gtkcenterbox.c 17.5 KB
Newer Older
Matthias Clasen's avatar
Matthias Clasen committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
/*
 * Copyright (c) 2017 Timm Bäder <mail@baedert.org>
 *
 * 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 <mail@baedert.org>
 */

/**
 * 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().
 *
 * # 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"
49 50
#include "gtkorientable.h"
#include "gtkorientableprivate.h"
51
#include "gtkbuildable.h"
52
#include "gtksizerequest.h"
Matthias Clasen's avatar
Matthias Clasen committed
53 54 55 56 57 58 59 60 61 62 63 64 65 66 67

struct _GtkCenterBox
{
  GtkWidget parent_instance;

  GtkWidget *start_widget;
  GtkWidget *center_widget;
  GtkWidget *end_widget;
};


struct _GtkCenterBoxClass
{
  GtkWidgetClass parent_class;
};
68 69


70
static void gtk_center_box_buildable_init (GtkBuildableIface *iface);
71

72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
G_DEFINE_TYPE_WITH_CODE (GtkCenterBox, gtk_center_box, GTK_TYPE_WIDGET,
                         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;
}
97 98

static void
99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
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,
                        GTK_ORIENTATION_HORIZONTAL,
                        for_size,
                        &sizes[0].minimum_size, &sizes[0].natural_size,
                        NULL, NULL);

  if (self->center_widget)
    gtk_widget_measure (self->center_widget,
                        GTK_ORIENTATION_HORIZONTAL,
                        for_size,
                        &sizes[1].minimum_size, &sizes[1].natural_size,
                        NULL, NULL);


  if (self->end_widget)
    gtk_widget_measure (self->end_widget,
                        GTK_ORIENTATION_HORIZONTAL,
                        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 = gtk_widget_get_hexpand (self->center_widget);
    }

  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 = gtk_widget_get_hexpand (self->start_widget);
    }

  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 = gtk_widget_get_hexpand (self->end_widget);
    }

  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)
212 213
{
  GtkCenterBox *self = GTK_CENTER_BOX (widget);
214 215 216 217 218 219 220
  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;
221

222
  if (self->start_widget)
223 224 225 226 227
    gtk_widget_measure (self->start_widget,
                        orientation,
                        for_size,
                        &start_min, &start_nat,
                        &min_baseline, &nat_baseline);
228

229
  if (self->center_widget)
230 231 232 233 234
    gtk_widget_measure (self->center_widget,
                        orientation,
                        for_size,
                        &center_min, &center_nat,
                        &min_baseline, &nat_baseline);
235 236

  if (self->end_widget)
237 238 239 240 241 242
    gtk_widget_measure (self->end_widget,
                        orientation,
                        for_size,
                        &end_min, &end_nat,
                        &min_baseline, &nat_baseline);

243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302
  *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 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;
  GtkRequestedSize sizes[3];

  if (for_size >= 0)
    gtk_center_box_distribute (self, -1, for_size, sizes);

  if (self->start_widget)
    gtk_widget_measure (self->start_widget,
                        orientation,
                        for_size >= 0 ? sizes[0].minimum_size : -1,
                        &start_min, &start_nat,
                        &min_baseline, &nat_baseline);

  if (self->center_widget)
    gtk_widget_measure (self->center_widget,
                        orientation,
                        for_size >= 0 ? sizes[1].minimum_size : -1,
                        &center_min, &center_nat,
                        &min_baseline, &nat_baseline);

  if (self->end_widget)
    gtk_widget_measure (self->end_widget,
                        orientation,
                        for_size >= 0 ? sizes[2].minimum_size : -1,
                        &end_min, &end_nat,
                        &min_baseline, &nat_baseline);

  *minimum = MAX (start_min, MAX (center_min, end_min));
  *natural = MAX (start_nat, MAX (center_nat, end_nat));
}

static void
gtk_center_box_measure (GtkWidget      *widget,
                        GtkOrientation  orientation,
                        int             for_size,
                        int            *minimum,
                        int            *natural,
                        int            *minimum_baseline,
                        int            *natural_baseline)
{
303
  if (orientation == GTK_ORIENTATION_HORIZONTAL)
304 305 306
    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);
307 308 309 310 311 312 313 314 315 316
}

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;
317 318 319 320
  GtkWidget *left;
  GtkWidget *right;
  int left_size = 0;
  int right_size = 0;
321 322 323 324 325
  GtkRequestedSize sizes[3];

  GTK_WIDGET_CLASS (gtk_center_box_parent_class)->size_allocate (widget, allocation);

  gtk_center_box_distribute (self, allocation->height, allocation->width, sizes);
326 327 328 329

  if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_LTR)
    {
      left = self->start_widget;
330
      left_size = sizes[0].minimum_size;
331
      right = self->end_widget;
332
      right_size = sizes[2].minimum_size;
333 334 335 336
    }
  else
    {
      right = self->start_widget;
337
      right_size = sizes[0].minimum_size;
338
      left = self->end_widget;
339
      left_size = sizes[2].minimum_size;
340
    }
341

342 343 344
  child_allocation.y = allocation->y;
  child_allocation.height = allocation->height;

345 346
  if (self->center_widget)
    {
347
      child_allocation.width = sizes[1].minimum_size;
348
      child_allocation.x = (allocation->width / 2) - (child_allocation.width / 2);
349 350

      /* Push in from start/end */
351 352 353 354
      if (left_size > child_allocation.x)
        child_allocation.x = left_size;
      else if (allocation->width - right_size < child_allocation.x + child_allocation.width)
        child_allocation.x = allocation->width - child_allocation.width - right_size;
355 356 357 358 359

      child_allocation.x += allocation->x;
      gtk_widget_size_allocate (self->center_widget, &child_allocation);
      gtk_widget_get_clip (self->center_widget, &child_clip);
      gdk_rectangle_union (&clip, &clip, &child_clip);
360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377
    }

  if (left)
    {
      child_allocation.width = left_size;
      child_allocation.x = allocation->x;
      gtk_widget_size_allocate (left, &child_allocation);
      gtk_widget_get_clip (left, &child_clip);
      gdk_rectangle_union (&clip, &clip, &child_clip);
    }

  if (right)
    {
      child_allocation.width = right_size;
      child_allocation.x = allocation->x + allocation->width - child_allocation.width;
      gtk_widget_size_allocate (right, &child_allocation);
      gtk_widget_get_clip (right, &child_clip);
      gdk_rectangle_union (&clip, &clip, &child_clip);
378 379 380 381 382 383 384 385 386 387 388
    }

  gtk_widget_set_clip (widget, &clip);
}

static void
gtk_center_box_snapshot (GtkWidget   *widget,
                         GtkSnapshot *snapshot)
{
  GtkCenterBox *self = GTK_CENTER_BOX (widget);

389 390
  if (self->start_widget)
    gtk_widget_snapshot_child (widget, self->start_widget, snapshot);
391 392 393 394

  if (self->center_widget)
    gtk_widget_snapshot_child (widget, self->center_widget, snapshot);

395 396
  if (self->end_widget)
    gtk_widget_snapshot_child (widget, self->end_widget, snapshot);
397 398
}

399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431
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));
}

432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455
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;
}

456 457 458 459 460 461 462 463
static void
gtk_center_box_class_init (GtkCenterBoxClass *klass)
{
  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);

  widget_class->measure = gtk_center_box_measure;
  widget_class->size_allocate = gtk_center_box_size_allocate;
  widget_class->snapshot = gtk_center_box_snapshot;
464
  widget_class->direction_changed = gtk_center_box_direction_changed;
465
  widget_class->get_request_mode = gtk_center_box_get_request_mode;
Matthias Clasen's avatar
Matthias Clasen committed
466 467 468

  gtk_widget_class_set_accessible_role (widget_class, ATK_ROLE_FILLER);
  gtk_widget_class_set_css_name (widget_class, "box");
469 470 471 472 473 474 475 476 477 478 479 480
}

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;
}

Matthias Clasen's avatar
Matthias Clasen committed
481 482 483 484 485 486 487 488 489
/**
 * gtk_center_box_new:
 *
 * Creates a new #GtkCenterBox.
 *
 * Returns: the new #GtkCenterBox.
 *
 * Since: 3.92
 */
490 491 492 493 494 495
GtkWidget *
gtk_center_box_new (void)
{
  return GTK_WIDGET (g_object_new (GTK_TYPE_CENTER_BOX, NULL));
}

Matthias Clasen's avatar
Matthias Clasen committed
496 497 498 499 500 501 502 503 504
/**
 * gtk_center_box_set_start_widget:
 * @self: a #GtkCenterBox
 * @child: the child
 *
 * Sets the start widget.
 *
 * Since: 3.92
 */
505 506 507 508 509 510 511 512 513 514
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));
515 516

  update_css_node_order (self);
517 518
}

Matthias Clasen's avatar
Matthias Clasen committed
519 520 521 522 523 524 525 526 527
/**
 * gtk_center_box_set_center_widget:
 * @self: a #GtkCenterBox
 * @child: the child
 *
 * Sets the center widget.
 *
 * Since: 3.92
 */
528 529
void
gtk_center_box_set_center_widget (GtkCenterBox *self,
Matthias Clasen's avatar
Matthias Clasen committed
530
                                 GtkWidget     *child)
531 532 533 534 535 536 537
{
  if (self->center_widget)
    gtk_widget_unparent (self->center_widget);

  self->center_widget = child;
  if (child)
    gtk_widget_set_parent (child, GTK_WIDGET (self));
538 539

  update_css_node_order (self);
540 541
}

Matthias Clasen's avatar
Matthias Clasen committed
542 543 544 545 546 547 548 549 550
/**
 * gtk_center_box_set_end_widget:
 * @self: a #GtkCenterBox
 * @child: the child
 *
 * Sets the end widget.
 *
 * Since: 3.92
 */
551 552 553 554 555 556 557 558 559 560
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));
561 562

  update_css_node_order (self);
563 564
}

Matthias Clasen's avatar
Matthias Clasen committed
565 566 567 568 569 570 571 572 573 574
/**
 * gtk_center_box_get_start_widget:
 * @self: a #GtkCenterBox
 *
 * Gets the start widget.
 *
 * Returns: the start widget.
 *
 * Since: 3.92
 */
575 576 577 578 579 580
GtkWidget *
gtk_center_box_get_start_widget (GtkCenterBox *self)
{
  return self->start_widget;
}

Matthias Clasen's avatar
Matthias Clasen committed
581 582 583 584 585 586 587 588 589 590
/**
 * gtk_center_box_get_center_widget:
 * @self: a #GtkCenterBox
 *
 * Gets the center widget.
 *
 * Returns: the center widget.
 *
 * Since: 3.92
 */
591 592 593 594 595 596
GtkWidget *
gtk_center_box_get_center_widget (GtkCenterBox *self)
{
  return self->center_widget;
}

Matthias Clasen's avatar
Matthias Clasen committed
597 598 599 600 601 602 603 604 605 606
/**
 * gtk_center_box_get_end_widget:
 * @self: a #GtkCenterBox
 *
 * Gets the end widget.
 *
 * Returns: the end widget.
 *
 * Since: 3.92
 */
607 608 609 610 611
GtkWidget *
gtk_center_box_get_end_widget (GtkCenterBox *self)
{
  return self->end_widget;
}