Table of Contents
Xaw - X Athena Widgets
Xaw is a widget set based on the X Toolkit Intrinsics (Xt)
Library. This release by the X.org Foundation includes additions and modifications
originally made for The XFree86 Project, Inc. This manual page describes
these changes as well as some of the common interfaces between its version
and the previous X Consortium release (Xaw6).
All of the Xaw widgets
now have the additional translations call-proc, declare, get-values and set-values.
The syntax for these actions is:
action-name (boolean-expression, arguments)
Action-name is one of call-proc, declare, get-values or set-values.
Boolean-expression
is composed with the operators | (or), & (and), ^ (xor), and ~ (not). The operands
can be a variable name, which starts with a $; a resource name without
the bindings . or *; or a constant name, including mine (event->xany.window
== XtWindow(widget)), faked (event->xany.send_event != 0), true (1)
and false
(0).
Arguments are self-explanatory; when starting with a $ they name a variable,
otherwise, they indicate a resource name.
- call-proc (boolean-expression, procedure-name)
- This action allows the evaluation of a boolean expression in the first
parameter before calling a action procedure. The procedure is only called
if the expression evaluates as true. Example:
call-proc("$inside & $pressed", notify)
- declare (boolean-expression, variable,
value, ...)
- This action is used to create new variables or change their values.
Any number of variable-value tuples may be specified. Example:
declare(1, $pressed, 1)
- get-values (boolean-expression, variable, value,
...)
- This action reads a widget resource value into a variable. Any number
of variable-value tuples may be specified. Example:
get-values(1, $fg, foreground, $bg, background)
- set-values (boolean-expression,
variable, value, ...)
- This action sets a widget resource to the given value,
which may be a variable. Any number of variable-value tuples may be specified.
Example:
set-values(1, foreground, $bg, background, $fg)
Here is a sample translation
to make a label widget behave like a button:
<Map>: get-values(1, $fg, foreground, $bg, background)\n<Btn1Down>: set-values(1,
foreground, yellow, background, gray30)\n<Btn1Up>: set-values(1, foreground,
$fg, background, $bg)
All of the Xaw widgets have now the additional resource displayList.
This resource allows drawing the widget decorations using commands embedded
in a resource string. The displayList resource has the syntax:
[class-name:]function-name
arguments[[{;\n}]...]
Class-name is any registered set of functions to draw
in the widget. Currently the only existing class is xlib, which provides
access to the Xlib drawing primitives.
Function-name is the drawing or configuration
function to be called, described bellow.
Arguments may be anything suitable
to the displayList function being called. When the function requires a coordinate,
the syntax is {+-}<integer> or <integer>/<integer>. Examples:
+0,+0 top, left
-0,-0 bottom, right
-+10,-+10 bottom+10, right+10
+0,1/2 left, vertical-center
- arc-mode mode
- Sets the arc mode. Accepted modes are "pieslice" and "chord",
which set the arc to ArcPieSlice or ArcChord, respectively. Example:
arc-mode chord
- bg color-spec
- background color-spec
- Sets the background color. color-spec must a valid
color specification. Example:
background red
- cap-style style
- Sets the cap style. Accepted styles are "notlast",
"butt", "round", and "projecting", which set the cap style to CapNotLast,
CapBut, CapRound or CapProjecting, respectively. Example:
cap-style round
- clip-mask pixmap-spec
- Sets the pixmap for the clip mask. Requires
a pixmap parameter, as described in the PIXMAPS section below. Example:
clip-mask xlogo11
- clip-origin x,y
- Sets the clip x and y origin. Requires
two arguments, the x and y coordinates. Example:
clip-origin 10,10
- clip-rects x1,y1,x2,y2 [...,xn,yn]
- clip-rectangles x1,y1,x2,y2 [...,xn,yn]
- Sets a list of rectangles to the
clip mask. The number of arguments must be a multiple of four. The arguments
are coordinates. The parser calculates the width and height of the rectangles.
Example:
clip-rects 0,0,10,20, 20,10,30,30
- coord-mode mode
- Changes the coord mode
for fill-polygon, draw-lines, and draw-points. Accepted parameters are "modeorigin"
and "previous", that sets the coord mode to CoordModeOrigin or CoordModePrevious,
respectively. Example:
coord-mode previous
- copy-area {pixmap-spec|.},dstx,dsty[,x2,y2,srcx,srcy]
- Calls
XCopyArea. The character . means copy the window contents; pixmap-spec is
as defined in the PIXMAPS section below. X2 and y2 are the coordinates
of the end copy, not the width and height; if not defined, the parser calculates
them. src_x and src_y default to zero. Example:
copy-area Term,10,10
- copy-plane {pixmap-spec|.},dstx,dsty[,x2,y2,srcx,srcy,plane]
- Calls XCopyPlane. The character . means copy the window contents; pixmap-spec
is as defined in the PIXMAPS section below. X2 and y2 are the coordinates
of the end copy, not the width and height; if not defined, the parser calculates
them. src_x and src_y default to zero. Plane defaults to one. Example:
copy-plane star,10,10
- dashes i1[...,in]
- Sets the dashes for line drawing. Accepts
up to 127 arguments. Example:
dashes 3,7 9,10
- draw-arc x1,y1,x2,y2[,start-angle,end-angle]
- Draws an arc.
The four first arguments are the rectangle enclosing the arc. The two
remaining arguments, if specified, are the start and end angle, in degrees.
Example:
draw-arc +0,+0,-1,-1,0,90
- draw-rect x1,y1,x2,y2
- draw-rectangle x1,y1,x2,y2
- Draws a rectangle. Requires four arguments,
which are the start and end coordinate pairs. Example:
draw-rect +1,+1,-5,-5
- draw-string x,y,"string"
- Draws a text string. Requires
three arguments, a x coordinate, a y coordinate, and a string. Strings
that have white space can be quoted with the " character; the backslash
character \ can also be used, but it will be necessary escape it twice.
Example:
draw-string 10,10, "Hello world!"
- exposures boolean
- Sets graphics exposures
in the GC. Allowed parameters are a integer or the strings "true", "false",
"on" and "off". Example:
exposures true
- fill-arc x1,y1,x2,y2[,start-angle,end-angle]
- Like draw-arc,
but fills the contents of the arc with the currently selected foreground.
Example:
fill-arc +0,+0,-1,-1,0,180
- fill-poly x1,y1 [...,xn,yn]
- fill-polygon x1,y1 [...,xn,yn]
- Like draw-lines, but fills the enclosed polygon
and joins the first and last point, if they are not at the same position.
Example:
fill-poly +0,+10, +10,+20, +30,+0
- fill-rect x1,y1,x2,y2
- fill-rectangle x1,y1,x2,y2
- Like draw-rect, but fills the contents of the
rectangle with the selected foreground color. Example:
fill-rect +10,+10,-20,-20
- fill-rule rule
- Sets the fill rule. Accepted parameters
are "evenodd" and "winding", which set the fill rule to EvenOddRule or
WindingRule, respectively. Example:
fill-rule winding
- fill-style style
- Sets the fill style. Allowed parameters
are "solid", "tiled", "stippled" and "opaquestippled", which set the fill
style to FillSolid, FillTiled, FillStippled or FillOpaqueStippled, respectively.
Example:
fill-style tiled
- font font-spec
- Sets the font for text functions. Example:
font -*-*-*-R-*-*-*-120-*-*-*-*-ISO8859-1
- fg color-spec
- foreground color-spec
- Like background, but sets the current foreground
color. Example:
foreground blue
- mask
- This command is useful when you want to draw only
in the region that really needs to be repainted. Requires no arguments.
- function function-spec
- Sets the specific GC function. Allowed parameters
are "set", "clear", "and", "andreverse", "copy", "andinverted", "noop",
"xor", "or", "nor", "equiv", "invert", "orreverse", "copyinverted" and
"nand", which set the function to GXset, GXclear, GXand, GXandReverse,
GXcopy, GXandInverted, GXnoop, GXxor, GXor, GXnor, GXequiv, GXinvert, GXorReverse,
GXcopyInverted or GXnand, respectively. Example:
function xor
- join-style style
- Sets the join style. Allowed parameters are
"miter", "round" and "bevel", which set the join style to JoinMiter, JoinRound
and JoinBevel, respectively. Example:
join-style round
- image {pixmap-spec},xs,ys,[xe,ye]
- This function is implemented
as a way to quickly compose complex decorations in widgets. Pixmap-spec
is as defined in the PIXMAPS section below. xs and ys are the coordinates
from where to start copying the pixmap; xe and ye are optional (they default
to xs + pixmap.width and ys + pixmap.height, respectively). If the pixmap
has a mask, the copy is masked accordingly. Example:
image pixmap.xpm,0,0,20,20
- line x1,y1,x2,y2
- draw-line x1,y1,x2,y2
- Draws a line with the current foreground color.
Requires four arguments, the starting and ending coordinate pairs. Example:
line +0,+0, -1,-1
- line-width integer
- Selects a line width for drawing. Example:
line-width 2
- line-style style
- Sets the line style. Accepted parameters are
"solid", "onoffdash" and "doubledash", which set the line style to LineSolid,
LineOnOffDash or LineDoubleDash, respectively. Example:
line-style onoffdash
- lines x1,y1,x2,y2 [...,xn,yn]
- draw-lines x1,y1,x2,y2 [...,xn,yn]
- Draws a list of lines. Any number of argument
pairs may be supplied. Example:
lines +0,-1, -1,-1, -1,+0
- paint-string x,y,"string"
- Identical to draw-string,
but also uses the background color. Example:
paint-string 10,20, "Sample text"
- point x,y
- draw-point x,y
- Draws a point. Requires two arguments, a coordinate pair.
Example:
point +10,+10
- plane-mask integer
- Sets the plane mask. Requires an integer
parameter. Example:
plane-mask -1
- points x1,y1 [...,xn,yn]
- draw-points x1,y1 [...,xn,yn]
- Draws a list of points at the specified coordinates.
Example:
points +1,+2, +1,+4, +1,+6
- segments x1,y1,x2,y2 [...,xn,yn]
- draw-segments x1,y1,x2,y2 [...,xn,yn]
- Draws a list of segment lines. The
number of parameters must be multiple of 4. Example:
segments +1,+2,+1,-3, +2,-2,-3,-2
- shape-mode mode
- Sets the shape mode used in
fill-polygon. Accepted parameters are "complex", "convex" or "nonconvex",
which set the shape mode to Complex, Convex or Nonconvex, accordingly.
Example:
shape-mode convex
- stipple pixmap-spec
- Sets the pixmap for a stipple. Requires
a pixmap parameter, as described in the PIXMAPS section below. Example:
stipple plaid
- subwindow-mode mode
- Sets the subwindow mode in the GC. Accepted
parameters are "includeinferiors" and "clipbychildren", which set the subwindow
mode to IncludeInferiors or ClipByChildren, respectively. Example:
subwindow-mode includeinferiors
- tile pixmap-spec
- Sets the pixmap for a tile.
Requires a pixmap parameter, as described in the PIXMAPS section below.
Example:
tile xlogo11?foreground=red&background=gray80
- ts-origin x,y
- Sets the tile
stipple x and y origin. Requires two arguments, a x and y coordinate. Example:
ts-origin 10,10
- umask
- Disables the GC mask, if it has been set with the
command mask. Requires no arguments.
Example for drawing a shadow effect
in a widget:
foreground gray30;draw-lines +1,-1,-1,-1,-1,+1;reground gray85;draw-lines -1,+0,+0,+0,+0,-1
A String to Pixmap converter has been added to Xaw. This converter
is meant to be extended, and has enough abstraction to allow loading several
image formats. It uses a format that resembles a URL, with the syntax:
[type:]name[?arg=val[{&}...]]
Type can be one of bitmap, gradient or xpm.
Name
may be a file name, or, in the case of type gradient, may be either vertical
or horizontal.
Arg=val is a list of arguments to the converter. An argument
list is preceded by a question mark, and multiple arguments are separated
by ampersands. The most common arguments are foreground and background.
Gradients also support the arguments start and end (colors with which
to start and end the gradient); the steps argument, to allow using less
colors; and the dimension argument to specify the size of the gradient. The
xpm converter understands the closeness argument, which aids in using fewer
colors (useful if you have a limited colormap).
Most of the changes
to this version of the Xaw library were done in the TextWidget, TextSrcObject,
TextSinkObject and related files.
A couple of highly visible changes in
the Text widget are due to many bugs in the Xaw6 implementation involving
scrollbars and auto-resizing. Scrollbars being added or removed caused several
problems in keeping the text cursor visible, and in Xaw6 it was very easy
to have a widget thinking the cursor was visible, when it was not. Also,
permitting automatic resizing of the widget to a larger geometry created
other problems, making it difficult to have a consistent layout in the
application, and, if the window manager did not interfere, windows larger
than the screen could result. Therefore, some functionality involving scrollbars
and auto-resizing has been disabled; see the section on new and modified
Text widget resources below.
The Text widget's default key bindings were
originally based on the Emacs text editor. In this release, even more operations
familiar to Emacs users have been added. New text actions include:
- indent
- Indents text blocks. Not bound by default. The Text widget also does not
attempt to perform auto-indentation of its source object by default.
- keyboard-reset
- Resets the keyboard state. Reverts the action multiplier to 1, and if undo
is enabled, toggles between undo and redo. Bound by default to Control<Key>G.
- kill-ring-yank
- In this version of Xaw, text killed in any text field is kept
in memory, allowing cut and paste operations internally to the program
between text fields. Bound by default to Meta<Key>Y.
- numeric
- Listed here only
for purposes of documentation. Called by default when one of the characters
1, 2, 3, 4, 5, 6, 7, 8, 9, 0, or - is typed, allowing composition of the
multiplication number of text actions.
- set-keyboard-focus
- Sets the input focus
of the top level widget to the text field. Not enabled by default, but
bound to the <Btn1Down> event.
- toggle-overwrite
- Toggles overwrite mode. In
overwrite mode, any text inserted in a text field will replace existing
text. Bound by default to <Key>Insert.
- undo
- Sets the enableUndo resource of
the textSrcObject. Not enabled by default, but bound to Control<Key>_.
New
and modified Text widget resources include:
- justify (Class Justify)
- Sets
the text justification. Can be one of left, right, center, or full. Only
enabled when the autoFill resource is set, and the resources leftColumn
and rightColumn are correctly set.
- leftColumn (Class Column)
- Specifies the
left column at which to break text. Text lines started with an alphanumeric
character will automatically start at this column.
- positionCallback (Class
Callback)
- Allows installation of a callback to be called every time the
cursor is moved, and/or the file changes its size. The callback is called
with a pointer to a structure containing the following data:
typedef struct {
int line_number;
int column_number;
XawTextPosition insert_position;
XawTextPosition last_position;
Boolean overwrite_mode;
} XawTextPositionInfo;
This callback is intended to help programmers write text editors based
on the Xaw widget set.
- resize (Class Resize)
- No longer supported, but recognized
for backward compatibility with resource specifications written for the
Xaw6 Text widget.
- rightColumn (Class Column)
- Specifies the right column
at which to break text. Text lines started with an alphanumeric character
will automatically end at this column.
- scrollHorizontal (Class Scroll)
- scrollVertical (Class Scroll)
- These resources control the placement of
scrollbars on the left and bottom edges of the Text widget. They accept
the values XawtextScrollAlways and XawtextScrollNever. A converter is registered
for this resource that will convert the following strings: always and never.
The value XawtextScrollWhenNeeded (and whenNeeded, recognized by the converter),
is accepted for backwards compatibility with resource specifications written
for the Xaw6 Text widget, but ignored (effectively treated as XawtextScrollNever).
The textSrcObject allows display of its contents to more
than one window, and also stores undo information. The new resources for
the textSrcObject are:
- callback (Class Callback)
- Previous versions of Xaw
had this resource in subclasses of the TextSource object. This was changed
to make it possible to tell the callback the state of the text when undo
is enabled.
- enableUndo (Class Undo)
- A boolean resource that enables or disables
the undo function. The default value is False.
- sourceChanged (Class Changed)
- Like the callback resource, this resource was previously in subclasses
of the TextSource object. It is now in the textSrcObject to control the
changed/unchanged state when undo is enabled.
The textSinkObject
subclasses asciiSinkObject and multiSinkObject have been changed slightly
to use a new cursor shape (no longer a caret at the baseline) that indicates
the input focus of the text widget, and allow specification of the cursor
color. The new resource is:
- cursorColor (Class Color)
- Sets the cursor color
of the text. This color is also used to draw selected text.
The simpleMenuWidget algorithm to lay out menu entries has been changed
to enable multiple columns when a single column does not fit on the screen.
It was also modified to enable submenus.
A new resource has
been added to the smeBSBObject to allow binding submenus to it. The new
resource is:
- menuName (Class MenuName)
- Specifies the name of the popup
widget to be popped up when the pointer is over the menu entry, or NULL.
Note that the named menu must be a child of the popup parent of the smeBSBObject.
Xaw is actively being developed. Programs intending to be fully
compatible with future releases of the Xaw library should use only the
public interfaces. While widget subclassification is not a bad thing, and
sometimes an encouraged programming practice, programs that access private
data structures may have problems with newer releases in the current stage
of Xaw development. Efforts are being made to avoid such problems and to
guarantee that newer releases will be source and binary compatible.
The
original X Consortium version of the Athena Widget Set and its documentation
were the work of many people, including Chris D. Peterson, Ralph Swick,
Mark Ackerman, Donna Converse, Jim Fulton, Loretta Guarino-Reid, Charles
Haynes, Rich Hyde, Mary Larson, Joel McCormack, Ron Newman, Jeanne Rich,
Terry Weissman, Mike Gancarz, Phil Karlton, Kathleen Langone, Ram Rao,
Smokey Wallace, Al Mento, and Jean Diaz.
The additions and modifications
to Xaw which were originally made for XFree86 were written by Paulo C'esar
Pereira de Andrade.
Athena Widget Set - C Language Interface
Table of Contents