PLBUTTON(2) System Calls Manual PLBUTTON(2)
NAME
plbutton, plcanvas, plcheckbutton, pledit, plentry, plframe, plgroup, plidollist, pllabel, pllist, plmenu, plmenubar, plmessage, plpopup,
plpulldown, plradiobutton, plscrollbar, plslider, pltextview - panel-creation functions
SYNOPSIS
#include <u.h>
#include <libg.h>
#include <panel.h>
Panel *plbutton(Panel *parent, int flags, Icon *label,
void (*hit)(Panel *pl, int))
Panel *plcanvas(Panel *parent, int flags,
void (*draw)(Panel*), void (*hit)(Panel*, Mouse*))
Panel *plcheckbutton(Panel *parent, int flags, Icon *label,
void (hit*)(Panel*, int, int))
Panel *pledit(Panel *parent, int flags, Point size, Rune *text,
int ntext, void (*hit)(Panel*))
Panel *plentry(Panel *parent, int flags, int width, char *text,
void (*enter)(Panel*, char*))
Panel *plframe(Panel *parent, int flags)
Panel *plgroup(Panel *parent, int flags)
Panel *pllabel(Panel *parent, int flags, Icon *label)
Panel *pllist(Panel *parent, int flags, char *(*gen)(int),
int length, void(*hit)(Panel*, int, int))
Panel *plmenu(Panel *parent, int flags, Icon **items,
int itemflags, void (*hit)(int, int))
Panel *plmenubar(Panel *parent, int flags, int itemflags,
Icon *label1, Panel *p1, Icon *label2, ...)
Panel *plmessage(Panel *parent, int flags, int width, char *text)
Panel *plpopup(Panel *parent, int flags,
Panel *left, Panel *middle, Panel *right)
Panel *plpulldown(Panel *parent, int flags,
Icon *label, Panel *pull, int side)
Panel *plradiobutton(Panel *parent, int flags, Icon *label,
void (*hit)(Panel*, int, int))
Panel *plscrollbar(Panel *parent, int flags)
Panel *plslider(Panel *parent, int flags, Point size,
void(*hit)(Panel*, int, int, int))
Panel *pltextview(Panel *parent, int flags, Point size,
Rtext *text, void (*hit)(Panel*, int, Rtext*))
DESCRIPTION
Each of these functions creates and initializes a new node of a Panel tree and returns a pointer to the newly created panel. Existing pan-
els may be reinitialized (for example to change the label on a button) by functions enumerated in plinitbutton(2).
The first two arguments of each panel-creation function are a pointer to the new panel's parent and the flags that control plpack (see
plinit(2)). Arguments of type Icon* (a synonym for void*) are either Bitmap or text labels. If the BITMAP bit of the flag word is set,
they are of type Bitmap*. Otherwise, their type is char*.
plbutton
plcheckbutton
plradiobutton
These three functions create pushbuttons. Plbutton creates an ordinary button. Plcheckbutton creates a button with a check mark
that toggles on and off when the button is hit. Plradiobutton likewise creates a button with a check mark, but with the additional
feature that toggling the check mark on toggles off the checks of its siblings in the Panel tree. All three take similar arguments:
label is the text or bitmap drawn on the button, and hit is the function called when a hit is registered on the button. Its argu-
ments are a pointer to the button and the mouse buttons active when the hit occurred. The hit functions of plcheckbutton and plra-
diobutton take a third argument that indicates the state of the button's check mark.
Occasionally, a button or other panel may wish to take no action on sensing a hit. This is indicated by passing a null hit function
pointer to the creation function.
plframe
plgroup
These two functions create compound panels that enclose their children in a rectangular area. The difference is that plframe draws
a frame around its children, but plgroup does not.
pllabel
plmessage
These two functions create passive (insensitive to mouse or keyboard events) panels. The pllabel entry draws a label containing a
text string or a Bitmap. Plmessage draws longer messages. Its arguments are the desired width of the panel, in pixels, and a
pointer to the text to be drawn. The text is displayed on multiple lines, wrapping around at word boundaries.
plcanvas
creates an empty rectangle in a panel tree. The draw argument is a function to be called by the panel library to redraw the panel.
Draw's argument points to the canvas to be drawn on. The hit argument is a function called whenever a mouse event is registered in
the panel. Its arguments are a pointer to the panel and a pointer to the mouse event. Hit receives all mouse events with points
within the canvas's rectangle and with a button down. In addition, an event is sent when the buttons are released over the canvas,
or when the mouse moves out of the canvas's rectangle. In the latter case, the mouse event's buttons field has the OUT bit set.
pledit creates a panel that displays editable single-font text. Arguments are the minimum acceptable size for the panel, a pointer to an
array of Runes that initializes the panel, the number of runes in the array, and a function to be called every time a selection is
swept out with the mouse. The functions pleget, plelen, plegetsel, plepaste, plesel, plescroll, and pleshowsel, described in
plinit(2), manipulate the contents of edit panels.
plentry
creates a single-line text entry panel. Arguments are the minimum acceptable width of the panel, in pixels, a string that is the
initial contents of the panel, and a hit function to be called whenever a newline is typed in the panel. The hit function's argu-
ments are a pointer to the panel and a pointer to the string entered. Clicking the mouse over an entry makes it the keyboard focus
(the recipient of typed characters), as does calling plgrabkb (described in plinit(2)).
pllist creates a panel containing a scrollable list of text items. Its arguments are gen, a pointer to a function that, when passed an
integer argument, returns the text of the appropriate list item, length, the minimum acceptable number of items to be displayed on
the screen, and hit, a function to be called when an item is selected with the mouse. Hit's arguments are a pointer to the panel,
which mouse buttons were used to make the selection, and the number of the item selected.
plmenu calls plgroup and plbutton to create an array of buttons. The items argument points to an array of strings or Bitmap pointers, one
per button. A null pointer ends the list. Itemflags is the flag argument used to create each button. The hit function's arguments
are the mouse buttons pressed to register the hit and the button's index in items.
plpopup
creates a group, as in plgroup, except that where plgroup always passes mouse events on to its children, plpopup may instead tempo-
rarily pop up a new panel and divert mouse events to it. The arguments left, middle, and right are pointers to panels to be popped
up when the corresponding mouse button is pushed. A null pointer causes events to pass through to plpopup's children.
plpulldown
plmenubar
Plpulldown creates a button that, when triggered by a mouse button push, temporarily pops up a new panel. The label argument points
to a Bitmap or text label, pull points to the panel that appears when the button is pushed, and side is a flag whose value is one of
PACKN, PACKE, PACKS, or PACKW, indicating the side of the button on which the pulled-down menu should appear. The plmenubar entry
calls plgroup and plpulldown to create an array of pull-down buttons. Its itemflags argument gives the flags to be used when creat-
ing each pull-down button. Then follow an indefinite number of pairs giving the labels and pulled-down panels of the buttons. The
list ends with a null label pointer.
plslider
creates a continuously variable slider. The size argument gives the smallest acceptable size. If size.x>size.y the slider is drawn
horizontally, otherwise vertically. The hit function is called whenever a mouse event changes the slider's value. Its arguments
are a pointer to the slider, the mouse buttons, the slider's value, and the possible range of values. The value is always between 0
and the range.
plscrollbar
creates a scroll bar. If the flags argument has PACKE or PACKW set, the scroll bar slides vertically, otherwise horizontally.
Scroll bars are associated with the panels that they scroll by a call to plscroll, described in plinit(2).
pltextview
creates a panel containing hit-sensitive formatted multi-font text with bitmap illustrations. Its arguments are the minimum accept-
able size of the panel, in pixels, a pointer to a data structure describing the text to be displayed, and a function to be called
upon registering a mouse hit. The arguments of the hit function are a pointer to the panel, the mouse buttons that caused the hit,
and a pointer to the text element that the mouse pointed at. The functions plrtstring and plrtbitmap, which create the Rtext data
structure that describes the text, are described in plinit(2).
SOURCE
/sys/src/libpanel
SEE ALSO
plinit(2), plinitbutton(2), graphics(2)
Tom Duff, ``A quick introduction to the panel library''.
PLBUTTON(2)