path: root/widgets/table/e-table-header-item.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * E-table-column-view.c: A canvas item based view of the ETableColumn.
 *
 * Author:
 *   Miguel de Icaza (miguel@gnu.org)
 *
 * Copyright 1999, Helix Code, Inc.
 */
#include <config.h>
#include <gtk/gtksignal.h>
#include <gtk/gtkdnd.h>
#include <libgnomeui/gnome-canvas.h>
#include <libgnomeui/gnome-canvas-util.h>
#include <libgnomeui/gnome-canvas-polygon.h>
#include <libgnomeui/gnome-canvas-rect-ellipse.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "e-util/e-cursors.h"
#include "e-util/e-xml-utils.h"
#include "e-table-header.h"
#include "e-table-header-item.h"
#include "e-table-col-dnd.h"

#include "add-col.xpm"
#include "remove-col.xpm"

/* Padding above and below of the string in the header display */
#define PADDING 4

#define MIN_ARROW_SIZE 10

#define GROUP_INDENT         10

/* Defines the tolerance for proximity of the column division to the cursor position */
#define TOLERANCE 2

#define ETHI_RESIZING(x) ((x)->resize_col != -1)

#define PARENT_OBJECT_TYPE gnome_canvas_item_get_type ()

#define ELEMENTS(x) (sizeof (x) / sizeof (x[0]))

static GnomeCanvasItemClass *ethi_parent_class;

static void ethi_request_redraw (ETableHeaderItem *ethi);
static void ethi_drop_table_header (ETableHeaderItem *ethi);


/*
 * DnD icons
 */
static GdkColormap *dnd_colormap;
static GdkPixmap *remove_col_pixmap, *remove_col_mask;
static GdkPixmap *add_col_pixmap, *add_col_mask;

enum {
    ARG_0,
    ARG_TABLE_HEADER,
    ARG_TABLE_X,
    ARG_TABLE_Y,
    ARG_TABLE_FONTSET,
    ARG_SORT_INFO
};

static GtkTargetEntry  ethi_drag_types [] = {
    { TARGET_ETABLE_COL_TYPE, 0, TARGET_ETABLE_COL_HEADER },
};

static GtkTargetEntry  ethi_drop_types [] = {
    { TARGET_ETABLE_COL_TYPE, 0, TARGET_ETABLE_COL_HEADER },
};

static void
ethi_destroy (GtkObject *object){
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (object);
    
    ethi_drop_table_header (ethi);

    if (ethi->sort_info){
        if (ethi->sort_info_changed_id)
            gtk_signal_disconnect (GTK_OBJECT(ethi->sort_info), ethi->sort_info_changed_id);
        gtk_object_unref (GTK_OBJECT(ethi->sort_info));
    }
    
    if (GTK_OBJECT_CLASS (ethi_parent_class)->destroy)
        (*GTK_OBJECT_CLASS (ethi_parent_class)->destroy) (object);
}

static void
ethi_update (GnomeCanvasItem *item, double *affine, ArtSVP *clip_path, int flags)
{
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (item);
    
    if (GNOME_CANVAS_ITEM_CLASS (ethi_parent_class)->update)
        (*GNOME_CANVAS_ITEM_CLASS (ethi_parent_class)->update)(item, affine, clip_path, flags);

    if (item->x1 != ethi->x1 ||
         item->y1 != ethi->y1 ||
         item->x2 != ethi->x1 + ethi->width ||
         item->y2 != ethi->y1 + ethi->height)
        {
            gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2);
            item->x1 = ethi->x1;
            item->y1 = ethi->y1;
            item->x2 = ethi->x1 + ethi->width;
            item->y2 = ethi->y1 + ethi->height;

            gnome_canvas_group_child_bounds (GNOME_CANVAS_GROUP (item->parent), item);
        }
    gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2);
}

static void
ethi_font_load (ETableHeaderItem *ethi, char *font)
{
    if (ethi->font)
        gdk_font_unref (ethi->font);
    
    ethi->font = gdk_fontset_load (font);
    if (ethi->font == NULL)
        ethi->font = gdk_font_load ("-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-iso8859-1");
    
    ethi->height = ethi->font->ascent + ethi->font->descent + PADDING;
    if (ethi->height < MIN_ARROW_SIZE + 4 + PADDING)
        ethi->height = MIN_ARROW_SIZE + 4 + PADDING;
}

static void
ethi_drop_table_header (ETableHeaderItem *ethi)
{
    GtkObject *header;
    
    if (!ethi->eth)
        return;

    header = GTK_OBJECT (ethi->eth);
    gtk_signal_disconnect (header, ethi->structure_change_id);
    gtk_signal_disconnect (header, ethi->dimension_change_id);

    gtk_object_unref (header);
    ethi->eth = NULL;
    ethi->width = 0;
}

static void 
structure_changed (ETableHeader *header, ETableHeaderItem *ethi)
{
    ethi->width = e_table_header_total_width (header) + ethi->group_indent_width;

    ethi_update (GNOME_CANVAS_ITEM (ethi), NULL, NULL, 0);
}

static void
dimension_changed (ETableHeader *header, int col, ETableHeaderItem *ethi)
{
    ethi->width = e_table_header_total_width (header) + ethi->group_indent_width;

    ethi_update (GNOME_CANVAS_ITEM (ethi), NULL, NULL, 0);
}

static void
ethi_add_table_header (ETableHeaderItem *ethi, ETableHeader *header)
{
    ethi->eth = header;
    gtk_object_ref (GTK_OBJECT (ethi->eth));
    ethi->width = e_table_header_total_width (header) + ethi->group_indent_width;

    ethi->structure_change_id = gtk_signal_connect (
        GTK_OBJECT (header), "structure_change",
        GTK_SIGNAL_FUNC(structure_changed), ethi);
    ethi->dimension_change_id = gtk_signal_connect (
        GTK_OBJECT (header), "dimension_change",
        GTK_SIGNAL_FUNC(dimension_changed), ethi);
}

static void
ethi_sort_info_changed (ETableSortInfo *sort_info, ETableHeaderItem *ethi)
{
    gnome_canvas_item_request_update (GNOME_CANVAS_ITEM(ethi));
}

static void
ethi_set_arg (GtkObject *o, GtkArg *arg, guint arg_id)
{
    GnomeCanvasItem *item;
    ETableHeaderItem *ethi;

    item = GNOME_CANVAS_ITEM (o);
    ethi = E_TABLE_HEADER_ITEM (o);

    switch (arg_id){
    case ARG_TABLE_HEADER:
        ethi_drop_table_header (ethi);
        ethi_add_table_header (ethi, E_TABLE_HEADER(GTK_VALUE_OBJECT (*arg)));
        break;

    case ARG_TABLE_X:
        ethi->x1 = GTK_VALUE_INT (*arg);
        break;

    case ARG_TABLE_Y:
        ethi->y1 = GTK_VALUE_INT (*arg);
        break;

    case ARG_TABLE_FONTSET:
        ethi_font_load (ethi, GTK_VALUE_STRING (*arg));
        break;

    case ARG_SORT_INFO:
        if (ethi->sort_info){
            if (ethi->sort_info_changed_id)
                gtk_signal_disconnect (GTK_OBJECT(ethi->sort_info), ethi->sort_info_changed_id);
            gtk_object_unref (GTK_OBJECT(ethi->sort_info));
        }
        ethi->sort_info = GTK_VALUE_POINTER (*arg);
        gtk_object_ref (GTK_OBJECT(ethi->sort_info));
        ethi->sort_info_changed_id = gtk_signal_connect (GTK_OBJECT(ethi->sort_info), "sort_info_changed",
                                GTK_SIGNAL_FUNC(ethi_sort_info_changed), ethi);
        break;
        
    }
    ethi_update (item, NULL, NULL, 0);
}

static int
ethi_find_col_by_x (ETableHeaderItem *ethi, int x)
{
    const int cols = e_table_header_count (ethi->eth);
    int x1 = ethi->x1;
    int col;

    if (x < x1)
        return -1;

    x1 += ethi->group_indent_width;
    
    for (col = 0; col < cols; col++){
        ETableCol *ecol = e_table_header_get_column (ethi->eth, col);

        if ((x >= x1) && (x <= x1 + ecol->width))
            return col;

        x1 += ecol->width;
    }
    return -1;
}

static void
ethi_remove_drop_marker (ETableHeaderItem *ethi)
{
    if (ethi->drag_mark == -1)
        return;
    
    ethi->drag_mark = -1;
    gtk_object_destroy (GTK_OBJECT (ethi->drag_mark_item));
    ethi->drag_mark_item = NULL;
}

static void
ethi_add_drop_marker (ETableHeaderItem *ethi, int col)
{
    GnomeCanvasPoints *points;
    int x;
    
    if (ethi->drag_mark == col)
        return;

    if (ethi->drag_mark_item)
        gtk_object_destroy (GTK_OBJECT (ethi->drag_mark_item));     

    ethi->drag_mark = col;
    
    ethi->drag_mark_item = gnome_canvas_item_new (
        GNOME_CANVAS_GROUP (GNOME_CANVAS_ITEM (ethi)->canvas->root),
        gnome_canvas_group_get_type (),
        "x", 0,
        "y", 0,
        NULL);
    
    points = gnome_canvas_points_new (3);

    x = e_table_header_col_diff (ethi->eth, 0, col);
    
    if (col > 0)
        x += ethi->group_indent_width;
    
    points->coords [0] = ethi->x1 + x - 5;
    points->coords [1] = ethi->y1;
    points->coords [2] = points->coords [0] + 10;
    points->coords [3] = points->coords [1];
    points->coords [4] = ethi->x1 + x;
    points->coords [5] = ethi->y1 + 5;
        
    gnome_canvas_item_new (
        GNOME_CANVAS_GROUP (ethi->drag_mark_item),
        gnome_canvas_polygon_get_type (),
        "points",     points,
        "fill_color", "red",
        NULL);

    points->coords [0] --;
    points->coords [1] += ethi->height - 1;
    points->coords [3] = points->coords [1];
    points->coords [5] = points->coords [1] - 6;
    
    gnome_canvas_item_new (
        GNOME_CANVAS_GROUP (ethi->drag_mark_item),
        gnome_canvas_polygon_get_type (),
        "points",     points,
        "fill_color", "red",
        NULL);
    
    gnome_canvas_points_unref (points);
}

#define gray50_width    2
#define gray50_height   2
static char gray50_bits [] = {
  0x02, 0x01, };

static void
ethi_add_destroy_marker (ETableHeaderItem *ethi)
{
    double x1;
    
    if (ethi->remove_item)
        gtk_object_destroy (GTK_OBJECT (ethi->remove_item));

    if (!ethi->stipple)
        ethi->stipple = gdk_bitmap_create_from_data  (NULL, gray50_bits, gray50_width, gray50_height);
    
    x1 = ethi->x1 + (double) e_table_header_col_diff (ethi->eth, 0, ethi->drag_col);
    ethi->remove_item = gnome_canvas_item_new (
        GNOME_CANVAS_GROUP (GNOME_CANVAS_ITEM (ethi)->canvas->root),
        gnome_canvas_rect_get_type (),
        "x1", x1 + 1,
        "y1", (double) ethi->y1 + 1,
        "x2", (double) x1 + e_table_header_col_diff (ethi->eth, ethi->drag_col, ethi->drag_col+1) - 2,
        "y2", (double) ethi->y1 + ethi->height - 2,
        "fill_color", "red",
        "fill_stipple", ethi->stipple,
        NULL);
}

static void
ethi_remove_destroy_marker (ETableHeaderItem *ethi)
{
    if (!ethi->remove_item)
        return;
    
    gtk_object_destroy (GTK_OBJECT (ethi->remove_item));
    ethi->remove_item = NULL;
}

static gboolean
ethi_drag_motion (GtkObject *canvas, GdkDragContext *context,
          gint x, gint y, guint time,
          ETableHeaderItem *ethi)
{
    /* Check if it's the correct ethi */
    if (ethi->drag_col == -1)
        return FALSE;

    gdk_drag_status (context, 0, time);
    if (GTK_WIDGET(canvas) == gtk_drag_get_source_widget (context)) {
        if ((x >= ethi->x1) && (x <= (ethi->x1 + ethi->width)) &&
            (y >= ethi->y1) && (y <= (ethi->y1 + ethi->height))){
            int col;
            
            col = ethi_find_col_by_x (ethi, x);
            if (col < ethi->eth->frozen_count)
                col = ethi->eth->frozen_count;
            
            if (col != -1){
                ethi_remove_destroy_marker (ethi);
                ethi_add_drop_marker (ethi, col);
                gdk_drag_status (context, context->suggested_action, time);
            } else {
                ethi_remove_drop_marker (ethi);
                ethi_add_destroy_marker (ethi);
            }
        } else {
            ethi_remove_drop_marker (ethi);
            ethi_add_destroy_marker (ethi);
        }
    }

    return TRUE;
}

static void
ethi_drag_end (GtkWidget *canvas, GdkDragContext *context, ETableHeaderItem *ethi)
{
    if (ethi->drag_col == -1)
        return;

    if (canvas == gtk_drag_get_source_widget (context)) {
        if (context->action == 0) {
            ethi_request_redraw (ethi);
            e_table_header_remove (ethi->eth, ethi->drag_col);
        }
        ethi_remove_drop_marker (ethi);
        ethi_remove_destroy_marker (ethi);
        ethi->drag_col = -1;
    }
}

static gboolean
ethi_drag_drop (GtkWidget *canvas,
        GdkDragContext *context,
        gint x,
        gint y,
        guint time,
        ETableHeaderItem *ethi)
{
    gboolean successful = FALSE;

    if (ethi->drag_col == -1)
        return FALSE;

    if (GTK_WIDGET(canvas) == gtk_drag_get_source_widget (context)) {
        if ((x >= ethi->x1) && (x <= (ethi->x1 + ethi->width)) &&
            (y >= ethi->y1) && (y <= (ethi->y1 + ethi->height))){
            int col;
            
            col = ethi_find_col_by_x (ethi, x);
            if (col < ethi->eth->frozen_count)
                col = ethi->eth->frozen_count;
            ethi_add_drop_marker (ethi, col);
            
            if (col != -1) {
                if (col != ethi->drag_col) {
                    ethi_request_redraw (ethi);
                    e_table_header_move (ethi->eth, ethi->drag_col, col);
                }
                successful = TRUE;
            }
        }
    }
    gtk_drag_finish (context, successful, successful, time);
    return successful;
}

static void
ethi_drag_leave (GtkWidget *widget, GdkDragContext *context, guint time, ETableHeaderItem *ethi)
{
    if (ethi->drag_col == -1)
        return;

    if (widget == gtk_drag_get_source_widget (context)) {
        ethi_remove_drop_marker (ethi);
        ethi_add_destroy_marker (ethi);
    }
}

static void
ethi_realize (GnomeCanvasItem *item)
{
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (item);
    GdkWindow *window;
    GdkColor c;
    
    if (GNOME_CANVAS_ITEM_CLASS (ethi_parent_class)-> realize)
        (*GNOME_CANVAS_ITEM_CLASS (ethi_parent_class)->realize)(item);

    window = GTK_WIDGET (item->canvas)->window;

    ethi->gc = gdk_gc_new (window);
    gnome_canvas_get_color (item->canvas, "black", &c);
    gdk_gc_set_foreground (ethi->gc, &c);

    if (!ethi->font)
        ethi_font_load (ethi, "-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-iso8859-1");

    /*
     * Now, configure DnD
     */
    gtk_drag_dest_set (GTK_WIDGET (item->canvas), 0,
               ethi_drop_types, ELEMENTS (ethi_drop_types),
               GDK_ACTION_MOVE);

    ethi->drag_motion_id = gtk_signal_connect (
        GTK_OBJECT (item->canvas), "drag_motion",
        GTK_SIGNAL_FUNC (ethi_drag_motion), ethi);

    ethi->drag_leave_id = gtk_signal_connect (
        GTK_OBJECT (item->canvas), "drag_leave",
        GTK_SIGNAL_FUNC (ethi_drag_leave), ethi);

    ethi->drag_end_id = gtk_signal_connect (
        GTK_OBJECT (item->canvas), "drag_end",
        GTK_SIGNAL_FUNC (ethi_drag_end), ethi);

    ethi->drag_drop_id = gtk_signal_connect (
        GTK_OBJECT (item->canvas), "drag_drop",
        GTK_SIGNAL_FUNC (ethi_drag_drop), ethi);
}

static void
ethi_unrealize (GnomeCanvasItem *item)
{
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (item);

    gdk_gc_unref (ethi->gc);
    ethi->gc = NULL;

    gtk_signal_disconnect (GTK_OBJECT (item->canvas), ethi->drag_motion_id);
    gtk_signal_disconnect (GTK_OBJECT (item->canvas), ethi->drag_end_id);
    gtk_signal_disconnect (GTK_OBJECT (item->canvas), ethi->drag_leave_id);
    gtk_signal_disconnect (GTK_OBJECT (item->canvas), ethi->drag_drop_id);

    if (ethi->stipple){
        gdk_bitmap_unref (ethi->stipple);
        ethi->stipple = NULL;
    }
    
    if (GNOME_CANVAS_ITEM_CLASS (ethi_parent_class)->unrealize)
        (*GNOME_CANVAS_ITEM_CLASS (ethi_parent_class)->unrealize)(item);
}

static void
draw_button (ETableHeaderItem *ethi, ETableCol *col,
         GdkDrawable *drawable, GdkGC *gc, GtkStyle *style,
         int x, int y, int width, int height, ETableColArrow arrow)
{
    GdkRectangle clip;
    int xtra;
    
    gdk_draw_rectangle (
        drawable, gc, TRUE,
        x + 1, y + 1, width - 2, height -2);
    
    gtk_draw_shadow (
        style, drawable, 
        GTK_STATE_NORMAL, GTK_SHADOW_OUT,
        x , y, width, height);

    clip.x = x + PADDING / 2;
    clip.y = y + PADDING / 2;
    clip.width = width - PADDING;
    clip.height = ethi->height;
    
    gdk_gc_set_clip_rectangle (ethi->gc, &clip);

    if (col->is_pixbuf){
        xtra = (clip.width - gdk_pixbuf_get_width (col->pixbuf))/2;
        
        xtra += PADDING / 2;

        gdk_pixbuf_render_to_drawable_alpha (col->pixbuf, 
                            drawable,
                            0, 0, 
                            x + xtra, y + (clip.height - gdk_pixbuf_get_height (col->pixbuf)) / 2,
                            gdk_pixbuf_get_width (col->pixbuf), gdk_pixbuf_get_height(col->pixbuf),
                            GDK_PIXBUF_ALPHA_FULL, 128,
                            GDK_RGB_DITHER_NORMAL,
                            0, 0);
    } else {
        /* Center the thing */
        xtra = (clip.width - gdk_string_measure (ethi->font, col->text))/2;
        
        /* Skip over border */
        if (xtra < 0)
            xtra = 0;

        xtra += PADDING / 2;
    
        gdk_draw_text (
                   drawable, ethi->font,
                   ethi->gc, x + xtra, y + ethi->height - ethi->font->descent - PADDING / 2,
                   col->text, strlen (col->text));
    }

    switch (arrow){
    case E_TABLE_COL_ARROW_NONE:
        break;
    case E_TABLE_COL_ARROW_UP:
    case E_TABLE_COL_ARROW_DOWN:
        gtk_paint_arrow   (gtk_widget_get_style (GTK_WIDGET(GNOME_CANVAS_ITEM(ethi)->canvas)),
                   drawable,
                   GTK_STATE_NORMAL,
                   GTK_SHADOW_IN,
                   &clip,
                   GTK_WIDGET(GNOME_CANVAS_ITEM(ethi)->canvas),
                   "header",
                   (arrow == E_TABLE_COL_ARROW_UP) ? GTK_ARROW_UP : GTK_ARROW_DOWN,
                   TRUE,
                   x + PADDING / 2 + clip.width - MIN_ARROW_SIZE - 2,
                   y + (ethi->height - MIN_ARROW_SIZE) / 2,
                   MIN_ARROW_SIZE,
                   MIN_ARROW_SIZE);
        break;
    }
}

static void
ethi_draw (GnomeCanvasItem *item, GdkDrawable *drawable, int x, int y, int width, int height)
{
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (item);
    GnomeCanvas *canvas = item->canvas;
    GdkGC *gc;
    const int cols = e_table_header_count (ethi->eth);
    int x1, x2;
    int col;
    GHashTable *arrows = g_hash_table_new (NULL, NULL);
    xmlNode *node;
    gint group_indent = 0;

#if 0
    printf ("My coords are: %g %g %g %g\n",
        item->x1, item->y1, item->x2, item->y2);
#endif

    if (ethi->sort_info) {
        xmlNode *grouping;
        gtk_object_get (GTK_OBJECT(ethi->sort_info),
                   "grouping", &grouping,
                   NULL);
        for (node = grouping->childs; node && strcmp (node->name, "leaf"); node = node->childs) {
            group_indent ++;
            g_hash_table_insert (arrows, 
                        (gpointer) e_xml_get_integer_prop_by_name (node, "column"), 
                        (gpointer) (e_xml_get_integer_prop_by_name (node, "ascending") ?
                            E_TABLE_COL_ARROW_DOWN : 
                            E_TABLE_COL_ARROW_UP));
        }
        if (node)
            g_hash_table_insert (arrows, 
                        (gpointer) e_xml_get_integer_prop_by_name (node, "column"), 
                        (gpointer) (e_xml_get_integer_prop_by_name (node, "ascending") ?
                            E_TABLE_COL_ARROW_DOWN : 
                            E_TABLE_COL_ARROW_UP));
    }

    ethi->group_indent_width = group_indent * GROUP_INDENT;
    ethi->width = e_table_header_total_width (ethi->eth) + ethi->group_indent_width;
    x1 = x2 = ethi->x1;
    x2 += ethi->group_indent_width;
    for (col = 0; col < cols; col++, x1 = x2){
        ETableCol *ecol = e_table_header_get_column (ethi->eth, col);
        int col_width;

        if (col == ethi->resize_col)
            col_width = ethi->resize_width;
        else
            col_width = ecol->width;
                
        x2 += col_width;
        
        if (x1 > (x + width))
            break;

        if (x2 < x)
            continue;
        
        gc = GTK_WIDGET (canvas)->style->bg_gc [GTK_STATE_ACTIVE];

        draw_button (ethi, ecol, drawable, gc,
                 GTK_WIDGET (canvas)->style,
                 x1 - x, ethi->y1 - y, x2 - x1, ethi->height, 
                 (ETableColArrow) g_hash_table_lookup (arrows, (gpointer) ecol->col_idx));
    }
    g_hash_table_destroy (arrows);
}

static double
ethi_point (GnomeCanvasItem *item, double x, double y, int cx, int cy,
        GnomeCanvasItem **actual_item)
{
    *actual_item = item;
    return 0.0;
}

/*
 * is_pointer_on_division:
 *
 * Returns whether @pos is a column header division;  If @the_total is not NULL,
 * then the actual position is returned here.  If @return_ecol is not NULL,
 * then the ETableCol that actually contains this point is returned here
 */
static gboolean
is_pointer_on_division (ETableHeaderItem *ethi, int pos, int *the_total, int *return_col)
{
    const int cols = e_table_header_count (ethi->eth);
    int col, total;

    total = 0;
    for (col = 0; col < cols; col++){
        ETableCol *ecol = e_table_header_get_column (ethi->eth, col);

        total += ecol->width;

        if ((total - TOLERANCE < pos)&& (pos < total + TOLERANCE)){
            if (return_col)
                *return_col = col;
            if (the_total)
                *the_total = total;

            return TRUE;
        }

        if (total > pos + TOLERANCE)
            return FALSE;
    }

    return FALSE;
}

#define convert(c,sx,sy,x,y) gnome_canvas_w2c (c,sx,sy,x,y)

static void
set_cursor (ETableHeaderItem *ethi, int pos)
{
    GtkWidget *canvas = GTK_WIDGET (GNOME_CANVAS_ITEM (ethi)->canvas);
        
    /* We might be invoked before we are realized */
    if (!canvas->window)
        return;

    if (is_pointer_on_division (ethi, pos, NULL, NULL))
        e_cursor_set (canvas->window, E_CURSOR_SIZE_X);
    else
        e_cursor_set (canvas->window, E_CURSOR_ARROW);
}

static void
ethi_request_redraw (ETableHeaderItem *ethi)
{
    GnomeCanvas *canvas = GNOME_CANVAS_ITEM (ethi)->canvas;
    
    /*
     * request a redraw
     */
    gnome_canvas_request_redraw (
        canvas, ethi->x1, ethi->y1, ethi->x1 + ethi->width, ethi->x1 + ethi->height);
}

static void
ethi_end_resize (ETableHeaderItem *ethi, int new_size)
{
    e_table_header_set_size (ethi->eth, ethi->resize_col, new_size);

    ethi->resize_col = -1;
    ethi_request_redraw (ethi);
}

static gboolean
ethi_maybe_start_drag (ETableHeaderItem *ethi, GdkEventMotion *event)
{
    if (!ethi->maybe_drag)
        return FALSE;

    if (MAX (abs (ethi->click_x - event->x),
         abs (ethi->click_y - event->y)) <= 3)
        return FALSE;

    return TRUE;
}

static void
ethi_start_drag (ETableHeaderItem *ethi, GdkEvent *event)
{
    GtkWidget *widget = GTK_WIDGET (GNOME_CANVAS_ITEM (ethi)->canvas);
    GtkTargetList *list;
    GdkDragContext *context;
    ETableCol *ecol;
    int col_width;
    GdkPixmap *pixmap;
    GdkGC *gc;
    GHashTable *arrows = g_hash_table_new (NULL, NULL);
    xmlNode *node;

    ethi->drag_col = ethi_find_col_by_x (ethi, event->motion.x);
    if (ethi->drag_col < ethi->eth->frozen_count && ethi->drag_col >= 0){
        ethi->maybe_drag = FALSE;
        ethi->drag_col = -1;
    }
    if (ethi->drag_col == -1)
        return;


    if (ethi->sort_info) {
        xmlNode *grouping;
        gtk_object_get (GTK_OBJECT(ethi->sort_info),
                   "grouping", &grouping,
                   NULL);
        for (node = grouping->childs; node && strcmp (node->name, "leaf"); node = node->childs) {
            g_hash_table_insert (arrows, 
                        (gpointer) e_xml_get_integer_prop_by_name (node, "column"), 
                        (gpointer) (e_xml_get_integer_prop_by_name (node, "ascending") ?
                            E_TABLE_COL_ARROW_DOWN : 
                            E_TABLE_COL_ARROW_UP));
        }
        if (node)
            g_hash_table_insert (arrows, 
                        (gpointer) e_xml_get_integer_prop_by_name (node, "column"), 
                        (gpointer) (e_xml_get_integer_prop_by_name (node, "ascending") ?
                            E_TABLE_COL_ARROW_DOWN : 
                            E_TABLE_COL_ARROW_UP));
    }

    list = gtk_target_list_new (ethi_drag_types, ELEMENTS (ethi_drag_types));
    context = gtk_drag_begin (widget, list, GDK_ACTION_MOVE, 1, event);

    ecol = e_table_header_get_column (ethi->eth, ethi->drag_col);
    if (ethi->drag_col == ethi->resize_col)
      col_width = ethi->resize_width;
    else
      col_width = ecol->width;
    pixmap = gdk_pixmap_new (widget->window, col_width, ethi->height, -1);
    gc = widget->style->bg_gc [GTK_STATE_ACTIVE];
    draw_button (ethi, ecol, pixmap, gc,
             widget->style,
             0, 0, col_width, ethi->height, 
             (ETableColArrow) g_hash_table_lookup (arrows, (gpointer) ecol->col_idx));
    gtk_drag_set_icon_pixmap        (context,
                     gdk_window_get_colormap (widget->window),
                     pixmap,
                     NULL,
                     col_width / 2,
                     ethi->height / 2);
    gdk_pixmap_unref (pixmap);

    ethi->maybe_drag = FALSE;
    g_hash_table_destroy (arrows);
}

/*
 * Handles the events on the ETableHeaderItem, particularly it handles resizing
 */
static int
ethi_event (GnomeCanvasItem *item, GdkEvent *e)
{
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (item);
    GnomeCanvas *canvas = item->canvas;
    const gboolean resizing = ETHI_RESIZING (ethi);
    int x, y, start, col;
    
    switch (e->type){
    case GDK_ENTER_NOTIFY:
        convert (canvas, e->crossing.x, e->crossing.y, &x, &y);
        set_cursor (ethi, x);
        break;

    case GDK_LEAVE_NOTIFY:
        e_cursor_set (GTK_WIDGET (canvas)->window, E_CURSOR_ARROW);
        break;
                
    case GDK_MOTION_NOTIFY:
        convert (canvas, e->motion.x, e->motion.y, &x, &y);
        if (resizing){
            int new_width;
            
            if (ethi->resize_guide == NULL){
                /* Quick hack until I actually bind the views */
                ethi->resize_guide = GINT_TO_POINTER (1);
                gnome_canvas_item_grab (item,
                            GDK_POINTER_MOTION_MASK |
                            GDK_BUTTON_RELEASE_MASK,
                            e_cursor_get (E_CURSOR_SIZE_X),
                            e->button.time);
            }

            new_width = x - ethi->resize_start_pos;

            if (new_width <= 0)
                new_width = 1;

            if (new_width < ethi->resize_min_width)
                new_width = ethi->resize_min_width;
            ethi_request_redraw (ethi);

            ethi->resize_width = new_width;
            e_table_header_set_size (ethi->eth, ethi->resize_col, ethi->resize_width);

            ethi_request_redraw (ethi);
        } else if (ethi_maybe_start_drag (ethi, &e->motion)){
            ethi_start_drag (ethi, e);
        } else
            set_cursor (ethi, x);
        break;
        
    case GDK_BUTTON_PRESS:
        convert (canvas, e->button.x, e->button.y, &x, &y);

        if (is_pointer_on_division (ethi, x, &start, &col)){
            ETableCol *ecol;
            
            /*
             * Record the important bits.
             *
             * By setting resize_pos to a non -1 value,
             * we know that we are being resized (used in the
             * other event handlers).
             */
            ecol = e_table_header_get_column (ethi->eth, col);

            if (!ecol->resizeable)
                break;
            ethi->resize_col = col;
            ethi->resize_width = ecol->width;
            ethi->resize_start_pos = start - ecol->width;
            ethi->resize_min_width = ecol->min_width;
        } else {
            if (e->button.button == 1){
                ethi->click_x = e->button.x;
                ethi->click_y = e->button.y;
                ethi->maybe_drag = TRUE;
            }
        }
        break;

    case GDK_2BUTTON_PRESS:
        if (!resizing)
            break;

        if (e->button.button != 1)
            break;
        break;
        
    case GDK_BUTTON_RELEASE: {
        gboolean needs_ungrab = FALSE;

        if (ethi->resize_col != -1){
            needs_ungrab = (ethi->resize_guide != NULL);
            ethi_end_resize (ethi, ethi->resize_width);
        } else if (ethi->maybe_drag && ethi->sort_info) {
            ETableCol *col;
            int model_col;
            xmlNode *node;
            xmlNode *grouping;

            gtk_object_get (GTK_OBJECT(ethi->sort_info),
                       "grouping", &grouping,
                       NULL);

            col = e_table_header_get_column (ethi->eth, ethi_find_col_by_x (ethi, e->button.x));
            model_col = col->col_idx;
            for (node = grouping->childs; node->childs && strcmp (node->name, "leaf"); node = node->childs) {
                if (model_col == e_xml_get_integer_prop_by_name (node, "column")){
                    int ascending = e_xml_get_integer_prop_by_name (node, "ascending");
                    ascending = ! ascending;
                    e_xml_set_integer_prop_by_name (node, "ascending", ascending);
                    break;
                }
            }
            if (!node){
            }
            if (node && !strcmp (node->name, "leaf")){
                if (model_col == e_xml_get_integer_prop_by_name (node, "column")){
                    int ascending = e_xml_get_integer_prop_by_name (node, "ascending");
                    ascending = ! ascending;
                    e_xml_set_integer_prop_by_name (node, "ascending", ascending);
                } else {
                    e_xml_set_integer_prop_by_name (node, "ascending", 1);
                    e_xml_set_integer_prop_by_name (node, "column", model_col);
                }
            }
            e_table_sort_info_changed (ethi->sort_info);
        }
        if (needs_ungrab)
            gnome_canvas_item_ungrab (item, e->button.time);

        ethi->maybe_drag = FALSE;
        break;
    }
    
    default:
        return FALSE;
    }
    return TRUE;
}

static void
ethi_class_init (GtkObjectClass *object_class)
{
    GnomeCanvasItemClass *item_class = (GnomeCanvasItemClass *) object_class;

    ethi_parent_class = gtk_type_class (PARENT_OBJECT_TYPE);
    
    object_class->destroy = ethi_destroy;
    object_class->set_arg = ethi_set_arg;

    item_class->update      = ethi_update;
    item_class->realize     = ethi_realize;
    item_class->unrealize   = ethi_unrealize;
    item_class->draw        = ethi_draw;
    item_class->point       = ethi_point;
    item_class->event       = ethi_event;
    
    gtk_object_add_arg_type ("ETableHeaderItem::ETableHeader", GTK_TYPE_OBJECT,
                 GTK_ARG_WRITABLE, ARG_TABLE_HEADER);
    gtk_object_add_arg_type ("ETableHeaderItem::x", GTK_TYPE_INT,
                 GTK_ARG_WRITABLE, ARG_TABLE_X);
    gtk_object_add_arg_type ("ETableHeaderItem::y", GTK_TYPE_INT,
                 GTK_ARG_WRITABLE, ARG_TABLE_Y);
    gtk_object_add_arg_type ("ETableHeaderItem::fontset", GTK_TYPE_STRING,
                 GTK_ARG_WRITABLE, ARG_TABLE_FONTSET);
    gtk_object_add_arg_type ("ETableHeaderItem::sort_info", GTK_TYPE_POINTER,
                 GTK_ARG_WRITABLE, ARG_SORT_INFO);

    /*
     * Create our pixmaps for DnD
     */
    dnd_colormap = gtk_widget_get_default_colormap ();
    remove_col_pixmap = gdk_pixmap_colormap_create_from_xpm_d (
        NULL, dnd_colormap,
        &remove_col_mask, NULL, remove_col_xpm);

    add_col_pixmap = gdk_pixmap_colormap_create_from_xpm_d (
        NULL, dnd_colormap,
        &add_col_mask, NULL, add_col_xpm);
}

static void
ethi_init (GnomeCanvasItem *item)
{
    ETableHeaderItem *ethi = E_TABLE_HEADER_ITEM (item);

    ethi->resize_col = -1;

    item->x1 = 0;
    item->y1 = 0;
    item->x2 = 0;
    item->y2 = 0;

    ethi->drag_col = -1;
    ethi->drag_mark = -1;
    
    ethi->sort_info = NULL;

    ethi->sort_info_changed_id = 0;

    ethi->group_indent_width = 0;
}

GtkType
e_table_header_item_get_type (void)
{
    static GtkType type = 0;

    if (!type){
        GtkTypeInfo info = {
            "ETableHeaderItem",
            sizeof (ETableHeaderItem),
            sizeof (ETableHeaderItemClass),
            (GtkClassInitFunc) ethi_class_init,
            (GtkObjectInitFunc) ethi_init,
            NULL, /* reserved 1 */
            NULL, /* reserved 2 */
            (GtkClassInitFunc) NULL
        };

        type = gtk_type_unique (PARENT_OBJECT_TYPE, &info);
    }

    return type;
}