

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  width: w height: h depth: d on: aDevice
create a new form with depth d on device, aDevice

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  width: w height: h fromArray: anArray on: aDevice
create a new form on device, aDevice and
initialize the pixels from anArray

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  width: w height: h offset: offs fromArray: anArray on: aDevice
create a new form on the default device

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  width: w height: h on: aDevice
create a new form on device, aDevice; depth is what device likes most

** This is an obsolete interface - do not use it (it may vanish in future versions) **

obsolete patterns
o  darkGreyFormBits
return a pattern usable to simulate darkGray on monochrome device

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  grey12Bits
return a pattern with 12% grey, usable for dithering

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  grey25Bits
return a pattern with 25% grey, usable for dithering

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  grey37Bits
return a pattern with 37% grey, usable for dithering

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  grey50Bits
return a pattern with 50% grey, usable for dithering

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  grey6Bits
return a pattern with 6% grey, usable for dithering

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  greyFormBits
return a pattern usable to simulate gray on monochrome device

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  lightGreyFormBits
return a pattern usable to simulate lightGray on monochrome device

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  veryDarkGreyFormBits
return a pattern usable to simulate veryDarkGray on monochrome device

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  veryLightGreyFormBits
return a pattern usable to simulate veryDarkGray on monochrome device

** This is an obsolete interface - do not use it (it may vanish in future versions) **


Instance protocol:

Compatibility-ST80
o  displayAt: aPoint
show the receiver on the current display screen
usage example(s):
     (Form dotOfSize:8) displayAt:10@10

o  displayOn: aGC at: aPoint rule: rule
draw in aGC.
Smalltalk-80 (2.x) compatibility

o  displayOn: aGC rule: rule
draw in aGC.
Smalltalk-80 (2.x) compatibility

o  displayOn: aGC x: x y: y
draw in aGC.
Smalltalk-80 (2.x) compatibility

o  displayOn: aGC x: x y: y rule: rule
draw in aGC.
Smalltalk-80 (2.x) compatibility

o  isOpen

o  offset
set the offset.
Smalltalk-80 compatibility

o  offset: org
set the offset.
Smalltalk-80 compatibility

o  preferredBounds

Compatibility-Squeak
o  colormapIfNeededForDepth: destDepth

o  magnify: aRectangle by: scale smoothing: smoothBoolean
Squeak compatibility:
a little inefficient hack: convert to image, then magnify,
then convert back

o  pixelAt: aPoint

o  pixelAt: aPoint put: aPixelValue

accessing
o  bits
return a ByteArray filled with my bits -
for depth 8 forms, 1 pixel/byte is filled;
for depth 1 forms, 8 pixels/byte are filled
for depth 4 forms, 2 pixels/byte are filled.
Padding is done row-wise to the next BYTE-boundary
If multiple pixels are contained in a single byte,
left bits are in the most significant bit positions.
(i.e. for width==13 and depth==1 it will return 2 bytes per scanline)

o  bits: aByteArray
set the forms bits;
for depth-8 forms, 1 pixel/byte is expected;
for depth-1 forms, 8 pixels/byte are expected
for depth-4 forms, 2 pixels/byte are expected.
Padding is expected to the next byte-boundary
(i.e. for width==13 and depth==1 2 bytes per scanline are expected)

o  bitsPerSample
for compatibility with Image class ...

o  colorMap
return the receiver's colormap

o  colorMap: anArrayOrColorMap
set the receiver's colormap

o  depth
return the receiver's depth

o  forgetBits
for image, which also keeps the bits - so there is
no need to hold them again here

o  mask
for compatibility with images; forms have no mask/alpha channel

o  maskedPixelsAre0

o  maskedPixelsAre0: something

o  photometric
for compatibility with Image class ...

o  samplesPerPixel
for compatibility with Image class ...

o  valueAt: aPoint
return the pixel at aPoint; the coordinates start with 0@0
in the upper left, increasing to the lower right

o  valueAt: aPoint put: value
set the pixel at aPoint; the coordinates start with 0@0
in the upper left, increasing to the lower right.

comanche processing
o  asHtmlElementIn: htmlContainer
( an extension from the stx:goodies/webServer/comanche package )
answer my HTML representation (String),
as I would look like inside htmlContainer

o  asHttpResponseTo: request
( an extension from the stx:goodies/webServer/comanche package )

o  asWebImage
( an extension from the stx:goodies/webServer/comanche package )
return a MIMEDocument

converting
o  asForm
convert & return the receiver into a Form instance - nothing to be done here

o  asImage
convert & return the receiver into an Image instance

o  asImageForm
convert & return the receiver into a ImageForm instance

copying
o  postCopy
redefined to copy the colorMap as well

editing
o  show
open an imageView on the receiver
usage example(s):
     (Form fromFile:'bitmaps/SBrowser.xbm') show

getting a device form
o  asFormOn: aDevice
convert & return the receiver into a Form instance
and associate it to a device (i.e. download its bits).
Added for protocol compatibility with Image.

o  asMonochromeFormOn: aDevice
added for protocol compatiblity with Image

o  exactOn: aDevice
for compatibility with color protocol - here, the same as #onDevice.

o  exactOrNearestOn: aDevice
for compatibility with color protocol - here, the same as #onDevice.

o  nearestOn: aDevice
for compatibility with color protocol - here, the same as #onDevice.

o  on: aDevice
associate the receiver to a device (i.e. download its bits);
return a deviceForm (possibly different from the receiver).

** This is an obsolete interface - do not use it (it may vanish in future versions) **

o  onDevice: aDevice
associate the receiver to a device (i.e. download its bits);
return a deviceForm (possibly different from the receiver).

image manipulations
o  clearMaskedPixels
Added for protocol compatibility with Image.

o  clearMaskedPixels: maskForm
clear any masked pixels.
This will allow faster drawing in the future.

o  darkened
return a darkened version of the receiver.
Added for protocol compatibility with Color and Image.
Here, the receiver is returned as a kludge
- actually should return a darkened image (or Color black ?) ..

o  easyMagnifiedBy: extent into: newForm
return a new form magnified by extent, aPoint.
If non-integral magnify is asked for, pass the work on to 'hardMagnifiedBy:'

o  flip: how
return a new form flipped horizontally or vertically

o  flipHorizontal
return a new form flipped vertically

o  flipVertical
return a new form flipped horizontally

o  hardMagnifiedBy: extent
return a new form magnified by extent, aPoint.
This method handles non-integral factors.

o  lightened
return a lightened version of the receiver.
Added for protocol compatibility with Color and Image.
Here, the receiver is returned unchanged as a kludge
- actually should return a lightened image (or Color white ?) ..

o  magnifiedBy: extent
return a new form magnified by extent, aPoint.
If non-integral magnify is asked for, pass the work on to 'hardMagnifiedBy:'
usage example(s):
     (ArrowButton upArrowButtonForm:#iris on:Screen current) magnifiedBy:(2 @ 2)
     (Form fromFile:'bitmaps/SBrowser.xbm') magnifiedBy:(2 @ 2)
     (Form fromFile:'bitmaps/SBrowser.xbm') magnifiedBy:(0.4 @ 0.4)

o  magnifiedTo: anExtent
return a new form magnified to have the size specified by extent.
This may distort the image if the arguments ratio is not the images ratio.
See also #magnifiedPreservingRatioTo: and #magnifiedBy:

o  magnifyBy: scale
obsolete: has been renamed to magnifiedBy: for ST-80 compatibility
and name consistency ...

** This is an obsolete interface - do not use it (it may vanish in future versions) **

initialization
o  initGC
redefined to setup the drawing colors to paint 1's on 0's
and to stop the server from sending exposure events for Forms -
(this would fill up stream-queue on some stupid (i.e. sco) systems

o  initialize

o  recreate
reconstruct the form after a snapin or a migration

o  releaseFromDevice
flush device data.
The sender has to take care that the Form has been
unregistered from (Finalization-)Lobby

misc ui support
o  inspectorClass
( an extension from the stx:libtool package )
redefined to launch an ImageInspector
(instead of the default InspectorView).

printing & storing
o  displayOn: aStreamOrGC

o  storeOn: aStream
append an ascii representation of the receiver to aStream,
from which a copy of the receiver can be reconstructed

private
o  beImmediateForm
read the pixels from the device into a local data array.
To make the image smaller (i.e. not keep all those bitmaps),
this is NOT done by default.
usage example(s):
     Form allInstances:[:f |
	f beImmediateForm
     ]

o  flushDeviceHandles
flush device handles (sent after a restart)

o  getBits
if the receiver was not created from a file, or
an array (i.e. it was drawn), read the pixels from the
device into a local data array. This has to be done before
an image is saved, or the receiver is storedBinary, since
the information present in the device is lost after restart/reload

o  restored
flush device data, when restored (sent after a binaryLoad)

o  width: w height: h
actual create of a monochrome form

o  width: w height: h depth: d
actual create of an arbitrary deep form (but, must be supported by device).
Return nil (after raising a notification) if the allocation failed

o  width: wIn height: hIn fromArray: anArray
actual create of a monochrome form from array.
This method is somewhat more complicated as it should be due to
supporting both byte-wise (ST/X-type) and short-word-wise (ST-80-type)
Arrays; in the later case, the shorts are first converted to bytes in
a ByteArray, then passed to the device.

o  width: w height: h offset: offs fromArray: anArray
actual create of a monochrome form from array

queries
o  ascentOn: aGC
displayOn: does not draw above baseline

o  bounds
return my bounds (added to make forms usable as VisualComponents)

o  colorFromValue: pixel
given a pixelValue, return the corresponding color.
For compatibility with Images

o  hasBits
return true, if the receiver has its pixel data available.
For forms, which were created from data, this is always true.
For forms, which were created as off-screen device forms on some
device, this is always false.

o  heightOn: aGC
return my height, if displayed on aGC;
since my height is independent of the device (the number of pixels),
return the pixel-height

o  isDithered
for compatibility with color protocol

o  isForm
return true, if the receiver is some kind of form;
true is returned here - the method is redefined from Object.

o  isImageOrForm
return true, if the receiver is some kind of image or form;
true is returned here - the method is redefined from Object.

o  widthOn: aGC
return my width, if displayed on aGC;
since my width is independent of the device (the number of pixels),
return the pixel-width


Private classes:

    ImageForm


ST/X 7.1.0.0; WebServer 1.663 at exept.de:8081; Mon, 20 Aug 2018 15:01:44 GMT