managedlist.c

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static const char CVSID[] = "$Id: managedList.c,v 1.12 2003/05/02 19:19:03 edg Exp $";
/*******************************************************************************
*									       *
* managedList.c -- User interface for reorderable list of records	       *
*									       *
* Copyright (C) 1999 Mark Edel						       *
*									       *
* This is free software; you can redistribute it and/or modify it under the    *
* terms of the GNU General Public License as published by the Free Software    *
* Foundation; either version 2 of the License, or (at your option) any later   *
* version.							               *
* 									       *
* This software is distributed in the hope that it will be useful, but WITHOUT *
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or        *
* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License        *
* for more details.							       *
* 									       *
* You should have received a copy of the GNU General Public License along with *
* software; if not, write to the Free Software Foundation, Inc., 59 Temple     *
* Place, Suite 330, Boston, MA  02111-1307 USA		                       *
*									       *
* Nirvana Text Editor	    						       *
* November, 1995							       *
*									       *
* Written by Mark Edel							       *
*									       *
*******************************************************************************/

#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif

#include "managedList.h"
#include "misc.h"

#include <stdio.h>
#include <string.h>

#include <X11/Intrinsic.h>
#include <Xm/Form.h>
#include <Xm/List.h>
#include <Xm/PushB.h>
#include <Xm/RowColumn.h>

#ifdef HAVE_DEBUG_H
#include "../debug.h"
#endif

/* Common data between the managed list callback functions */
typedef struct {
    Widget listW, deleteBtn, copyBtn, moveUpBtn, moveDownBtn;
    void *(*getDialogDataCB)(void *, int, int *, void *);
    void *getDialogDataArg;
    void (*setDialogDataCB)(void *, void *);
    void *setDialogDataArg;
    void *(*copyItemCB)(void *);
    void (*freeItemCB)(void *);
    int (*deleteConfirmCB)(int, void *);
    void *deleteConfirmArg;
    int maxItems;
    int *nItems;
    void **itemList;
    int lastSelection;
} managedListData;

static void destroyCB(Widget w, XtPointer clientData, XtPointer callData);
static void deleteCB(Widget w, XtPointer clientData, XtPointer callData);
static void copyCB(Widget w, XtPointer clientData, XtPointer callData);
static void moveUpCB(Widget w, XtPointer clientData, XtPointer callData);
static void moveDownCB(Widget w, XtPointer clientData, XtPointer callData);
static int incorporateDialogData(managedListData *ml, int listPos,
    	int explicit);
static void updateDialogFromList(managedListData *ml, int selection);
static void updateListWidgetItem(managedListData *ml, int listPos);
static void listSelectionCB(Widget w, XtPointer clientData, XtPointer callData);
static int selectedListPosition(managedListData *ml);
static void selectItem(Widget listW, int itemIndex, int updateDialog);

/*
** Create a user interface to help manage a list of arbitrary data records
** which users can edit, add, delete, and reorder.
**
** The caller creates the overall dialog for presenting the data to the user,
** but embeds the list and button widgets created here (and list management
** code they activate) to handle the organization of the overall list.
**
** This routine creates a form widget containing the buttons and list widget
** with which the user interacts with the list data.  ManageListAndButtons
** can be used alternatively to take advantage of the management code with a
** different arrangement of the widgets (this routine puts buttons in a
** column on the left, list on the right) imposed here.
**
** "args" and "argc" are passed to the form widget creation routine, so that
** attachments can be specified for embedding the form in a dialog.
**
** See ManageListAndButtons for a description of the remaining arguments.
*/
Widget CreateManagedList(Widget parent, char *name, Arg *args,
    	int argC, void **itemList, int *nItems, int maxItems, int nColumns,
    	void *(*getDialogDataCB)(void *, int, int *, void *),
    	void *getDialogDataArg, void (*setDialogDataCB)(void *, void *),
    	void *setDialogDataArg, void (*freeItemCB)(void *))
{
    int ac;
    Arg al[20];
    XmString s1;
    Widget form, rowCol, listW;
    Widget deleteBtn, copyBtn, moveUpBtn, moveDownBtn;
    XmString *placeholderTable;
    char *placeholderStr;

    form = XmCreateForm(parent, name, args, argC);
    XtManageChild(form);
    rowCol = XtVaCreateManagedWidget("mlRowCol", xmRowColumnWidgetClass, form,
    	    XmNpacking, XmPACK_COLUMN,
    	    XmNleftAttachment, XmATTACH_FORM,
    	    XmNtopAttachment, XmATTACH_FORM,
    	    XmNbottomAttachment, XmATTACH_FORM, NULL);
    deleteBtn = XtVaCreateManagedWidget("delete", xmPushButtonWidgetClass,
    	    rowCol, XmNlabelString, s1=XmStringCreateSimple("Delete"), NULL);
    XmStringFree(s1);
    copyBtn = XtVaCreateManagedWidget("copy", xmPushButtonWidgetClass, rowCol,
    	    XmNlabelString, s1=XmStringCreateSimple("Copy"), NULL);
    XmStringFree(s1);
    moveUpBtn = XtVaCreateManagedWidget("moveUp", xmPushButtonWidgetClass,
    	    rowCol, XmNlabelString, s1=XmStringCreateSimple("Move ^"), NULL);
    XmStringFree(s1);
    moveDownBtn = XtVaCreateManagedWidget("moveDown", xmPushButtonWidgetClass,
    	    rowCol, XmNlabelString, s1=XmStringCreateSimple("Move v"), NULL);
    XmStringFree(s1);
    
    /* AFAIK the only way to make a list widget n-columns wide is to make up
       a fake initial string of that width, and create it with that */
    placeholderStr = XtMalloc(nColumns+1);
    memset(placeholderStr, 'm', nColumns);
    placeholderStr[nColumns] = '\0';
    placeholderTable = StringTable(1, placeholderStr);
    XtFree(placeholderStr);
 
    ac = 0;
    XtSetArg(al[ac], XmNscrollBarDisplayPolicy, XmAS_NEEDED); ac++;
    XtSetArg(al[ac], XmNlistSizePolicy, XmCONSTANT); ac++;
    XtSetArg(al[ac], XmNitems, placeholderTable); ac++;
    XtSetArg(al[ac], XmNitemCount, 1); ac++;
    XtSetArg(al[ac], XmNtopAttachment, XmATTACH_FORM); ac++;
    XtSetArg(al[ac], XmNleftAttachment, XmATTACH_WIDGET); ac++;
    XtSetArg(al[ac], XmNleftWidget, rowCol); ac++;
    XtSetArg(al[ac], XmNrightAttachment, XmATTACH_FORM); ac++;
    XtSetArg(al[ac], XmNbottomAttachment, XmATTACH_FORM); ac++;
    listW = XmCreateScrolledList(form, "list", al, ac);
    AddMouseWheelSupport(listW);
    XtManageChild(listW);
    FreeStringTable(placeholderTable);

    return ManageListAndButtons(listW, deleteBtn, copyBtn, moveUpBtn,
    	    moveDownBtn, itemList, nItems, maxItems, getDialogDataCB,
    	    getDialogDataArg, setDialogDataCB, setDialogDataArg, freeItemCB);
}

/*
** Manage a list widget and a set of buttons which represent a list of
** records.  The caller provides facilities for editing the records
** individually, and this code handles the organization of the overall list,
** such that the user can modify, add, and delete records, and re-order the
** list.
**
** The format for the list of records managed by this code should be an
** array of size "maxItems" of pointers to record structures.  The records
** themselves can be of any format, but the first field of the structure
** must be a pointer to a character string which will be displayed as the
** item name in the list.  The list "itemList", and the number of items
** "nItems" are automatically updated by the list management routines as the
** user makes changes.
**
** The caller must provide routines for transferring data to and from the
** dialog fields dedicated to displaying and editing records in the list.
** The callback "setDialogDataCB" must take the contents of the item pointer
** passed to it, and display the data it contains, erasing any previously
** displayed data.  The format of the setDialogData callback is:
**
**    void setDialogDataCB(void *item, void *cbArg)
**
**	 item:	a pointer to the record to be displayed
**
**  	 cbArg:	an arbitrary argument passed on to the callback routine
**
** The callback "setDialogDataCB" must allocate (with XtMalloc) and return a
** new record reflecting the current contents of the dialog fields.  It may
** do error checking on the data that the user has entered, and can abort
** whatever operation triggered the request by setting "abort" to True.
** This routine is called in a variety of contexts, such as the user
** clicking on a list item, or requesting that a copy be made of the current
** list item.  To aide in communicating errors to the user, the boolean value
** "explicitRequest" distinguishes between the case where the user has
** specifically requested that the fields be read, and the case where he
** may be surprised that errors are being reported, and require further
** explanation.  The format of the getDialogData callback is:
**
**    void *getDialogDataCB(void *oldItem, int explicitRequest, int *abort,
**  	      void *cbArg)
**
**	 oldItem: a pointer to the existing record being modified in the
**	    dialog, or NULL, if the user is modifying the "New" item.
**
**	 explicitRequest: True if the user directly asked for the records
**	    to be changed (as with an OK or Apply button).  If a less direct
**	    process resulted in the request, the user might need extra
**	    explanation and possibly a chance to proceed using the existing
**	    stored data (to use the data from oldItem, the routine should
**	    make a new copy).
**
**	 abort: Can be set to True if the dialog fields contain errors.
**	    Setting abort to True, stops whetever process made the request
**	    for updating the data in the list from the displayed data, and
**	    forces the user to remain focused on the currently displayed
**	    item until he either gives up or gets it right.
**
**	 cbArg: arbitrary data, passed on from where the callback was
**	    established in the list creation routines
**
**    The return value should be an allocated
**
** The callback "freeItemCB" should free the item passed to it:
**
**    void freeItemCB(void *item, void *cbArg)
**
**	 item:	a pointer to the record to be freed
**
** The difference between ManageListAndButtons and CreateManagedList, is that
** in this routine, the caller creates the list and button widgets and passes
** them here so that they be arranged explicitly, rather than relying on the
** default style imposed by CreateManagedList.  ManageListAndButtons simply
** attaches the appropriate callbacks to process mouse and keyboard input from
** the widgets.
*/
Widget ManageListAndButtons(Widget listW, Widget deleteBtn, Widget copyBtn,
    	Widget moveUpBtn, Widget moveDownBtn, void **itemList, int *nItems,
	int maxItems, void *(*getDialogDataCB)(void *, int, int *, void *),
    	void *getDialogDataArg, void (*setDialogDataCB)(void *, void *),
    	void *setDialogDataArg, void (*freeItemCB)(void *))
{
    managedListData *ml;
    
    /* Create a managedList data structure to hold information about the
       widgets, callbacks, and current state of the list */
    ml = (managedListData *)XtMalloc(sizeof(managedListData));
    ml->listW = listW;
    ml->deleteBtn = deleteBtn;
    ml->copyBtn = copyBtn;
    ml->moveUpBtn = moveUpBtn;
    ml->moveDownBtn = moveDownBtn;
    ml->getDialogDataCB = NULL;
    ml->getDialogDataArg = setDialogDataArg;
    ml->setDialogDataCB = NULL;
    ml->setDialogDataArg = setDialogDataArg;
    ml->freeItemCB = freeItemCB;
    ml->deleteConfirmCB = NULL;
    ml->deleteConfirmArg = NULL;
    ml->nItems = nItems;
    ml->maxItems = maxItems;
    ml->itemList = itemList;
    ml->lastSelection = 1;

    /* Make the managed list data structure accessible from the list widget
       pointer, and make sure it gets freed when the list is destroyed */
    XtVaSetValues(ml->listW, XmNuserData, ml, NULL);
    XtAddCallback(ml->listW, XmNdestroyCallback, destroyCB, ml);
    
    /* Add callbacks for button and list actions */
    XtAddCallback(ml->deleteBtn, XmNactivateCallback, deleteCB, ml);
    XtAddCallback(ml->copyBtn, XmNactivateCallback, copyCB, ml);
    XtAddCallback(ml->moveUpBtn, XmNactivateCallback, moveUpCB, ml);
    XtAddCallback(ml->moveDownBtn, XmNactivateCallback, moveDownCB, ml);
    XtAddCallback(ml->listW, XmNbrowseSelectionCallback, listSelectionCB, ml);
    
    /* Initialize the list and buttons (don't set up the callbacks until
       this is done, so they won't get called on creation) */
    updateDialogFromList(ml, -1);
    ml->getDialogDataCB = getDialogDataCB;
    ml->setDialogDataCB = setDialogDataCB;
    
    return ml->listW;
}

/*
** Update the currently selected list item from the dialog fields, using
** the getDialogDataCB callback.  "explicitRequest" is a boolean value
** passed to on to the getDialogDataCB callback to help set the tone for
** how error messages are presented (see ManageListAndButtons for more
** information).
*/
int UpdateManagedList(Widget listW, int explicitRequest)
{
    managedListData *ml;
    
    /* Recover the pointer to the managed list structure from the widget's
       userData pointer */
    XtVaGetValues(listW, XmNuserData, &ml, NULL);
    
    /* Make the update */
    return incorporateDialogData(ml, selectedListPosition(ml), explicitRequest);
}

/*
** Update the displayed list and data to agree with a data list which has
** been changed externally (not by the ManagedList list manager).
*/
void ChangeManagedListData(Widget listW)
{
    managedListData *ml;
    
    /* Recover the pointer to the managed list structure from the widget's
       userData pointer */
    XtVaGetValues(listW, XmNuserData, &ml, NULL);
    
    updateDialogFromList(ml, -1);
}

/*
** Change the selected item in the managed list given the index into the
** list being managed.
*/
void SelectManagedListItem(Widget listW, int itemIndex)
{
    selectItem(listW, itemIndex, True);
}

/*
** Return the index of the item currently selected in the list
*/