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diff --git a/doc/pack.n b/doc/pack.n new file mode 100644 index 0000000..580f252 --- /dev/null +++ b/doc/pack.n @@ -0,0 +1,266 @@ +'\" +'\" Copyright (c) 1990-1994 The Regents of the University of California. +'\" Copyright (c) 1994-1996 Sun Microsystems, Inc. +'\" +'\" See the file "license.terms" for information on usage and redistribution +'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. +'\" +'\" SCCS: @(#) pack.n 1.19 96/08/27 13:21:48 +'\" +.so man.macros +.TH pack n 4.0 Tk "Tk Built-In Commands" +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +pack \- Geometry manager that packs around edges of cavity +.SH SYNOPSIS +\fBpack \fIoption arg \fR?\fIarg ...\fR? +.BE + +.SH DESCRIPTION +.PP +The \fBpack\fR command is used to communicate with the packer, +a geometry manager that arranges the children of a parent by +packing them in order around the edges of the parent. +The \fBpack\fR command can have any of several forms, depending +on the \fIoption\fR argument: +.TP +\fBpack \fIslave \fR?\fIslave ...\fR? ?\fIoptions\fR? +If the first argument to \fBpack\fR is a window name (any value +starting with ``.''), then the command is processed in the same +way as \fBpack configure\fR. +.TP +\fBpack configure \fIslave \fR?\fIslave ...\fR? ?\fIoptions\fR? +The arguments consist of the names of one or more slave windows +followed by pairs of arguments that specify how +to manage the slaves. +See ``THE PACKER ALGORITHM'' below for details on how the options +are used by the packer. +The following options are supported: +.RS +.TP +\fB\-after \fIother\fR +\fIOther\fR must the name of another window. +Use its master as the master for the slaves, and insert +the slaves just after \fIother\fR in the packing order. +.TP +\fB\-anchor \fIanchor\fR +\fIAnchor\fR must be a valid anchor position such as \fBn\fR +or \fBsw\fR; it specifies where to position each slave in its +parcel. +Defaults to \fBcenter\fR. +.TP +\fB\-before \fIother\fR +\fIOther\fR must the name of another window. +Use its master as the master for the slaves, and insert +the slaves just before \fIother\fR in the packing order. +.TP +\fB\-expand \fIboolean\fR +Specifies whether the slaves should be expanded to consume +extra space in their master. +\fIBoolean\fR may have any proper boolean value, such as \fB1\fR +or \fBno\fR. +Defaults to 0. +.TP +\fB\-fill \fIstyle\fR +If a slave's parcel is larger than its requested dimensions, this +option may be used to stretch the slave. +\fIStyle\fR must have one of the following values: +.RS +.TP +\fBnone\fR +Give the slave its requested dimensions plus any internal padding +requested with \fB\-ipadx\fR or \fB\-ipady\fR. This is the default. +.TP +\fBx\fR +Stretch the slave horizontally to fill the entire width of its +parcel (except leave external padding as specified by \fB\-padx\fR). +.TP +\fBy\fR +Stretch the slave vertically to fill the entire height of its +parcel (except leave external padding as specified by \fB\-pady\fR). +.TP +\fBboth\fR +Stretch the slave both horizontally and vertically. +.RE +.TP +\fB\-in \fIother\fR +Insert the slave(s) at the end of the packing order for the master +window given by \fIother\fR. +.TP +\fB\-ipadx \fIamount\fR +\fIAmount\fR specifies how much horizontal internal padding to +leave on each side of the slave(s). +\fIAmount\fR must be a valid screen distance, such as \fB2\fR or \fB.5c\fR. +It defaults to 0. +.TP +\fB\-ipady \fIamount\fR +\fIAmount\fR specifies how much vertical internal padding to +leave on each side of the slave(s). +\fIAmount\fR defaults to 0. +.TP +\fB\-padx \fIamount\fR +\fIAmount\fR specifies how much horizontal external padding to +leave on each side of the slave(s). +\fIAmount\fR defaults to 0. +.TP +\fB\-pady \fIamount\fR +\fIAmount\fR specifies how much vertical external padding to +leave on each side of the slave(s). +\fIAmount\fR defaults to 0. +.TP +\fB\-side \fIside\fR +Specifies which side of the master the slave(s) will be packed against. +Must be \fBleft\fR, \fBright\fR, \fBtop\fR, or \fBbottom\fR. +Defaults to \fBtop\fR. +.LP +If no \fB\-in\fR, \fB\-after\fR or \fB\-before\fR option is specified +then each of the slaves will be inserted at the end of the packing list +for its parent unless it is already managed by the packer (in which +case it will be left where it is). +If one of these options is specified then all the slaves will be +inserted at the specified point. +If any of the slaves are already managed by the geometry manager +then any unspecified options for them retain their previous values rather +than receiving default values. +.RE +.TP +\fBpack forget \fIslave \fR?\fIslave ...\fR? +Removes each of the \fIslave\fRs from the packing order for its +master and unmaps their windows. +The slaves will no longer be managed by the packer. +.TP +\fBpack info \fIslave\fR +Returns a list whose elements are the current configuration state of +the slave given by \fIslave\fR in the same option-value form that +might be specified to \fBpack configure\fR. +The first two elements of the list are ``\fB\-in \fImaster\fR'' where +\fImaster\fR is the slave's master. +.TP +\fBpack propagate \fImaster\fR ?\fIboolean\fR? +If \fIboolean\fR has a true boolean value such as \fB1\fR or \fBon\fR +then propagation is enabled for \fImaster\fR, which must be a window +name (see ``GEOMETRY PROPAGATION'' below). +If \fIboolean\fR has a false boolean value then propagation is +disabled for \fImaster\fR. +In either of these cases an empty string is returned. +If \fIboolean\fR is omitted then the command returns \fB0\fR or +\fB1\fR to indicate whether propagation is currently enabled +for \fImaster\fR. +Propagation is enabled by default. +.TP +\fBpack slaves \fImaster\fR +Returns a list of all of the slaves in the packing order for \fImaster\fR. +The order of the slaves in the list is the same as their order in +the packing order. +If \fImaster\fR has no slaves then an empty string is returned. + +.SH "THE PACKER ALGORITHM" +.PP +For each master the packer maintains an ordered list of slaves +called the \fIpacking list\fR. +The \fB\-in\fR, \fB\-after\fR, and \fB\-before\fR configuration +options are used to specify the master for each slave and the slave's +position in the packing list. +If none of these options is given for a slave then the slave +is added to the end of the packing list for its parent. +.PP +The packer arranges the slaves for a master by scanning the +packing list in order. +At the time it processes each slave, a rectangular area within +the master is still unallocated. +This area is called the \fIcavity\fR; for the first slave it +is the entire area of the master. +.PP +For each slave the packer carries out the following steps: +.IP [1] +The packer allocates a rectangular \fIparcel\fR for the slave +along the side of the cavity given by the slave's \fB\-side\fR option. +If the side is top or bottom then the width of the parcel is +the width of the cavity and its height is the requested height +of the slave plus the \fB\-ipady\fR and \fB\-pady\fR options. +For the left or right side the height of the parcel is +the height of the cavity and the width is the requested width +of the slave plus the \fB\-ipadx\fR and \fB\-padx\fR options. +The parcel may be enlarged further because of the \fB\-expand\fR +option (see ``EXPANSION'' below) +.IP [2] +The packer chooses the dimensions of the slave. +The width will normally be the slave's requested width plus +twice its \fB\-ipadx\fR option and the height will normally be +the slave's requested height plus twice its \fB\-ipady\fR +option. +However, if the \fB\-fill\fR option is \fBx\fR or \fBboth\fR +then the width of the slave is expanded to fill the width of the parcel, +minus twice the \fB\-padx\fR option. +If the \fB\-fill\fR option is \fBy\fR or \fBboth\fR +then the height of the slave is expanded to fill the width of the parcel, +minus twice the \fB\-pady\fR option. +.IP [3] +The packer positions the slave over its parcel. +If the slave is smaller than the parcel then the \fB\-anchor\fR +option determines where in the parcel the slave will be placed. +If \fB\-padx\fR or \fB\-pady\fR is non-zero, then the given +amount of external padding will always be left between the +slave and the edges of the parcel. +.PP +Once a given slave has been packed, the area of its parcel +is subtracted from the cavity, leaving a smaller rectangular +cavity for the next slave. +If a slave doesn't use all of its parcel, the unused space +in the parcel will not be used by subsequent slaves. +If the cavity should become too small to meet the needs of +a slave then the slave will be given whatever space is +left in the cavity. +If the cavity shrinks to zero size, then all remaining slaves +on the packing list will be unmapped from the screen until +the master window becomes large enough to hold them again. + +.SH "EXPANSION" +.PP +If a master window is so large that there will be extra space +left over after all of its slaves have been packed, then the +extra space is distributed uniformly among all of the slaves +for which the \fB\-expand\fR option is set. +Extra horizontal space is distributed among the expandable +slaves whose \fB\-side\fR is \fBleft\fR or \fBright\fR, +and extra vertical space is distributed among the expandable +slaves whose \fB\-side\fR is \fBtop\fR or \fBbottom\fR. + +.SH "GEOMETRY PROPAGATION" +.PP +The packer normally computes how large a master must be to +just exactly meet the needs of its slaves, and it sets the +requested width and height of the master to these dimensions. +This causes geometry information to propagate up through a +window hierarchy to a top-level window so that the entire +sub-tree sizes itself to fit the needs of the leaf windows. +However, the \fBpack propagate\fR command may be used to +turn off propagation for one or more masters. +If propagation is disabled then the packer will not set +the requested width and height of the packer. +This may be useful if, for example, you wish for a master +window to have a fixed size that you specify. + +.SH "RESTRICTIONS ON MASTER WINDOWS" +.PP +The master for each slave must either be the slave's parent +(the default) or a descendant of the slave's parent. +This restriction is necessary to guarantee that the +slave can be placed over any part of its master that is +visible without danger of the slave being clipped by its parent. + +.SH "PACKING ORDER" +.PP +If the master for a slave is not its parent then you must make sure +that the slave is higher in the stacking order than the master. +Otherwise the master will obscure the slave and it will appear as +if the slave hasn't been packed correctly. +The easiest way to make sure the slave is higher than the master is +to create the master window first: the most recently created window +will be highest in the stacking order. +Or, you can use the \fBraise\fR and \fBlower\fR commands to change +the stacking order of either the master or the slave. + +.SH KEYWORDS +geometry manager, location, packer, parcel, propagation, size |