/* * Copyright (c) 2017 Timm Bäder * * 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) 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 Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * Author: Timm Bäder */ /** * SECTION:gtkcenterbox * @Short_description: A centering container * @Title: GtkCenterBox * @See_also: #GtkBox * * The GtkCenterBox widget arranges three children in a horizontal * or vertical arrangement, keeping the middle child centered as well * as possible. * * To add children to GtkCenterBox, use gtk_center_box_set_start_widget(), * gtk_center_box_set_center_widget() and gtk_center_box_set_end_widget(). * * The sizing and positioning of children can be influenced with the * align and expand properties of the children. * * # GtkCenterBox as GtkBuildable * * The GtkCenterBox implementation of the GtkBuildable interface supports * placing children in the 3 positions by specifying “start”, “center” or * “end” as the “type” attribute of a element. * * # CSS nodes * * GtkCenterBox uses a single CSS node with name box. * * In horizontal orientation, the nodes of the children are always arranged * from left to right. So :first-child will always select the leftmost child, * regardless of text direction. * * In vertical orientation, the are arranged from top to bottom. */ #include "config.h" #include "gtkcenterbox.h" #include "gtkcssnodeprivate.h" #include "gtkwidgetprivate.h" #include "gtkorientable.h" #include "gtkorientableprivate.h" #include "gtkbuildable.h" #include "gtksizerequest.h" #include "gtktypebuiltins.h" #include "gtkprivate.h" #include "gtkintl.h" struct _GtkCenterBox { GtkWidget parent_instance; GtkWidget *start_widget; GtkWidget *center_widget; GtkWidget *end_widget; GtkOrientation orientation; GtkBaselinePosition baseline_pos; }; struct _GtkCenterBoxClass { GtkWidgetClass parent_class; }; enum { PROP_0, PROP_BASELINE_POSITION, PROP_ORIENTATION }; static void gtk_center_box_buildable_init (GtkBuildableIface *iface); G_DEFINE_TYPE_WITH_CODE (GtkCenterBox, gtk_center_box, GTK_TYPE_WIDGET, G_IMPLEMENT_INTERFACE (GTK_TYPE_ORIENTABLE, NULL) G_IMPLEMENT_INTERFACE (GTK_TYPE_BUILDABLE, gtk_center_box_buildable_init)) static void gtk_center_box_buildable_add_child (GtkBuildable *buildable, GtkBuilder *builder, GObject *child, const gchar *type) { if (g_strcmp0 (type, "start") == 0) gtk_center_box_set_start_widget (GTK_CENTER_BOX (buildable), GTK_WIDGET (child)); else if (g_strcmp0 (type, "center") == 0) gtk_center_box_set_center_widget (GTK_CENTER_BOX (buildable), GTK_WIDGET (child)); else if (g_strcmp0 (type, "end") == 0) gtk_center_box_set_end_widget (GTK_CENTER_BOX (buildable), GTK_WIDGET (child)); else GTK_BUILDER_WARN_INVALID_CHILD_TYPE (GTK_CENTER_BOX (buildable), type); } static void gtk_center_box_buildable_init (GtkBuildableIface *iface) { iface->add_child = gtk_center_box_buildable_add_child; } static gboolean get_expand (GtkWidget *widget, GtkOrientation orientation) { if (orientation == GTK_ORIENTATION_HORIZONTAL) return gtk_widget_get_hexpand (widget); else return gtk_widget_get_vexpand (widget); } static void gtk_center_box_distribute (GtkCenterBox *self, gint for_size, gint size, GtkRequestedSize *sizes) { int center_size = 0; int start_size = 0; int end_size = 0; gboolean center_expand = FALSE; gboolean start_expand = FALSE; gboolean end_expand = FALSE; int avail; sizes[0].minimum_size = sizes[0].natural_size = 0; sizes[1].minimum_size = sizes[1].natural_size = 0; sizes[2].minimum_size = sizes[2].natural_size = 0; if (self->start_widget) gtk_widget_measure (self->start_widget, self->orientation, for_size, &sizes[0].minimum_size, &sizes[0].natural_size, NULL, NULL); if (self->center_widget) gtk_widget_measure (self->center_widget, self->orientation, for_size, &sizes[1].minimum_size, &sizes[1].natural_size, NULL, NULL); if (self->end_widget) gtk_widget_measure (self->end_widget, self->orientation, for_size, &sizes[2].minimum_size, &sizes[2].natural_size, NULL, NULL); if (self->center_widget) { center_size = CLAMP (size - (sizes[0].minimum_size + sizes[2].minimum_size), sizes[1].minimum_size, sizes[1].natural_size); center_expand = get_expand (self->center_widget, self->orientation); } if (self->start_widget) { avail = MIN ((size - center_size) / 2, size - (center_size + sizes[2].minimum_size)); start_size = CLAMP (avail, sizes[0].minimum_size, sizes[0].natural_size); start_expand = get_expand (self->start_widget, self->orientation); } if (self->end_widget) { avail = MIN ((size - center_size) / 2, size - (center_size + sizes[0].minimum_size)); end_size = CLAMP (avail, sizes[2].minimum_size, sizes[2].natural_size); end_expand = get_expand (self->end_widget, self->orientation); } if (self->center_widget) { int center_pos; center_pos = (size / 2) - (center_size / 2); /* Push in from start/end */ if (start_size > center_pos) center_pos = start_size; else if (size - end_size < center_pos + center_size) center_pos = size - center_size - end_size; else if (center_expand) { center_size = size - 2 * MAX (start_size, end_size); center_pos = (size / 2) - (center_size / 2); } if (start_expand) start_size = center_pos; if (end_expand) end_size = size - (center_pos + center_size); } else { avail = size - (start_size + end_size); if (start_expand && end_expand) { start_size += avail / 2; end_size += avail / 2; } else if (start_expand) { start_size += avail; } else if (end_expand) { end_size += avail; } } sizes[0].minimum_size = start_size; sizes[1].minimum_size = center_size; sizes[2].minimum_size = end_size; } static void gtk_center_box_measure_orientation (GtkWidget *widget, GtkOrientation orientation, int for_size, int *minimum, int *natural, int *minimum_baseline, int *natural_baseline) { GtkCenterBox *self = GTK_CENTER_BOX (widget); int min_baseline, nat_baseline; int start_min = 0; int start_nat = 0; int center_min = 0; int center_nat = 0; int end_min = 0; int end_nat = 0; if (self->start_widget) gtk_widget_measure (self->start_widget, orientation, for_size, &start_min, &start_nat, &min_baseline, &nat_baseline); if (self->center_widget) gtk_widget_measure (self->center_widget, orientation, for_size, ¢er_min, ¢er_nat, &min_baseline, &nat_baseline); if (self->end_widget) gtk_widget_measure (self->end_widget, orientation, for_size, &end_min, &end_nat, &min_baseline, &nat_baseline); *minimum = start_min + center_min + end_min; *natural = center_nat + 2 * MAX (start_nat, end_nat); } static void gtk_center_box_measure_opposite (GtkWidget *widget, GtkOrientation orientation, int for_size, int *minimum, int *natural, int *minimum_baseline, int *natural_baseline) { GtkCenterBox *self = GTK_CENTER_BOX (widget); int child_min, child_nat; int child_min_baseline, child_nat_baseline; int total_min, above_min, below_min; int total_nat, above_nat, below_nat; GtkWidget *child[3]; GtkRequestedSize sizes[3]; int i; child[0] = self->start_widget; child[1] = self->center_widget; child[2] = self->end_widget; if (for_size >= 0) gtk_center_box_distribute (self, -1, for_size, sizes); above_min = below_min = above_nat = below_nat = -1; total_min = total_nat = 0; for (i = 0; i < 3; i++) { if (child[i] == NULL) continue; gtk_widget_measure (child[i], orientation, for_size >= 0 ? sizes[i].minimum_size : -1, &child_min, &child_nat, &child_min_baseline, &child_nat_baseline); if (child_min_baseline >= 0) { below_min = MAX (below_min, child_min - child_min_baseline); above_min = MAX (above_min, child_min_baseline); below_nat = MAX (below_nat, child_nat - child_nat_baseline); above_nat = MAX (above_nat, child_nat_baseline); } else { total_min = MAX (total_min, child_min); total_nat = MAX (total_nat, child_nat); } } if (above_min >= 0) { int min_baseline = -1; int nat_baseline = -1; total_min = MAX (total_min, above_min + below_min); total_nat = MAX (total_nat, above_nat + below_nat); switch (self->baseline_pos) { case GTK_BASELINE_POSITION_TOP: min_baseline = above_min; nat_baseline = above_nat; break; case GTK_BASELINE_POSITION_CENTER: min_baseline = above_min + (total_min - (above_min + below_min)) / 2; nat_baseline = above_nat + (total_nat - (above_nat + below_nat)) / 2; break; case GTK_BASELINE_POSITION_BOTTOM: min_baseline = total_min - below_min; nat_baseline = total_nat - below_nat; break; } if (minimum_baseline) *minimum_baseline = min_baseline; if (natural_baseline) *natural_baseline = nat_baseline; } *minimum = total_min; *natural = total_nat; } static void gtk_center_box_measure (GtkWidget *widget, GtkOrientation orientation, int for_size, int *minimum, int *natural, int *minimum_baseline, int *natural_baseline) { GtkCenterBox *self = GTK_CENTER_BOX (widget); if (self->orientation == orientation) gtk_center_box_measure_orientation (widget, orientation, for_size, minimum, natural, minimum_baseline, natural_baseline); else gtk_center_box_measure_opposite (widget, orientation, for_size, minimum, natural, minimum_baseline, natural_baseline); } static void gtk_center_box_size_allocate (GtkWidget *widget, GtkAllocation *allocation) { GtkCenterBox *self = GTK_CENTER_BOX (widget); GtkAllocation child_allocation; GtkAllocation clip = *allocation; GtkAllocation child_clip; GtkWidget *child[3]; int child_size[3]; int child_pos[3]; GtkRequestedSize sizes[3]; int size; int for_size; int baseline; int i; GTK_WIDGET_CLASS (gtk_center_box_parent_class)->size_allocate (widget, allocation); if (self->orientation == GTK_ORIENTATION_HORIZONTAL) { size = allocation->width; for_size = allocation->height; baseline = gtk_widget_get_allocated_baseline (widget); } else { size = allocation->height; for_size = allocation->width; baseline = -1; } /* Allocate child sizes */ gtk_center_box_distribute (self, for_size, size, sizes); if (self->orientation == GTK_ORIENTATION_HORIZONTAL && gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL) { child[0] = self->end_widget; child[1] = self->center_widget; child[2] = self->start_widget; child_size[0] = sizes[2].minimum_size; child_size[1] = sizes[1].minimum_size; child_size[2] = sizes[0].minimum_size; } else { child[0] = self->start_widget; child[1] = self->center_widget; child[2] = self->end_widget; child_size[0] = sizes[0].minimum_size; child_size[1] = sizes[1].minimum_size; child_size[2] = sizes[2].minimum_size; } /* Determine baseline */ if (self->orientation == GTK_ORIENTATION_HORIZONTAL && baseline == -1) { int min_above, nat_above; int min_below, nat_below; gboolean have_baseline; have_baseline = FALSE; min_above = nat_above = 0; min_below = nat_below = 0; for (i = 0; i < 3; i++) { if (gtk_widget_get_valign (child[i]) == GTK_ALIGN_BASELINE) { int child_min_height, child_nat_height; int child_min_baseline, child_nat_baseline; child_min_baseline = child_nat_baseline = -1; gtk_widget_measure (child[i], GTK_ORIENTATION_VERTICAL, child_size[i], &child_min_height, &child_nat_height, &child_min_baseline, &child_nat_baseline); if (child_min_baseline >= 0) { have_baseline = TRUE; min_below = MAX (min_below, child_min_height - child_min_baseline); nat_below = MAX (nat_below, child_nat_height - child_nat_baseline); min_above = MAX (min_above, child_min_baseline); nat_above = MAX (nat_above, child_nat_baseline); } } } if (have_baseline) { /* TODO: This is purely based on the minimum baseline. * When things fit we should use the natural one */ switch (self->baseline_pos) { case GTK_BASELINE_POSITION_TOP: baseline = min_above; break; case GTK_BASELINE_POSITION_CENTER: baseline = min_above + (allocation->height - (min_above + min_below)) / 2; break; case GTK_BASELINE_POSITION_BOTTOM: baseline = allocation->height - min_below; break; } } } /* Allocate child positions */ child_pos[0] = 0; child_pos[1] = (size / 2) - (child_size[1] / 2); child_pos[2] = size - child_size[2]; if (child[1]) { /* Push in from start/end */ if (child_size[0] > child_pos[1]) child_pos[1] = child_size[0]; else if (size - child_size[2] < child_pos[1] + child_size[1]) child_pos[1] = size - child_size[1] - child_size[2]; } child_allocation = *allocation; for (i = 0; i < 3; i++) { if (child[i] == NULL) continue; if (self->orientation == GTK_ORIENTATION_HORIZONTAL) { child_allocation.x = allocation->x + child_pos[i]; child_allocation.y = allocation->y; child_allocation.width = child_size[i]; child_allocation.height = allocation->height; } else { child_allocation.x = allocation->x; child_allocation.y = allocation->y + child_pos[i]; child_allocation.width = allocation->width; child_allocation.height = child_size[i]; } gtk_widget_size_allocate_with_baseline (child[i], &child_allocation, allocation->y + baseline); gtk_widget_get_clip (child[i], &child_clip); gdk_rectangle_union (&clip, &clip, &child_clip); } gtk_widget_set_clip (widget, &clip); } static void gtk_center_box_snapshot (GtkWidget *widget, GtkSnapshot *snapshot) { GtkCenterBox *self = GTK_CENTER_BOX (widget); if (self->start_widget) gtk_widget_snapshot_child (widget, self->start_widget, snapshot); if (self->center_widget) gtk_widget_snapshot_child (widget, self->center_widget, snapshot); if (self->end_widget) gtk_widget_snapshot_child (widget, self->end_widget, snapshot); } static void update_css_node_order (GtkCenterBox *self) { GtkCssNode *parent; GtkCssNode *first; GtkCssNode *last; parent = gtk_widget_get_css_node (GTK_WIDGET (self)); if (gtk_widget_get_direction (GTK_WIDGET (self)) == GTK_TEXT_DIR_LTR) { first = self->start_widget ? gtk_widget_get_css_node (self->start_widget) : NULL; last = self->end_widget ? gtk_widget_get_css_node (self->end_widget) : NULL; } else { first = self->end_widget ? gtk_widget_get_css_node (self->end_widget) : NULL; last = self->start_widget ? gtk_widget_get_css_node (self->start_widget) : NULL; } if (first) gtk_css_node_insert_after (parent, first, NULL); if (last) gtk_css_node_insert_before (parent, last, NULL); } static void gtk_center_box_direction_changed (GtkWidget *widget, GtkTextDirection previous_direction) { update_css_node_order (GTK_CENTER_BOX (widget)); } static GtkSizeRequestMode gtk_center_box_get_request_mode (GtkWidget *widget) { GtkCenterBox *self = GTK_CENTER_BOX (widget); gint count[3] = { 0, 0, 0 }; if (self->start_widget) count[gtk_widget_get_request_mode (self->start_widget)]++; if (self->center_widget) count[gtk_widget_get_request_mode (self->center_widget)]++; if (self->end_widget) count[gtk_widget_get_request_mode (self->end_widget)]++; if (!count[GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH] && !count[GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT]) return GTK_SIZE_REQUEST_CONSTANT_SIZE; else return count[GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT] > count[GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH] ? GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT : GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH; } static void gtk_center_box_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { GtkCenterBox *self = GTK_CENTER_BOX (object); switch (prop_id) { case PROP_BASELINE_POSITION: gtk_center_box_set_baseline_position (self, g_value_get_enum (value)); break; case PROP_ORIENTATION: { GtkOrientation orientation = g_value_get_enum (value); if (self->orientation != orientation) { self->orientation = orientation; _gtk_orientable_set_style_classes (GTK_ORIENTABLE (self)); gtk_widget_queue_resize (GTK_WIDGET (self)); g_object_notify (object, "orientation"); } } break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gtk_center_box_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) { GtkCenterBox *self = GTK_CENTER_BOX (object); switch (prop_id) { case PROP_BASELINE_POSITION: g_value_set_enum (value, self->baseline_pos); break; case PROP_ORIENTATION: g_value_set_enum (value, self->orientation); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gtk_center_box_class_init (GtkCenterBoxClass *klass) { GObjectClass *object_class = G_OBJECT_CLASS (klass); GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass); object_class->set_property = gtk_center_box_set_property; object_class->get_property = gtk_center_box_get_property; widget_class->measure = gtk_center_box_measure; widget_class->size_allocate = gtk_center_box_size_allocate; widget_class->snapshot = gtk_center_box_snapshot; widget_class->direction_changed = gtk_center_box_direction_changed; widget_class->get_request_mode = gtk_center_box_get_request_mode; g_object_class_override_property (object_class, PROP_ORIENTATION, "orientation"); g_object_class_install_property (object_class, PROP_BASELINE_POSITION, g_param_spec_enum ("baseline-position", P_("Baseline position"), P_("The position of the baseline aligned widgets if extra space is available"), GTK_TYPE_BASELINE_POSITION, GTK_BASELINE_POSITION_CENTER, GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY)); gtk_widget_class_set_accessible_role (widget_class, ATK_ROLE_FILLER); gtk_widget_class_set_css_name (widget_class, "box"); } static void gtk_center_box_init (GtkCenterBox *self) { gtk_widget_set_has_window (GTK_WIDGET (self), FALSE); self->start_widget = NULL; self->center_widget = NULL; self->end_widget = NULL; self->orientation = GTK_ORIENTATION_HORIZONTAL; self->baseline_pos = GTK_BASELINE_POSITION_CENTER; } /** * gtk_center_box_new: * * Creates a new #GtkCenterBox. * * Returns: the new #GtkCenterBox. * * Since: 3.92 */ GtkWidget * gtk_center_box_new (void) { return GTK_WIDGET (g_object_new (GTK_TYPE_CENTER_BOX, NULL)); } /** * gtk_center_box_set_start_widget: * @self: a #GtkCenterBox * @child: the child * * Sets the start widget. * * Since: 3.92 */ void gtk_center_box_set_start_widget (GtkCenterBox *self, GtkWidget *child) { if (self->start_widget) gtk_widget_unparent (self->start_widget); self->start_widget = child; if (child) gtk_widget_set_parent (child, GTK_WIDGET (self)); update_css_node_order (self); } /** * gtk_center_box_set_center_widget: * @self: a #GtkCenterBox * @child: the child * * Sets the center widget. * * Since: 3.92 */ void gtk_center_box_set_center_widget (GtkCenterBox *self, GtkWidget *child) { if (self->center_widget) gtk_widget_unparent (self->center_widget); self->center_widget = child; if (child) gtk_widget_set_parent (child, GTK_WIDGET (self)); update_css_node_order (self); } /** * gtk_center_box_set_end_widget: * @self: a #GtkCenterBox * @child: the child * * Sets the end widget. * * Since: 3.92 */ void gtk_center_box_set_end_widget (GtkCenterBox *self, GtkWidget *child) { if (self->end_widget) gtk_widget_unparent (self->end_widget); self->end_widget = child; if (child) gtk_widget_set_parent (child, GTK_WIDGET (self)); update_css_node_order (self); } /** * gtk_center_box_get_start_widget: * @self: a #GtkCenterBox * * Gets the start widget. * * Returns: the start widget. * * Since: 3.92 */ GtkWidget * gtk_center_box_get_start_widget (GtkCenterBox *self) { return self->start_widget; } /** * gtk_center_box_get_center_widget: * @self: a #GtkCenterBox * * Gets the center widget. * * Returns: the center widget. * * Since: 3.92 */ GtkWidget * gtk_center_box_get_center_widget (GtkCenterBox *self) { return self->center_widget; } /** * gtk_center_box_get_end_widget: * @self: a #GtkCenterBox * * Gets the end widget. * * Returns: the end widget. * * Since: 3.92 */ GtkWidget * gtk_center_box_get_end_widget (GtkCenterBox *self) { return self->end_widget; } /** * gtk_center_box_set_baseline_position: * @self: a #GtkCenterBox * @position: a #GtkBaselinePosition * * Sets the baseline position of a center box. * * This affects only horizontal boxes with at least one baseline * aligned child. If there is more vertical space available than * requested, and the baseline is not allocated by the parent then * @position is used to allocate the baseline wrt. the extra space * available. * * Since: 3.92 */ void gtk_center_box_set_baseline_position (GtkCenterBox *self, GtkBaselinePosition position) { g_return_if_fail (GTK_IS_CENTER_BOX (self)); if (self->baseline_pos != position) { self->baseline_pos = position; g_object_notify (G_OBJECT (self), "baseline-position"); gtk_widget_queue_resize (GTK_WIDGET (self)); } } /** * gtk_center_box_get_baseline_position: * @self: a #GtkCenterBox * * Gets the value set by gtk_center_box_set_baseline_position(). * * Returns: the baseline position * * Since: 3.92 */ GtkBaselinePosition gtk_center_box_get_baseline_position (GtkCenterBox *self) { g_return_val_if_fail (GTK_IS_CENTER_BOX (self), GTK_BASELINE_POSITION_CENTER); return self->baseline_pos; }