diff options
Diffstat (limited to 'gtk/gtkwidget.c')
| -rw-r--r-- | gtk/gtkwidget.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c index 52f0203573..882bd57f34 100644 --- a/gtk/gtkwidget.c +++ b/gtk/gtkwidget.c @@ -2317,6 +2317,167 @@ gtk_widget_size_allocate (GtkWidget *widget, } } +/** + * gtk_widget_common_ancestor: + * @widget_a: a #GtkWidget + * @widget_b: a #GtkWidget + * + * Find the common ancestor of @widget_a and @widget_b that + * is closest to the two widgets. + * + * Return value: the closest common ancestor of @widget_a and + * @widget_b or %NULL if @widget_a and @widget_b do not + * share a common ancestor. + **/ +static GtkWidget * +gtk_widget_common_ancestor (GtkWidget *widget_a, + GtkWidget *widget_b) +{ + GtkWidget *parent_a; + GtkWidget *parent_b; + gint depth_a = 0; + gint depth_b = 0; + + parent_a = widget_a; + while (parent_a->parent) + { + parent_a = parent_a->parent; + depth_a++; + } + + parent_b = widget_b; + while (parent_b->parent) + { + parent_b = parent_b->parent; + depth_b++; + } + + if (parent_a != parent_b) + return NULL; + + while (depth_a > depth_b) + { + widget_a = widget_a->parent; + depth_a--; + } + + while (depth_b > depth_a) + { + widget_b = widget_b->parent; + depth_b--; + } + + while (widget_a != widget_b) + { + widget_a = widget_a->parent; + widget_b = widget_b->parent; + } + + return widget_a; +} + +/** + * gtk_widget_translate_coordinates: + * @src_widget: a #GtkWidget + * @dest_widget: a #GtkWidget + * @src_x: X position relative to @src_widget + * @src_y: Y position relative to @src_widget + * @dest_x: location to store X position relative to @dest_widget + * @dest_y: location to store Y position relative to @dest_widget + * + * Translate coordinates relative to @src_widget's allocation to coordinates + * relative to @dest_widget's allocations. In order to perform this + * operation, both widgets must be realized, and must share a common + * toplevel. + * + * Return value: %FALSE if either widget was not realized, or there + * was no common ancestor. In this case, nothing is stored in + * *@dest_x and *@dest_y. Otherwise %TRUE. + **/ +gboolean +gtk_widget_translate_coordinates (GtkWidget *src_widget, + GtkWidget *dest_widget, + gint src_x, + gint src_y, + gint *dest_x, + gint *dest_y) +{ + GtkWidget *ancestor; + GdkWindow *window; + + g_return_if_fail (GTK_IS_WIDGET (src_widget)); + g_return_if_fail (GTK_IS_WIDGET (dest_widget)); + + ancestor = gtk_widget_common_ancestor (src_widget, dest_widget); + if (!ancestor || !GTK_WIDGET_REALIZED (src_widget) || !GTK_WIDGET_REALIZED (dest_widget)) + return FALSE; + + /* Translate from allocation relative to window relative */ + if (!GTK_WIDGET_NO_WINDOW (src_widget) && src_widget->parent) + { + gint wx, wy; + gdk_window_get_position (src_widget->window, &wx, &wy); + + src_x -= wx - src_widget->allocation.x; + src_y -= wy - src_widget->allocation.y; + } + else + { + src_x += src_widget->allocation.x; + src_y += src_widget->allocation.y; + } + + /* Translate to the common ancestor */ + window = src_widget->window; + while (window != ancestor->window) + { + gint dx, dy; + + gdk_window_get_position (window, &dx, &dy); + + src_x += dx; + src_y += dy; + + window = gdk_window_get_parent (window); + } + + /* And back */ + window = dest_widget->window; + while (window != ancestor->window) + { + gint dx, dy; + + gdk_window_get_position (window, &dx, &dy); + + src_x -= dx; + src_y -= dy; + + window = gdk_window_get_parent (window); + } + + /* Translate from window relative to allocation relative */ + if (!GTK_WIDGET_NO_WINDOW (dest_widget) && dest_widget->parent) + { + gint wx, wy; + gdk_window_get_position (dest_widget->window, &wx, &wy); + + src_x += wx - dest_widget->allocation.x; + src_y += wy - dest_widget->allocation.y; + } + else + { + src_x -= dest_widget->allocation.x; + src_y -= dest_widget->allocation.y; + } + + if (dest_x) + *dest_x = src_x; + if (dest_y) + *dest_y = src_y; + + return TRUE; +} + static void gtk_widget_real_size_allocate (GtkWidget *widget, GtkAllocation *allocation) |