tixForm
tixForm(n) Tix Built-In Commands tixForm(n)
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NAME
tixForm - Geometry manager based on attachment rules
SYNOPSIS
tixForm option arg ?arg ...?
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DESCRIPTION
The tixForm command is used to communicate with the tixForm Geometry
Manager, a geometry manager that arranges the geometry of the children
in a parent window according to attachment rules. The tixForm geometry
manager is very flexible and powerful; it can be used to emulate all
the existing features of the Tk packer and placer geometry managers
(see pack(n), place(n)). The tixForm command can have any of several
forms, depending on the option argument:
tixForm slave ?options?
If the first argument to tixForm is a window name (any value
starting with ``.''), then the command is processed in the same
way as tixForm configure.
tixForm check master
This command checks whether there is circular dependency in the
attachments of the master's slaves (see the section CIRCULAR
DEPENDENCY below). It returns the Boolean value TRUE if it dis-
cover circular dependency and FALSE otherwise.
tixForm configure slave ?-option value ...?
Sets or adjusts the attachment values of the slave window
according to the -option value argument pairs.
-b attachment
Abbreviation for the -bottom option.
-bottom attachment
Specifies an attachment for the bottom edge of the slave
window. The attachment must specied according to the sec-
tion SPECIFYING ATTACHMENTS below.
-bottomspring weight
Specifies the weight of the spring at the bottom edge of
the slave window. See the section USING SPRINGS below.
-bp value
Abbreviation for the -padbottom option.
-bs weight
Abbreviation for the -bottomspring option.
-fill master
Specifies the fillings when springs are used for this
widget. The value must be x, y, both or none.
-in master
Places the slave window into the specified master window.
If the slave was originally in another master window, all
attachment values with respect to the original master
window are discarded. Even if the attachment values are
the same as in the original master window, they need to
be specified again. The -in flag, when needed, must
appear as the first flag after the name of the slave.
Otherwise an error is generated.
-l attachment
Abbreviation for the -left option.
-left attachment
Specifies an attachment for the left edge of the slave
window. The attachment must specied according to the sec-
tion SPECIFYING ATTACHMENTS below.
-leftspring weight
Specifies the weight of the spring at the left edge of
the slave window. See the section USING SPRINGS below.
-lp value
Abbreviation for the -padleft option.
-ls weight
Abbreviation for the -leftspring option.
-padbottom value
Specifies the amount of external padding to leave on the
bottom side of the slave. The value may have any of the
forms acceptable to Tk_GetPixels(3).
-padleft value
Specifies the amount of external padding to leave on the
left side of the slave.
-padright value
Specifies the amount of external padding to leave on the
right side of the slave.
-padtop value
Specifies the amount of external padding to leave on the
top side of the slave.
-padx value
Specifies the amount of external padding to leave on both
the left and the right sides of the slave.
-pady value
Specifies the amount of external padding to leave on both
the top and the bottom sides of the slave.
-r attachment
Abbreviation for the -right option.
-right attachment
Specifies an attachment for the right edge of the slave
window. The attachment must specied according to the sec-
tion SPECIFYING ATTACHMENTS below.
-rightspring weight
Specifies the weight of the spring at the right edge of
the slave window. See the section USING SPRINGS below.
-rp value
Abbreviation for the -padright option.
-rs weight
Abbreviation for the -rightspring option.
-t attachment
Abbreviation for the -top option.
-top attachment
Specifies an attachment for the top edge of the slave
window. The attachment must specied according to the sec-
tion SPECIFYING ATTACHMENTS below.
-topspring weight
Specifies the weight of the spring at the top edge of the
slave window. See the section USING SPRINGS below.
-tp value
Abbreviation for the -padtop option.
-ts weight
Abbreviation for the -topspring option.
tixForm forget slave ?slave ...?
Removes each of the slaves from its master and unmaps their win-
dows. The slaves will no longer be managed by tixForm. All
attachment values with respect to their master windows are dis-
carded. If another slave is attached to this slave, then the
attachment of the other slave will be changed to grid attachment
based on its geometry.
tixForm grid master ?x_size y_size?
When x_size and y_size are given, this command returns the num-
ber of grids of the master window in a pair of integers of the
form {x_size y_size}. When both x_size and y_size are given,
this command changes the number of horizontal and vertical grids
on the master window.
tixForm info slave ?option?
Queries the attachment options of a slave window. option can be
any of the options accepted by the tixForm configure command. If
option is given, only the value of that option is returned.
Otherwise, this command returns a list whose elements are the
current configuration state of the slave given in the same
option-value form that might be specified to tixForm configure.
The first two elements in this list list are "-in master" where
master is the slave's master window.
tixForm slaves master
Returns a list of all of the slaves for the master window. The
order of the slaves in the list is the same as their order in
the packing order. If master has no slaves then an empty string
is returned.
SPECIFYING ATTACHMENTS
One can specify an attachment for each side of a slave window managed
by tixForm. An attachment is specified in the the form "-side
{anchor_point offset}". -side can be one of -top, -bottom, -left or
-right.
Offset is given in screen units (i.e. any of the forms acceptable to
Tk_GetPixels). A positive offset indicates shifting to a position to
the right or bottom of an anchor point. A negative offset indicates
shifting to a position to the left or top of an anchor point.
Anchor_point can be given in one of the following forms:
Grid Attachment
The master window is divided into a number of horizontal
and vertical grids. By default the master window is
divided into 100x100 grids; the number of grids can be
adjusted by the tixForm grid command. A grid attachment
anchor point is given by a % sign followed by an integer
value. For example, %0 spceifies the first grid line (the
top or left edge of the master window). %100 spceifies
the last grid line (the bottom or right edge of the mas-
ter window).
Opposite Side Attachment
Opposite attachment specifies an anchor point located on
the opposite side of another slave widget, which must be
managed by tixForm in the same master window. An opposite
attachment anchor point is given by the name of another
widget. For example, "tixForm .b -top {.a 0}" attaches
the top side of the widget .b to the bottom of the widget
.a.
Parallel Side Attachment
Opposite attachment specifies an anchor point located on
the same side of another slave widget, which must be man-
aged by tixForm in the same master window. An parallel
attachment anchor point is given by the sign & follwed by
the name of another widget. For example, "tixForm .b
-top {&.a 0}" attaches the top side of the widget .b to
the top of the widget .a, making the top sides of these
two widgets at the same vertical position in their parent
window.
No Attachment
Specifies a side of the slave to be attached to nothing,
indicated by the keyword none. When the none anchor point
is given, the offser must be zero.
When a side of a slave is attached to {none 0}, the posi-
tion of this side is calculated by the position of the
other side and the natural size of the slave. For exam-
ple, if a the left side of a widget is attached to {%0
100}, its right side attached to {none 0}, and the natu-
ral size of the widget is 50 pixels, the right side of
the widget will be positioned at pixel {%0 149}.
When both -top and -bottom are attached to none, then by
default -top will be attached to {%0 0}. When both -left
and -right are attached to none, then by default -left
will be attached to {%0 0}.
Shifting effects can be achieved by specifying a non-zero offset with
an anchor point. In the following example, the top side of widget .b is
attached to the bottom of .a; hence .b always appears below .a. Also,
the left edge of .b is attached to the left side of .a with a 10 pixel
offest. Therefore, the left edge of .b is always shifted 10 pixels to
the right of .a's left edge:
tixForm .b -left {.a 10} -top {.a 0}
ABBREVIATIONS: Certain abbreviations can be made on the attachment
specifications: First an offset of zero can be omitted. Thus, the fol-
lowing two lines are equivalent:
tixForm .b -top {.a 0} -right {%100 0}
tixForm .b -top {.a} -right {%100}
Also, because of the way TCL handles lists, when you omit the offset,
you can also leave out the braces. So you can further simplify the
above to:
tixForm .b -top .a -right %100
In the second case, when the anchor point is omitted, the offset must
be given. A default anchor point is chosen according to the value of
the offset. If the anchor point is 0 or positive, the default anchor
point %0 is used; thus, "tixForm .b -top 15" attaches the top edge of
.b to a position 15 pixels below the top edge of the master window. If
the anchor point is "-0" or negative, the default anchor point %100 is
used; thus, "tixForm .a -right -2" attaches the right edge of .a to a
position 2 pixels to the left of the master window's right edge. An
further example below shows a command with its equivalent abbreviation.
tixForm .b -top {%0 10} -bottom {%100 0}
tixForm .b -top 10 -bottom -0
USING SPRINGS
To be written.
ALGORITHM OF TIXFORM
TixForm starts with any slave in the list of slaves of the master win-
dow. Then it tries to determine the position of each side of the slave.
If the attachment of a side of the slave is grid attachment, the posi-
tion of the side is readily determined.
If the attachment of this side is none, then tixForm tries to determine
the position of the opposite side first, and then use the position of
the opposite side and the natural size of the slave to determine the
position of this side.
If the attachment is opposite or parallel widget attachments, then tix-
Form tries to determine the positions of the other widget first, and
then use the positions of the other widget and the natural size of the
slave determine the position of this side. This recursive algorithmis
carried on until the positions of all slaves are determined.
CIRCULAR DEPENDENCY
The algorithm of tixForm will fail if a circular dependency exists in
the attachments of the slaves. For example:
tixForm .c -left .b
tixForm .b -right .c
In this example, the position of the left side of .b depends on the
right side of .c, which in turn depends on the left side of .b.
When a circular dependency is discovered during the execution of the
tixForm algorithm, tixForm will generate a background error and the
geometry of the slaves are undefined (and will be arbitrary). Notice
that tixForm only executes the algorithm when the specification of the
slaves' attachments is complete. Therefore, it allows intermediate
states of circular dependency during the specification of the slaves'
attachments. Also, unlike the Motif Form manager widget, tixForm
defines circular dependency as "dependency in the same dimension".
Therefore, the following code fragment will does not have circular
dependency because the two widgets do not depend on each other in the
same dimension (.b depends .c in the horizontal dimension and .c
depends on .b in the vertical dimension):
tixForm .b -left .c
tixForm .c -top .b
BUGS
Springs have not been fully implemented yet.
KEYWORDS
Tix(n), Form, Geometry Management
Tix 4.0 tixForm(n)
