diff options
Diffstat (limited to 'e-util/e-canvas-utils.c')
| -rw-r--r-- | e-util/e-canvas-utils.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/e-util/e-canvas-utils.c b/e-util/e-canvas-utils.c new file mode 100644 index 0000000000..ec3aad3858 --- /dev/null +++ b/e-util/e-canvas-utils.c @@ -0,0 +1,222 @@ +/* + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) version 3. + * + * 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with the program; if not, see <http://www.gnu.org/licenses/> + * + * + * Authors: + * Chris Lahey <clahey@ximian.com> + * + * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com) + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "e-canvas-utils.h" + +void +e_canvas_item_move_absolute (GnomeCanvasItem *item, + gdouble dx, + gdouble dy) +{ + cairo_matrix_t translate; + + g_return_if_fail (GNOME_IS_CANVAS_ITEM (item)); + + cairo_matrix_init_translate (&translate, dx, dy); + + gnome_canvas_item_set_matrix (item, &translate); +} + +static double +compute_offset (gint top, + gint bottom, + gint page_top, + gint page_bottom) +{ + gint size = bottom - top; + gint offset = 0; + + if (top <= page_top && bottom >= page_bottom) + return 0; + + if (bottom > page_bottom) + offset = (bottom - page_bottom); + if (top < page_top + offset) + offset = (top - page_top); + + if (top <= page_top + offset && bottom >= page_bottom + offset) + return offset; + + if (top < page_top + size * 3 / 2 + offset) + offset = top - (page_top + size * 3 / 2); + if (bottom > page_bottom - size * 3 / 2 + offset) + offset = bottom - (page_bottom - size * 3 / 2); + if (top < page_top + size * 3 / 2 + offset) + offset = top - ((page_top + page_bottom - (bottom - top)) / 2); + + return offset; +} + +static void +e_canvas_show_area (GnomeCanvas *canvas, + gdouble x1, + gdouble y1, + gdouble x2, + gdouble y2) +{ + GtkAdjustment *h, *v; + gint dx = 0, dy = 0; + gdouble page_size; + gdouble lower; + gdouble upper; + gdouble value; + + g_return_if_fail (canvas != NULL); + g_return_if_fail (GNOME_IS_CANVAS (canvas)); + + h = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (canvas)); + page_size = gtk_adjustment_get_page_size (h); + lower = gtk_adjustment_get_lower (h); + upper = gtk_adjustment_get_upper (h); + value = gtk_adjustment_get_value (h); + dx = compute_offset (x1, x2, value, value + page_size); + if (dx) + gtk_adjustment_set_value (h, CLAMP (value + dx, lower, upper - page_size)); + + v = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (canvas)); + page_size = gtk_adjustment_get_page_size (v); + lower = gtk_adjustment_get_lower (v); + upper = gtk_adjustment_get_upper (v); + value = gtk_adjustment_get_value (v); + dy = compute_offset (y1, y2, value, value + page_size); + if (dy) + gtk_adjustment_set_value (v, CLAMP (value + dy, lower, upper - page_size)); +} + +void +e_canvas_item_show_area (GnomeCanvasItem *item, + gdouble x1, + gdouble y1, + gdouble x2, + gdouble y2) +{ + g_return_if_fail (item != NULL); + g_return_if_fail (GNOME_IS_CANVAS_ITEM (item)); + + gnome_canvas_item_i2w (item, &x1, &y1); + gnome_canvas_item_i2w (item, &x2, &y2); + + e_canvas_show_area (item->canvas, x1, y1, x2, y2); +} + +static gboolean +e_canvas_area_shown (GnomeCanvas *canvas, + gdouble x1, + gdouble y1, + gdouble x2, + gdouble y2) +{ + GtkAdjustment *h, *v; + gint dx = 0, dy = 0; + gdouble page_size; + gdouble lower; + gdouble upper; + gdouble value; + + g_return_val_if_fail (canvas != NULL, FALSE); + g_return_val_if_fail (GNOME_IS_CANVAS (canvas), FALSE); + + h = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (canvas)); + page_size = gtk_adjustment_get_page_size (h); + lower = gtk_adjustment_get_lower (h); + upper = gtk_adjustment_get_upper (h); + value = gtk_adjustment_get_value (h); + dx = compute_offset (x1, x2, value, value + page_size); + if (CLAMP (value + dx, lower, upper - page_size) - value != 0) + return FALSE; + + v = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (canvas)); + page_size = gtk_adjustment_get_page_size (v); + lower = gtk_adjustment_get_lower (v); + upper = gtk_adjustment_get_upper (v); + value = gtk_adjustment_get_value (v); + dy = compute_offset (y1, y2, value, value + page_size); + if (CLAMP (value + dy, lower, upper - page_size) - value != 0) + return FALSE; + return TRUE; +} + +gboolean +e_canvas_item_area_shown (GnomeCanvasItem *item, + gdouble x1, + gdouble y1, + gdouble x2, + gdouble y2) +{ + g_return_val_if_fail (item != NULL, FALSE); + g_return_val_if_fail (GNOME_IS_CANVAS_ITEM (item), FALSE); + + gnome_canvas_item_i2w (item, &x1, &y1); + gnome_canvas_item_i2w (item, &x2, &y2); + + return e_canvas_area_shown (item->canvas, x1, y1, x2, y2); +} + +typedef struct { + gdouble x1; + gdouble y1; + gdouble x2; + gdouble y2; + GnomeCanvas *canvas; +} DoubsAndCanvas; + +static gboolean +show_area_timeout (gpointer data) +{ + DoubsAndCanvas *dac = data; + + e_canvas_show_area (dac->canvas, dac->x1, dac->y1, dac->x2, dac->y2); + g_object_unref (dac->canvas); + g_free (dac); + return FALSE; +} + +void +e_canvas_item_show_area_delayed (GnomeCanvasItem *item, + gdouble x1, + gdouble y1, + gdouble x2, + gdouble y2, + gint delay) +{ + DoubsAndCanvas *dac; + + g_return_if_fail (item != NULL); + g_return_if_fail (GNOME_IS_CANVAS_ITEM (item)); + + gnome_canvas_item_i2w (item, &x1, &y1); + gnome_canvas_item_i2w (item, &x2, &y2); + + dac = g_new (DoubsAndCanvas, 1); + dac->x1 = x1; + dac->y1 = y1; + dac->x2 = x2; + dac->y2 = y2; + dac->canvas = item->canvas; + g_object_ref (item->canvas); + g_timeout_add (delay, show_area_timeout, dac); +} |