/*
 * One-pane widget module
 *
 * Naming convention:
 * buf: internal (mmap'd) buffer, which is static.
 * text: GtkText widget data, which is variable.
 *
 * Copyright INOUE Seiichiro <inoue@ainet.or.jp>, licensed under the GPL.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "diff.h"
#include "gui.h"
#include "dtextmap.h"
#include "onepane-widget.h"
#include "misc.h"
#include "gtktext-support.h"
#include "linenum.h"
#include "style.h"


/* Private function declarations */
static void gdiff_onepane_class_init(GdiffOnePaneClass *klass);
static void gdiff_onepane_init(GdiffOnePane *onepane);
static void gdiff_onepane_finalize(GtkObject *object);

static void gdiff_onepane_display(GdiffBasePane *basepane);
static void gdiff_onepane_show_linenum(GdiffBasePane *basepane, gboolean to_show);
static gboolean gdiff_onepane_toggle_textwrap(GdiffBasePane *basepane);
static void gdiff_onepane_set_highlight(GdiffBasePane *basepane, gboolean to_highlight);
static void gdiff_onepane_move_diff(GdiffBasePane *basepane, MoveDiff mv_diff);
static gboolean gdiff_onepane_search_string(GdiffBasePane *basepane, const char *string, WhichFile whichfile);

static void guts_onepane_display(GdiffOnePane *onepane);
static void draw_text(GdiffOnePane *onepane);
static void show_hide_numbers(GdiffOnePane *onepane, gboolean b_show);
static void calc_ln_columns(GdiffOnePane *onepane, int max_nlines);
static void guts_move_diff(GdiffOnePane *onepane, MoveDiff mv_diff);
static void change_lines_bgcolor(GdiffOnePane *onepane, const DiffLines *dlines, WhichFile whichfile, GdkColor *bg_color);
static gboolean guts_search_string_firstfile(GdiffOnePane *onepane, const char *string);
static void centering_text(GdiffOnePane *onepane, int tln);


static GdiffBasePaneClass *parent_class = NULL;

GtkType
gdiff_onepane_get_type(void)
{
	static GtkType onepane_type = 0;

	if (!onepane_type) {
		static const GtkTypeInfo onepane_info = {
			"GdiffOnePane",
			sizeof(GdiffOnePane),
			sizeof(GdiffOnePaneClass),
			(GtkClassInitFunc)gdiff_onepane_class_init,
			(GtkObjectInitFunc)gdiff_onepane_init,
			/* reserved_1 */ NULL,
			/* reserved_2 */ NULL,
			(GtkClassInitFunc)NULL,
		};
		onepane_type = gtk_type_unique(GDIFF_TYPE_BASEPANE, &onepane_info);
	}
  
	return onepane_type;
}

static void
gdiff_onepane_class_init(GdiffOnePaneClass *klass)
{
	GtkObjectClass *object_class;
	GdiffBasePaneClass *basepane_class;
	
	object_class = (GtkObjectClass*)klass;
	basepane_class = (GdiffBasePaneClass*)klass;
	parent_class = gtk_type_class(GDIFF_TYPE_BASEPANE);

	object_class->finalize = gdiff_onepane_finalize;

	basepane_class->display = gdiff_onepane_display;
	basepane_class->show_linenum = gdiff_onepane_show_linenum;
	basepane_class->toggle_textwrap = gdiff_onepane_toggle_textwrap;
	basepane_class->set_highlight = gdiff_onepane_set_highlight;
	basepane_class->move_diff = gdiff_onepane_move_diff;
	basepane_class->search_string = gdiff_onepane_search_string;
}

static void
gdiff_onepane_init(GdiffOnePane *onepane)
{
	GdiffBasePane *basepane;
	GtkBin *bin;
	GtkWidget *text;
	GtkWidget *scrollwin;
	int n;

	basepane = GDIFF_BASEPANE(onepane);
	bin = GTK_BIN(basepane);

	scrollwin = gtk_scrolled_window_new(NULL, NULL);
	/* XXX: I can't use horizontal scrollbar,
	   because of the current text widget's limitation. */
	gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scrollwin),
								   GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
	gtk_container_add(GTK_CONTAINER(bin), scrollwin);
	gtk_widget_show(scrollwin);
	
	text = gtk_text_new(NULL, NULL);
	onepane->text = text;
	style_set_text(text);
	gtext_set_editable(text, FALSE);
	gtext_set_word_wrap(text, FALSE);
	gtext_set_line_wrap(text, PANE_PREF(onepane).line_wrap);
	gtk_container_add(GTK_CONTAINER(scrollwin), text);
	gtk_widget_grab_focus(text);

	gtk_widget_show(text);
	
	PANE_PREF(onepane).view_type = NO_VIEW;/* not determined here */

	for (n = 0; n < MAX_NUM_COMPARE_FILES; n++) {
		onepane->search_ln[n] = 0;
	}
	onepane->search_tln = 0;
	onepane->search_tpoint = 0;
	onepane->search_tindex = 0;
}

static void
gdiff_onepane_finalize(GtkObject *object)
{
	GdiffOnePane *onepane;

	g_return_if_fail(object != NULL);
	g_return_if_fail(GDIFF_IS_ONEPANE(object));

	onepane = GDIFF_ONEPANE(object);
	
	dtmap_delete(onepane->dtmap);

	(*GTK_OBJECT_CLASS(parent_class)->finalize)(object);
}


GtkWidget*
gdiff_onepane_new(DiffDir *diffdir, DiffFiles *dfiles)
{
	GdiffOnePane *onepane;
	const FileInfo *fi1 = dfiles_get_fileinfo(dfiles, FIRST_FILE, TRUE);

	onepane = gtk_type_new(GDIFF_TYPE_ONEPANE);

	_gdiff_basepane_set_backend(GDIFF_BASEPANE(onepane), diffdir, dfiles);/*XXX*/
	
	/* One-pane internal data */
	onepane->dtmap = dtmap_new(fi1->nlines);
	onepane->n_col = -1;
	if (dfiles->is_diff3)
		PANE_PREF(onepane).view_type = ONEPANE3_VIEW;
	else
		PANE_PREF(onepane).view_type = ONEPANE2_VIEW;

	/* workaround */
	gtk_widget_ensure_style(onepane->text);
	
	guts_onepane_display(onepane);
	
	return GTK_WIDGET(onepane);
}


/** Interfaces **/
static void
gdiff_onepane_display(GdiffBasePane *basepane)
{
	GdiffOnePane *onepane;

	g_return_if_fail(basepane != NULL);
	g_return_if_fail(GDIFF_IS_ONEPANE(basepane));

	onepane = GDIFF_ONEPANE(basepane);

	guts_onepane_display(onepane);
}

/**
 * gdiff_onepane_show_linenum:
 * Show(Hide) the line numbers on text widget.
 * Input:
 * gboolean to_show; TRUE implies to show. FALSE implies to hide.
 **/
static void
gdiff_onepane_show_linenum(GdiffBasePane *basepane, gboolean to_show)
{
	GdiffOnePane *onepane;

	g_return_if_fail(basepane != NULL);
	g_return_if_fail(GDIFF_IS_ONEPANE(basepane));

	onepane = GDIFF_ONEPANE(basepane);
	
	if (to_show != PANE_PREF(onepane).show_line_num) {
		show_hide_numbers(onepane, to_show);
		PANE_PREF(onepane).show_line_num = to_show;
	}
}

/**
 * gdiff_onepane_toggle_textwrap:
 **/
static gboolean
gdiff_onepane_toggle_textwrap(GdiffBasePane *basepane)
{
	GdiffOnePane *onepane;
	gboolean b_wrap;
	
	g_return_val_if_fail(basepane != NULL, FALSE);
	g_return_val_if_fail(GDIFF_IS_ONEPANE(basepane), FALSE);

	onepane = GDIFF_ONEPANE(basepane);

	b_wrap = !(GTK_TEXT(onepane->text)->line_wrap);
	gtext_set_line_wrap(onepane->text, b_wrap);
	PANE_PREF(onepane).line_wrap = b_wrap;	

	return b_wrap;
}

/**
 * gdiff_onepane_set_highlight:
 * Take care of the current highlight.
 * Input:
 * gboolean to_highlight; TRUE implies to enable highlight. FALSE implies to disable.
 **/
static void
gdiff_onepane_set_highlight(GdiffBasePane *basepane, gboolean to_highlight)
{
	GdiffOnePane *onepane;

	g_return_if_fail(basepane != NULL);
	g_return_if_fail(GDIFF_IS_ONEPANE(basepane));

	onepane = GDIFF_ONEPANE(basepane);

	if (to_highlight != PANE_PREF(onepane).highlight) {
		if (GDIFF_BASEPANE(onepane)->cur_dlines_node) {
			const DiffLines *dlines = GDIFF_BASEPANE(onepane)->cur_dlines_node->data;
			GdkColor *bg_color;

			if (to_highlight == TRUE) {
				bg_color = &PANE_PREF(onepane).diff_hl[FIRST_FILE];
				change_lines_bgcolor(onepane, dlines, FIRST_FILE, bg_color);
			} else {
				bg_color = &PANE_PREF(onepane).diff_bg[FIRST_FILE];
				change_lines_bgcolor(onepane, dlines, FIRST_FILE, bg_color);
			}
		}
		PANE_PREF(onepane).highlight = to_highlight;
	}
}

/**
 * gdiff_onepane_move_diff:
 * Move to a difference, such as next, previous, first or last.
 **/ 
static void
gdiff_onepane_move_diff(GdiffBasePane *basepane, MoveDiff mv_diff)
{
	GdiffOnePane *onepane;

	g_return_if_fail(basepane != NULL);
	g_return_if_fail(GDIFF_IS_ONEPANE(basepane));

	onepane = GDIFF_ONEPANE(basepane);

	guts_move_diff(onepane, mv_diff);
}

/**
 * gdiff_onepane_search_string:
 * @string is null-byte-terminated. Return TRUE if found.
 **/ 
static gboolean
gdiff_onepane_search_string(GdiffBasePane *basepane, const char *string, WhichFile whichfile)
{
	GdiffOnePane *onepane;

	g_return_val_if_fail(basepane != NULL, FALSE);
	g_return_val_if_fail(GDIFF_IS_ONEPANE(basepane), FALSE);

	if (string == NULL || string[0] == '\0')
		return FALSE;
	
	onepane = GDIFF_ONEPANE(basepane);

	if (whichfile == FIRST_FILE)
		return guts_search_string_firstfile(onepane, string);
	else
		return FALSE;/* not implemented */
}


/** Internal functions **/
/**
 * guts_onepane_display:
 * Show the diff result in one-pane mode.
 **/
static void
guts_onepane_display(GdiffOnePane *onepane)
{
	draw_text(onepane);
	if (PANE_PREF(onepane).show_line_num == TRUE) {
		show_hide_numbers(onepane, TRUE);
	}
}

/**
 * draw_text:
 * Draw text with coloring different parts.
 * Two buffers are drawn on the same text.
 * During drawing, update dtmap.
 **/
static void
draw_text(GdiffOnePane *onepane)
{
	DiffFiles *dfiles = PANE_DFILES(onepane);
	const FileInfo *fi[MAX_NUM_COMPARE_FILES];
	MBuffer *mbuf[MAX_NUM_COMPARE_FILES];
	const char *buf_pt[MAX_NUM_COMPARE_FILES];
	int buf_ln1;
	int buf_lenb[MAX_NUM_COMPARE_FILES];
	DTextMap *dtmap = onepane->dtmap;
	GtkWidget *text = onepane->text;
	GdkFont *font = text->style->font;
	GList *node;/* node of DiffLines list */
	FontProp fprop;
	GdkColor *fg_color[MAX_NUM_COMPARE_FILES];
	GdkColor *bg_color[MAX_NUM_COMPARE_FILES];
	int oldpos = 0;
	int pos;
	int n;
	int num_files = PANE_DFILES(onepane)->is_diff3 ? 3 : 2;
	DispAttr attr = 0;
	
	for (n = 0; n < num_files; n++) {
		fi[n] = dfiles_get_fileinfo(dfiles, n, TRUE);
		mbuf[n] = PANE_MBUF(onepane, n);
		fg_color[n] = &PANE_PREF(onepane).diff_fg[n];
		bg_color[n] = &PANE_PREF(onepane).diff_bg[n];
		mbuf_goto_top(mbuf[n]);
	}
	
	if (fi[0]->buf == NULL && fi[1]->buf == NULL && fi[2]->buf == NULL) /* Maybe, the file has been deleted. */
		return;

 	fprop.font = font;
	gtext_freeze(text);
	for (node = dfiles->dlines_list; node; node = node->next) {
		const DiffLines *dlines = node->data;
		/* Use local variables for readability */
		int begin[MAX_NUM_COMPARE_FILES];
		int end[MAX_NUM_COMPARE_FILES];

		for (n = 0; n < num_files; n++) {
			begin[n] = dlines->between[n].begin;
			end[n] = dlines->between[n].end;
		}
		
		fprop.fg = fprop.bg = NULL;
		buf_ln1 = mbuf[FIRST_FILE]->cur_ln;
		buf_pt[FIRST_FILE] = mbuf[FIRST_FILE]->cur_pt;
		buf_lenb[FIRST_FILE] = mbuf_goto_line(mbuf[FIRST_FILE], begin[FIRST_FILE]) - buf_pt[FIRST_FILE];
		pos = gtext_insert_buf(text, &fprop, buf_pt[FIRST_FILE],
							   mbuf[FIRST_FILE]->cur_pt - buf_pt[FIRST_FILE]);
		dtmap_append_displn(dtmap, DA_COMMON, oldpos, pos - oldpos,
							buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE],
							begin[FIRST_FILE] - buf_ln1);
		oldpos = pos;

		buf_pt[FIRST_FILE] = mbuf[FIRST_FILE]->cur_pt;
		mbuf_goto_line(mbuf[FIRST_FILE], end[FIRST_FILE] + 1);

		if (dlines->difftype == CHANGE
			|| dlines->difftype & ONLY_CHANGE
			|| dlines->difftype == F12ADD || dlines->difftype == F31ADD) {
			WhichFile startfile = SECOND_FILE;
			WhichFile lastfile = num_files;
			
			fprop.fg = fg_color[FIRST_FILE];
			fprop.bg = bg_color[FIRST_FILE];
			buf_lenb[FIRST_FILE] = mbuf[FIRST_FILE]->cur_pt - buf_pt[FIRST_FILE];
			pos = gtext_insert_buf(text, &fprop, buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE]);
			dtmap_append_displn(dtmap, DA_CHANGE, oldpos, pos - oldpos,
								buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE],
								end[FIRST_FILE]+1 - begin[FIRST_FILE]);
			oldpos = pos;

			if (dlines->difftype & F1ONLY || dlines->difftype & F2ONLY || dlines->difftype == F12ADD) {
				/* This should be distinguished. */
				startfile = SECOND_FILE;
				lastfile = SECOND_FILE + 1;
			} else if (dlines->difftype & F3ONLY || dlines->difftype == F31ADD) {
				startfile = THIRD_FILE;
				lastfile = THIRD_FILE + 1;
			}
				
			for (n = startfile; n < lastfile; n++) {
				fprop.fg = fg_color[n];
				fprop.bg = bg_color[n];
				buf_pt[n] = mbuf_goto_line(mbuf[n], begin[n]);
				buf_lenb[n] = mbuf_goto_line(mbuf[n], end[n] + 1) - buf_pt[n];
				pos = gtext_insert_buf(text, &fprop, buf_pt[n], buf_lenb[n]);
				if (n == SECOND_FILE)
					attr = DA_CHANGE_O;
				else if (n == THIRD_FILE)
					attr = DA_CHANGE_O2;
				dtmap_append_displn(dtmap, attr, oldpos, pos - oldpos,
									buf_pt[n], buf_lenb[n], end[n]+1 - begin[n]);
				oldpos = pos;
			}
		} else if (dlines->difftype & F1ONLY) {/* ONLY_ADD */
			fprop.fg = fg_color[FIRST_FILE];
			fprop.bg = bg_color[FIRST_FILE];
			buf_lenb[FIRST_FILE] = mbuf[FIRST_FILE]->cur_pt - buf_pt[FIRST_FILE];
			pos = gtext_insert_buf(text, &fprop, buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE]);
			dtmap_append_displn(dtmap, DA_ONLY, oldpos, pos - oldpos,
								buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE],
								end[FIRST_FILE]+1 - begin[FIRST_FILE]);
			oldpos = pos;
		} else if (dlines->difftype == F23ADD
				   || ((dlines->difftype & ONLY_ADD)
					   && ((dlines->difftype & F2ONLY) || (dlines->difftype & F3ONLY)))) {
			WhichFile startfile = SECOND_FILE;
			WhichFile lastfile = num_files;
			WhichFile whichfile = dlines->difftype & F3ONLY ? THIRD_FILE : SECOND_FILE;/* XXX */
			
			fprop.fg = fprop.bg = NULL;
			buf_lenb[FIRST_FILE] = mbuf[FIRST_FILE]->cur_pt - buf_pt[FIRST_FILE];
			pos = gtext_insert_buf(text, &fprop, buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE]);

			if (whichfile == SECOND_FILE)
				attr = DA_O_ONLY;
			else if (whichfile == THIRD_FILE)
				attr = DA_O2_ONLY;
			dtmap_append_displn(dtmap, attr, oldpos, pos - oldpos,
								buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE],
								end[FIRST_FILE]+1 - begin[FIRST_FILE]);
			oldpos = pos;
			
			if (dlines->difftype & F2ONLY) {
				startfile = SECOND_FILE;
				lastfile = SECOND_FILE + 1;
			} else if (dlines->difftype & F3ONLY) {
				startfile = THIRD_FILE;
				lastfile = THIRD_FILE + 1;
			}
			for (n = startfile; n < lastfile; n++) {
				fprop.fg = fg_color[n];
				fprop.bg = bg_color[n];
				buf_pt[n] = mbuf_goto_line(mbuf[n], begin[n]);
				buf_lenb[n] = mbuf_goto_line(mbuf[n], end[n] + 1) - buf_pt[n];
				pos = gtext_insert_buf(text, &fprop, buf_pt[n], buf_lenb[n]);
				if (n == SECOND_FILE)
					attr = DA_ONLY_O;
				else if (n == THIRD_FILE)
					attr = DA_ONLY_O2;
				dtmap_append_displn(dtmap, attr, oldpos, pos - oldpos,
									buf_pt[n], buf_lenb[n],
									end[n]+1 - begin[n]);
				oldpos = pos;
			}
		}
	}
	/* Draw the remained part */
	fprop.fg = fprop.bg = NULL;
	buf_ln1 = mbuf[FIRST_FILE]->cur_ln;
	buf_pt[FIRST_FILE] = mbuf[FIRST_FILE]->cur_pt;
	buf_lenb[FIRST_FILE] = mbuf_goto_line(mbuf[FIRST_FILE], fi[FIRST_FILE]->nlines + 1) - buf_pt[FIRST_FILE];
	pos = gtext_insert_buf(text, &fprop, buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE]);
	dtmap_append_displn(dtmap, DA_COMMON, oldpos, pos - oldpos,
						buf_pt[FIRST_FILE], buf_lenb[FIRST_FILE],
						fi[FIRST_FILE]->nlines+1 - buf_ln1);

	gtext_thaw(text);
}


/**
 * show_hide_numbers:
 * Show(Hide) line numbers on the head of each lines.
 * This takes care of two buffers(merged text) at the same time.
 **/
static void
show_hide_numbers(GdiffOnePane *onepane, gboolean b_show)
{
	DiffFiles *dfiles = PANE_DFILES(onepane);
	const FileInfo *fi[MAX_NUM_COMPARE_FILES];
	DTextMap *dtmap = onepane->dtmap;
	GtkWidget *text = onepane->text;
	GdkFont *font = text->style->font;
	FontProp fprop;
	GdkColor *fg_color[MAX_NUM_COMPARE_FILES];
	GdkColor *bg_color[MAX_NUM_COMPARE_FILES];
	LineFormat lformat;
	int ln_col_size;
	DispLines *displn;
	int ln[MAX_NUM_COMPARE_FILES];
	int num_files = PANE_DFILES(onepane)->is_diff3 ? 3 : 2;
	int n;
	
	for (n = 0; n < num_files; n++) {
		ln[n] = 1;
		fi[n] = dfiles_get_fileinfo(dfiles, n, TRUE);
		fg_color[n] = &PANE_PREF(onepane).diff_fg[n];
		bg_color[n] = &PANE_PREF(onepane).diff_bg[n];
	}
	
	if (fi[0]->buf == NULL && fi[1]->buf == NULL && fi[2]->buf == NULL) /* Maybe, the file has been deleted. */
		return;

	if (onepane->n_col < 0)
		calc_ln_columns(onepane,
						MAX(MAX(fi[0]->nlines, fi[1]->nlines), fi[1]->nlines));
	lformat.n_col = onepane->n_col;
	ln_col_size = lformat.n_col + MARK_LENGTH;
	
	fprop.font = font;
	gtext_freeze(text);
	for (displn = dtmap_first_displn(dtmap, DA_ANY); displn; displn = dtmap_next_displn(dtmap, DA_ANY)) {
		if (displn->attr & (DA_COMMON | DA_O_ONLY)) {
			fprop.fg = fprop.bg = NULL;
			lformat.format = onepane->format_common;
		} else if (displn->attr & DA_BASE) {
			fprop.fg = fg_color[FIRST_FILE];
			fprop.bg = bg_color[FIRST_FILE];
			lformat.format = onepane->format_diff[FIRST_FILE];
		} else if (displn->attr & DA_OTHER) {
			fprop.fg = fg_color[SECOND_FILE];
			fprop.bg = bg_color[SECOND_FILE];
			lformat.format = onepane->format_diff[SECOND_FILE];
		} else if (displn->attr & DA_OTHER2) {
			fprop.fg = fg_color[THIRD_FILE];
			fprop.bg = bg_color[THIRD_FILE];
			lformat.format = onepane->format_diff[THIRD_FILE];
		} else {
			g_assert_not_reached();
		}
		mbuf_goto_top(MBUFFER(displn));
		if (displn->attr & DA_BASE) {
			insert_remove_line_numbers(text, b_show, displn->pos, &fprop,
									   MBUFFER(displn), ln[FIRST_FILE],
									   ln[FIRST_FILE] + MBUFFER(displn)->nl,
									   &lformat);
			ln[FIRST_FILE] += MBUFFER(displn)->nl;
		} else if (displn->attr & DA_OTHER) {
			insert_remove_line_numbers(text, b_show, displn->pos, &fprop,
									   MBUFFER(displn), ln[SECOND_FILE],
									   ln[SECOND_FILE] + MBUFFER(displn)->nl,
									   &lformat);
		} else if (displn->attr & DA_OTHER2) {
			insert_remove_line_numbers(text, b_show, displn->pos, &fprop,
									   MBUFFER(displn), ln[THIRD_FILE],
									   ln[THIRD_FILE] + MBUFFER(displn)->nl,
									   &lformat);
		}

		if (displn->attr & (DA_COMMON | DA_O_ONLY | DA_OTHER)) {
			ln[SECOND_FILE] += MBUFFER(displn)->nl;
		}
		if (displn->attr & (DA_COMMON | DA_O2_ONLY | DA_OTHER2)) {
			ln[THIRD_FILE] += MBUFFER(displn)->nl;
		}

		if (b_show == TRUE) {
			dtmap_inc_displn(dtmap, displn, MBUFFER(displn)->nl * ln_col_size);
		} else {
			dtmap_dec_displn(dtmap, displn, MBUFFER(displn)->nl * ln_col_size);
		}
	}
	gtext_thaw(text);
}

/* calculate column size of line numbers, and store it */
static void
calc_ln_columns(GdiffOnePane *onepane, int max_nlines)
{
	int n_col;
	
	n_col = calc_number_places(max_nlines);
	onepane->n_col = n_col;
	g_snprintf(onepane->format_common, sizeof(onepane->format_common),
			   "%%%dd%s", n_col, MARK_COMMON);/* e.g. "%4d  " */
	g_snprintf(onepane->format_diff[FIRST_FILE],
			   sizeof(onepane->format_diff[FIRST_FILE]),
			   "%%%dd%s", n_col, MARK_FILE1);/* e.g. "%4d< " */
	g_snprintf(onepane->format_diff[SECOND_FILE],
			   sizeof(onepane->format_diff[SECOND_FILE]),
			   "%%%dd%s", n_col, MARK_FILE2);/* e.g. "%4d> " */
	if (PANE_DFILES(onepane)->is_diff3)
		g_snprintf(onepane->format_diff[THIRD_FILE],
				   sizeof(onepane->format_diff[THIRD_FILE]),
				   "%%%dd%s", n_col, MARK_FILE3);/* e.g. "%4d^ " */
}

/* Routines for move to a difference */
/**
 * guts_move_diff:
 **/
static void
guts_move_diff(GdiffOnePane *onepane, MoveDiff mv_diff)
{
	DiffFiles *dfiles = PANE_DFILES(onepane);
	DTextMap *dtmap = onepane->dtmap;
	GtkWidget *text = onepane->text;
	int cur_ln; /* current line number */
	const GList *dlines_node;
	const DiffLines *dlines = NULL;
	
	if ((PANE_PREF(onepane).highlight == TRUE)/* revert the current one */
		&& (mv_diff != MOVED_CURRENT || mv_diff != MOVED_CUR_NOSCROLL)) {
		GdkColor *bg_color;

		if (GDIFF_BASEPANE(onepane)->cur_dlines_node) {
			const DiffLines *dlines	= GDIFF_BASEPANE(onepane)->cur_dlines_node->data;
			bg_color = &PANE_PREF(onepane).diff_bg[FIRST_FILE];
			change_lines_bgcolor(onepane, dlines, FIRST_FILE, bg_color);
		}
	}

	if (mv_diff == MOVED_REL_NEXT) {
		/* Relative moves are special features. */
		/* Driven by the first file's different position. */
		cur_ln = gtext_guess_visible_bottom_line(text, dtmap->total_nl);
		dlines_node = dfiles_find_rel_nextl(dfiles, FIRST_FILE, cur_ln);
		dlines = dlines_node ? dlines_node->data : NULL;
	} else if (mv_diff == MOVED_REL_PREV) {
		cur_ln = gtext_guess_visible_top_line(text, dtmap->total_nl);
		dlines_node = dfiles_find_rel_prevl(dfiles, FIRST_FILE, cur_ln);
		dlines = dlines_node ? dlines_node->data : NULL;
	} else {
		/* findfn_table is defined in fileview.c */
		int i;
		
		for (i = 0; i < NUM_FTABLE; i++) {
			if (findfn_table[i].mv_diff == mv_diff)
				break;
		}
		g_assert(findfn_table[i].find_fn != NULL);
		/* find the node */
		dlines_node = (findfn_table[i].find_fn)(dfiles,
												GDIFF_BASEPANE(onepane)->cur_dlines_node);
		dlines = dlines_node ? dlines_node->data : NULL;
		GDIFF_BASEPANE(onepane)->cur_dlines_node = dlines_node;
	}

	if (mv_diff != MOVED_CUR_NOSCROLL && dlines) {
		/* Use local variables for readability */
		int begin1 = dlines->between[FIRST_FILE].begin;
		int tbegin1 = dtmap_map_b2t(dtmap, begin1);

		if (PANE_PREF(onepane).line_wrap == TRUE) {
			gtext_gotoline_wrap(text, tbegin1, dtmap->total_nl);
		} else {
			gtext_gotoline_nonwrap(text, tbegin1, dtmap->total_nl);
		}
	}
	
	if (PANE_PREF(onepane).highlight == TRUE) {
		GdkColor *bg_color;

		if (dlines) {
			bg_color = &PANE_PREF(onepane).diff_hl[FIRST_FILE];
			change_lines_bgcolor(onepane, dlines, FIRST_FILE, bg_color);
		}
	}
}

/* Currently, used for highlight */
static void
change_lines_bgcolor(GdiffOnePane *onepane, const DiffLines *dlines, WhichFile whichfile, GdkColor *bg_color)
{
	DTextMap *dtmap = onepane->dtmap;
	GtkWidget *text = onepane->text;
	DispLines *displn = dtmap_lookup_by_bufln(dtmap, dlines->between[whichfile].begin);
	const char *buf_pt;
	GdkFont *font = text->style->font;
	FontProp fprop;
	GdkColor *fg_color = &PANE_PREF(onepane).diff_fg[whichfile];
	
	fprop.font = font;
	fprop.fg = fg_color;
	fprop.bg = bg_color;
	
	if (displn && !(displn->attr & DA_HIDE)) {
		gtext_freeze(text);
		gtext_set_point(text, displn->pos);
		gtext_forward_delete(text, displn->len);
		buf_pt = mbuf_goto_top(MBUFFER(displn));
		gtext_insert_buf(text, &fprop, buf_pt, mbuf_goto_bottom(MBUFFER(displn)) - buf_pt);
		if (PANE_PREF(onepane).show_line_num == TRUE) {
			int ln = dtmap_bufln_by_displn(dtmap, displn);
			LineFormat lformat;
			
			lformat.n_col = onepane->n_col;
			lformat.format = onepane->format_diff[whichfile];
			mbuf_goto_top(MBUFFER(displn));
			insert_remove_line_numbers(text, TRUE, displn->pos, &fprop,
									   MBUFFER(displn), ln, ln + MBUFFER(displn)->nl,
									   &lformat);
		}
		gtext_thaw(text);
	}
}


/**
 * guts_search_string_firstfile:
 * See guts_search_string() in twopane-widget.c about details.
 **/
static gboolean
guts_search_string_firstfile(GdiffOnePane *onepane, const char *string)
{
	MBuffer *mbuf = PANE_MBUF(onepane, FIRST_FILE);
	DTextMap *dtmap = onepane->dtmap;
	GtkWidget *text = onepane->text;
	int lenb = strlen(string);
	int ln; /* line number in buf */
	int tln; /* line number in text */
	int cached_tindex;
	int cached_tln;
	int cached_tpoint;

	/* At first, search in the current line from the next index. */
	cached_tln = onepane->search_tln;
	cached_tpoint = onepane->search_tpoint;
	cached_tindex = onepane->search_tindex + 1;
	if (gtext_search_string(text, string, lenb, cached_tln, cached_tln, &cached_tpoint, &cached_tindex) == TRUE) {
		onepane->search_tindex = cached_tindex;/* store for the next search */
		centering_text(onepane, cached_tln);
		return TRUE;
	}

	/* If not found in the current line, continue searching from the next line */
	/* First, search in mbuf */
	ln = onepane->search_ln[FIRST_FILE] + 1;
	ln = mbuf_search_string(mbuf, ln, string, lenb);
	onepane->search_ln[FIRST_FILE] = ln;/* store for the next search */
	if (ln == 0) {/* not found */
		gdk_beep();
		return FALSE;
	} else { /* Found in mbuf, try to find it in text widget */
		tln = dtmap_map_b2t(dtmap, ln);
		cached_tindex = 0;/* dummy */
		if (gtext_search_string(text, string, lenb, tln, cached_tln, &cached_tpoint, &cached_tindex) == FALSE)
			g_warning("guts_search_string wrong result.");

		/* store these for the next search */
		onepane->search_tln = tln;
		onepane->search_tpoint = cached_tpoint;
		onepane->search_tindex = cached_tindex;

		centering_text(onepane, tln);
		
		return TRUE;
	}
}

static void
centering_text(GdiffOnePane *onepane, int tln)
{
	DTextMap *dtmap = onepane->dtmap;
	GtkWidget *text = onepane->text;

	if (PANE_PREF(onepane).line_wrap == TRUE) {
		gtext_gotoline_wrap(text, tln, dtmap->total_nl);
	} else {
		gtext_gotoline_nonwrap(text, tln, dtmap->total_nl);
	}
}