chrome/browser/ui/views/tabs/stacked_tab_strip_layout.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/views/tabs/stacked_tab_strip_layout.h"
   6
   7 #include <stdio.h>
   8
   9 #include "base/logging.h"
  10 #include "base/strings/string_number_conversions.h"
  11 #include "content/public/browser/user_metrics.h"
  12
  13 using base::UserMetricsAction;
  14
  15 StackedTabStripLayout::StackedTabStripLayout(const gfx::Size& size,
  16                                              int overlap,
  17                                              int stacked_padding,
  18                                              int max_stacked_count,
  19                                              views::ViewModelBase* view_model)
  20     : size_(size),
  21       overlap_(overlap),
  22       stacked_padding_(stacked_padding),
  23       max_stacked_count_(max_stacked_count),
  24       view_model_(view_model),
  25       x_(0),
  26       width_(0),
  27       pinned_tab_count_(0),
  28       pinned_tab_to_non_pinned_tab_(0),
  29       active_index_(-1),
  30       first_tab_x_(0) {
  31 }
  32
  33 StackedTabStripLayout::~StackedTabStripLayout() {
  34 }
  35
  36 void StackedTabStripLayout::SetXAndPinnedCount(int x, int pinned_tab_count) {
  37   first_tab_x_ = x;
  38   x_ = x;
  39   pinned_tab_count_ = pinned_tab_count;
  40   pinned_tab_to_non_pinned_tab_ = 0;
  41   if (!requires_stacking() || tab_count() == pinned_tab_count) {
  42     ResetToIdealState();
  43     return;
  44   }
  45   if (pinned_tab_count > 0) {
  46     pinned_tab_to_non_pinned_tab_ = x - ideal_x(pinned_tab_count - 1);
  47     first_tab_x_ = ideal_x(0);
  48   }
  49   SetIdealBoundsAt(active_index(), ConstrainActiveX(ideal_x(active_index())));
  50   LayoutByTabOffsetAfter(active_index());
  51   LayoutByTabOffsetBefore(active_index());
  52 }
  53
  54 void StackedTabStripLayout::SetWidth(int width) {
  55   if (width_ == width)
  56     return;
  57
  58   width_ = width;
  59   if (!requires_stacking()) {
  60     ResetToIdealState();
  61     return;
  62   }
  63   SetActiveBoundsAndLayoutFromActiveTab();
  64 }
  65
  66 void StackedTabStripLayout::SetActiveIndex(int index) {
  67   int old = active_index();
  68   active_index_ = index;
  69   if (old == active_index() || !requires_stacking())
  70     return;
  71   SetIdealBoundsAt(active_index(), ConstrainActiveX(ideal_x(active_index())));
  72   LayoutByTabOffsetBefore(active_index());
  73   LayoutByTabOffsetAfter(active_index());
  74   AdjustStackedTabs();
  75 }
  76
  77 void StackedTabStripLayout::DragActiveTab(int delta) {
  78   if (delta == 0 || !requires_stacking())
  79     return;
  80
  81   content::RecordAction(UserMetricsAction("StackedTab_DragActiveTab"));
  82   int initial_x = ideal_x(active_index());
  83   // If we're at a particular edge and start dragging, expose all the tabs after
  84   // the tab (or before when dragging to the left).
  85   if (delta > 0 && initial_x == GetMinX(active_index())) {
  86     LayoutByTabOffsetAfter(active_index());
  87     AdjustStackedTabs();
  88   } else if (delta < 0 && initial_x == GetMaxX(active_index())) {
  89     LayoutByTabOffsetBefore(active_index());
  90     ResetToIdealState();
  91   }
  92   int x = delta > 0 ?
  93       std::min(initial_x + delta, GetMaxDragX(active_index())) :
  94       std::max(initial_x + delta, GetMinDragX(active_index()));
  95   if (x != initial_x) {
  96     SetIdealBoundsAt(active_index(), x);
  97     if (delta > 0) {
  98       PushTabsAfter(active_index(), (x - initial_x));
  99       LayoutForDragBefore(active_index());
 100     } else {
 101       PushTabsBefore(active_index(), initial_x - x);
 102       LayoutForDragAfter(active_index());
 103     }
 104     delta -= (x - initial_x);
 105   }
 106   if (delta > 0)
 107     ExpandTabsBefore(active_index(), delta);
 108   else if (delta < 0)
 109     ExpandTabsAfter(active_index(), -delta);
 110   AdjustStackedTabs();
 111 }
 112
 113 void StackedTabStripLayout::SizeToFit() {
 114   if (!tab_count())
 115     return;
 116
 117   if (!requires_stacking()) {
 118     ResetToIdealState();
 119     return;
 120   }
 121
 122   if (ideal_x(0) != first_tab_x_) {
 123     // Tabs have been dragged to the right. Pull in the tabs from left to right
 124     // to fill in space.
 125     int delta = ideal_x(0) - first_tab_x_;
 126     int i = 0;
 127     for (; i < pinned_tab_count_; ++i) {
 128       gfx::Rect pinned_bounds(view_model_->ideal_bounds(i));
 129       pinned_bounds.set_x(ideal_x(i) - delta);
 130       view_model_->set_ideal_bounds(i, pinned_bounds);
 131     }
 132     for (; delta > 0 && i < tab_count() - 1; ++i) {
 133       const int exposed = tab_offset() - (ideal_x(i + 1) - ideal_x(i));
 134       SetIdealBoundsAt(i, ideal_x(i) - delta);
 135       delta -= exposed;
 136     }
 137     AdjustStackedTabs();
 138     return;
 139   }
 140
 141   const int max_x = width_ - size_.width();
 142   if (ideal_x(tab_count() - 1) == max_x)
 143     return;
 144
 145   // Tabs have been dragged to the left. Pull in tabs from right to left to fill
 146   // in space.
 147   SetIdealBoundsAt(tab_count() - 1, max_x);
 148   for (int i = tab_count() - 2; i > pinned_tab_count_ &&
 149            ideal_x(i + 1) - ideal_x(i) > tab_offset(); --i) {
 150     SetIdealBoundsAt(i, ideal_x(i + 1) - tab_offset());
 151   }
 152   AdjustStackedTabs();
 153 }
 154
 155 void StackedTabStripLayout::AddTab(int index, int add_types, int start_x) {
 156   if (add_types & kAddTypeActive)
 157     active_index_ = index;
 158   else if (active_index_ >= index)
 159     active_index_++;
 160   if (add_types & kAddTypePinned)
 161     pinned_tab_count_++;
 162   x_ = start_x;
 163   if (!requires_stacking() || normal_tab_count() <= 1) {
 164     ResetToIdealState();
 165     return;
 166   }
 167   int active_x = (index + 1 == tab_count()) ?
 168       width_ - size_.width() : ideal_x(index + 1);
 169   SetIdealBoundsAt(active_index(), ConstrainActiveX(active_x));
 170   LayoutByTabOffsetAfter(active_index());
 171   LayoutByTabOffsetBefore(active_index());
 172   AdjustStackedTabs();
 173
 174   if ((add_types & kAddTypeActive) == 0)
 175     MakeVisible(index);
 176 }
 177
 178 void StackedTabStripLayout::RemoveTab(int index, int start_x, int old_x) {
 179   if (index == active_index_)
 180     active_index_ = std::min(active_index_, tab_count() - 1);
 181   else if (index < active_index_)
 182     active_index_--;
 183   bool removed_pinned_tab = index < pinned_tab_count_;
 184   if (removed_pinned_tab) {
 185     pinned_tab_count_--;
 186     DCHECK_GE(pinned_tab_count_, 0);
 187   }
 188   int delta = start_x - x_;
 189   x_ = start_x;
 190   if (!requires_stacking()) {
 191     ResetToIdealState();
 192     return;
 193   }
 194   if (removed_pinned_tab) {
 195     for (int i = pinned_tab_count_; i < tab_count(); ++i)
 196       SetIdealBoundsAt(i, ideal_x(i) + delta);
 197   }
 198   SetActiveBoundsAndLayoutFromActiveTab();
 199   AdjustStackedTabs();
 200 }
 201
 202 void StackedTabStripLayout::MoveTab(int from,
 203                                     int to,
 204                                     int new_active_index,
 205                                     int start_x,
 206                                     int pinned_tab_count) {
 207   x_ = start_x;
 208   pinned_tab_count_ = pinned_tab_count;
 209   active_index_ = new_active_index;
 210   if (!requires_stacking() || tab_count() == pinned_tab_count_) {
 211     ResetToIdealState();
 212   } else {
 213     SetIdealBoundsAt(active_index(),
 214                      ConstrainActiveX(ideal_x(active_index())));
 215     LayoutByTabOffsetAfter(active_index());
 216     LayoutByTabOffsetBefore(active_index());
 217     AdjustStackedTabs();
 218   }
 219   pinned_tab_to_non_pinned_tab_ = pinned_tab_count > 0 ?
 220       start_x - ideal_x(pinned_tab_count - 1) : 0;
 221   first_tab_x_ = pinned_tab_count > 0 ? ideal_x(0) : start_x;
 222 }
 223
 224 bool StackedTabStripLayout::IsStacked(int index) const {
 225   if (index == active_index() || tab_count() == pinned_tab_count_ ||
 226       index < pinned_tab_count_)
 227     return false;
 228   if (index > active_index())
 229     return ideal_x(index) != ideal_x(index - 1) + tab_offset();
 230   return ideal_x(index + 1) != ideal_x(index) + tab_offset();
 231 }
 232
 233 void StackedTabStripLayout::SetActiveTabLocation(int x) {
 234   if (!requires_stacking())
 235     return;
 236
 237   const int index = active_index();
 238   if (index <= pinned_tab_count_)
 239     return;
 240
 241   x = std::min(GetMaxX(index), std::max(x, GetMinX(index)));
 242   if (x == ideal_x(index))
 243     return;
 244
 245   SetIdealBoundsAt(index, x);
 246   LayoutByTabOffsetBefore(index);
 247   LayoutByTabOffsetAfter(index);
 248 }
 249
 250 #if !defined(NDEBUG)
 251 std::string StackedTabStripLayout::BoundsString() const {
 252   std::string result;
 253   for (int i = 0; i < view_model_->view_size(); ++i) {
 254     if (!result.empty())
 255       result += " ";
 256     if (i == active_index())
 257       result += "[";
 258     result += base::IntToString(view_model_->ideal_bounds(i).x());
 259     if (i == active_index())
 260       result += "]";
 261   }
 262   return result;
 263 }
 264 #endif
 265
 266 void StackedTabStripLayout::Reset(int x,
 267                                   int width,
 268                                   int pinned_tab_count,
 269                                   int active_index) {
 270   x_ = x;
 271   width_ = width;
 272   pinned_tab_count_ = pinned_tab_count;
 273   pinned_tab_to_non_pinned_tab_ = pinned_tab_count > 0 ?
 274       x - ideal_x(pinned_tab_count - 1) : 0;
 275   first_tab_x_ = pinned_tab_count > 0 ? ideal_x(0) : x;
 276   active_index_ = active_index;
 277   ResetToIdealState();
 278 }
 279
 280 void StackedTabStripLayout::ResetToIdealState() {
 281   if (tab_count() == pinned_tab_count_)
 282     return;
 283
 284   if (!requires_stacking()) {
 285     SetIdealBoundsAt(pinned_tab_count_, x_);
 286     LayoutByTabOffsetAfter(pinned_tab_count_);
 287     return;
 288   }
 289
 290   if (normal_tab_count() == 1) {
 291     // TODO: might want to shrink the tab here.
 292     SetIdealBoundsAt(pinned_tab_count_, 0);
 293     return;
 294   }
 295
 296   int available_width = width_ - x_;
 297   int leading_count = active_index() - pinned_tab_count_;
 298   int trailing_count = tab_count() - active_index();
 299   if (width_for_count(leading_count + 1) + max_stacked_width() <
 300       available_width) {
 301     SetIdealBoundsAt(pinned_tab_count_, x_);
 302     LayoutByTabOffsetAfter(pinned_tab_count_);
 303   } else if (width_for_count(trailing_count) + max_stacked_width() <
 304              available_width) {
 305     SetIdealBoundsAt(tab_count() - 1, width_ - size_.width());
 306     LayoutByTabOffsetBefore(tab_count() - 1);
 307   } else {
 308     int index = active_index();
 309     do {
 310       int stacked_padding =
 311           stacked_padding_for_count(index - pinned_tab_count_);
 312       SetIdealBoundsAt(index, x_ + stacked_padding);
 313       LayoutByTabOffsetAfter(index);
 314       LayoutByTabOffsetBefore(index);
 315       index--;
 316     } while (index >= pinned_tab_count_ && ideal_x(pinned_tab_count_) != x_ &&
 317              ideal_x(tab_count() - 1) != width_ - size_.width());
 318   }
 319   AdjustStackedTabs();
 320 }
 321
 322 void StackedTabStripLayout::MakeVisible(int index) {
 323   // Currently no need to support tabs openning before |index| visible.
 324   if (index <= active_index() || !requires_stacking() || !IsStacked(index))
 325     return;
 326
 327   int ideal_delta = width_for_count(index - active_index()) - overlap_;
 328   if (ideal_x(index) - ideal_x(active_index()) == ideal_delta)
 329     return;
 330
 331   // First push active index as far to the left as it'll go.
 332   int active_x = std::max(GetMinX(active_index()),
 333                           std::min(ideal_x(index) - ideal_delta,
 334                                    ideal_x(active_index())));
 335   SetIdealBoundsAt(active_index(), active_x);
 336   LayoutUsingCurrentBefore(active_index());
 337   LayoutUsingCurrentAfter(active_index());
 338   AdjustStackedTabs();
 339   if (ideal_x(index) - ideal_x(active_index()) == ideal_delta)
 340     return;
 341
 342   // If we get here active_index() is left aligned. Push |index| as far to
 343   // the right as possible.
 344   int x = std::min(GetMaxX(index), active_x + ideal_delta);
 345   SetIdealBoundsAt(index, x);
 346   LayoutByTabOffsetAfter(index);
 347   for (int next_x = x, i = index - 1; i > active_index(); --i) {
 348     next_x = std::max(GetMinXCompressed(i), next_x - tab_offset());
 349     SetIdealBoundsAt(i, next_x);
 350   }
 351   LayoutUsingCurrentAfter(active_index());
 352   AdjustStackedTabs();
 353 }
 354
 355 int StackedTabStripLayout::ConstrainActiveX(int x) const {
 356   return std::min(GetMaxX(active_index()),
 357                   std::max(GetMinX(active_index()), x));
 358 }
 359
 360 void StackedTabStripLayout::SetActiveBoundsAndLayoutFromActiveTab() {
 361   int x = ConstrainActiveX(ideal_x(active_index()));
 362   SetIdealBoundsAt(active_index(), x);
 363   LayoutUsingCurrentBefore(active_index());
 364   LayoutUsingCurrentAfter(active_index());
 365   AdjustStackedTabs();
 366 }
 367
 368 void StackedTabStripLayout::LayoutByTabOffsetAfter(int index) {
 369   for (int i = index + 1; i < tab_count(); ++i) {
 370     int max_x = width_ - size_.width() -
 371         stacked_padding_for_count(tab_count() - i - 1);
 372     int x = std::min(max_x,
 373                      view_model_->ideal_bounds(i - 1).x() + tab_offset());
 374     SetIdealBoundsAt(i, x);
 375   }
 376 }
 377
 378 void StackedTabStripLayout::LayoutByTabOffsetBefore(int index) {
 379   for (int i = index - 1; i >= pinned_tab_count_; --i) {
 380     int min_x = x_ + stacked_padding_for_count(i - pinned_tab_count_);
 381     int x = std::max(min_x, ideal_x(i + 1) - (tab_offset()));
 382     SetIdealBoundsAt(i, x);
 383   }
 384 }
 385
 386 void StackedTabStripLayout::LayoutUsingCurrentAfter(int index) {
 387   for (int i = index + 1; i < tab_count(); ++i) {
 388     int min_x = width_ - width_for_count(tab_count() - i);
 389     int x = std::max(min_x,
 390                      std::min(ideal_x(i), ideal_x(i - 1) + tab_offset()));
 391     x = std::min(GetMaxX(i), x);
 392     SetIdealBoundsAt(i, x);
 393   }
 394 }
 395
 396 void StackedTabStripLayout::LayoutUsingCurrentBefore(int index) {
 397   for (int i = index - 1; i >= pinned_tab_count_; --i) {
 398     int max_x = x_ + width_for_count(i - pinned_tab_count_);
 399     if (i > pinned_tab_count_)
 400       max_x -= overlap_;
 401     max_x = std::min(max_x, ideal_x(i + 1) - stacked_padding_);
 402     SetIdealBoundsAt(
 403         i, std::min(max_x,
 404                     std::max(ideal_x(i), ideal_x(i + 1) - tab_offset())));
 405   }
 406 }
 407
 408 void StackedTabStripLayout::PushTabsAfter(int index, int delta) {
 409   for (int i = index + 1; i < tab_count(); ++i)
 410     SetIdealBoundsAt(i, std::min(ideal_x(i) + delta, GetMaxDragX(i)));
 411 }
 412
 413 void StackedTabStripLayout::PushTabsBefore(int index, int delta) {
 414   for (int i = index - 1; i > pinned_tab_count_; --i)
 415     SetIdealBoundsAt(i, std::max(ideal_x(i) - delta, GetMinDragX(i)));
 416 }
 417
 418 void StackedTabStripLayout::LayoutForDragAfter(int index) {
 419   for (int i = index + 1; i < tab_count(); ++i) {
 420     const int min_x = ideal_x(i - 1) + stacked_padding_;
 421     const int max_x = ideal_x(i - 1) + tab_offset();
 422     SetIdealBoundsAt(
 423         i, std::max(min_x, std::min(ideal_x(i), max_x)));
 424   }
 425 }
 426
 427 void StackedTabStripLayout::LayoutForDragBefore(int index) {
 428   for (int i = index - 1; i >= pinned_tab_count_; --i) {
 429     const int max_x = ideal_x(i + 1) - stacked_padding_;
 430     const int min_x = ideal_x(i + 1) - tab_offset();
 431     SetIdealBoundsAt(
 432         i, std::max(min_x, std::min(ideal_x(i), max_x)));
 433   }
 434
 435   if (pinned_tab_count_ == 0)
 436     return;
 437
 438   // Pull in the pinned tabs.
 439   const int delta = (pinned_tab_count_ > 1) ? ideal_x(1) - ideal_x(0) : 0;
 440   for (int i = pinned_tab_count_ - 1; i >= 0; --i) {
 441     gfx::Rect pinned_bounds(view_model_->ideal_bounds(i));
 442     if (i == pinned_tab_count_ - 1)
 443       pinned_bounds.set_x(ideal_x(i + 1) - pinned_tab_to_non_pinned_tab_);
 444     else
 445       pinned_bounds.set_x(ideal_x(i + 1) - delta);
 446     view_model_->set_ideal_bounds(i, pinned_bounds);
 447   }
 448 }
 449
 450 void StackedTabStripLayout::ExpandTabsBefore(int index, int delta) {
 451   for (int i = index - 1; i >= pinned_tab_count_ && delta > 0; --i) {
 452     const int max_x = ideal_x(active_index()) -
 453         stacked_padding_for_count(active_index() - i);
 454     int to_resize = std::min(delta, max_x - ideal_x(i));
 455
 456     if (to_resize <= 0)
 457       continue;
 458     SetIdealBoundsAt(i, ideal_x(i) + to_resize);
 459     delta -= to_resize;
 460     LayoutForDragBefore(i);
 461   }
 462 }
 463
 464 void StackedTabStripLayout::ExpandTabsAfter(int index, int delta) {
 465   if (index == tab_count() - 1)
 466     return;  // Nothing to expand.
 467
 468   for (int i = index + 1; i < tab_count() && delta > 0; ++i) {
 469     const int min_compressed =
 470         ideal_x(active_index()) + stacked_padding_for_count(i - active_index());
 471     const int to_resize = std::min(ideal_x(i) - min_compressed, delta);
 472     if (to_resize <= 0)
 473       continue;
 474     SetIdealBoundsAt(i, ideal_x(i) - to_resize);
 475     delta -= to_resize;
 476     LayoutForDragAfter(i);
 477   }
 478 }
 479
 480 void StackedTabStripLayout::AdjustStackedTabs() {
 481   if (!requires_stacking() || tab_count() <= pinned_tab_count_ + 1)
 482     return;
 483
 484   AdjustLeadingStackedTabs();
 485   AdjustTrailingStackedTabs();
 486 }
 487
 488 void StackedTabStripLayout::AdjustLeadingStackedTabs() {
 489   int index = pinned_tab_count_ + 1;
 490   while (index < active_index() &&
 491          ideal_x(index) - ideal_x(index - 1) <= stacked_padding_ &&
 492          ideal_x(index) <= x_ + max_stacked_width()) {
 493     index++;
 494   }
 495   if (ideal_x(index) - ideal_x(index - 1) <= stacked_padding_ &&
 496       ideal_x(index) <= x_ + max_stacked_width()) {
 497     index++;
 498   }
 499   if (index <= pinned_tab_count_ + max_stacked_count_ - 1)
 500     return;
 501   int max_stacked = index;
 502   int x = x_;
 503   index = pinned_tab_count_;
 504   for (; index < max_stacked - max_stacked_count_ - 1; ++index)
 505     SetIdealBoundsAt(index, x);
 506   for (; index < max_stacked; ++index, x += stacked_padding_)
 507     SetIdealBoundsAt(index, x);
 508 }
 509
 510 void StackedTabStripLayout::AdjustTrailingStackedTabs() {
 511   int index = tab_count() - 1;
 512   int max_stacked_x = width_ - size_.width() - max_stacked_width();
 513   while (index > active_index() &&
 514          ideal_x(index) - ideal_x(index - 1) <= stacked_padding_ &&
 515          ideal_x(index - 1) >= max_stacked_x) {
 516     index--;
 517   }
 518   if (index > active_index() &&
 519       ideal_x(index) - ideal_x(index - 1) <= stacked_padding_ &&
 520       ideal_x(index - 1) >= max_stacked_x) {
 521     index--;
 522   }
 523   if (index >= tab_count() - max_stacked_count_)
 524     return;
 525   int first_stacked = index;
 526   int x = width_ - size_.width() -
 527       std::min(tab_count() - first_stacked, max_stacked_count_) *
 528       stacked_padding_;
 529   for (; index < first_stacked + max_stacked_count_;
 530        ++index, x += stacked_padding_) {
 531     SetIdealBoundsAt(index, x);
 532   }
 533   for (; index < tab_count(); ++index)
 534     SetIdealBoundsAt(index, x);
 535 }
 536
 537 void StackedTabStripLayout::SetIdealBoundsAt(int index, int x) {
 538   view_model_->set_ideal_bounds(index, gfx::Rect(gfx::Point(x, 0), size_));
 539 }
 540
 541 int StackedTabStripLayout::GetMinX(int index) const {
 542   int leading_count = index - pinned_tab_count_;
 543   int trailing_count = tab_count() - index;
 544   return std::max(x_ + stacked_padding_for_count(leading_count),
 545                   width_ - width_for_count(trailing_count));
 546 }
 547
 548 int StackedTabStripLayout::GetMaxX(int index) const {
 549   int leading_count = index - pinned_tab_count_;
 550   int trailing_count = tab_count() - index - 1;
 551   int trailing_offset = stacked_padding_for_count(trailing_count);
 552   int leading_size = width_for_count(leading_count) + x_;
 553   if (leading_count > 0)
 554     leading_size -= overlap_;
 555   return std::min(width_ - trailing_offset - size_.width(), leading_size);
 556 }
 557
 558 int StackedTabStripLayout::GetMinDragX(int index) const {
 559   return x_ + stacked_padding_for_count(index - pinned_tab_count_);
 560 }
 561
 562 int StackedTabStripLayout::GetMaxDragX(int index) const {
 563   const int trailing_offset =
 564       stacked_padding_for_count(tab_count() - index - 1);
 565   return width_ - trailing_offset - size_.width();
 566 }
 567
 568 int StackedTabStripLayout::GetMinXCompressed(int index) const {
 569   DCHECK_GT(index, active_index());
 570   return std::max(
 571       width_ - width_for_count(tab_count() - index),
 572       ideal_x(active_index()) +
 573           stacked_padding_for_count(index - active_index()));
 574 }