cdk_scroll(3)

NAME
cdk_scroll - curses scrolling list widget.

SYNOPSIS

cc [ flag ... ] file ... -lcdk [ library ... ]

#include <cdk.h>

int activateCDKScroll (
    CDKSCROLL *scroll,
    chtype * actions);

void addCDKScrollItem (
    CDKSCROLL *scroll,
    const char *item);

void deleteCDKScrollItem (
    CDKSCROLL *scroll,
    int position);

void destroyCDKScroll (
    CDKSCROLL *scroll);

void drawCDKScroll (
    CDKSCROLL *scroll,
    boolean box);

void eraseCDKScroll (
    CDKSCROLL *scroll);

boolean getCDKScrollBox (
    CDKSCROLL *scroll);

int getCDKScrollCurrent(
    CDKSCROLL *scroll);

int getCDKScrollCurrentItem (
    CDKSCROLL *widget);

chtype getCDKScrollHighlight (
    CDKSCROLL *scroll,
    chtype highlight);

int getCDKScrollCurrentTop (
    CDKSCROLL *widget);

int getCDKScrollItems (
    CDKSCROLL *scroll,
    char **itemList);

int injectCDKScroll (
    CDKSCROLL *scroll,
    chtype input);

void insertCDKScrollItem (
    CDKSCROLL *scroll,
    const char *item);

void moveCDKScroll (
    CDKSCROLL *scroll,
    int xpos,
    int ypos,
    boolean relative,
    boolean refresh);

CDKSCROLL *newCDKScroll (
    CDKSCREEN *cdkscreen,
    int xpos,
    int ypos,
    int spos,
    int height,
    int width,
    const char *title,
    CDK_CONST char **itemList,
    int items,
    boolean numbers,
    chtype highlight,
    boolean box,
    boolean shadow);

void positionCDKScroll (
    CDKSCROLL *scroll);

void setCDKScroll (
    CDKSCROLL *scroll,
    CDK_CONST char **itemList,
    int items,
    boolean numbers,
    chtype highlight,
    boolean box);

void setCDKScrollBackgroundAttrib (
    CDKSCROLL *scroll,
    chtype attribute);

void setCDKScrollBackgroundColor (
    CDKSCROLL *scroll,
    const char * color);

void setCDKScrollBox (
    CDKSCROLL *scroll,
    boolean box);

void setCDKScrollBoxAttribute (
    CDKSCROLL *scroll,
    chtype character);

void setCDKScrollCurrent(
    CDKSCROLL *scroll,
    intitem);

void setCDKScrollCurrentItem (
    CDKSCROLL *widget,
    intitem);

int getCDKScrollCurrentTop (
    CDKSCROLL *widget);

void setCDKScrollHighlight (
    CDKSCROLL *scroll,
    chtype highlight);

void setCDKScrollHorizontalChar (
    CDKSCROLL *scroll,
    chtype character);

void setCDKScrollItems (
    CDKSCROLL *scroll,
    CDK_CONST char **itemList,
    int listSize,
    boolean numbers);

void setCDKScrollLLChar (
    CDKSCROLL *scroll,
    chtype character);

void setCDKScrollLRChar (
    CDKSCROLL *scroll,
    chtype character);

void setCDKScrollPosition (
    CDKSCROLL *scroll,
    intitem);

void setCDKScrollPostProcess (
    CDKSCROLL *scroll,
    PROCESSFN callback,
    void * data);

void setCDKScrollPreProcess (
    CDKSCROLL *scroll,
    PROCESSFN callback,
    void * data);

void setCDKScrollULChar (
    CDKSCROLL *scroll,
    chtype character);

void setCDKScrollURChar (
    CDKSCROLL *scroll,
    chtype character);

void setCDKScrollVerticalChar (
    CDKSCROLL *scroll,
    chtype character);

DESCRIPTION
The Cdk scroll widget creates a scrolling list. The following are functions which create or manipulate the Cdk scrolling list widget.

AVAILABLE FUNCTIONS

activateCDKScroll
    activates the scroll widget and lets the user interact with the widget. The parameter scroll points 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 widget data exitType to vNORMAL. If the character entered into this widget was ESCAPE then the widget will return a value of -1 and the widget data exitType will be set to vESCAPE_HIT.

addCDKScrollItem
    allows the user to add an item into an existing scrolling list. The scroll parameter points 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.

deleteCDKScrollItem
    allows the user to add an item into an existing scrolling list. The scroll parameter points to the scrolling list to add the item to. The parameter f2position is an int which specifies which element to remove.

destroyCDKScroll
    removes the widget from the screen and frees memory the object used.

drawCDKScroll
    draws the scroll widget on the screen. If the box option is true, the widget is drawn with a box.

eraseCDKScroll
    removes the widget from the screen. This does NOT destroy the widget.

getCDKScrollBox
    returns true if the widget will be drawn with a box around it.

getCDKScrollCurrent
    returns the current item's index.

getCDKScrollCurrentItem
    returns the current item number in the scroller.

getCDKScrollHighlight
    returns the attribute of the highlight bar.

getCDKScrollCurrentTop
    returns the top line of the scroller, counting from zero.

getCDKScrollItems
    fills the parameter itemList with the contents of the scrolling list. It returns the number of elements in the scrolling list.

injectCDKScroll
    injects a single character into the widget. The parameter scroll points to a non-NULL scroll widget. The parameter character is the character to inject into the widget. The return value and side-effect (setting the widget data exitType) depend upon the injected character:

    RETURN or TAB
        the function returns a value ranging from zero to one less than the number of items, representing the item selected. The widget data exitType is set to vNORMAL.

    ESCAPE
        the function returns -1. The widget data exitType is set to vESCAPE_HIT.

    Otherwise
        unless modified by preprocessing, postprocessing or key bindings, the function returns -1. The widget data exitType is set to vEARLY_EXIT.

insertCDKScrollItem
    allows the user to add an item into an existing scrolling list. The scroll parameter points 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 before the current item in the list.

moveCDKScroll
    moves the given widget to the given position. The parameters xpos and ypos are the new position of the widget. The parameter xpos may be an integer or one of the pre-defined values TOP, BOTTOM, and CENTER. The parameter ypos may be an integer or one of the pre-defined values 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 TOP, BOTTOM, LEFT, RIGHT, or CENTER when relative = TRUE. (weird things may happen). The final parameter refresh is a boolean value which states whether the widget will get refreshed after the move.

newCDKScroll
    creates a scroll widget and returns a pointer to it. Parameters:

    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 may be an integer or one of the pre-defined values LEFT, RIGHT, and CENTER.

    ypos
        controls the placement of the object along the vertical axis. This parameter may be an integer value or one of the pre-defined values TOP, BOTTOM, and CENTER.

    spos
        is where the scroll bar is to be placed. This may be 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.

    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.

    title
        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.

    itemList
        is the list of items to be displayed in the scrolling list.

    items
        is the number of elements in the given list.

    numbers
        is true if you want the items in the list to have a number attached to the front of the list items.

    highlight
        specifies the display attribute of the currently selected item.

    box is true if the widget should be drawn with a box around it.

    shadow
        is true to turn the shadow on around this widget.

    If the widget could not be created then a NULL pointer is returned.

positionCDKScroll
    allows the user to move the widget around the screen via the cursor/keypad keys. See cdk_position (3) for key bindings.

setCDKScroll
    lets the programmer modify certain elements of an existing scroll widget. The parameter names correspond to the same parameter names listed in the newCDKScroll function.

setCDKScrollBackgroundAttrib
    sets the background attribute of the widget. The parameter attribute is a curses attribute, e.g., A_BOLD.

setCDKScrollBackgroundColor
    sets the background color of the widget. The parameter color is in the format of the Cdk format strings. See cdk_display (3).

setCDKScrollBox
    sets whether the widget will be drawn with a box around it.

setCDKScrollBoxAttribute
    sets the attribute of the box.

setCDKScrollCurrent
    sets the index for the current item.

setCDKScrollCurrentItem
    set the current item number in the scroller.

setCDKScrollCurrentTop
    set the top line number of the scroller.

setCDKScrollHighlight
    sets the attribute of the highlight bar.

setCDKScrollHorizontalChar
    sets the horizontal drawing character for the box to the given character.

setCDKScrollItems
    sets the contents of the scrolling list.

setCDKScrollLLChar
    sets the lower left hand corner of the widget's box to the given character.

setCDKScrollLRChar
    sets the lower right hand corner of the widget's box to the given character.

setCDKScrollPosition
    sets the current item in the widget to the given position.

setCDKScrollPostProcess
    allows the user to have the widget call a function after the key has been applied to the widget. The parameter function is the callback function. The parameter data points to data passed to the callback function. To learn more about post-processing see cdk_process (3).

setCDKScrollPreProcess
    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 is the callback function. The parameter data points to data passed to the callback function. To learn more about pre-processing see cdk_process (3).

setCDKScrollULChar
    sets the upper left hand corner of the widget's box to the given character.

setCDKScrollURChar
    sets the upper right hand corner of the widget's box to the given character.

setCDKScrollVerticalChar
    sets the vertical drawing character for the box to the given character.

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 | Shift the list left one column.
Right Arrow | Shift the list right one column.
Up Arrow | Select the previous item in the list.
Down Arrow | Select the next item in the list.
Prev Page
Ctrl-B | Scroll one page backward.
Next Page
Ctrl-F | Scroll one page forward.
1
<
g
Home | Move to the first element in the list.
>
G
End | Move to the last element in the list.
$ | Shift the list to the far right.
| | Shift the list to the far left.
Return | Exit the widget and return the index of the selected item. Also set the widget data exitType to vNORMAL.
Tab | Exit the widget and return the index of the selected item. Also set the widget data exitType to vNORMAL.
Escape | Exit the widget and return -1. Also set the widget data exitType to vESCAPE_HIT.
Ctrl-L | Refreshes the screen.

SEE ALSO
cdk(3), cdk_binding(3), cdk_display(3), cdk_position(3), cdk_screen(3)