path: root/widgets/misc/e-reflow.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* 
 * e-reflow.c
 * Copyright (C) 2000  Helix Code, Inc.
 * Author: Chris Lahey <clahey@helixcode.com>
 *
 * This library 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 program 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 this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <config.h>
#include <gnome.h>
#include <math.h>
#include "e-reflow.h"
#include "gal/e-text/e-text.h"
#include "e-canvas-utils.h"
#include "e-canvas.h"
#include "gal/util/e-util.h"

static void e_reflow_init       (EReflow         *reflow);
static void e_reflow_class_init (EReflowClass    *klass);
static void e_reflow_set_arg (GtkObject *o, GtkArg *arg, guint arg_id);
static void e_reflow_get_arg (GtkObject *object, GtkArg *arg, guint arg_id);
static void e_reflow_destroy (GtkObject *object);
static gboolean e_reflow_event (GnomeCanvasItem *item, GdkEvent *event);
static void e_reflow_realize (GnomeCanvasItem *item);
static void e_reflow_unrealize (GnomeCanvasItem *item);
static void e_reflow_draw (GnomeCanvasItem *item, GdkDrawable *drawable,
                    int x, int y, int width, int height);
static void e_reflow_update (GnomeCanvasItem *item, double affine[6], ArtSVP *clip_path, gint flags);
static double e_reflow_point (GnomeCanvasItem *item, double x, double y, int cx, int cy, GnomeCanvasItem **actual_item);
static void e_reflow_reflow (GnomeCanvasItem *item, int flags);
static void e_reflow_real_add_item(EReflow *e_reflow, GnomeCanvasItem *item, gint *position);
static void set_empty(EReflow *e_reflow);

static void e_reflow_resize_children (GnomeCanvasItem *item);

#define E_REFLOW_DIVIDER_WIDTH 2
#define E_REFLOW_BORDER_WIDTH 7
#define E_REFLOW_FULL_GUTTER (E_REFLOW_DIVIDER_WIDTH + E_REFLOW_BORDER_WIDTH * 2)

static GnomeCanvasGroupClass *parent_class = NULL;

/* The arguments we take */
enum {
    ARG_0,
    ARG_MINIMUM_WIDTH,
    ARG_WIDTH,
    ARG_HEIGHT,
    ARG_EMPTY_MESSAGE,
};

GtkType
e_reflow_get_type (void)
{
  static GtkType reflow_type = 0;

  if (!reflow_type)
    {
      static const GtkTypeInfo reflow_info =
      {
        "EReflow",
        sizeof (EReflow),
        sizeof (EReflowClass),
        (GtkClassInitFunc) e_reflow_class_init,
        (GtkObjectInitFunc) e_reflow_init,
        /* reserved_1 */ NULL,
        /* reserved_2 */ NULL,
        (GtkClassInitFunc) NULL,
      };

      reflow_type = gtk_type_unique (gnome_canvas_group_get_type (), &reflow_info);
    }

  return reflow_type;
}

static void
e_reflow_class_init (EReflowClass *klass)
{
    GtkObjectClass *object_class;
    GnomeCanvasItemClass *item_class;

    object_class = (GtkObjectClass*) klass;
    item_class = (GnomeCanvasItemClass *) klass;

    parent_class = gtk_type_class (gnome_canvas_group_get_type ());
  
    gtk_object_add_arg_type ("EReflow::minimum_width", GTK_TYPE_DOUBLE, 
                 GTK_ARG_READWRITE, ARG_MINIMUM_WIDTH); 
    gtk_object_add_arg_type ("EReflow::width", GTK_TYPE_DOUBLE, 
                 GTK_ARG_READABLE, ARG_WIDTH); 
    gtk_object_add_arg_type ("EReflow::height", GTK_TYPE_DOUBLE, 
                 GTK_ARG_READWRITE, ARG_HEIGHT);
    gtk_object_add_arg_type ("EReflow::empty_message", GTK_TYPE_STRING, 
                 GTK_ARG_READWRITE, ARG_EMPTY_MESSAGE);

    klass->add_item       = e_reflow_real_add_item;
 
    object_class->set_arg = e_reflow_set_arg;
    object_class->get_arg = e_reflow_get_arg;
    object_class->destroy = e_reflow_destroy;
  
    /* GnomeCanvasItem method overrides */
    item_class->event     = e_reflow_event;
    item_class->realize   = e_reflow_realize;
    item_class->unrealize = e_reflow_unrealize;
    item_class->draw      = e_reflow_draw;
    item_class->update    = e_reflow_update;
    item_class->point     = e_reflow_point;
}

static void
e_reflow_init (EReflow *reflow)
{
    reflow->items = NULL;
    reflow->columns = NULL;
    reflow->column_width = 150;

    reflow->minimum_width = 10;
    reflow->width = 10;
    reflow->height = 10;
    reflow->idle = 0;

    reflow->empty_message = NULL;
    reflow->empty_text = NULL;

    reflow->column_drag = FALSE;

    reflow->need_height_update = FALSE;
    reflow->need_column_resize = FALSE;

    reflow->default_cursor_shown = TRUE;
    reflow->arrow_cursor = NULL;
    reflow->default_cursor = NULL;

    e_canvas_item_set_reflow_callback(GNOME_CANVAS_ITEM(reflow), e_reflow_reflow);
}

static void
e_reflow_set_arg (GtkObject *o, GtkArg *arg, guint arg_id)
{
    GnomeCanvasItem *item;
    EReflow *e_reflow;

    item = GNOME_CANVAS_ITEM (o);
    e_reflow = E_REFLOW (o);
    
    switch (arg_id){
    case ARG_HEIGHT:
        e_reflow->height = GTK_VALUE_DOUBLE (*arg);
        e_canvas_item_request_reflow(item);
        break;
    case ARG_MINIMUM_WIDTH:
        e_reflow->minimum_width = GTK_VALUE_DOUBLE (*arg);
        if (GNOME_CANVAS_ITEM_REALIZED & GTK_OBJECT_FLAGS(o))
            set_empty(e_reflow);
        e_canvas_item_request_reflow(item);
        break;
    case ARG_EMPTY_MESSAGE:
        g_free(e_reflow->empty_message);
        e_reflow->empty_message = g_strdup(GTK_VALUE_STRING (*arg));
        if (GNOME_CANVAS_ITEM_REALIZED & GTK_OBJECT_FLAGS(o))
            set_empty(e_reflow);
    }
}

static void
e_reflow_get_arg (GtkObject *object, GtkArg *arg, guint arg_id)
{
    EReflow *e_reflow;

    e_reflow = E_REFLOW (object);

    switch (arg_id) {
    case ARG_MINIMUM_WIDTH:
        GTK_VALUE_DOUBLE (*arg) = e_reflow->minimum_width;
        break;
    case ARG_WIDTH:
        GTK_VALUE_DOUBLE (*arg) = e_reflow->width;
        break;
    case ARG_HEIGHT:
        GTK_VALUE_DOUBLE (*arg) = e_reflow->height;
        break;
    case ARG_EMPTY_MESSAGE:
        GTK_VALUE_STRING (*arg) = g_strdup(e_reflow->empty_message);
        break;
    default:
        arg->type = GTK_TYPE_INVALID;
        break;
    }
}

static void
e_reflow_destroy (GtkObject *object)
{
    EReflow *reflow = E_REFLOW(object);

    g_list_foreach(reflow->items, (GFunc) gtk_object_unref, NULL);
    g_list_free(reflow->items);
    reflow->items = NULL;
    
    g_free(reflow->empty_message);
  
    GTK_OBJECT_CLASS(parent_class)->destroy (object);
}

static void
e_reflow_realize (GnomeCanvasItem *item)
{
    EReflow *e_reflow;
    GnomeCanvasGroup *group;
    GList *list;
    GtkAdjustment *adjustment;

    e_reflow = E_REFLOW (item);
    group = GNOME_CANVAS_GROUP( item );

    if (GNOME_CANVAS_ITEM_CLASS(parent_class)->realize)
        (* GNOME_CANVAS_ITEM_CLASS(parent_class)->realize) (item);
    
    e_reflow->arrow_cursor = gdk_cursor_new (GDK_SB_H_DOUBLE_ARROW);
    e_reflow->default_cursor = gdk_cursor_new (GDK_LEFT_PTR);

    for(list = e_reflow->items; list; list = g_list_next(list)) {
        GnomeCanvasItem *item = GNOME_CANVAS_ITEM(list->data);
        gnome_canvas_item_set(item,
                      "width", (double) e_reflow->column_width,
                      NULL);
    }

    set_empty(e_reflow);

    e_canvas_item_request_reflow(item);
    
    adjustment = gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas));
    adjustment->step_increment = (e_reflow->column_width + E_REFLOW_FULL_GUTTER) / 2;
    adjustment->page_increment = adjustment->page_size - adjustment->step_increment;
    gtk_adjustment_changed(adjustment);
    
    if (!item->canvas->aa) {
    }
}

static void
e_reflow_unrealize (GnomeCanvasItem *item)
{
  EReflow *e_reflow;

  e_reflow = E_REFLOW (item);

  if (!item->canvas->aa)
    {
    }
  
  gdk_cursor_destroy (e_reflow->arrow_cursor);
  gdk_cursor_destroy (e_reflow->default_cursor);
  e_reflow->arrow_cursor = NULL;
  e_reflow->default_cursor = NULL;

  g_list_free (e_reflow->columns);
  e_reflow->columns = NULL;

  if (GNOME_CANVAS_ITEM_CLASS(parent_class)->unrealize)
    (* GNOME_CANVAS_ITEM_CLASS(parent_class)->unrealize) (item);
}

static gint
e_reflow_pick_line (EReflow *e_reflow, double x)
{
    x += E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH;
    x /= e_reflow->column_width + E_REFLOW_FULL_GUTTER;
    return x;
}

static gboolean
e_reflow_event (GnomeCanvasItem *item, GdkEvent *event)
{
    EReflow *e_reflow;
 
    e_reflow = E_REFLOW (item);

    switch( event->type )
        {
        case GDK_KEY_PRESS:
            if (event->key.keyval == GDK_Tab || 
                event->key.keyval == GDK_KP_Tab || 
                event->key.keyval == GDK_ISO_Left_Tab) {
                GList *list;
                for (list = e_reflow->items; list; list = list->next) {
                    GnomeCanvasItem *item = GNOME_CANVAS_ITEM (list->data);
                    EFocus has_focus;
                    gtk_object_get(GTK_OBJECT(item),
                               "has_focus", &has_focus,
                               NULL);
                    if (has_focus) {
                        if (event->key.state & GDK_SHIFT_MASK)
                            list = list->prev;
                        else
                            list = list->next;
                        if (list) {
                            item = GNOME_CANVAS_ITEM(list->data);
                            gnome_canvas_item_set(item,
                                          "has_focus", (event->key.state & GDK_SHIFT_MASK) ? E_FOCUS_END : E_FOCUS_START,
                                          NULL);
                            return 1;
                        } else {
                            return 0;
                        }
                    }
                }
            }
            break;
        case GDK_BUTTON_PRESS:
            switch(event->button.button) 
                {
                case 1:
                    {
                        GdkEventButton *button = (GdkEventButton *) event;
                        double n_x, max_x;
                        n_x = button->x;
                        n_x += E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH;
                        n_x = fmod(n_x,(e_reflow->column_width + E_REFLOW_FULL_GUTTER));

                        max_x = E_REFLOW_BORDER_WIDTH;
                        max_x += (e_reflow->column_width + E_REFLOW_FULL_GUTTER) * e_reflow->column_count;
                        if ( button->y >= E_REFLOW_BORDER_WIDTH && button->y <= e_reflow->height - E_REFLOW_BORDER_WIDTH && n_x < E_REFLOW_FULL_GUTTER && max_x > button->x ) {
                            e_reflow->which_column_dragged = e_reflow_pick_line(e_reflow, button->x);
                            e_reflow->start_x = e_reflow->which_column_dragged * (e_reflow->column_width + E_REFLOW_FULL_GUTTER) - E_REFLOW_DIVIDER_WIDTH / 2;
                            e_reflow->temp_column_width = e_reflow->column_width;
                            e_reflow->column_drag = TRUE;
                          
                            gnome_canvas_item_grab (item, 
                                        GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK,
                                        e_reflow->arrow_cursor,
                                        button->time);
                          
                            e_reflow->previous_temp_column_width = -1;
                            e_reflow->need_column_resize = TRUE;
                            gnome_canvas_item_request_update(item);
                            return TRUE;
                        }
                    }
                    break;
                case 4:
                    {
                        GtkAdjustment *adjustment = gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas));
                        gdouble new_value = adjustment->value;
                        new_value -= adjustment->step_increment;
                        gtk_adjustment_set_value(adjustment, new_value);
                    }
                    break;
                case 5: 
                    {
                        GtkAdjustment *adjustment = gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas));
                        gdouble new_value = adjustment->value;
                        new_value += adjustment->step_increment;
                        if ( new_value > adjustment->upper - adjustment->page_size )
                            new_value = adjustment->upper - adjustment->page_size;
                        gtk_adjustment_set_value(adjustment, new_value);
                    }
                    break;
                }
            break;
        case GDK_BUTTON_RELEASE:
            if (e_reflow->column_drag) {
                gdouble old_width = e_reflow->column_width;
                GdkEventButton *button = (GdkEventButton *) event;
                GtkAdjustment *adjustment = gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas));
                e_reflow->temp_column_width = e_reflow->column_width +
                    (button->x - e_reflow->start_x)/(e_reflow->which_column_dragged - e_reflow_pick_line(e_reflow, adjustment->value));
                if ( e_reflow->temp_column_width < 50 )
                    e_reflow->temp_column_width = 50;
                e_reflow->column_drag = FALSE;
                if ( old_width != e_reflow->temp_column_width ) {
                    gtk_adjustment_set_value(adjustment, adjustment->value + e_reflow_pick_line(e_reflow, adjustment->value) * (e_reflow->temp_column_width - e_reflow->column_width));
                    e_reflow->column_width = e_reflow->temp_column_width;
                    adjustment->step_increment = (e_reflow->column_width + E_REFLOW_FULL_GUTTER) / 2;
                    adjustment->page_increment = adjustment->page_size - adjustment->step_increment;
                    gtk_adjustment_changed(adjustment);
                    e_reflow_resize_children(item);
                    e_canvas_item_request_reflow(item);
                }
                e_reflow->need_column_resize = TRUE;
                gnome_canvas_item_request_update(item);
                gnome_canvas_item_ungrab (item, button->time);
                return TRUE;
            }
            break;
        case GDK_MOTION_NOTIFY:
            if (e_reflow->column_drag) {
                double old_width = e_reflow->temp_column_width;
                GdkEventMotion *motion = (GdkEventMotion *) event;
                GtkAdjustment *adjustment = gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas));
                e_reflow->temp_column_width = e_reflow->column_width +
                    (motion->x - e_reflow->start_x)/(e_reflow->which_column_dragged - e_reflow_pick_line(e_reflow, adjustment->value));
                if (e_reflow->temp_column_width < 50)
                    e_reflow->temp_column_width = 50;
                if (old_width != e_reflow->temp_column_width) {
                    e_reflow->need_column_resize = TRUE;
                    gnome_canvas_item_request_update(item);
                }
                return TRUE;
            } else {
                GdkEventMotion *motion = (GdkEventMotion *) event;
                double n_x, max_x;

                n_x = motion->x;
                n_x += E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH;
                n_x = fmod(n_x,(e_reflow->column_width + E_REFLOW_FULL_GUTTER));

                max_x = E_REFLOW_BORDER_WIDTH;
                max_x += (e_reflow->column_width + E_REFLOW_FULL_GUTTER) * e_reflow->column_count;

                if ( motion->y >= E_REFLOW_BORDER_WIDTH && motion->y <= e_reflow->height - E_REFLOW_BORDER_WIDTH && n_x < E_REFLOW_FULL_GUTTER && max_x > motion->x) {
                    if ( e_reflow->default_cursor_shown ) {
                        gdk_window_set_cursor(GTK_WIDGET(item->canvas)->window, e_reflow->arrow_cursor);
                        e_reflow->default_cursor_shown = FALSE;
                    }
                } else 
                    if ( ! e_reflow->default_cursor_shown ) {
                        gdk_window_set_cursor(GTK_WIDGET(item->canvas)->window, e_reflow->default_cursor);
                        e_reflow->default_cursor_shown = TRUE;
                    }
                
            }
            break;
        case GDK_ENTER_NOTIFY:
            if (!e_reflow->column_drag) {
                GdkEventCrossing *crossing = (GdkEventCrossing *) event;
                double n_x, max_x;
                n_x = crossing->x;
                n_x += E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH;
                n_x = fmod(n_x,(e_reflow->column_width + E_REFLOW_FULL_GUTTER));

                max_x = E_REFLOW_BORDER_WIDTH;
                max_x += (e_reflow->column_width + E_REFLOW_FULL_GUTTER) * e_reflow->column_count;
                if ( crossing->y >= E_REFLOW_BORDER_WIDTH && crossing->y <= e_reflow->height - E_REFLOW_BORDER_WIDTH && n_x < E_REFLOW_FULL_GUTTER && max_x > crossing->x) {
                    if ( e_reflow->default_cursor_shown ) {
                        gdk_window_set_cursor(GTK_WIDGET(item->canvas)->window, e_reflow->arrow_cursor);
                        e_reflow->default_cursor_shown = FALSE;
                    }
                }
            }
            break;
        case GDK_LEAVE_NOTIFY:
            if (!e_reflow->column_drag) {
                GdkEventCrossing *crossing = (GdkEventCrossing *) event;
                double n_x;
                n_x = crossing->x;
                n_x += E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH;
                n_x = fmod(n_x,(e_reflow->column_width + E_REFLOW_FULL_GUTTER));
                if ( !( crossing->y >= E_REFLOW_BORDER_WIDTH && crossing->y <= e_reflow->height - E_REFLOW_BORDER_WIDTH && n_x < E_REFLOW_FULL_GUTTER ) ) {
                    if ( ! e_reflow->default_cursor_shown ) {
                        gdk_window_set_cursor(GTK_WIDGET(item->canvas)->window, e_reflow->default_cursor);
                        e_reflow->default_cursor_shown = TRUE;
                    }
                }
            }
            break;
        default:
            break;
        }
  
    if (GNOME_CANVAS_ITEM_CLASS( parent_class )->event)
        return (* GNOME_CANVAS_ITEM_CLASS( parent_class )->event) (item, event);
    else
        return 0;
}

static void
e_reflow_real_add_item(EReflow *e_reflow, GnomeCanvasItem *item, gint *position)
{
    e_reflow->items = g_list_append(e_reflow->items, item);
    gtk_object_ref(GTK_OBJECT(item));
    if (GTK_OBJECT_FLAGS (e_reflow) & GNOME_CANVAS_ITEM_REALIZED) {
        gnome_canvas_item_set(item,
                      "width", (double) e_reflow->column_width,
                      NULL);
        e_reflow_post_add_item(e_reflow, item);
        e_canvas_item_request_reflow(item);
    }
    if (position)
        *position = g_list_index(e_reflow->items, item);
}

static void e_reflow_draw (GnomeCanvasItem *item, GdkDrawable *drawable,
                    int x, int y, int width, int height)
{
    int x_rect, y_rect, width_rect, height_rect;
    gdouble running_width;
    EReflow *e_reflow = E_REFLOW(item);
    int i;
    double column_width;

    if (GNOME_CANVAS_ITEM_CLASS(parent_class)->draw)
        GNOME_CANVAS_ITEM_CLASS(parent_class)->draw (item, drawable, x, y, width, height);
    column_width = e_reflow->column_width;
    running_width = E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
    x_rect = running_width;
    y_rect = E_REFLOW_BORDER_WIDTH;
    width_rect = E_REFLOW_DIVIDER_WIDTH;
    height_rect = e_reflow->height - (E_REFLOW_BORDER_WIDTH * 2);

    /* Compute first column to draw. */
    i = x;
    i /= column_width + E_REFLOW_FULL_GUTTER;
    running_width += i * (column_width + E_REFLOW_FULL_GUTTER);

    for ( ; i < e_reflow->column_count; i++) {
        if ( running_width > x + width )
            break;
        x_rect = running_width;
        gtk_paint_flat_box(GTK_WIDGET(item->canvas)->style,
                   drawable,
                   GTK_STATE_ACTIVE,
                   GTK_SHADOW_NONE,
                   NULL,
                   GTK_WIDGET(item->canvas),
                   "reflow",
                   x_rect - x,
                   y_rect - y,
                   width_rect,
                   height_rect);
        running_width += E_REFLOW_DIVIDER_WIDTH + E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
    }
    if (e_reflow->column_drag) {
        int start_line = e_reflow_pick_line(e_reflow,
                            gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas))->value); 
        i = x - start_line * (column_width + E_REFLOW_FULL_GUTTER);
        running_width = start_line * (column_width + E_REFLOW_FULL_GUTTER);
        column_width = e_reflow->temp_column_width;
        running_width -= start_line * (column_width + E_REFLOW_FULL_GUTTER);
        i += start_line * (column_width + E_REFLOW_FULL_GUTTER);
        running_width += E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
        x_rect = running_width;
        y_rect = E_REFLOW_BORDER_WIDTH;
        width_rect = E_REFLOW_DIVIDER_WIDTH;
        height_rect = e_reflow->height - (E_REFLOW_BORDER_WIDTH * 2);

        /* Compute first column to draw. */
        i /= column_width + E_REFLOW_FULL_GUTTER;
        running_width += i * (column_width + E_REFLOW_FULL_GUTTER);
        
        for ( ; i < e_reflow->column_count; i++) {
            if ( running_width > x + width )
                break;
            x_rect = running_width;
            gdk_draw_rectangle(drawable,
                       GTK_WIDGET(item->canvas)->style->fg_gc[GTK_STATE_NORMAL],
                       TRUE,
                       x_rect - x,
                       y_rect - y,
                       width_rect - 1,
                       height_rect - 1);                       
            running_width += E_REFLOW_DIVIDER_WIDTH + E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
        }
    }
}

static void
e_reflow_update (GnomeCanvasItem *item, double affine[6], ArtSVP *clip_path, gint flags)
{
    EReflow *e_reflow;
    double x0, x1, y0, y1;

    e_reflow = E_REFLOW (item);

    if (GNOME_CANVAS_ITEM_CLASS(parent_class)->update)
        GNOME_CANVAS_ITEM_CLASS(parent_class)->update (item, affine, clip_path, flags);
    
    x0 = item->x1;
    y0 = item->y1;
    x1 = item->x2;
    y1 = item->y2;
    if ( x1 < x0 + e_reflow->width )
        x1 = x0 + e_reflow->width;
    if ( y1 < y0 + e_reflow->height )
        y1 = y0 + e_reflow->height;
    item->x2 = x1;
    item->y2 = y1;

    if (e_reflow->need_height_update) {
        x0 = item->x1;
        y0 = item->y1;
        x1 = item->x2;
        y1 = item->y2;
        if ( x0 > 0 )
            x0 = 0;
        if ( y0 > 0 )
            y0 = 0;
        if ( x1 < E_REFLOW(item)->width )
            x1 = E_REFLOW(item)->width;
        if ( x1 < E_REFLOW(item)->height )
            x1 = E_REFLOW(item)->height;

        gnome_canvas_request_redraw(item->canvas, x0, y0, x1, y1);
        e_reflow->need_height_update = FALSE;
    } else if (e_reflow->need_column_resize) {
        int x_rect, y_rect, width_rect, height_rect;
        int start_line = e_reflow_pick_line(e_reflow,
                            gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas))->value); 
        gdouble running_width;
        int i;
        double column_width;
        
        if ( e_reflow->previous_temp_column_width != -1 ) {
            running_width = start_line * (e_reflow->column_width + E_REFLOW_FULL_GUTTER);
            column_width = e_reflow->previous_temp_column_width;
            running_width -= start_line * (column_width + E_REFLOW_FULL_GUTTER);
            running_width += E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
            y_rect = E_REFLOW_BORDER_WIDTH;
            width_rect = E_REFLOW_DIVIDER_WIDTH;
            height_rect = e_reflow->height - (E_REFLOW_BORDER_WIDTH * 2);
            
            for ( i = 0; i < e_reflow->column_count; i++) {
                x_rect = running_width;
                gnome_canvas_request_redraw(item->canvas, x_rect, y_rect, x_rect + width_rect, y_rect + height_rect);
                running_width += E_REFLOW_DIVIDER_WIDTH + E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
            }
        }
        
        if ( e_reflow->temp_column_width != -1 ) {
            running_width = start_line * (e_reflow->column_width + E_REFLOW_FULL_GUTTER);
            column_width = e_reflow->temp_column_width;
            running_width -= start_line * (column_width + E_REFLOW_FULL_GUTTER);
            running_width += E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
            y_rect = E_REFLOW_BORDER_WIDTH;
            width_rect = E_REFLOW_DIVIDER_WIDTH;
            height_rect = e_reflow->height - (E_REFLOW_BORDER_WIDTH * 2);
            
            for ( i = 0; i < e_reflow->column_count; i++) {
                x_rect = running_width;
                gnome_canvas_request_redraw(item->canvas, x_rect, y_rect, x_rect + width_rect, y_rect + height_rect);
                running_width += E_REFLOW_DIVIDER_WIDTH + E_REFLOW_BORDER_WIDTH + column_width + E_REFLOW_BORDER_WIDTH;
            }
        }
        
        e_reflow->previous_temp_column_width = e_reflow->temp_column_width;
        e_reflow->need_column_resize = FALSE;
    }
}

static void
e_reflow_resize_children (GnomeCanvasItem *item)
{
    GList *list;
    EReflow *e_reflow;

    e_reflow = E_REFLOW (item);
    for ( list = e_reflow->items; list; list = list->next ) {
        GnomeCanvasItem *child = GNOME_CANVAS_ITEM(list->data);
        gnome_canvas_item_set(child,
                      "width", (double) e_reflow->column_width,
                      NULL);
    }
}

static double
e_reflow_point (GnomeCanvasItem *item,
        double x, double y, int cx, int cy,
        GnomeCanvasItem **actual_item)
{
    double distance = 1;

    *actual_item = NULL;

    if (GNOME_CANVAS_ITEM_CLASS(parent_class)->point)
        distance = GNOME_CANVAS_ITEM_CLASS(parent_class)->point (item, x, y, cx, cy, actual_item);
    if ((int) (distance * item->canvas->pixels_per_unit + 0.5) <= item->canvas->close_enough && *actual_item)
        return distance;
    
    *actual_item = item;
    return 0;
#if 0
    if (y >= E_REFLOW_BORDER_WIDTH && y <= e_reflow->height - E_REFLOW_BORDER_WIDTH) {
            float n_x;
        n_x = x;
        n_x += E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH;
        n_x = fmod(n_x, (e_reflow->column_width + E_REFLOW_FULL_GUTTER));
        if (n_x < E_REFLOW_FULL_GUTTER) {
            *actual_item = item;
            return 0;
        }
    }
    return distance;
#endif
}

static void
_reflow( EReflow *e_reflow )
{
    gdouble running_height;
    GList *list;
    double item_height;

    if (e_reflow->columns) {
        g_list_free (e_reflow->columns);
        e_reflow->columns = NULL;
    }

    e_reflow->column_count = 0;

    if (e_reflow->items == NULL) {
        e_reflow->columns = NULL;
        e_reflow->column_count = 0;
        return;
    }

    list = e_reflow->items;
    
    gtk_object_get (GTK_OBJECT(list->data),
            "height", &item_height,
            NULL);
    running_height = E_REFLOW_BORDER_WIDTH + item_height + E_REFLOW_BORDER_WIDTH;
    e_reflow->columns = g_list_append (e_reflow->columns, list);
    e_reflow->column_count = 1;

    list = g_list_next(list);

    for ( ; list; list = g_list_next(list)) {
        gtk_object_get (GTK_OBJECT(list->data),
                "height", &item_height,
                NULL);
        if (running_height + item_height + E_REFLOW_BORDER_WIDTH > e_reflow->height) {
            running_height = E_REFLOW_BORDER_WIDTH + item_height + E_REFLOW_BORDER_WIDTH;
            e_reflow->columns = g_list_append (e_reflow->columns, list);
            e_reflow->column_count ++;
        } else {
            running_height += item_height + E_REFLOW_BORDER_WIDTH;
        }
    }
}

static void
set_empty(EReflow *e_reflow)
{
    if (e_reflow->items == NULL) {
        if (e_reflow->empty_text) {
            if (e_reflow->empty_message) {
                gnome_canvas_item_set(e_reflow->empty_text,
                              "width", e_reflow->minimum_width,
                              "text", e_reflow->empty_message,
                              NULL);
                e_canvas_item_move_absolute(e_reflow->empty_text,
                                e_reflow->minimum_width / 2,
                                0);
            } else {
                gtk_object_destroy(GTK_OBJECT(e_reflow->empty_text));
                e_reflow->empty_text = NULL;
            }
        } else {
            if (e_reflow->empty_message)
                e_reflow->empty_text = 
                    gnome_canvas_item_new(GNOME_CANVAS_GROUP(e_reflow),
                                  e_text_get_type(),
                                  "anchor", GTK_ANCHOR_N,
                                  "width", e_reflow->minimum_width,
                                  "clip", TRUE,
                                  "use_ellipsis", TRUE,
                                  "font_gdk", GTK_WIDGET(GNOME_CANVAS_ITEM(e_reflow)->canvas)->style->font,
                                  "fill_color", "black",
                                  "justification", GTK_JUSTIFY_CENTER,
                                  "text", e_reflow->empty_message,
                                  "draw_background", FALSE,
                                  NULL);
            e_canvas_item_move_absolute(e_reflow->empty_text,
                            e_reflow->minimum_width / 2,
                            0);
        }
    } else {
        if (e_reflow->empty_text) {
            gtk_object_destroy(GTK_OBJECT(e_reflow->empty_text));
            e_reflow->empty_text = NULL;
        }
    }
}

static void
e_reflow_reflow( GnomeCanvasItem *item, int flags )
{
    EReflow *e_reflow = E_REFLOW(item);
    if ( GTK_OBJECT_FLAGS( e_reflow ) & GNOME_CANVAS_ITEM_REALIZED ) {

        gdouble old_width;
        gdouble running_width;

        _reflow (e_reflow);
        
        old_width = e_reflow->width;
        
        running_width = E_REFLOW_BORDER_WIDTH;

        if (e_reflow->items == NULL) {
        } else {
            GList *list;
            GList *next_column;
            gdouble item_height;
            gdouble running_height;

            running_height = E_REFLOW_BORDER_WIDTH;
            
            list = e_reflow->items;
            gtk_object_get (GTK_OBJECT(list->data),
                    "height", &item_height,
                    NULL);
            e_canvas_item_move_absolute(GNOME_CANVAS_ITEM(list->data),
                            (double) running_width,
                            (double) running_height);
            running_height += item_height + E_REFLOW_BORDER_WIDTH;
            next_column = g_list_next(e_reflow->columns);
            list = g_list_next(list);
            
            for( ; list; list = g_list_next(list)) {
                gtk_object_get (GTK_OBJECT(list->data),
                        "height", &item_height,
                        NULL);

                if (next_column && (next_column->data == list)) {
                    next_column = g_list_next (next_column);
                    running_height = E_REFLOW_BORDER_WIDTH;
                    running_width += e_reflow->column_width + E_REFLOW_BORDER_WIDTH + E_REFLOW_DIVIDER_WIDTH + E_REFLOW_BORDER_WIDTH;
                }
                e_canvas_item_move_absolute(GNOME_CANVAS_ITEM(list->data),
                                (double) running_width,
                                (double) running_height);

                running_height += item_height + E_REFLOW_BORDER_WIDTH;
            }
                 
        }
        e_reflow->width = running_width + e_reflow->column_width + E_REFLOW_BORDER_WIDTH;
        if ( e_reflow->width < e_reflow->minimum_width )
            e_reflow->width = e_reflow->minimum_width;
        if (old_width != e_reflow->width)
            e_canvas_item_request_parent_reflow(item);
    }
}

void
e_reflow_add_item(EReflow *e_reflow, GnomeCanvasItem *item, gint *position)
{
    if (E_REFLOW_CLASS(GTK_OBJECT(e_reflow)->klass)->add_item)
        (E_REFLOW_CLASS(GTK_OBJECT(e_reflow)->klass)->add_item) (e_reflow, item, position);
}

void
e_reflow_post_add_item(EReflow *e_reflow, GnomeCanvasItem *item)
{
    set_empty(e_reflow);
}