/* editor.c -- create a full-blown Motif editor application complete
** with a menubar, facilities to read and write files, text search
** and replace, clipboard support and so forth.
*/

#include <Xm/Text.h>
#include <Xm/TextF.h>
#include <Xm/LabelG.h>
#include <Xm/PushBG.h>
#include <Xm/RowColumn.h>
#include <Xm/MainW.h>
#include <Xm/Form.h>
#include <Xm/FileSB.h>
#include <X11/Xos.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>

Widget text_edit, search_text, replace_text, text_output;

#define FILE_OPEN          0
#define FILE_SAVE          1
#define FILE_EXIT          2
#define EDIT_CUT           0
#define EDIT_COPY          1
#define EDIT_PASTE         2
#define EDIT_CLEAR         3
#define SEARCH_FIND_NEXT   0
#define SEARCH_SHOW_ALL    1
#define SEARCH_REPLACE     2
#define SEARCH_CLEAR       3

main (int argc, char *argv[])
{
	XtAppContext app_context;
	Widget       toplevel, main_window, menubar, form, search_panel, label_w;
	void         file_cb(Widget, XtPointer, XtPointer);
	void         edit_cb(Widget, XtPointer, XtPointer);
	void         search_cb(Widget, XtPointer, XtPointer);
	Arg          args[10]; 
	int          n = 0;
	XmString     open, save, exit, exit_acc, file, edit, cut, clear, copy, 
		     paste, search, next, find, replace;
	
	XtSetLanguageProc (NULL, NULL, NULL);
	toplevel = XtVaOpenApplication (&app_context, "Xeditor", NULL, 0, &argc, argv, NULL,
					sessionShellWidgetClass, NULL);

	main_window = XmCreateMainWindow (toplevel, "main_window", NULL, 0);
	/* Create a simple MenuBar that contains three menus */
	file = XmStringCreateLocalized ("File");
	edit = XmStringCreateLocalized ("Edit");
	search = XmStringCreateLocalized ("Search");
	menubar = XmVaCreateSimpleMenuBar (main_window, "menubar",
					   XmVaCASCADEBUTTON, file, 'F',
					   XmVaCASCADEBUTTON, edit, 'E',
					   XmVaCASCADEBUTTON, search, 'S',
					   NULL);
	XmStringFree (file);
	XmStringFree (edit);
	XmStringFree (search);
	
	/* First menu is the File menu -- callback is file_cb() */
	open = XmStringCreateLocalized ("Open...");
	save = XmStringCreateLocalized ("Save...");
	exit = XmStringCreateLocalized ("Exit");
	exit_acc = XmStringCreateLocalized ("Ctrl+C");
	XmVaCreateSimplePulldownMenu (menubar, "file_menu", 0, file_cb,
	                              XmVaPUSHBUTTON, open, 'O', NULL, NULL,
				      XmVaPUSHBUTTON, save, 'S', NULL, NULL,
				      XmVaSEPARATOR,
				      XmVaPUSHBUTTON, exit, 'x', "Ctrl<Key>c", exit_acc,
				      NULL);
	XmStringFree (open);
	XmStringFree (save);
	XmStringFree (exit);
	XmStringFree (exit_acc);

	/* ...create the "Edit" menu --  callback is edit_cb() */
	cut = XmStringCreateLocalized ("Cut");
	copy = XmStringCreateLocalized ("Copy");
	clear = XmStringCreateLocalized ("Clear");
	paste = XmStringCreateLocalized ("Paste");
	XmVaCreateSimplePulldownMenu (menubar, "edit_menu", 1, edit_cb,
	                              XmVaPUSHBUTTON, cut, 't', NULL, NULL,
				      XmVaPUSHBUTTON, copy, 'C', NULL, NULL,
				      XmVaPUSHBUTTON, paste, 'P', NULL, NULL,
				      XmVaSEPARATOR,
				      XmVaPUSHBUTTON, clear, 'l', NULL, NULL,
				      NULL);
	XmStringFree (cut);
	XmStringFree (copy);
	XmStringFree (paste);

	/* create the "Search" menu -- callback is search_cb() */
	next = XmStringCreateLocalized ("Find Next");
	find = XmStringCreateLocalized ("Show All");
	replace = XmStringCreateLocalized ("Replace Text");
	XmVaCreateSimplePulldownMenu (menubar, "search_menu", 2, search_cb,
				      XmVaPUSHBUTTON, next, 'N', NULL, NULL,
				      XmVaPUSHBUTTON, find, 'A', NULL, NULL,
				      XmVaPUSHBUTTON, replace, 'R', NULL, NULL,
				      XmVaSEPARATOR,
				      XmVaPUSHBUTTON, clear, 'C', NULL, NULL,
				      NULL);
	XmStringFree (next);
	XmStringFree (find);
	XmStringFree (replace);
	XmStringFree (clear);
	XtManageChild (menubar); 

	/* create a form work are */
	form = XmCreateForm (main_window, "form", NULL, 0);

	/* create horizontal RowColumn inside the form */
	n = 0;
	XtSetArg (args[n], XmNorientation, XmHORIZONTAL); n++;
	XtSetArg (args[n], XmNpacking, XmPACK_TIGHT); n++;
	XtSetArg (args[n], XmNtopAttachment, XmATTACH_FORM); n++;
	XtSetArg (args[n], XmNleftAttachment, XmATTACH_FORM); n++;
	XtSetArg (args[n], XmNrightAttachment, XmATTACH_FORM); n++;
	search_panel = XmCreateRowColumn (form, "search_panel", args, n);

	/* Create two TextField widgets with Labels... */
	label_w = XmCreateLabelGadget (search_panel, "Search Pattern:", NULL, 0);
	XtManageChild (label_w);
	search_text = XmCreateTextField (search_panel, "search_text", NULL, 0);
	XtManageChild (search_text);
	label_w = XmCreateLabelGadget (search_panel, "Replace Pattern:",  NULL, 0);
	XtManageChild (label_w);
	replace_text = XmCreateTextField (search_panel, "replace_text", NULL, 0);
	XtManageChild (replace_text);
	XtManageChild (search_panel);

	n = 0;
	XtSetArg (args[n], XmNeditable, False); n++;
	XtSetArg (args[n], XmNcursorPositionVisible, False); n++;
	XtSetArg (args[n], XmNshadowThickness, 0); n++;
	XtSetArg (args[n], XmNleftAttachment, XmATTACH_FORM); n++;
	XtSetArg (args[n], XmNrightAttachment, XmATTACH_FORM); n++;
	XtSetArg (args[n], XmNbottomAttachment, XmATTACH_FORM); n++;
	text_output = XmCreateTextField (form, "text_output", args, n);
	XtManageChild (text_output);

	n = 0;
	XtSetArg (args[n], XmNrows,  10); n++;
	XtSetArg (args[n], XmNcolumns, 80); n++;
	XtSetArg (args[n], XmNeditMode, XmMULTI_LINE_EDIT); n++;
	XtSetArg (args[n], XmNtopAttachment, XmATTACH_WIDGET); n++;
	XtSetArg (args[n], XmNtopWidget, search_panel); n++;
	XtSetArg (args[n], XmNleftAttachment, XmATTACH_FORM); n++;
	XtSetArg (args[n], XmNrightAttachment, XmATTACH_FORM); n++;
	XtSetArg (args[n], XmNbottomAttachment, XmATTACH_WIDGET); n++;
	XtSetArg (args[n], XmNbottomWidget, text_output); n++;
	text_edit = XmCreateScrolledText (form, "text_edit", args, n);
	XtManageChild (text_edit);

	XtManageChild (form);
	XtManageChild (main_window);
	XtRealizeWidget (toplevel);
	XtAppMainLoop (app_context);
}

/* file_select_cb() -- callback routine for "OK" button in
** FileSelectionDialogs.
*/
void file_select_cb (Widget dialog, XtPointer client_data, XtPointer call_data)
{
	char        buf[256], *filename, *text;
	struct stat statb;
	long        len;
	FILE       *fp;
	int         reason = (int) client_data;

	XmFileSelectionBoxCallbackStruct *cbs = (XmFileSelectionBoxCallbackStruct *) call_data;
	
	if (!(filename = XmStringUnparse (cbs->value, XmFONTLIST_DEFAULT_TAG, 
					  XmCHARSET_TEXT, XmCHARSET_TEXT, NULL, 0, 
					  XmOUTPUT_ALL)))
		return; /* must have been an internal error */
	
	if (*filename == NULL) {
		XtFree (filename);
		XBell (XtDisplay (text_edit), 50);
		XmTextSetString (text_output, "Choose a file.");
		return; /* nothing typed */
	}
	
	if (reason == FILE_SAVE) {
		if (!(fp = fopen (filename, "w"))) {
			perror (filename);
			(void) sprintf (buf, "Can't save to %s.", filename);
			XmTextSetString (text_output, buf);
			XtFree (filename);
			return;
		}
		
		/* saving -- get text from Text widget... */
		text = XmTextGetString (text_edit);
		len = XmTextGetLastPosition (text_edit);
		/* write it to file (check for error) */
		if (fwrite (text, sizeof (char), len, fp) != len)
			(void) strcpy (buf, "Warning: did not write entire file!");
		else {
			/* make sure a newline terminates file */
			if (text[len-1] != '\n')
				fputc ('\n', fp);
				
			(void) sprintf (buf, "Saved %ld bytes to %s.", len, filename);
		}
	}
	else { /* reason == FILE_OPEN */
		/* make sure the file is a regular text file and open it */
		if (stat (filename, &statb) == -1 ||  (statb.st_mode & S_IFMT) != S_IFREG ||  
		       !(fp = fopen (filename, "r"))) {
			perror (filename);
			(void) sprintf (buf, "Can't read %s.", filename);
			XmTextSetString (text_output, buf);
			XtFree (filename);
			return;
		}
		
		/* put the contents of the file in the Text widget by
		** allocating enough space for the entire file, reading the
		** file into the space, and using XmTextSetString() to show
		** the file. 
		*/
		
		len = statb.st_size;
		if (!(text = XtMalloc ((unsigned)(len+1)))) /* +1 for NULL */
			(void) sprintf (buf, "%s: XtMalloc(%ld) failed", len, filename);
		else {
			if (fread (text, sizeof (char), len, fp) != len)
				(void) sprintf (buf, "Warning: did not read entire file!");
			else
				(void) sprintf (buf, "Loaded %ld bytes from %s.", len, filename);
			text[len] = 0; /* NULL-terminate */
			XmTextSetString (text_edit, text);
		}
	}
	
	XmTextSetString (text_output, buf); 
	/* purge output message */
	/* free all allocated space. */
	XtFree (text);
	XtFree (filename);

	(void) fclose (fp);

	XtUnmanageChild (dialog);
}

/* popdown_cb() -- callback routine for "Cancel" button. */
void popdown_cb (Widget w, XtPointer client_data, XtPointer call_data)
{
	XtUnmanageChild (w);
}

/* file_cb() -- a menu item from the "File" pulldown menu was selected */
void file_cb (Widget w, XtPointer client_data, XtPointer call_data)
{
	static Widget open_dialog, save_dialog;
	Widget   dialog = NULL;
	XmString button, title;
	int      reason = (int) client_data;
	
	if (reason == FILE_EXIT)
		exit (0); 

	XmTextSetString (text_output, NULL);   /* clear message area */
	
	if (reason == FILE_OPEN && open_dialog)
		dialog = open_dialog;
	else if (reason == FILE_SAVE && save_dialog)
		dialog = save_dialog;
		
	if (dialog) {
		XtManageChild (dialog);
		
		/* make sure that dialog is raised to top of window stack */
		
		XMapRaised (XtDisplay (dialog), XtWindow (XtParent (dialog)));

		return;
	}

	dialog = XmCreateFileSelectionDialog (text_edit, "Files", NULL, 0);
	
	XtAddCallback (dialog, XmNcancelCallback, popdown_cb, NULL);
	XtAddCallback (dialog, XmNokCallback, file_select_cb, (XtPointer) reason);
	
	if (reason == FILE_OPEN) {
		button = XmStringCreateLocalized ("Open");
		title = XmStringCreateLocalized ("Open File");
		open_dialog = dialog;
	}
	else { /* reason == FILE_SAVE */
		button = XmStringCreateLocalized ("Save");
		title = XmStringCreateLocalized ("Save File");
		save_dialog = dialog;
	}
	
	XtVaSetValues (dialog, XmNokLabelString, button, XmNdialogTitle, title, NULL);
	XmStringFree (button);
	XmStringFree (title);

	XtManageChild (dialog);
}

/* search_cb() -- a menu item from the "Search" pulldown menu selected */
void search_cb (Widget w, XtPointer client_data, XtPointer call_data)
{
	char          *search_pat, *p, *string, *new_pat, buf[256];
	XmTextPosition pos = 0;
	int            len, nfound = 0;
	int            search_len, pattern_len;
	int            reason = (int) client_data;
	Boolean        found = False;
	
	XmTextSetString (text_output, NULL);   /* clear message area */
	
	if (reason == SEARCH_CLEAR) {
		pos = XmTextGetLastPosition (text_edit);
		XmTextSetHighlight (text_edit, 0, pos, XmHIGHLIGHT_NORMAL);
		return;
	}
	
	if (!(string = XmTextGetString (text_edit)) || !*string) {
		XmTextSetString (text_output, "No text to search.");
		return;
	}
	
	if (!(search_pat = XmTextGetString (search_text)) || !*search_pat) {
		XmTextSetString (text_output, "Specify a search pattern.");
		XtFree (string);
		return;
	}
	
	new_pat = XmTextGetString (replace_text);
	search_len = strlen (search_pat);
	pattern_len = strlen (new_pat);

	if (reason == SEARCH_FIND_NEXT) {
		pos = XmTextGetCursorPosition (text_edit) + 1;
		found = XmTextFindString (text_edit, pos, search_pat, XmTEXT_FORWARD, &pos);
		
		if (!found)
			found = XmTextFindString (text_edit, 0, search_pat, XmTEXT_FORWARD, &pos); 
			
		if (found)
			nfound++;
	}
	else { /* reason == SEARCH_SHOW_ALL || reason == SEARCH_REPLACE */
		do {
			found = XmTextFindString (text_edit, pos, search_pat, XmTEXT_FORWARD, &pos); 
			
			if (found) {
				nfound++; 
				
				if (reason == SEARCH_SHOW_ALL)
					XmTextSetHighlight (text_edit, pos, pos + search_len, XmHIGHLIGHT_SELECTED);
				else
					XmTextReplace (text_edit, pos, pos + search_len, new_pat);
		
				pos++;
			}
		} while (found);
	}
	
	if (nfound == 0)
		XmTextSetString (text_output, "Pattern not found.");
	else {
		switch (reason) {
			case SEARCH_FIND_NEXT : (void) sprintf (buf, "Pattern found at position %ld.", pos);
						XmTextSetInsertionPosition (text_edit, pos);
						break;
			case SEARCH_SHOW_ALL  : (void) sprintf (buf, "Found %d occurrences.", nfound);
						break;
			case SEARCH_REPLACE   : (void) sprintf (buf, "Made %d replacements.", nfound);
		}
		
		XmTextSetString (text_output, buf);
	}
	
	XtFree (string);
	XtFree (search_pat);
	XtFree (new_pat);
}

/* edit_cb() -- the callback routine for the items in the edit menu */
void edit_cb (Widget widget, XtPointer client_data, XtPointer call_data)
{
	Boolean result = True;
	int     reason = (int) client_data;
	XEvent *event = ((XmPushButtonCallbackStruct *) call_data)->event;
	Time    when;
	
	XmTextSetString (text_output, NULL); /* clear message area */
	
	if (event != NULL && reason == EDIT_CUT || reason == EDIT_COPY || reason == EDIT_CLEAR) {
		switch (event->type) {
			case ButtonRelease : when = event->xbutton.time; break;
			case KeyRelease    : when = event->xkey.time; break;
			default            : when = CurrentTime; break;
		}
	}

	switch (reason) {
		case EDIT_CUT   : result = XmTextCut (text_edit, when); break;
		case EDIT_COPY  : result = XmTextCopy (text_edit, when); break;
		case EDIT_PASTE : result = XmTextPaste (text_edit); /* FALLTHROUGH */
		case EDIT_CLEAR : XmTextClearSelection (text_edit, when); break;
	}
	
	if (result == False)
		XmTextSetString (text_output, "There is no selection.");
}