This document isn't totally up-to-date with Version 3.1 yet. One of
these days...
This programmer's reference for the ListTree widget uses HTML3 tables,
support for which is becoming very common among WWW browsers. Both Netscape
and Mosaic (the most common browsers) support tables, and support for tables in
Chimera (my browser of choice) will
be included in version 2.0.
To use the ListTree widget in an application, include the three source code
files ListTree.c, ListTree.h, and ListTreeP.h with the rest of the source code
for the application. Include the object ListTree.o in the Makefile rule that
compiles the application.
In source code that uses the ListTree widget, include the following two header
files before references to the plot widget:
#include <X11/Intrinsic.h>
#include "ListTree.h"
To create the ListTree widget, use the following code as an example:
tree=XmCreateScrolledListTree(parent,"tree",NULL,0);
This example creates an empty ListTree widget as the child of
some container widget named parent. The ListTree widget now creates its own
scrollbars and does not have to be placed in a scrolling container widget.
It is also now dependent on the Motif widget set; I broke my rules about
using Motif in non-free programs because the LessTif project is far enough
along that the scrollbars are quite stable. Once LessTif is complete, there
will be no reason to use any other toolkit.
List items must be
added to the widget using convenience functions, because I couldn't think of
a good way to add heirarchal items through resources. The convenience
function method is also very easy, so this design decision wasn't difficult.
Adding items to the list is outlined below:
int i;
ListTreeItem *level1,*level2;
level1=ListTreeAdd(tree,NULL,"Item 1");
level1=ListTreeAdd(tree,NULL,"Item 2");
level2=ListTreeAdd(tree,level1,"Item 3");
This adds three items to the ListTree widget tree,
where Item 3 is a child of
Item 2, and both Item 1 and Item 2 are root level items.
See
Public Functions
below for descriptions of all of the convenience
functions.
The following structure is returned from the ListTreeAdd convenience
function, and is used whenever an item is referenced.
typedef struct _ListTreeItem {
Boolean open;
Boolean highlighted;
char *text;
int length;
int x,y,ytext;
int count;
Dimension height;
ListTreeItemType type;
struct _ListTreeItem *parent,*firstchild,*prevsibling,*nextsibling;
Pixmap openPixmap,closedPixmap;
XtPointer user_data;
} ListTreeItem;
When this structure is returned for an item, the value points to the actual
item, not a copy of the item. Do not modify any value in the structure
except for the user_data entry, which is provided for your use. (Use the
ListTreeRenameItem() public function to modify the text
in the item.)
I'll rephrase this for emphasis: the items returned from the widget are
the actual items the widget uses when it draws the tree. So, unless you want
to Mess Things Up Real Good and crash your program, don't fiddle with the
item structure.
OK, disclaimer out of the way, there is a lot of information available
here that I didn't want to take away from you, gentle programmer. Stuff like
open may be safely modified, but stay away from changing any of the
positions or dimensions. Bad news to mess with those.
Really, Really, Really, don't modify parent, firstchild, prevsibling,
or nextsibling.
I mean it, because it is possible to throw the widget into an infinite
loop.
Trust me.
The ListTree widget defines the following new resources:
Name | Class | Type | Default
|
---|
XtNbranchOpenPixmap | XtCPixmap | Pixmap | XtUnspecifiedPixmap
|
XtNbranchPixmap | XtCPixmap | Pixmap | XtUnspecifiedPixmap
|
XtNclickPixmapToOpen | XtCBoolean | Boolean | True
|
XtNdoIncrementalHighlightCallback | XtCBoolean | Boolean | False
|
XtNfont | XtCFont | XFontStruct* | XtDefaultFont
|
XtNforeground | XtCForeground | Pixel | XtDefaultForeground
|
XtNhighlightPath | XtCBoolean | Boolean | False
|
XtNhorizontalSpacing | XtCMargin | Dimension | 2
|
XtNindent | XtCMargin | Dimension | 0
|
XtNleafOpenPixmap | XtCPixmap | Pixmap | XtUnspecifiedPixmap
|
XtNleafPixmap | XtCPixmap | Pixmap | XtUnspecifiedPixmap
|
XtNlineWidth | XtCMargin | Dimension | 0
|
XtNmargin | XtCMargin | Dimension | 2
|
XtNspacing | XtCMargin | Dimension | 4
|
XtNverticalSpacing | XtCMargin | Dimension | 0
|
- XtNbranchOpenPixmap
- Pixmap to use for an item that is open and has children.
- XtNbranchOpenPixmap
- Pixmap to use for an item that is closed and has children.
- XtNclickPixmapToOpen
- If True, a single click on the pixmap of an item is equivalent to a double
click on the item's text.
- XtNdoIncrementalHighlightCallback
- Calls the highlight callback after each item is highlighted; otherwise
only calls the callback after the button has been released and all items have
been highlighted.
- XtNfont
- Font to use for items.
- XtNforeground
- Foreground color for text. Also used for the bitmap color, if any of
the Pixmap resources is defined instead as a bitmap.
- XtNhighlightPath
- Highlights the item's parents when an item is opened.
- XtNhorizontalSpacing
- Pixel distance between the Pixmap and item text.
- XtNindent
- Pixel distance to indent a new level of items. Note that this distance
is in addition to the width of the Pixmap.
- XtNleafOpenPixmap
- Pixmap to use for an item that is open and does not have children.
- XtNleafPixmap
- Pixmap to use for an item that is closed and does not have children.
- XtNlineWidth
- Specifies the line width used to draw the list heirarchy.
- XtNmargin
- Pixel distance between the border of the widget and any text or Pixmap.
- XtNverticalSpacing
- Pixel distance between neighboring items in the list.
The ListTree widget defines the following callback resources:
- XtNactivateCallback
- Called when any item is opened or closed.
- XtNhighlightCallback
- Called when any item is highlighted.
- XtNmenuCallback
- Called when the right mouse button is pressed over an item.
- XtNdestroyItemCallback
- Called for each items that is deleted. This allows for the graceful
freeing of anything allocated for user_data.
This callback is called whenever an item is opened, or if an item is
explicitly closed. The following structure is sent to the callback.
typedef struct _ListTreeActivateStruct {
int reason;
ListTreeItem *item;
Boolean open;
ListTreeItem **path;
int count;
} ListTreeActivateStruct;
- reason
- One of two constants, XtBRANCH or XtLEAF, indicating that the item
has children or does not, respectively.
- item
- Pointer to the item selected (or unselected).
- open
- The state of the selected item.
- path
- The path from the root of the list to the selected item, including the
selected item.
- count
- The number of items in path.
This callback is called whether the item is opened or closed, and
is passed the following structure.
typedef struct _ListTreeMultiReturnStruct {
ListTreeItem **items;
int count;
} ListTreeMultiReturnStruct;
- items
- Pointer to a list of pointers that holds all of the highlighted items.
- count
- The number of highlighted items.
This callback can be used to post a menu over the item, or some other
application defined function may be implemented. It is passed the ItemReturn
structure.
typedef struct _ListTreeItemReturnStruct {
int reason;
ListTreeItem *item;
XEvent *event;
} ListTreeItemReturnStruct;
- reason
- The constant XtMENU.
- item
- Pointer to the highlighted item.
- event
- The XEvent that triggered the callback (should be cast to a pointer to
an XButtonEvent).
Called whenever an item is deleted, the callback function is passed the
ItemReturn structure.
typedef struct _ListTreeItemReturnStruct {
int reason;
ListTreeItem *item;
XEvent *event;
} ListTreeItemReturnStruct;
- reason
- The constant XtDESTROY.
- item
- Pointer to the highlighted item.
- event
- This is not used and is assigned the value NULL.
Three other callbacks did exist in previous versions of the widget, but I
removed them. I warned ya! :)
All changes to the widget are reflected immediately, unless a call to
ListTreeRefreshOff() is made before updating. ListTreeRefreshOn() must be
called before the list will start to update itself again.
I could probably have gone on forever writing convenience functions for
more and more generalized states, but I'd still be typing the source code, and
not working on this here primo-excellent documentation. :) So, this is where
the "batteries not included" phrase enters in: it is up to you to customize
the widget for your own use. The entire tree of items contained in the
widget is available for parsing by you by calling ListTreeFirstItem()
and using the firstchild and nextsibling fields of the
ListTreeItem structure.
Be careful not to copy over the text field of a ListTreeItem,
because it is a malloced string. Use ListTreeRenameItem() if you need
to change a name.
-
- Widget XmCreateScrolledListTree(Widget parent, char *name,
Arg *args, Cardinal count)
- Creates a ListTree widget as a child of an XmScrolledWindow (which in
turn is a child of parent), and returns its widget ID.
-
- void ListTreeRefreshOff(ListTreeWidget w)
- Turns off the automatic updating of the list. Useful when adding many
items to the list.
- void ListTreeRefreshOn(ListTreeWidget w)
- Turns on the automatic updating.
-
- ListTreeItem *ListTreeAdd(ListTreeWidget w, ListTreeItem *parent, char *string)
- Adds an item to the list as a child of parent. If parent is
NULL, adds the item as a root item. All items are added at the end of
the list of children of that parent; i.e. they are not sorted.
Returns NULL if an error occurs.
- int ListTreeDelete(ListTreeWidget w, ListTreeItem *item)
- Removes item and all of its children from the list.
Returns 1 if successful, 0 if failure.
- int ListTreeDeleteChildren(ListTreeWidget w, ListTreeItem *item)
- Removes only the children of item from the list.
Returns 1 if successful, 0 if failure.
- void ListTreeRenameItem(ListTreeWidget w, ListTreeItem *item, char *string)
- Changes the text of item to string.
- int ListTreeReparent(ListTreeWidget w, ListTreeItem *item, ListTreeItem *newparent)
- Moves item to become a new child of newparent.
Returns 1 if successful, 0 if failure.
- int ListTreeReparentChildren(ListTreeWidget w, ListTreeItem *item, ListTreeItem *newparent)
- Moves the children of item to become a new children
of newparent.
Returns 1 if successful, 0 if failure.
- void ListTreeGetPathname(ListTreeReturnStruct * ret, char *dir)
-
Copies the path of the given list structure to the supplied pointer.
- void ListTreeGetPathnameFromItem(ListTreeItem * item, char *dir)
-
Copies the path of the given item to the supplied pointer.
- Position ListTreeGetItemPosition(ListTreeWidget w, ListTreeItem * item)
-
Retrieves the Position of the given item
-
- int ListTreeOrderChildren(ListTreeWidget w, ListTreeItem *item)
- Alphabetize the children of item.
Returns 1 if successful, 0 if failure.
- int ListTreeOrderSiblings(ListTreeWidget w, ListTreeItem *item)
- Alphabetize all siblings of item.
Returns 1 if successful, 0 if failure.
- int ListTreeUserOrderChildren(ListTreeWidget w, ListTreeItem *item,int (*func)())
- Orders the children of item according to a user-specified
procedure.
Returns 1 if successful, 0 if failure.
- int ListTreeUserOrderSiblings(ListTreeWidget w, ListTreeItem *item,int (*func)())
- Orders all siblings of item according to a user-specified
procedure.
Returns 1 if successful, 0 if failure.
- Note for the user order subroutines:
- func() should be a pointer to
a function that can be fed to qsort(). I.e. it takes two void pointers
and returns an integer that is negative if the first item should be listed
before the second, positive if the first should be listed after the second,
and zero if the two items go in the same position. The list that is sorted
by qsort is a list of ListTreeItem pointers, so each void pointer to your
sorting function must cast into a pointer to a ListTreeItem pointer. A bit
of code would probably make this clearer: the following code is from
ListTree.c that is used to alphabetize the list.
int
AlphabetizeItems(const void *item1, const void *item2)
{
return strcmp((*((ListTreeItem **) item1))->text,
(*((ListTreeItem **) item2))->text);
}
-
- ListTreeItem *ListTreeFirstItem(ListTreeWidget w)
- Returns the first item in list. Returns NULL if there are no items
in the list.
- ListTreeItem *ListTreeFindSiblingName(ListTreeWidget w, ListTreeItem *item, char *name)
- Searches for name among the siblings of item.
Returns NULL if the name is not found.
- ListTreeItem *ListTreeFindChildName(ListTreeWidget w, ListTreeItem *item, char *name)
- Searches for name among the children of item.
Returns NULL if the name is not found.
-
- void ListTreeHighlightItem(ListTreeWidget w, ListTreeItem *item)
- Highlights item and unhighlights previously highlighted items.
- void ListTreeHighlightAll(ListTreeWidget w)
- Highlights all items currently visible in the widget. Only top level
items and items that are direct descendants of open items are highlighted.
I.e. items whose parents are closed are not highlighted.
- void ListTreeClearHighlighted(ListTreeWidget w)
- Unhighlights any items currently selected in the widget.
- void ListTreeGetHighlighted(ListTreeWidget w,ListTreeMultiReturnStruct *ret)
- Fills the return struct with the items currently selected in the widget.
- void ListTreeSetHighlighted(ListTreeWidget w, ListTreeItem **items, int count, Boolean clear)
- Unhighlights any previously highlighted items if clear is True.
Then, highlights count
items from the list items. If count is negative, the list items
should be NULL terminated.
ListTree :
Programmer's Reference