sketchboard.gadget Reference¶
Comprehensive function reference for sketchboard.gadget, synthesised from the AmigaOS NDK 3.2 Release 4 (Autodocs/sketchboard).
This page documents 6 functions of sketchboard.gadget. Each function entry follows the canonical autodoc format. struct Name, union Name, enum Name are clickable links to the type definition in the types reference.
Function index¶
sketchboard.gadget()¶
**sketchboard.gadget -- sketchboard gadget class
SUPERCLASS
gadgetclass
REQUIRES
bevel.image
DESCRIPTION
This class is intended to be used to edit smaller bitmaps with a
limited set of drawing tools. It is used by the Pointer preferences
as well as the IconEdit utility.
Special features include bitmap scaling, an optional grid pattern
and optional hot spot indicator.
METHODS
OM_NEW -- Create the sketchboard.gadget object. Passed to superclass.
OM_DISPOSE -- Destroy the gadget and then pass to superclass.
OM_GET -- Obtain the value of an attribute. Passed to superclass.
OM_SET -- Set object attributes. Passed to superclass first.
OM_UPDATE -- Update object attributes. Passed to superclass first.
GM_HELPTEST -- Determine if gadget help was hit.
GM_HITTEST -- Determine if gadget was hit.
GM_RENDER -- Render the gadget with state.
GM_GOACTIVE -- Activate the gadget.
GM_GOINACTIVE -- Deactivate the gadget.
GM_HANDLEINPUT -- Handle input while gadget is active.
GM_EXTENT -- Inquire about gadget rendering extent.
GM_LAYOUT -- Calculate relative gadget coordinates.
GM_DOMAIN -- Obtain gadget sizing requirements.
SGM_Clear -- Set drawing area to current pen color.
SGM_Undo -- Undo the last change.
SGM_Redo -- Redo the last change.
SGM_Scroll -- Scroll contents of drawing area by dx/dy pixels.
All other methods are passed to the superclass.
ATTRIBUTES
GA_ReadOnly (BOOL)
This attribute overrides the behavior of the superclass
to set and clear the GFLG_SELECTED flag. Set the gadget to
read only when accessing the SGA_BitMap.
Defaults to FALSE.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
GA_Disabled (BOOL)
This attribute overrides the behavior of the superclass
to also set and clear the GFLG_SELECTED flag.
Defaults to FALSE.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
GA_HintInfo (CONST_STRPTR)
Specify the text to use as the hint info for this gadget.
You can change this attribute at any time, and it will over-
ride any text specified in the windows HintInfo array. See
window.class autodoc for more information.
Defaults to NULL.
Applicability is (OM_NEW, OM_SET).
SGA_BitMap (struct BitMap *)
Pointer to the source bitmap which will be copied from
when used with OM_NEW, OM_SET and OM_UPDATE. This bitmap
is only read from.
The sketchboard object always uses its own internal bitmap
for editing. The internal bitmap can be retrieved using
this attribute and OM_GET. Set the gadget to GA_ReadOnly
before invoking OM_GET and be ready to handle a NULL
pointer if the gadget has not yet been layed out.
Defaults to NULL (blank).
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_MouseX (UWORD)
The current mouse X coordinate within the drawing area.
When using OM_GET, initialize the tag value to the
mouse X coordinate relative to the gadget's bounds.
This value will then be scaled to provide the mouse X
coordinate within the drawing area.
When SGA_Scale is 1 there is no scaling because each
pixel is exactly one square in the drawing area. When
SGA_Scale is 2 there are 2 pixels for every one square
withing the drawing area and so forth.
Applicability is (OM_GET, OM_NOTIFY)
SGA_MouseY (UWORD)
The current mouse Y coordinate within the drawing area.
When using OM_GET, initialize the tag value to the
mouse Y coordinate relative to the gadget's bounds.
This value will then be scaled to provide the mouse Y
coordinate within the drawing area.
When SGA_Scale is 1 there is no scaling because each
pixel is exactly one square in the drawing area. When
SGA_Scale is 2 there are 2 pixels for every one square
withing the drawing area and so forth.
Applicability is (OM_GET, OM_NOTIFY)
SGA_Width (UWORD)
The width of the drawing in pixels.
Defaults to 32.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_Height (UWORD)
The height of the drawing in pixels.
Defaults to 32.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_APen (UBYTE)
Current primary drawing pen.
Defaults to 1.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET, OM_NOTIFY)
SGA_Tool (UWORD)
The currently active drawing tool which is one of the following:
SGTOOL_FREEHAND_DOTS - freehand dots only
SGTOOL_FREEHAND - freehand connected lines
SGTOOL_ELLIPSE - ellipse
SGTOOL_ELLIPSE_FILLED - filled ellipse
SGTOOL_RECT - rectangle
SGTOOL_RECT_FILLED - filled rectangle
SGTOOL_LINE - single line
SGTOOL_FILL - flood fill an area
SGTOOL_GETPEN - get primary pen (SGA_APen notifies)
SGTOOL_HOTSPOT - set image hot spot
SGTOOL_SELECT - selecting a part of the image for cut, c
opy or move SGTOOL_MOVE - move the image og selection
Defaults to SGTOOL_FREEHAND_DOTS.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET, OM_NOTIFY)
SGA_UndoAvailable (BOOL)
This attribute indicates whether an undo operation is possible
with the currently selected SGA_Tool.
Applicability is (OM_GET, OM_NOTIFY)
SGA_RedoAvailable (BOOL)
This attribute indicates whether a redo operation is possible
with the currently selected SGA_Tool.
Applicability is (OM_GET, OM_NOTIFY)
SGA_ShowGrid (BOOL)
This attribute enables or disables the drawing grid.
Defaults to TRUE.
Applicability is (OM_NEW, OM_SET, OM_UPDATE)
SGA_ScaleByCtrlMouseWheel (BOOL)
Enables Scaling by user turning the mouse wheel with Ctrl held do
wn
Defaults to FALSE
Applicability is (OM_GET)
SGA_Scale (UWORD)
Determines the scaling factor to use starting from 1.
Defaults to 3.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_AfPt (UWORD *)
Control the area fill pattern for the space not being
edited around the image.
Defaults to NULL (checkerboard pattern).
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_AfPtSize (WORD)
Size of area fill pattern.
Defaults to 1.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_HPropTotal (UWORD)
Total horizontal size of the sketch when scaled. For use
when interconnecting with a propgclass object or similar.
Applicability is (OM_GET, OM_NOTIFY)
SGA_HPropTop (UWORD)
Top of the horizontal size of the sketch when scaled. For
use when interconnecting with a propgclass object or similar.
Applicability is (OM_SET, OM_UPDATE, OM_GET, OM_NOTIFY)
SGA_HPropVisible (UWORD)
Visible horizontal size of the sketch when scaled. For use
when interconnecting with a propgclass object or similar.
Applicability is (OM_GET, OM_NOTIFY)
SGA_VPropTotal (UWORD)
Total vertical size of the sketch when scaled. For use
when interconnecting with a propgclass object or similar.
Applicability is (OM_GET, OM_NOTIFY)
SGA_VPropTop (UWORD)
Top of the vertical size of the sketch when scaled. For
use when interconnecting with a propgclass object or similar.
Applicability is (OM_SET, OM_UPDATE, OM_GET, OM_NOTIFY)
SGA_VPropVisible (UWORD)
Visible vertical size of the sketch when scaled. For use
when interconnecting with a propgclass object or similar.
Applicability is (OM_GET, OM_NOTIFY)
SGA_HotSpot (ULONG)
The current hot spot location packed into a ULONG. The
upper word is the X position while the lower word is the
Y position. The hot spot will be rendered as a small square.
Defaults to -1 (no hot spot).
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET)
SGA_Changed (BOOL)
The flag will be set to TRUE when the drawing has been
changed in some way.
Defaults to FALSE.
Applicability is (OM_NEW, OM_SET, OM_UPDATE, OM_GET, OM_NOTIFY)
SGA_RastPort (struct RastPort *)
This attribute is for subclass implementors only. It points
the the layered RastPort being used for the drawing. The
pointer may change when SGA_SketchWidth or SGA_SketchHeight
changes. It is also possible it may be NULL.
Applicability is (OM_GET)
SGA_SketchBoardRect (struct Rectangle *)
This attribute is for subclass implementors only. It defines
the area bounds where the actual rendering takes place
relative to the top left corner of the parent window. This
is a read only attribute.
Applicability is (OM_GET)
SGA_SubWidth (UWORD)
SGA_SubHeight (UWORD)
These attribute are currently not implemented.
SGA_DoubleScaleX (BOOL)
SGA_DoubleScaleY (BOOL)
Internally double X/Y scale. Useful if showing a lores/non-
interlaced image on a hires/interlaced screen.
Applicability is (OM_NEW, OM_SET)
SGA_TopLayerBitmap (struct BitMap *)
A bitmap that acts as top layer on
top of the image itself. The use can move this bitmap
around with the Move tool. Many actions like change of
tool or selecting another area may dispose the internal
SGA_TopLayerBitmap.
After OM_SETting this attribute you can release the bitmap
as the gadget copies it to its own one.
For OM_GET this will return a pointer to the gadget's bitmap;
don't cache this pointer!
Be prepared to handle NULL pointers (out of memory, no
selection, or gadget hasn't been layouted).
NOTE: when setting or getting this you also need to
do SGA_TopLayerWidth.
Applicability is (OM_GET, OM_NEW, OM_SET)
SGA_TopLayerWidth (WORD)
The real width of the SGA_TopLayerBitmap.
It can be 0 if there is no selection.
Applicability is (OM_GET, OM_NEW, OM_SET)
SGA_WithBevel (BOOL)
Whether to use a bevel.
Defaults to TRUE. Applicability is (OM_NEW)
SGA_WithBevel (BOOL)
Whether to use a bevel.
Defaults to TRUE. Applicability is (OM_NEW)
SGA_ScrollWheelResponse (ULONG)
See <gadgets/sketchboard.h> for possible values.
Defaults to SGSCROLLWHEEL_SCROLLANDZOOM. (IS) (V47)
SGA_MaxUndoSteps (ULONG)
Defaults to 16. (IS) (V47)
SGA_UpdatedBitMap (struct BitMap *)
Exactly the same as SGA_BitMap EXCEPT it doesn't reset the
change stack, but instead records this update as a step in
the change stack. (ISG) (V47)
SGA_MaxScale (ULONG)
Maximum scale. Defaults to 16.
Probably shouldn't be much bigger. (ISG) (V47.19)**
SGM_Clear()¶
SGM_Clear -- Set drawing area to current pen color.
Synopsis
ULONG result = IDoMethodA(APTR obj, struct spGeneral* msg);
Function
This method clears the entire sketchboard to the current pen color.
Since V47 it clears the selection if there is one. Old applications t
hat don't activate the select tool will not see a difference.
Inputs
obj - sketchboard object pointer
msg - pointer to fully initialized struct spGeneral with the
MethodID set to SGM_Clear
(see <gadgets/sketchboard.h>)
RESULT
Returns 1 if changes were rendered or 0 if not.
See also
intuition.library/DoGadgetMethodA()
SGM_Redo()¶
SGM_Redo -- Redo the last change.
Synopsis
ULONG result = IDoMethodA(APTR obj, struct spGeneral* msg);
Function
This method redoes the last change to the sketchboard.
Inputs
obj - sketchboard object pointer
msg - pointer to fully initialized struct spGeneral with the
MethodID set to SGM_Redo
(see <gadgets/sketchboard.h>)
RESULT
Returns 1 if changes were rendered or 0 if not.
See also
SGM_Undo, intuition.library/DoGadgetMethodA()
SGM_Scroll()¶
SGM_Scroll -- Scroll the contents by dx/dy pixels.
Synopsis
ULONG result = IDoMethodA(APTR obj, struct spScrollRaster* msg);
Function
This method scrolls the sketchboard by dx/dy pixels. The
delta amounts are specified in the spScrollRaster message.
Inputs
obj - sketchboard object pointer
msg - pointer to fully initialized struct spScrollRaster
(see <gadgets/sketchboard.h>)
RESULT
Returns 1 if changes were rendered or 0 if not.
See also
intuition.library/DoGadgetMethodA()
SGM_Undo()¶
SGM_Undo -- Undo the last change.
Synopsis
ULONG result = IDoMethodA(APTR obj, struct spGeneral* msg);
Function
This method undoes the last change to the sketchboard.
Inputs
obj - sketchboard object pointer
msg - pointer to fully initialized struct spGeneral with the
MethodID set to SGM_Undo
(see <gadgets/sketchboard.h>)
RESULT
Returns 1 if changes were rendered or 0 if not.
See also
SGM_Redo, intuition.library/DoGadgetMethodA()
SKETCHBOARD_GetClass()¶
SKETCHBOARD_GetClass -- Gets pointer to the sketchboard class.
Synopsis
sketchboard_class = SKETCHBOARD_GetClass();
D0
Class * class = SKETCHBOARD_GetClass();
Function
Obtains the pointer to the sketchboard gadget class for use with
NewObject(). This function always returns a valid pointer so
you do not need to check it. The reason is that if the library
opens fine, then the pointer returned is already setup. (Of course
this implies that if opening the library fails, you shouldn't be
calling this.)
Note that this function does not create the class, that is done
when the class library is opened.
RESULT
class - Pointer to the sketchboard class.