The Cdk scroll widget creates a scrolling list. The following are functions
which create or manipulate the Cdk scrolling list widget.
AVAILABLE FUNCTIONS
CDKSCROLL *newCDKScroll (CDKSCREEN *screen, int xpos, int ypos, int spos, int height, int width, char *title, char **scrollList, int scrollListLength, boolean numbers, chtype highlight, boolean box, boolean shadow);
This function creates a pointer to a scroll widget. The screen parameter
is the screen you wish this widget to be placed in. The parameter xpos
controls the placement of the object along the horizontal axis. This parameter
can accept an integer value or one of the pre-defined values of LEFT,
RIGHT, and CENTER. The parameter ypos controls the placement
of the object along the vertical axis. This parameter can accept an integer
value or one of the pre-defined values of TOP, BOTTOM, and CENTER.
The parameter spos is where the scroll bar is to be placed. This can
accept one of three values: LEFT, which puts the scroll bar on the left
of the scrolling list. RIGHT which puts the scroll bar on the right side
of the list, and NONE which does not add a scroll bar. The parameters
height and width control the height and width of the widget. If
you provide a value of zero for either of the height or the width, the widget will
be created with the full width and height of the screen. If you provide a negative
value, the widget will be created the full height or width minus the value provided.
The title parameter is the string which will be displayed
at the top of the widget. The title can be more than one line; just provide a
carriage return character at the line break. The parameter scrollList is
the list of items to be displayed in the scrolling list; scrollListLength
is the number of elements in the given list. The parameter numbers is a
boolean value stating that you want the items in the list to have a number
attached to the front of the list items. The highlight parameter specifies
the display attribute of the currently selected item. The box parameter
states whether the widget will be drawn with a box around it or not. The shadow
parameter accepts a boolean value to turn the shadow on or off around this widget.
If the widget could not be created then a NULL pointer is returned.
int activateCDKScroll (CDKSCROLL *scroll, chtype *actions);
This function activates the scroll widget and lets the user interact with the
widget. The parameter scroll is a pointer to a non-NULL scroll widget.
If the actions parameter is passed with a non-NULL value, the characters
in the array will be injected into the widget. To activate the widget
interactively pass in a NULL pointer for actions. If the character entered
into this widget is RETURN or TAB then this function will return a
value from 0 to the number of items-1, representing the item selected. It
will also set the structure member exitType to vNORMAL. If the
character entered into this widget was ESCAPE then the widget will return
a value of -1 and the structure member exitType will be set to
vESCAPE_HIT.
int injectCDKScroll (CDKSCROLL *scroll, chtype character);
This function injects a single character into the widget. The parameter
scroll is a pointer to a non-NULL scroll widget. The parameter
character is the character to inject into the widget. If the character
injected into this widget was RETURN then the character injected into
this widget is RETURN or TAB then this function will return a
value from 0 to the number of items-1, representing the item selected. It
will also set the structure member exitType to vNORMAL. If the
character entered into this widget was ESCAPE then the widget will return
a value of -1 and the structure member exitType will be set to
vESCAPE_HIT. Any other character injected into the widget will set the
structure member exitType to vEARLY_EXIT and the function will
return -1.
This function lets the programmer modify certain elements of an already defined
scroll widget. The parameter names correspond to the same parameter names listed
in the newCDKScroll function.
void setCDKScrollItems (CDKSCROLL *scroll, char **itemList, int listSize, boolean numbers);
This function sets the contents of the scrolling list.
int getCDKScrollItems (CDKSCROLL *scroll, char **itemList);
This fills the parameter itemList with the contents of the scrolling
list. It returns the number of elements in the scrolling list.
This function allows the user to add an item into an already defined scrolling
list. The scroll parameter is a pointer to the scrolling list to add the
item to. The parameter item is a char * representing the new item
to add. The item is always added to the end of the list.
void deleteCDKScrollItem (CDKSCROLL *scroll, int position);
This function allows the user to add an item into an already defined scrolling
list. The scroll parameter is a pointer to the scrolling list to add the
item to. The parameter f2position is an int which specifies which
element to remove.
This sets the background color of the widget. The parameter color
is in the format of the Cdk format strings. To get more information look
at the cdk_display manual page.
void moveCDKScroll (CDKSCROLL *scroll, int xpos, int ypos, boolean relative, boolean refresh);
This function moves the given widget to the given position. The parameters
xpos and ypos is the new position of the widget. The parameter
xpos can accept an integer value or one of the pre-defined values of
TOP, BOTTOM, and CENTER. The parameter ypos can
accept an integer value or one of the pre-defined values of LEFT,
RIGHT, and CENTER. The parameter relative states whether
the xpos/ypos pair is a relative move or an absolute move. For
example if xpos = 1 and ypos = 2 and relative = TRUE,
then the widget would move one row down and two columns right. If the value
of relative was FALSE then the widget would move to the position
(1,2). Do not use the values of TOP, BOTTOM, LEFT,
RIGHT, or CENTER when relative = TRUE. (wierd things
may happen). The final parameter refresh is a boolean value which states
whether the widget will get refreshed after the move or not.
void positionCDKScroll (CDKSCROLL *scroll);
This function allows the user to move the widget around the screen via the
cursor/keypad keys. The following key bindings can be used to move the
widget around the screen.
Key Bindings
Key Action
Up Arrow Moves the widget up one line.
Down Arrow Moves the widget down one line.
Left Arrow Moves the widget left one column
Right Arrow Moves the widget right one column
Keypad-1 Moves the widget down one line
and left one column.
Keypad-2 Moves the widget down one line.
Keypad-3 Moves the widget down one line
and right one column.
Keypad-4 Moves the widget left one column
Keypad-5 Centers the widget both vertically
and horizontally.
Keypad-6 Moves the widget right one column
Keypad-7 Moves the widget up one line
and left one column.
Keypad-8 Moves the widget up one line.
Keypad-9 Moves the widget up one line
and right one column.
t Moves the widget to the top of the screen.
b Moves the widget to the bottom of the screen.
l Moves the widget to the left of the screen.
r Moves the widget to the right of the screen.
c Centers the widget between the left and
right of the window.
C Centers the widget between the top and
bottom of the window.
Escape Returns the widget to it's original position.
Return Exits the function and leaves the widget
where it was.
Keypad means that if the keyboard you are using has a keypad, then the
Num-Lock light has to be on in order to use the keys as listed. (The
numeric keys at the top of the keyboard will work as well.)
This function allows the user to have the widget call a function after a key
is hit and before the key is applied to the widget. The parameter function
if of type PROCESSFN. The parameter data is a pointer to
void. To learn more about pre-processing read the cdk_process
manual page.
This function allows the user to have the widget call a function after the
key has been applied to the widget. The parameter function if of type
PROCESSFN. The parameter data is a pointer to void. To
learn more about post-processing read the cdk_process manual page.
This function allows the user to create special key bindings. The
widgetType parameter is a defined type which states what Cdk object
type is being used. To learn more about the type EObjectType read the
cdk_binding manual page. The object parameter is the pointer to
the widget object. The key is the character to bind. The function
is the function type. To learn more about the key binding callback function
types read the cdk_binding manual page. The last parameter data
is a pointer to any data that needs to get passed to the callback function.
KEY BINDINGS
When the widget is activated there are several default key bindings which will
help the user enter or manipulate the information quickly. The following table
outlines the keys and their actions for this widget.
Key Action
Left Arrow Shifts the whole list left one character.
Right Arrow Shifts the whole list right one character.
Up Arrow Selects the next item up in the list.
Down Arrow Selects the next item down in the list.
Prev Page Moves one page backwards.
Ctrl-B Moves one page backwards.
Next Page Moves one page forwards.
Ctrl-F Moves one page forwards.
g Moves to the first element in the list.
1 Moves to the first element in the list.
G Moves to the last element in the list.
$ Shifts the whole list to the far right.
| Shifts the whole list to the far left.
Return Exits the widget and returns an integer
value representing which item was
selected. This also sets the structure
member exitType in the widget pointer
to the value of vNORMAL.
Tab Exits the widget and returns an integer
value representing which item was
selected. This also sets the structure
member exitType in the widget
pointer to the value of vNORMAL.
Escape Exits the widget and returns -1. This
also sets the structure member
exitType in the widget pointer to
the value of vESCAPE_HIT.
Ctrl-L Refreshes the screen.