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.TH XRPUSHBUTTON 3X "Xrlib Version 10"
.fi
.ad 1
.SH NAME
XrPushButton - an editor that controls a set of pushbuttons.
.SH SYNOPSIS
#include <X/Xlib.h>
.br
#include <Xr/Xrlib.h>
.sp 1
xrEditor *
.br
.B XrPushButton (instance, message, data)
.in 7
.nf
xrEditor * instance;
INT32      message;
INT8     * data;
.fi
.in
.sp 1
.SH DESCRIPTION
.sp
.P
The push button editor is used to create and process a
group of related push buttons within a given window.  
The number of push buttons, and how they are displayed,
is completely controlled by the application.
Each push button may include an optional text label, which will 
be displayed in the center of the oval representing
the button.
This label may be a single line of text, or it may
be multiple lines of text.
.P
The size of the push buttons are proportional to the
size of the font being used to display the text labels.
By allowing an application to specify this font,
the size of the push buttons can be adjusted for individual displays.
.P
An application may specify one of the push buttons
to be treated as a default selection.
This implies that that button will be drawn with a double wide
border around it.
This feature may be disabled, if not needed.
.sp
.P
This field editor supports two distinct sets of state flags:
those associated with the whole instance (which are modified using
.B MSG_GETSTATE
and
.B MSG_SETSTATE),
and those which are assigned to the individual pushbuttons (which
are modified using
.B MSG_GETITEMSTATES
and
.B MSG_SETITEMSTATES).
The state flags which are associated with the instance as a whole
have precedence over the individual state flags.
For example, if the
.B XrVISIBLE
flags is cleared for the instance, then none of the pushbuttons
will be displayed, regardless of their individual state flag settings.
But, if the
.B XrVISIBLE
flag is set for the instance, then the field editor will look at the
state of the
.B XrVISIBLE
flag associated with each pushbutton, to determine if the
entity should be displayed.
.P
Using the cursor and the mouse, a user is able to interactively
select a push button, by moving the cursor over one
of the buttons, and 'clicking' the mouse button.
When the mouse button is depressed, the selected push button
will be drawn as active (solid filled); when the user releases
the mouse button, the selected push button will be redrawn as
inactive (not filled), and an event will be returned to the
application, notifying it that a push button was selected.
.P
When the editor draws the specified push button instance,
it will attempt to space out the individual buttons, to take
full advantage of the specified 
.I editorRect.
If the rectangle is larger than needed, then the extra
space will be divided equally as blank space between the
rows and columns.
If the rectangle is too small, then the request will fail.
.P
When displaying a push button editor instance, the button
sizes may vary between the various rows and columns.
However, to help prevent the instance from looking disorganized,
the following steps will be taken:
.sp
.in 8
Each button within a particular horizontal row, will
be the same height.
.sp
Each button within a particular vertical column, will
be the same width.
.in

.SH EDITOR MESSAGES
.IP MSG_NEW
This message will be the means by which an application program
can create a push button editor instance in a window.  It will
expect the 
.I instance
parameter to be set to
.B NULL,
and the
.I data 
parameter to point to a filled out instance of the following structure:
.sp
.nf
     typedef struct {
          Window       editorWindowId;
          RECTANGLE    editorRect;
          INT8         editorState;
          INT32        editorFGColor;
          INT32        editorBGColor;
          FontInfo   * editorFont;
          INT16        numFields;
          INT16        numCols;
          INT16        defaultButton;
          INT16        borderWidth;
          INT8      ** labels;
          INT8       * stateFlags;
      } xrPushButtonInfo;
.fi
.sp
.in 7
.ul 1
editorWindowId
.br
.in
.in 9
This field indicates the window to which the editor instance
is to be attached.
Anytime the instance is redrawn, it will be redrawn in this window.
.in
.sp
.in 7
.ul 1
editorRect
.br
.in
.in 9
This describes the location and size of the region 
into which the push button instance is to be located.
If the rectangle is larger than is needed to hold the specified
instance, then the extra space will be used as padding
between the individual push buttons.
If the rectangle is too small, then the request will fail.
.in
.sp
.in 7
.ul 1
editorState
.br
.in
.in 9
This field contains the initial value of the state flags
for this editor instance.
It can be composed of any combination of the
.B XrSENSITIVE
and
.B XrVISIBLE
flags.
.in
.sp
.in 7
.ul 1
editorFGColor
.br
.in
.in 9
This field specifies the foreground color
to be used when drawing the editor instance.
This is used when displaying the button labels,
and for filling an active button.
If this is set to -1, the default foreground color (see
.B XrInit(3X)
) will be used.
.in
.sp
.in 7
.ul 1
editorBGColor
.br
.in
.in 9
This field specifies the background color
to be used when drawing the editor instance.
This is used for filling the interior of an inactive button.
If this is set to -1, the default background color (see
.B XrInit(3X)
) will be used.
.in
.sp
.in 7
.ul 1
editorFont
.br
.in
.in 9
This is a pointer to a structure which describes the font
to be used when creating this editor instance.
If the pointer has been set to 
.B NULL, 
then the editor will use the default system base font.
The font is important not only because it determines how
the labels will look, but it is also used to determine
how large the buttons should be.
.in
.sp
.in 7
.ul 1
numFields
.br
.in
.in 9
This value indicates the total number of push buttons which are
included in this instance.
Once specified, this value cannot be changed.
.in
.sp
.in 7
.ul 1
numCols
.br
.in
.in 9
This value indicates the number of columns into which the
push buttons are to be displayed.
Using this value, and 
.I numFields, 
the editor will automatically calculate the number of rows.
If this value is greater than 
.I numFields,
then the create request will fail.
.in
.sp
.in 7
.ul 1
defaultButton
.br
.in
.in 9
This value indicates which push button should be displayed
as the default selection; this involves drawing the button
with a double wide border.
This value must be in the range 
.I 0 - (numFields - 1);
any value outside this range will disable this feature.
Setting this field to -1 is the standard way to disable
this feature.
.in
.sp
.in 7
.ul 1
borderWidth
.br
.in
.in 9
This value describes the width
of the border surrounding each of the push buttons.
This value must be greater than zero.
.in
.sp
.in 7
.ul 1
labels
.br
.in
.in 9
This is a pointer to an array of 
.B NULL 
terminated
character strings, representing the labels associated with each push button.
If this pointer is set to 
.B NULL, 
then none of the buttons will have labels.
If any of the pointers within the array are 
.B NULL, 
or if a label has a length of zero, then those buttons will not have labels.
The first entry in the array will correspond to push button 0,
the second to push button 1, etc.
The editor will not keep a copy of each of these strings;
instead, it will only keep a copy of the pointer to
the string array.
It will rely on the application to NOT modify these strings,
once the instance has been created.
.sp
As was stated earlier, a label may be a single line of text,
or multiple lines of text.
To create multiple lines, insert a NEWLINE character (octal 012)
at the end of each line of the label.
.in
.sp
.in 7
.ul 1
stateFlags
.br
.in
.in 9
This is a pointer to an array of 8 bit integer values, each containing the
initial state flag settings to be associated with each pushbutton
in the instance.
If this pointer has been set to
.B NULL,
then the state flags for each entity will be set to
.B XrSENSITIVE
and
.B XrVISIBLE.
The first entry in the array corresponds to pushbutton 0, etc.
.in
.sp
.IP
The editor will then draw the push button editor instance in the 
specified window.
.IP
Upon successful completion, a pointer to the newly created
editor structure will be returned to the application.
This value must be used there after, whenever the application
wishes to refer to this particular editor instance.

.IP MSG_FREE
This message is the mechanism by which an editor instance can be destroyed.
The only parameter of importance is the
.I instance
parameter, which is a pointer to the
editor structure, returned by the 
.B MSG_NEW 
message; this parameter specifies which instance is to be destroyed.
.IP
When a push button instance is destroyed, it will be internally
disconnected from the window to which it was attached, it
will no longer handle mouse selects, and it will be removed from the
window, if the instance is visible.
.IP
After an editor instance has been destroyed, no further
messages should be issued in regard to that instance.

.IP MSG_GETSTATE
This message returns the current state of the 
.B XrVISIBLE 
and 
.B XrSENSITIVE
flags for the specified push button instance.  The
.I instance
parameter specifies which instance to use. 
The 
.I data 
parameter should be a pointer to an 8 bit integer value,
into which the current state flags will be placed.
REMEMBER: these are the state flags for the whole instance;
not the state flags for the individual buttons.

.IP MSG_SETSTATE
This message allows an application program to modify the setting of
the 
.B XrSENSITIVE 
and 
.B XrVISIBLE 
flags, for a given push button editor instance.
The 
.I data 
parameter is interpreted as an 8 bit integer value,
containing the new state flag values.
After saving the new state flags, the editor instance will be redrawn,
to reflect the new state.
If an instance is not visible, then the
rectangle which it occupies will be drawn using the background tile
for the window, thus making it invisible. 
If an instance is visible, but not sensitive, 
then each push button will be drawn and filled with a 50% pattern.

.IP MSG_GETITEMSTATES
This message allows an application to obtain a copy of the individual
state flags associated with each of the pushbuttons contained within
the specified editor instance.
These state flags differ from the state flags obtained using
.B MSG_GETSTATE.
The
.I instance
parameter must specify the editor instance to be queried, while the
.I data
parameter should point to an array of 8 bit integer values.
The state flags will be returned by means of this array.
The flags associated with pushbutton 0 will be returned in the first slot
in the array, etc.

.IP MSG_SETITEMSTATES
This message allows an application to modify the individual state flags
associated with each of the pushbuttons contained within the
specified editor instance.
Presently, only the
.B XrVISIBLE
and
.B XrSENSITIVE
flags are supported.
The
.I instance
parameter must specify the editor instance which is to be modified, while the
.I data
parameter should point to an array of 8 bit integer values.
The new state flags which are to be assigned to each entity within
the instance will be obtained from this array.
The value in the first slot of the array will be assigned to
pushbutton 0, etc.
After the new state flags have been saved, only those pushbuttons
whose state flags changed will be redrawn.

.IP MSG_GETITEMCOUNT
This message allows an application to obtain a count, which
indicates the number of individual push buttons in the specified instance.
The editor will assume that the 
.I instance
parameter specifies the editor instance to query, and the
.I data 
parameter points
to a 32 bit integer value; the item count value will be
returned by means of this integer.
.IP
This message is useful when used in conjunction with the
.B MSG_GETITEMRECTS 
message.
It allows an application to obtain the number of items in the
instance, so that the application can then allocate enough
memory to hold the rectangle information returned by
.B MSG_GETITEMRECTS.

.IP MSG_GETITEMRECTS
This message returns the coordinates for the rectangle which
describes each of the individual push buttons.
The message will expect the
.I instance
parameter to specify the editor instance to query, and the
.I data 
parameter to point to a structure of the following format:
.sp
.nf
	RECTANGLE   itemRects[x];
.fi
.sp
This array will then be filled with the rectangle information, and
returned to the application.
.IP
Before an application can make this call, it needs to know
the number of items in the specified instance, so that it can
allocate a structure large enough to hold all of the rectangle
information.
The application should use the 
.B MSG_GETITEMCOUNT 
message to
obtain this information; the application can then allocate
an array large enough to hold all of the rectangle entries.
.IP
The order of the rectangle items returned in the array directly
correlates to the order the items were originally created in.
The first element in the array will describe button 0, the
second button 1, etc.
.IP
This message is useful to those applications which have a need
of knowing where the individual items in a push button instance are located.
The most common use would be by a forms controller, which would
use the information to place an 'active field' indicator by a
given item.

.IP MSG_REDRAW
This editor provides an application with the means for
requesting that an instance of push buttons be redrawn.
The current values, labels and font information will be used.
.IP
When this message is issued, the
.I instance 
parameter must be
a pointer to the editor structure associated with the instance
to be redrawn.
The
.I data
parameter must be a 32 bit integer 
which specifies the type of redraw to perform.
.IP
This message is useful for when an application wishes to modify
the value or the state flags for a particular button.
The application need only modify the appropriate values in
the shared arrays, and then issue a
.B MSG_REDRAW 
request; the editor instance will automatically be drawn to match
the new data.
.IP
The push button editor supports the following redraw mode:
.sp
.in 8
.nf
.B - XrREDRAW_ALL
.fi
.in
.IP
When the 
.B XrREDRAW_ALL 
option is specified, the complete editor instance will be redrawn.
.IP
If any other redraw mode is specified, then the request will fail.

.IP MSG_SIZE
This message allows an application to obtain the rectangle needed to
contain a push button editor instance.
The push button editor expects the 
.I instance
parameter to be set to
.B NULL,
and the
.I data 
parameter to point to an instance of the following structure:
.sp
.nf
     typedef struct {
          Window       editorWindowId;
          RECTANGLE    editorRect;
          INT8         editorState;
          INT32        editorFGColor;
          INT32        editorBGColor;
          FontInfo   * editorFont;
          INT16        numFields;
          INT16        numCols;
          INT16        defaultButton;
          INT16        borderWidth;
          INT8      ** labels;
          INT8       * stateFlags;
 } xrPushButtonInfo;
.fi
.sp
.IP
The only fields which must be filled out by the application program BEFORE
issuing this call, are the 
.I numFields, numCols, labels, borderWidth, defaultButton
and 
.I editorFont 
fields; all other fields are ignored.
.IP
In return, the
.I editorRect
field will be filled in with the coordinates for the 0
based rectangle needed to contain the instance; an
application can then offset and stretch this rectangle,
to position it where ever it likes, within its window.
.IP
If 
.I numCols > numFields, 
then the request will fail.

.IP MSG_MOVE
This message provides an application with a means for quickly relocating 
a particular editor instance within a window.
The size of the 
.I editorRect 
associated with the instance is not changed.
To relocate an editor instance, a new origin point for the instance's
.I editorRect 
must be specified; the top left corner of the editor rectangle 
will then be translated such that it now coincides with the new origin.
The origin point is interpreted as an absolute position within the window.
.IP
When this message is issued, the
.I instance
parameter must point to the editor structure associated with the
instance which is to be moved, while the
.I data
parameter must point to a 
.I POINT 
structure, containing the new
.I editorRect 
origin.
.IP
When an editor instance is relocated, the field editor will automatically
remove the visual image of the instance from the window, and will then redraw
the instance at its new location; this occurs only if the instance is
visible.

.IP MSG_RESIZE
This message provides an application with a means for both changing the
size of the 
.I editorRect
associated with a particular editor instance, and also the location of
the new
.I editorRect.
All restrictions regarding the
.I editorRect
size which applied when the instance was first created using
.B MSG_NEW,
still apply.
If an invalid 
.I editorRect
is specified, then the resize request will fail.
.IP
When this message is issued, the
.I instance
parameter must point to the editor structure associated with the instance
which is to be resized, while the
.I data
parameter must point to a 
.I RECTANGLE 
structure containing the
new size and origin for the 
.I editorRect.
.IP
When an editor instance is resized, the field editor will automatically
remove the visual image of the instance from the window, and will then
redraw the instance using the new size and location information; this
occurs only if the instance is visible.

.IP MSG_EDIT
Normally, an application will not issue this message;
it is usually issued by the Xrlib input routines,
when an input event occurs within a push button instance.
.IP
When such an event occurs, a
.B MSG_EDIT 
message will be issued to the editor, with
the first parameter,
.I instance,
indicating which push button instance to process, and
the third parameter,
.I data,
pointing to an 
.I XEvent
structure.
.IP
The push button editor only handles an event if 
event maps to an
.B XrSELECT
event, as described by
.B XrMapButton(3X)
and
.B XrInit(3X);
all others are ignored.  When a select event
occurs within a push button instance, the first thing done is to determine
if one of the individual push buttons was selected.
.IP
If one of the push buttons was selected, then that button
will be drawn as active (filled), and the editor will then
wait for the user to release the select button.
When the user releases the select button, the push button
will again be drawn as inactive (not filled).
Afterwards, an input event will be added to the front of the
application's input queue, informing it that one
of the push buttons has been selected. 
The returned 
.I xrEvent
structure is set to the following value:
.sp
.in 8
.nf
type      = XrXRAY
source    = the window id
inputType = XrEDITOR
inputCode = XrPUSHBUTTON
value1    = XrSELECT
value2    = index of button which was selected.
valuePtr  = pointer to instance's editor structure
.fi
.in
.IP
If a select occurs within a push button instance, but not within
the boundary of a button, then the editor will do
nothing but push an input event onto the front of the application's
input queue.
The event will notify the application that the editor was selected,
but no action took place.
It will also include the cursor position at the time the select
event occurred.
The returned 
.I xrEvent
structure is set to the following value:
.sp
.in 8
.nf
type      = XrXRAY
source    = the window id
inputType = XrEDITOR
inputCode = XrPUSHBUTTON
value1    = NULL
valuePt   = cursor position
valuePtr  = pointer to instance's editor structure
.fi
.in

.SH RETURN VALUE
Upon successful completion of any of the messages, a non-NULL
value will be returned.
In the case of 
.B MSG_NEW,
this non-NULL value will be the pointer to the newly created
editor instance structure.
.P
If a message request fails, then a NULL value is returned.

.SH ERROR CONDITIONS
Messages to the push button editor will fail, set the
.I xrErrno
global and return a NULL
value, under the following conditions:
.sp
.IP MSG_NEW
.I data
is set to NULL [XrINVALIDPTR].
.IP
.I editorWindowId
is an invalid Id [XrINVALIDID].
.IP
.I numCols > numFields [XrINVALIDPARM].
.IP
The width specified in
.I borderWidth
is zero [XrINVALIDPARM].
.IP
An invalid editor rectangle is specified [XrINVALIDRECT].
.IP
A call to 'X' failed { XMakePixmap() } [XrXCALLFAILED].
.IP
Memory cannot be allocated [XrOUTOFMEM].
.sp
.IP MSG_REDRAW
A redraw mode other than
.B XrREDRAW_ALL
is specified [XrINVALIDOPTION].
.sp
.IP MSG_SIZE
.I data
is set to NULL [XrINVALIDPTR].
.IP
.I numCols > numFields [XrINVALIDPARM].
.IP
The width specified in
.I borderWidth
is zero [XrINVALIDPARM].
.sp
.IP MSG_RESIZE
An invalid editor rectangle is specified [XrINVALIDRECT].
.sp
.IP "MSG_GETSTATE, MSG_MOVE, MSG_RESIZE, MSG_GETITEMRECTS,"
.IP "MSG_GETITEMSTATES, MSG_SETITEMSTATES and MSG_GETITEMCOUNT"
.I data
is set to NULL [XrINVALIDPTR].
.sp
.IP "All messages, except MSG_NEW and MSG_SIZE"
The
.I instance
parameter is set to NULL [XrINVALIDID].

.SH "SEE ALSO"
XrInput(3X), XrInit(3X)
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