source: trunk/third/gtkhtml3/src/htmlclue.c @ 21116

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*  This file is part of the GtkHTML library.

    Copyright (C) 1997 Martin Jones (mjones@kde.org)
    Copyright (C) 1997 Torben Weis (weis@kde.org)
    Copyright (C) 1999, 2000 Helix Code, Inc.

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.
*/

#include <config.h>
#include "htmlclue.h"
#include "htmlclueflow.h"
#include "htmlobject.h"
#include "htmlsearch.h"
#include "htmltextslave.h"
#include "htmltype.h"


#define HC_CLASS(x) (HTML_CLUE_CLASS (HTML_OBJECT (x)->klass))

HTMLClueClass html_clue_class;
static HTMLObjectClass *parent_class = NULL;

static void set_parent (HTMLObject *o, HTMLObject *tail, HTMLObject *parent);


/* HTMLObject methods.  */

static void
destroy (HTMLObject *o)
{
        HTMLObject *p;
        HTMLObject *next;

        for (p = HTML_CLUE (o)->head; p != NULL; p = next) {
                next = p->next;
                html_object_destroy (p);
        }
        HTML_CLUE (o)->head = NULL;
        HTML_CLUE (o)->tail = NULL;
                        
        HTML_OBJECT_CLASS (parent_class)->destroy (o);
}

static gint
get_n_children (HTMLObject *o)
{
        HTMLObject *cur = HTML_CLUE (o)->head;
        gint n_children = 0;

        while (cur) {
                n_children ++;
                cur = html_object_next_not_slave (cur);
        }

        return n_children;
}

static HTMLObject *
get_child (HTMLObject *o, gint index)
{
        HTMLObject *cur = HTML_CLUE (o)->head;

        g_return_val_if_fail (index >= 0, NULL);

        while (cur) {
                if (!index)
                        break;
                index --;
                cur = html_object_next_not_slave (cur);
        }

        return cur;
}

static gint
get_child_index (HTMLObject *self, HTMLObject *child)
{
        HTMLObject *cur = HTML_CLUE (self)->head;
        gint index = 0;

        while (cur) {
                if (cur == child)
                        return index;
                index ++;
                cur = html_object_next_not_slave (cur);
        }

        return -1;
}

static guint
get_recursive_length (HTMLObject *self)
{
        HTMLObject *o = HTML_CLUE (self)->head;
        guint len = 0;

        while (o) {
                len += html_object_get_recursive_length (o);
                o = o->next;
        }

        return len;
}

static void
copy (HTMLObject *self,
      HTMLObject *dest)
{
        (* HTML_OBJECT_CLASS (parent_class)->copy) (self, dest);

        HTML_CLUE (dest)->head = NULL;
        HTML_CLUE (dest)->tail = NULL;
        HTML_CLUE (dest)->curr = NULL;

        HTML_CLUE (dest)->valign = HTML_CLUE (self)->valign;
        HTML_CLUE (dest)->halign = HTML_CLUE (self)->halign;
}

static HTMLObject *
op_helper (HTMLObject *self, HTMLEngine *e, GList *from, GList *to, GList *left, GList *right, guint *len, gboolean cut)
{
        HTMLClue *clue = HTML_CLUE (self);
        HTMLObject *cc;
        HTMLObject *o, *last, *cnext, *child;

        cc   = html_object_dup (self);
        o    = (from) ? HTML_OBJECT (from->data) : clue->head;
        last = (to)   ? HTML_OBJECT (to->data)   : clue->tail;

        if ((o == NULL) && (last == NULL))
                return cc;

        if (HTML_IS_TEXT_SLAVE (last))
                last = html_object_prev_not_slave (last);

        g_assert (o->parent == self);
        g_assert (last->parent == self);

        while (o) {
                cnext = html_object_next_not_slave (o);
                child = cut ? html_object_op_cut (o, e,
                                              html_object_get_bound_list (o, from),
                                              html_object_get_bound_list (o, to),
                                              left ? left->next : NULL, right ? right->next : NULL, len)
                        : html_object_op_copy (o, cc, e,
                                               html_object_get_bound_list (o, from),
                                               html_object_get_bound_list (o, to), len);
                if (child)
                        html_clue_append (HTML_CLUE (cc), child);

                if (o == last)
                        break;
                o = cnext;
        }

        return cc;
}

static HTMLObject *
op_copy (HTMLObject *self, HTMLObject *parent, HTMLEngine *e, GList *from, GList *to, guint *len)
{
        return op_helper (self, e, from, to, NULL, NULL, len, FALSE);
}

static HTMLObject *
op_cut (HTMLObject *self, HTMLEngine *e, GList *from, GList *to, GList *left, GList *right, guint *len)
{
        HTMLObject *rv;
        HTMLClue *clue;

        clue = HTML_CLUE (self);
        rv   = op_helper (self, e, from, to, left, right, len, TRUE);
        if (!clue->head) {
                if (self->parent)
                        html_object_remove_child (self->parent, self);
                html_object_destroy (self);
        } else
                html_object_change_set (self, HTML_CHANGE_ALL_CALC);

        return rv;
}

static gboolean
merge (HTMLObject *self, HTMLObject *with, HTMLEngine *e, GList **left, GList **right, HTMLCursor *cursor)
{
        HTMLClue   *clue1, *clue2;

        clue1 = HTML_CLUE (self);
        clue2 = HTML_CLUE (with);

        html_clue_append (clue1, clue2->head);
        clue2->head = NULL;
        clue2->tail = NULL;

        html_object_change_set (self, HTML_CHANGE_ALL_CALC);
        return TRUE;
}

static void
remove_child (HTMLObject *self, HTMLObject *child)
{
        html_clue_remove (HTML_CLUE (self), child);
}

static void
split (HTMLObject *self, HTMLEngine *e, HTMLObject *child, gint offset, gint level, GList **left, GList **right)
{
        HTMLObject *dup;
        HTMLClue *clue;

        clue = HTML_CLUE (self);
        dup  = html_object_dup (self);

        HTML_CLUE (dup)->tail  = HTML_CLUE (self)->tail;
        HTML_CLUE (self)->tail = child->prev;
        if (child->prev)
                        child->prev->next = NULL;
        child->prev = NULL;
        if (child == HTML_CLUE (self)->head)
                HTML_CLUE (self)->head = NULL;
        HTML_CLUE (dup)->head  = child;
        set_parent (child, NULL, dup);

        if (self->parent && HTML_OBJECT_TYPE (self->parent) != HTML_TYPE_TABLE)
                html_clue_append_after (HTML_CLUE (self->parent), dup, self);

        self->x = 0;
        self->y = 0;

        *left  = g_list_prepend (*left, self);
        *right = g_list_prepend (*right, dup);

        level--;
        if (level)
                html_object_split (self->parent, e, dup, 0, level, left, right);
}

static void
draw (HTMLObject *o,
      HTMLPainter *p,
      gint x, gint y,
      gint width, gint height,
      gint tx, gint ty)
{
        HTMLObject *obj;
        
        if (y + height < o->y - o->ascent || y > o->y + o->descent)
                return;

        tx += o->x;
        ty += o->y - o->ascent;
        
        for (obj = HTML_CLUE (o)->head; obj != 0; obj = obj->next) {
                if (!(obj->flags & HTML_OBJECT_FLAG_ALIGNED)) {
                        html_object_draw (obj,
                                          p,
                                          x - o->x, y - (o->y - o->ascent),
                                          width, height,
                                          tx, ty);
                }
        }
}

static void
set_max_height (HTMLObject *o, HTMLPainter *painter, gint height)
{
        HTMLClue *clue = HTML_CLUE (o);
        HTMLObject *obj;

        if (o->ascent < height) {
                for (obj = HTML_CLUE (o)->head; obj != 0; obj = obj->next) {
                        html_object_set_max_height (obj, painter, height);
                        if (clue->valign == HTML_VALIGN_MIDDLE)
                                obj->y += (height - o->ascent)/2;
                        else if (clue->valign == HTML_VALIGN_BOTTOM)
                                obj->y += height - o->ascent;
                }

                o->ascent = height;
        }
}

static void
reset (HTMLObject *clue)
{
        HTMLObject *obj;

        for (obj = HTML_CLUE (clue)->head; obj != NULL; obj = obj->next)
                html_object_reset (obj);

        HTML_CLUE (clue)->curr = NULL;

        (* HTML_OBJECT_CLASS (parent_class)->reset) (HTML_OBJECT (clue));
}

static gboolean
html_clue_real_calc_size (HTMLObject *o, HTMLPainter *painter, GList **changed_objs)
{
        gboolean changed;

        /* If we have already called calc_size for the children, then just
           continue from the last object done in previous call. */
        if (HTML_CLUE (o)->curr == NULL) {
                o->ascent = 0;
                HTML_CLUE (o)->curr = HTML_CLUE (o)->head;
        }

        changed = FALSE;

        while (HTML_CLUE (o)->curr != NULL) {
                changed |= html_object_calc_size (HTML_CLUE (o)->curr, painter, changed_objs);
                HTML_CLUE (o)->curr = HTML_CLUE (o)->curr->next;
        }

        /* Remember the last object so that we can start from here next time
           we are called */
        HTML_CLUE (o)->curr = HTML_CLUE (o)->tail;

        return changed;
}

static gint
calc_preferred_width (HTMLObject *o,
                      HTMLPainter *painter)
{
        gint prefWidth = 0;
        HTMLObject *obj;
        
        for (obj = HTML_CLUE (o)->head; obj != 0; obj = obj->next) {
                gint w;

                w = html_object_calc_preferred_width (obj, painter);
                if (w > prefWidth)
                        prefWidth = w;
        }

        return prefWidth;
}

/* FIXME: This should be in HTMLClueV.  */
static gint
calc_min_width (HTMLObject *o,
                HTMLPainter *painter)
{
        HTMLObject *obj;
        gint minWidth = 0;
        
        for (obj = HTML_CLUE (o)->head; obj != 0; obj = obj->next) {
                gint w;

                w = html_object_calc_min_width (obj, painter);
                if (w > minWidth)
                        minWidth = w;
        }
        
        return minWidth;
}

static HTMLAnchor *
find_anchor (HTMLObject *self, const char *name, gint *x, gint *y)
{
        HTMLClue *clue;
        HTMLObject *obj;
        HTMLAnchor *anchor;

        *x += self->x;
        *y += self->y - self->ascent;

        clue = HTML_CLUE (self);

        for ( obj = clue->head; obj != NULL; obj = obj->next ) {
                if ((anchor = html_object_find_anchor ( obj, name, x, y)) != 0 )
                        return anchor;
        }

        *x -= self->x;
        *y -= self->y - self->ascent;

        return 0;
}

static HTMLObject*
check_point (HTMLObject *o,
             HTMLPainter *painter,
             gint x, gint y,
             guint *offset_return,
             gboolean for_cursor)
{
        HTMLObject *obj;
        HTMLObject *obj2;

        if (x < o->x || x >= o->x + o->width
            || y >= o->y + o->descent || y < o->y - o->ascent)
                return NULL;

        x = x - o->x;
        y = y - o->y + o->ascent;

        for (obj = HTML_CLUE (o)->head; obj != 0; obj = obj->next) {
                obj2 = html_object_check_point (obj, painter,
                                                x, y, offset_return,
                                                for_cursor);
                if (obj2 != NULL)
                        return obj2;
        }

        return NULL;
}

static gint
check_page_split (HTMLObject *self, HTMLPainter *painter, gint y)
{
        HTMLClue *clue;
        HTMLObject *p;
        gint last_under = 0;

        clue = HTML_CLUE (self);
        for (p = clue->head; p != NULL; p = p->next) {
                gint y1, y2;

                y1 = p->y - p->ascent;
                y2 = p->y + p->descent;

                if (y1 > y)
                        return last_under;

                if (y >= y1 && y < y2)
                        return html_object_check_page_split (p, painter, y - y1) + y1;
                last_under = y2;
        }

        return y;
}

static void
forall (HTMLObject *self,
        HTMLEngine *e,
        HTMLObjectForallFunc func,
        gpointer data)
{
        HTMLObject *p, *pnext;

        for (p = HTML_CLUE (self)->head; p != NULL; p = pnext) {
                pnext = p->next;
                html_object_forall (p, e, func, data);
        }

        html_object_class.forall (self, e, func, data);
}

static gboolean
is_container (HTMLObject *self)
{
        return TRUE;
}

static gboolean
save (HTMLObject *self,
      HTMLEngineSaveState *state)
{
        HTMLObject *p;
        HTMLClue *clue;

        clue = HTML_CLUE (self);

        for (p = clue->head; p != NULL; p = p->next) {
                if (! html_object_save (p, state))
                    return FALSE;
        }

        return TRUE;
}

static gboolean
save_plain (HTMLObject *self,
            HTMLEngineSaveState *state,
            gint requested_width)
{
        HTMLObject *p;
        HTMLClue *clue;

        clue = HTML_CLUE (self);

        for (p = clue->head; p != NULL; p = p->next) {
                if (! html_object_save_plain (p, state, requested_width))
                    return FALSE;
        }

        return TRUE;
}

/* HTMLClue methods.  */

static gint
get_left_clear (HTMLClue *o, gint y)
{
        return y;
}

static gint
get_right_clear (HTMLClue *o, gint y)
{
        return y;
}

static void
find_free_area (HTMLClue *clue,
                HTMLPainter *painter,
                gint y,
                gint width, gint height,
                gint indent, gint *y_pos,
                gint *lmargin, gint *rmargin)
{
        *y_pos = y;
        *lmargin = 0;
        *rmargin = MAX (HTML_OBJECT (clue)->max_width, HTML_OBJECT (clue)->width);
}

static void
append_right_aligned (HTMLClue *clue, HTMLPainter *painter, HTMLClue *aclue, gint *lmargin, gint *rmargin, gint indent)
{
        /* This needs to be implemented in the subclasses.  */
        g_warning ("`%s' does not implement `append_right_aligned()'.",
                   html_type_name (HTML_OBJECT_TYPE (clue)));
}

static gboolean
appended (HTMLClue *clue, HTMLClue *aclue)
{
        return FALSE;
}

static gboolean
search (HTMLObject *obj, HTMLSearch *info)
{
        HTMLObject *cur;
        HTMLClue *clue = HTML_CLUE (obj);
        gboolean next = FALSE;

        /* search_next? */
        if (html_search_child_on_stack (info, obj)) {
                cur  = html_search_pop (info);
                cur = (info->forward) ? cur->next : cur->prev;
                next = TRUE;
        } else
                cur = (info->forward) ? clue->head : clue->tail;

        while (cur) {
                html_search_push (info, cur);
                if (html_object_search (cur, info))
                        return TRUE;

                html_search_pop (info);
                cur = (info->forward) ? cur->next : cur->prev;
        }

        if (next)
                return html_search_next_parent (info);

        return FALSE;
}

static void
append_selection_string (HTMLObject *self,
                         GString *buffer)
{
        HTMLObject *o = HTML_CLUE (self)->head;

        while (o) {
                html_object_append_selection_string (o, buffer);
                o = o->next;
        }
}

static HTMLObject *
head (HTMLObject *self)
{
        return HTML_CLUE (self)->head;
}

static HTMLObject *
tail (HTMLObject *self)
{
        HTMLObject *obj;

        obj = HTML_CLUE (self)->tail;
        return (obj && HTML_OBJECT_TYPE (obj) == HTML_TYPE_TEXTSLAVE) ? html_object_prev_not_slave (obj) : obj;
}


void
html_clue_type_init (void)
{
        html_clue_class_init (&html_clue_class, HTML_TYPE_CLUE, sizeof (HTMLClue));
}

void
html_clue_class_init (HTMLClueClass *klass,
                      HTMLType type,
                      guint size)
{
        HTMLObjectClass *object_class;

        g_return_if_fail (klass != NULL);

        object_class = HTML_OBJECT_CLASS (klass);
        html_object_class_init (object_class, type, size);
        
        /* HTMLObject functions */
        object_class->destroy = destroy;
        object_class->copy = copy;
        object_class->op_copy = op_copy;
        object_class->op_cut = op_cut;
        object_class->merge = merge;
        object_class->remove_child = remove_child;
        object_class->split = split;
        object_class->draw = draw;
        object_class->set_max_height = set_max_height;
        object_class->reset = reset;
        object_class->calc_size = html_clue_real_calc_size;
        object_class->calc_preferred_width = calc_preferred_width;
        object_class->calc_min_width = calc_min_width;
        object_class->check_point = check_point;
        object_class->check_page_split = check_page_split;
        object_class->find_anchor = find_anchor;
        object_class->forall = forall;
        object_class->is_container = is_container;
        object_class->save = save;
        object_class->save_plain = save_plain;
        object_class->search = search;
        object_class->append_selection_string = append_selection_string;
        object_class->head = head;
        object_class->tail = tail;
        object_class->get_recursive_length = get_recursive_length;
        object_class->get_n_children = get_n_children;
        object_class->get_child = get_child;
        object_class->get_child_index = get_child_index;

        /* HTMLClue methods.  */
        klass->get_left_clear = get_left_clear;
        klass->get_right_clear = get_right_clear;
        klass->find_free_area = find_free_area;
        klass->append_right_aligned = append_right_aligned;
        klass->appended = appended;

        parent_class = &html_object_class;
}

void
html_clue_init (HTMLClue *clue,
                HTMLClueClass *klass)
{
        HTMLObject *object;

        object = HTML_OBJECT (clue);
        html_object_init (object, HTML_OBJECT_CLASS (klass));

        clue->head = NULL;
        clue->tail = NULL;
        clue->curr = NULL;

        clue->valign = HTML_VALIGN_TOP;
        clue->halign = HTML_HALIGN_LEFT;
}


gint
html_clue_get_left_clear (HTMLClue *clue, gint y)
{
        return (* HC_CLASS (clue)->get_left_clear) (clue, y);
}

gint
html_clue_get_right_clear (HTMLClue *clue, gint y)
{
        return (* HC_CLASS (clue)->get_right_clear) (clue, y);
}

void
html_clue_find_free_area (HTMLClue *clue,
                          HTMLPainter *painter,
                          gint y,
                          gint width, gint height, gint indent, gint *y_pos,
                          gint *lmargin, gint *rmargin)
{
        (* HC_CLASS (clue)->find_free_area) (clue, painter, y, width, height, indent, y_pos, lmargin, rmargin);
}

void
html_clue_append_right_aligned (HTMLClue *clue, HTMLPainter *painter,
                                HTMLClue *aclue, gint *lmargin, gint *rmargin, gint indent)
{
        g_assert (clue != NULL);
        g_assert (aclue != NULL);

        html_object_change_set (HTML_OBJECT (clue), HTML_OBJECT (aclue)->change);

        (* HC_CLASS (clue)->append_right_aligned) (clue, painter, aclue, lmargin, rmargin, indent);
}

void
html_clue_append_left_aligned (HTMLClue *clue, HTMLPainter *painter,
                               HTMLClue *aclue, gint *lmargin, gint *rmargin, gint indent)
{
        g_assert (clue != NULL);
        g_assert (aclue != NULL);

        html_object_change_set (HTML_OBJECT (clue), HTML_OBJECT (aclue)->change);

        (* HC_CLASS (clue)->append_left_aligned) (clue, painter, aclue, lmargin, rmargin, indent);
}

gboolean
html_clue_appended (HTMLClue *clue, HTMLClue *aclue)
{
        return (* HC_CLASS (clue)->appended) (clue, aclue);
}


/* Utility functions.  */

static HTMLObject *
get_tail (HTMLObject *p)
{
        if (p == NULL)
                return NULL;

        while (p->next != NULL)
                p = p->next;

        return p;
}

static void
set_parent (HTMLObject *o,
            HTMLObject *tail,
            HTMLObject *parent)
{
        while (o) {
                html_object_set_parent (o, parent);
                if (o == tail)
                        break;
                o = o->next;
        }
}

/**
 * html_clue_append_after:
 * @clue: An HTMLClue.
 * @o: An HTMLObject.
 * @where: A child of @clue.
 * 
 * Insert @o and its successors in @clue after @clue's element @where.
 **/
void
html_clue_append_after (HTMLClue *clue,
                        HTMLObject *o,
                        HTMLObject *where)
{
        HTMLObject *tail;

        g_return_if_fail (o != NULL);
        g_return_if_fail (html_object_is_clue (HTML_OBJECT (clue)));

        if (where == NULL) {
                html_clue_prepend (clue, o);
                return;
        }
        g_return_if_fail (where->parent == HTML_OBJECT (clue));

        html_object_change_set (HTML_OBJECT (clue), o->change);

        tail = get_tail (o);

        if (where->next != NULL)
                where->next->prev = tail;
        tail->next = where->next;

        where->next = o;
        o->prev = where;

        if (where == clue->tail)
                clue->tail = tail;

        set_parent (o, tail, HTML_OBJECT (clue));
}

/**
 * html_clue_append:
 * @clue: An HTMLClue.
 * @o: An HTMLObject.
 * 
 * Append @o and its successors to @clue.
 **/
void
html_clue_append (HTMLClue *clue,
                  HTMLObject *o)
{
        HTMLObject *tail;

        g_return_if_fail (clue != NULL);
        g_return_if_fail (html_object_is_clue (HTML_OBJECT (clue)));
        g_return_if_fail (o != NULL);

        html_object_change_set (HTML_OBJECT (clue), o->change);

        tail = get_tail (o);

        if (! clue->head) {
                clue->head = o;
                o->prev = NULL;
        } else {
                clue->tail->next = o;
                o->prev = clue->tail;
        }

        clue->tail = tail;
        tail->next = NULL;

        html_object_set_parent (o, HTML_OBJECT (clue));

        set_parent (o, tail, HTML_OBJECT (clue));
}

/**
 * html_clue_prepend:
 * @clue: An HTMLClue.
 * @o: An HTMLObject.
 * 
 * Prepend @o and its successors to @clue.
 **/
void
html_clue_prepend (HTMLClue *clue,
                   HTMLObject *o)
{
        HTMLObject *tail;

        g_return_if_fail (clue != NULL);
        g_return_if_fail (o != NULL);

        html_object_change_set (HTML_OBJECT (clue), o->change);

        tail = get_tail (o);

        if (! clue->head) {
                clue->head = o;
                clue->tail = tail;
                o->prev = NULL;
        } else {
                o->next = clue->head;
                clue->head->prev = o;
                clue->head = o;
        }

        o->prev = NULL;

        set_parent (o, tail, HTML_OBJECT (clue));
}

/**
 * html_clue_remove:
 * @clue: An HTMLClue.
 * @o: An HTMLObject.
 * 
 * Remove object @o from the clue.
 **/
void
html_clue_remove (HTMLClue *clue,
                  HTMLObject *o)
{
        g_return_if_fail (clue != NULL);
        g_return_if_fail (o != NULL);
        g_return_if_fail (clue == HTML_CLUE (o->parent));

        if (o == clue->head)
                clue->head = o->next;
        if (o == clue->tail)
                clue->tail = o->prev;

        if (o->next != NULL)
                o->next->prev = o->prev;
        if (o->prev != NULL)
                o->prev->next = o->next;

        o->parent = NULL;
        o->prev = NULL;
        o->next = NULL;
}

void
html_clue_remove_text_slaves (HTMLClue *clue)
{
        HTMLObject *p;
        HTMLObject *pnext;

        g_return_if_fail (clue != NULL);

        for (p = clue->head; p != NULL; p = pnext) {
                pnext = p->next;

                if (HTML_OBJECT_TYPE (p) == HTML_TYPE_TEXTSLAVE) {
                        html_clue_remove (clue, p);
                        html_object_destroy (p);
                }
        }
}


gboolean
html_clue_is_empty (HTMLClue *clue)
{
        if (clue->head == NULL)
                return TRUE;
        if (clue->head == clue->tail
            && HTML_IS_CLUEFLOW (clue->head) && html_clueflow_is_empty (HTML_CLUEFLOW (clue->head)))
                return TRUE;
        return FALSE;
}