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prefab: Compound - windows for ITV toolkit


include "draw.m";
include "prefab.m";
prefab := load Prefab Prefab->PATH;

Compound: adt
    image:     ref Draw->Image;
    environ:   ref Environ;
    r:         Draw->Rect;
    title:     ref Element;
    contents:  ref Element;
    iconbox:   fn(env: ref Environ,
               p: Draw->Point, title: string, icon,
               mask: ref Draw->Image):
               ref Compound;
    textbox:   fn(env: ref Environ,
               r: Draw->Rect,  title, text: string):
               ref Compound;
    layoutbox: fn(env: ref Environ,
               r: Draw->Rect,  title: string, lay: list of Layout):
               ref Compound;
    box:       fn(env: ref Environ,
               p: Draw->Point, title, elist: ref Element):
               ref Compound;
    draw:      fn(comp: self ref Compound);
    redraw:      fn(comp: self ref Compound, r: Draw->Rect);
    scroll:    fn(comp: self ref Compound, elem: ref Element,
			d: Draw->Point);
    show:      fn(comp: self ref Compound, elem: ref Element): int;
    select:    fn(comp: self ref Compound,
               elem: ref Element, i: int, c: chan of int):
               (int, int, ref Element);
    tagselect: fn(comp: self ref Compound,
               elem: ref Element, i: int, c: chan of int):
               (int, int, ref Element);
    highlight: fn(comp: self ref Compound,
               elem: ref Element, on: int);


Compound is the data type defining boxes drawn on the screen. Each appears in a new window, Compound.image, and holds a (possibly nil) title Element and contents Element. It occupies the space on the screen defined by Compound.r. Allocating a Compound creates a window but does not draw it; after the Compound is built, Compound.draw must be called to make it visible. Compounds have a border around them, drawn in Style.edgecolor and contain from top to bottom the title (if any), a horizontal line (if there is a title), and the contents.

Compound.iconbox(env, p, title, icon, mask)
Creates a Compound whose contents are made by calling Element.icon (see prefab-element(2)) using the icon and mask. The Compound's upper left corner is at p; its size is determined by the size of the icon and mask.
Compound.textbox(env, r, title, text)
Creates a Compound whose contents are made by calling Element.text using the supplied text. As with Element.text, the resulting contents Element will be actually a list of text Elements if the text occupies multiple lines on the screen. The rectangle behaves as in Element.text.
Compound.layoutbox(env, r, title, layoutlist)
Like Compound.textbox, but based on Element.layout rather than Element.text.
Compound.box(env, p, title, element)
Creates a Compound whose contents are made from an existing Element. To build complex structures, use the Element-building functions, size the Element appropriately, and use Compound.box. The result is positioned with its upper left corner at p, and with size determined by that of the Element.

However a Compound is built, its size computation makes allowance for the border and title. Moreover, if the requested size and placement makes part appear offscreen, the result may be moved to display it better.

This function uses the description of the title and contents to paint the on-screen image. It takes no arguments; all the information is included in the description.
Like Compound.draw, but restricts the drawing to the specified Rect r.

Compound.select( element, index, c ): (int, int, Element) The channel c is a chan of int connected to an IR remote control interface, typically acquired through the program's Context (see draw-context(2)). The element is contained in the Compound, and may be at any level of its structure. It is most usefully a list, but may be a singleton, in which case it behaves like a list of one element. The arrow keys on the remote control scroll through the members of the list, using the Style.highlightcolor associated with each member element to indicate selection. A Select key on the remote control triggers select to return a tuple (key, index, elem); key is the key code of the action (here Select), index is the number of the element in the list (ignoring separators), and elem is the list member highlighted when the key was hit. Any other key returns the same tuple with index -1 and the value of the key. The elem returned is always the most recently highlighted, even if the result was not a selection. When select returns, it always restores the default appearance of the list.

Compound.tagselect( element, index, c): (int, int, Element) Like Compound.select, but rather than selecting among all the elements of a list, it selects among only those elements with defined tags in the structure contained within the specified element.
Set the highlighting to be ``on'' or ``off'' for the element within the compound.
Like Element.scroll: scroll the element within the compound. The updated image is redrawn after the scrolling.
Compound.show(elementd) Like Element.show: make sure the element is visible within the rectangle of the top-level Element of the Compound, that is, in effect call Element.show(Compound.contents, element);




prefab-element(2), prefab-environ(2), prefab-style(2)

PREFAB-COMPOUND(2 ) Rev:  Thu Feb 15 14:43:26 GMT 2007