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

/* ETable widget - utilities for drawing table header buttons
 *
 * Copyright (C) 2000 Ximian, Inc.
 *
 * Authors: Chris Lahey <clahey@ximian.com>
 *          Miguel de Icaza <miguel@ximian.com>
 *          Federico Mena-Quintero <federico@ximian.com>
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h> /* strlen() */
#include <glib.h>
#include "e-table-defines.h"
#include "e-table-header-utils.h"



/**
 * e_table_header_compute_height:
 * @ecol: Table column description.
 * @style: Style for the button's bevel.
 * @font: Font for the button's text, or NULL if no font is available.
 *
 * Computes the minimum height required for a table header button.
 *
 * Return value: The height of the button, in pixels.
 **/
double
e_table_header_compute_height (ETableCol *ecol, GtkStyle *style, GdkFont *font)
{
    int ythick;
    int height;

    g_return_val_if_fail (ecol != NULL, -1);
    g_return_val_if_fail (E_IS_TABLE_COL (ecol), -1);
    g_return_val_if_fail (style != NULL, -1);

    ythick = style->klass->ythickness;

    if (font)
        height = font->ascent + font->descent;
    else
        height = 16; /* FIXME: default? */

    if (ecol->is_pixbuf) {
        g_assert (ecol->pixbuf != NULL);
        height = MAX (height, gdk_pixbuf_get_height (ecol->pixbuf));
    }

    height = MAX (height, MIN_ARROW_SIZE);

    height += 2 * (ythick + HEADER_PADDING);

    return height;
}

double
e_table_header_width_extras (GtkStyle *style)
{
    g_return_val_if_fail (style != NULL, -1);

    return 2 * (style->klass->xthickness + HEADER_PADDING);
}

/* Creates a pixmap that is a composite of a background color and the upper-left
 * corner rectangle of a pixbuf.
 */
static GdkPixmap *
make_composite_pixmap (GdkDrawable *drawable, GdkGC *gc,
               GdkPixbuf *pixbuf, GdkColor *bg, int width, int height,
               int dither_xofs, int dither_yofs)
{
    int pwidth, pheight;
    GdkPixmap *pixmap;
    GdkPixbuf *tmp;
    int color;

    pwidth = gdk_pixbuf_get_width (pixbuf);
    pheight = gdk_pixbuf_get_height (pixbuf);
    g_assert (width <= pwidth && height <= pheight);

    color = ((bg->red & 0xff00) << 8) | (bg->green & 0xff00) | ((bg->blue & 0xff00) >> 8);

    if (width >= pwidth && height >= pheight) {
        tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, width, height);
        if (!tmp)
            return NULL;

        gdk_pixbuf_composite_color (pixbuf, tmp,
                        0, 0,
                        width, height,
                        0, 0,
                        1.0, 1.0,
                        GDK_INTERP_NEAREST,
                        255,
                        0, 0,
                        16,
                        color, color);
    } else {
        int x, y, rowstride;
        GdkPixbuf *fade;
        guchar *pixels;

        /* Do a nice fade of the pixbuf down and to the right */

        fade = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, width, height);
        if (!fade)
            return NULL;

        gdk_pixbuf_copy_area (pixbuf,
                      0, 0,
                      width, height,
                      fade,
                      0, 0);

        rowstride = gdk_pixbuf_get_rowstride (fade);
        pixels = gdk_pixbuf_get_pixels (fade);

        for (y = 0; y < height; y++) {
            guchar *p;
            int yfactor;

            p = pixels + y * rowstride;

            if (height < pheight)
                yfactor = height - y;
            else
                yfactor = height;

            for (x = 0; x < width; x++) {
                int xfactor;

                if (width < pwidth)
                    xfactor = width - x;
                else
                    xfactor = width;

                p[3] = ((int) p[3] * xfactor * yfactor / (width * height));
                p += 4;
            }
        }

        tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, width, height);
        if (!tmp) {
            gdk_pixbuf_unref (fade);
            return NULL;
        }

        gdk_pixbuf_composite_color (fade, tmp,
                        0, 0,
                        width, height,
                        0, 0,
                        1.0, 1.0,
                        GDK_INTERP_NEAREST,
                        255,
                        0, 0,
                        16,
                        color, color);

        gdk_pixbuf_unref (fade);
    }

    pixmap = gdk_pixmap_new (drawable, width, height, gdk_rgb_get_visual ()->depth);
    gdk_draw_rgb_image_dithalign (pixmap, gc,
                      0, 0,
                      width, height,
                      GDK_RGB_DITHER_NORMAL,
                      gdk_pixbuf_get_pixels (tmp),
                      gdk_pixbuf_get_rowstride (tmp),
                      dither_xofs, dither_yofs);
    gdk_pixbuf_unref (tmp);

    return pixmap;
}

/**
 * e_table_header_draw_button:
 * @drawable: Destination drawable.
 * @ecol: Table column for the header information.
 * @style: Style to use for drawing the button.
 * @font: Font for the button's text.
 * @state: State of the table widget.
 * @widget: The table widget.
 * @gc: GC to use for drawing.
 * @x: Leftmost coordinate of the button.
 * @y: Topmost coordinate of the button.
 * @width: Width of the region to draw.
 * @height: Height of the region to draw.
 * @button_width: Width for the complete button.
 * @button_height: Height for the complete button.
 * @arrow: Arrow type to use as a sort indicator.
 * 
 * Draws a button suitable for a table header.
 **/
void
e_table_header_draw_button (GdkDrawable *drawable, ETableCol *ecol,
                GtkStyle *style, GdkFont *font, GtkStateType state,
                GtkWidget *widget, GdkGC *gc,
                int x, int y, int width, int height,
                int button_width, int button_height,
                ETableColArrow arrow)
{
    int xthick, ythick;
    int inner_x, inner_y;
    int inner_width, inner_height;

    g_return_if_fail (drawable != NULL);
    g_return_if_fail (ecol != NULL);
    g_return_if_fail (E_IS_TABLE_COL (ecol));
    g_return_if_fail (style != NULL);
    g_return_if_fail (font != NULL);
    g_return_if_fail (widget != NULL);
    g_return_if_fail (GTK_IS_WIDGET (widget));
    g_return_if_fail (button_width > 0 && button_height > 0);

    xthick = style->klass->xthickness;
    ythick = style->klass->ythickness;

    /* Button bevel */

    gtk_paint_box (style, drawable, state, GTK_SHADOW_OUT,
               NULL, widget, "button",
               x, y, button_width, button_height);

    /* Inside area */

    inner_width = button_width - 2 * (xthick + HEADER_PADDING);
    inner_height = button_height - 2 * (ythick + HEADER_PADDING);

    if (inner_width < 1 || inner_height < 1)
        return; /* nothing fits */

    inner_x = x + xthick + HEADER_PADDING;
    inner_y = y + ythick + HEADER_PADDING;

    /* Arrow */

    switch (arrow) {
    case E_TABLE_COL_ARROW_NONE:
        break;

    case E_TABLE_COL_ARROW_UP:
    case E_TABLE_COL_ARROW_DOWN: {
        int arrow_width, arrow_height;

        arrow_width = MIN (MIN_ARROW_SIZE, inner_width);
        arrow_height = MIN (MIN_ARROW_SIZE, inner_height);

        gtk_paint_arrow (style, drawable, state,
                 GTK_SHADOW_IN, NULL, widget, "header",
                 (arrow == E_TABLE_COL_ARROW_UP) ? GTK_ARROW_UP : GTK_ARROW_DOWN,
                 TRUE,
                 inner_x + inner_width - arrow_width,
                 inner_y + (inner_height - arrow_height) / 2,
                 arrow_width, arrow_height);

        inner_width -= arrow_width + HEADER_PADDING;
        break;
    }

    default:
        g_assert_not_reached ();
        return;
    }

    if (inner_width < 1)
        return; /* nothing else fits */

    /* Pixbuf or label */

    if (ecol->is_pixbuf) {
        int pwidth, pheight;
        int clip_width, clip_height;
        GdkPixmap *pixmap;

        g_assert (ecol->pixbuf != NULL);

        pwidth = gdk_pixbuf_get_width (ecol->pixbuf);
        pheight = gdk_pixbuf_get_height (ecol->pixbuf);

        clip_width = MIN (pwidth, inner_width);
        clip_height = MIN (pheight, inner_height);

        pixmap = make_composite_pixmap (drawable, gc,
                        ecol->pixbuf, &style->bg[state],
                        clip_width, clip_height,
                        inner_x,
                        inner_y + (inner_height - clip_height) / 2);
        if (pixmap) {
            gdk_draw_pixmap (drawable, gc, pixmap,
                     0, 0,
                     inner_x,
                     inner_y + (inner_height - clip_height) / 2,
                     clip_width, clip_height);
            gdk_pixmap_unref (pixmap);
        }
    } else {
        int ypos;

        ypos = inner_y + (inner_height - font->ascent - font->descent) / 2 + font->ascent;

        e_table_draw_elided_string (drawable, font, gc,
                        inner_x, ypos,
                        ecol->text, inner_width, TRUE);
    }
}

/* Computes the length of a string that needs to be trimmed for elision */
static int
compute_elision_length (GdkFont *font, const char *str, int max_width)
{
    int len;
    int l = 0, left, right;
    int rbearing;

    len = strlen (str);

    if (len <= 0)
      return 0;

    left = 0;
    right = len;

    while (left < right) {
        l = (left + right) / 2;
        gdk_text_extents (font, str, l, NULL, &rbearing, NULL, NULL, NULL);

        if (rbearing < max_width)
            left = l + 1;
        else if (rbearing > max_width)
            right = l;
        else
            return l;
    }

    if (rbearing > max_width)
        return MAX (0, l - 1);
    else
        return l;
}

/* Default width of the elision arrow in pixels */
#define ARROW_WIDTH 4

/**
 * e_table_draw_elided_string:
 * @drawable: Destination drawable.
 * @font: Font for the text.
 * @gc: GC to use for drawing.
 * @x: X insertion point for the string.
 * @y: Y insertion point for the string's baseline.
 * @str: String to draw.
 * @max_width: Maximum width in which the string must fit.
 * @center: Whether to center the string in the available area if it does fit.
 * 
 * Draws a string, possibly trimming it so that it fits inside the specified
 * maximum width.  If it does not fit, an elision indicator is drawn after the
 * last character that does fit.
 **/
void
e_table_draw_elided_string (GdkDrawable *drawable, GdkFont *font, GdkGC *gc,
                int x, int y, const char *str, int max_width, gboolean center)
{
    int rbearing;
    int width;

    g_return_if_fail (drawable != NULL);
    g_return_if_fail (font != NULL);
    g_return_if_fail (gc != NULL);
    g_return_if_fail (str != NULL);
    g_return_if_fail (max_width >= 0);

    gdk_string_extents (font, str, NULL, &rbearing, &width, NULL, NULL);

    if (rbearing <= max_width) {
        int xpos;

        if (center)
            xpos = x + (max_width - width) / 2;
        else
            xpos = x;

        gdk_draw_string (drawable, font, gc, xpos, y, str);
    } else {
        int arrow_width;
        int len;
        int i;

        if (max_width < ARROW_WIDTH + 1)
            arrow_width = max_width - 1;
        else
            arrow_width = ARROW_WIDTH;

        len = compute_elision_length (font, str, max_width - arrow_width - 1);
        gdk_draw_text (drawable, font, gc, x, y, str, len);

        gdk_text_extents (font, str, len, NULL, &rbearing, NULL, NULL, NULL);

        y -= font->ascent;

        for (i = 0; i < arrow_width; i++) {
            int h;

            h = 2 * i + 1;

            gdk_draw_line (drawable, gc,
                       x + rbearing + arrow_width - i,
                       y + (font->ascent + font->descent - h) / 2,
                       x + rbearing + arrow_width - i,
                       y + (font->ascent + font->descent - h) / 2 + h - 1);
        }
    }
}