dali-toolkit/internal/controls/scrollable/item-view/item-view-impl.cpp

   1 /*
   2  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 // CLASS HEADER
  19 #include <dali-toolkit/internal/controls/scrollable/item-view/item-view-impl.h>
  20
  21 // EXTERNAL INCLUDES
  22 #include <algorithm>
  23 #include <dali/public-api/animation/active-constraint.h>
  24 #include <dali/public-api/animation/constraint.h>
  25 #include <dali/public-api/animation/constraints.h>
  26 #include <dali/public-api/common/set-wrapper.h>
  27 #include <dali/public-api/common/stage.h>
  28 #include <dali/public-api/events/mouse-wheel-event.h>
  29 #include <dali/public-api/events/touch-event.h>
  30 #include <dali/public-api/object/type-registry.h>
  31 #include <dali/public-api/object/type-registry-helper.h>
  32
  33 // INTERNAL INCLUDES
  34 #include <dali-toolkit/public-api/controls/scrollable/item-view/item-factory.h>
  35 #include <dali-toolkit/internal/controls/scrollable/bouncing-effect-actor.h>
  36 #include <dali-toolkit/internal/controls/scrollable/scroll-connector-impl.h>
  37
  38 using std::string;
  39 using std::set;
  40 using namespace Dali;
  41
  42 namespace // Unnamed namespace
  43 {
  44
  45 //Type registration
  46
  47 DALI_TYPE_REGISTRATION_BEGIN( Toolkit::ItemView, Toolkit::Scrollable, NULL )
  48 DALI_TYPE_REGISTRATION_END()
  49
  50 const float DEFAULT_MINIMUM_SWIPE_SPEED = 1.0f;
  51 const float DEFAULT_MINIMUM_SWIPE_DISTANCE = 3.0f;
  52 const float DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION = 0.1f;
  53
  54 const float DEFAULT_MINIMUM_SWIPE_DURATION = 0.45f;
  55 const float DEFAULT_MAXIMUM_SWIPE_DURATION = 2.6f;
  56
  57 const float DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS = 20.0f; // 1 updates per 20 items
  58 const int MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT = 500;  // 0.5 second
  59
  60 const float DEFAULT_ANCHORING_DURATION = 1.0f;  // 1 second
  61
  62 const float MILLISECONDS_PER_SECONDS = 1000.0f;
  63
  64 const Vector2 OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE( 720.0f, 42.0f );
  65 const float OVERSHOOT_BOUNCE_ACTOR_RESIZE_THRESHOLD = 180.0f;
  66 const Vector4 OVERSHOOT_OVERLAY_NINE_PATCH_BORDER(0.0f, 0.0f, 1.0f, 12.0f);
  67 const float DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION = 0.2f;
  68
  69 const string LAYOUT_POSITION_PROPERTY_NAME( "item-view-layout-position" );
  70 const string POSITION_PROPERTY_NAME( "item-view-position" );
  71 const string MINIMUM_LAYOUT_POSITION_PROPERTY_NAME( "item-view-minimum-layout-position" );
  72 const string SCROLL_SPEED_PROPERTY_NAME( "item-view-scroll-speed" );
  73 const string SCROLL_DIRECTION_PROPERTY_NAME( "item-view-scroll-direction" );
  74 const string OVERSHOOT_PROPERTY_NAME( "item-view-overshoot" );
  75
  76 /**
  77  * Local helper to convert pan distance (in actor coordinates) to the layout-specific scrolling direction
  78  */
  79 float CalculateScrollDistance(Vector2 panDistance, Toolkit::ItemLayout& layout)
  80 {
  81   Radian scrollDirection(layout.GetScrollDirection());
  82
  83   float cosTheta = cosf(scrollDirection);
  84   float sinTheta = sinf(scrollDirection);
  85
  86   return panDistance.x * sinTheta + panDistance.y * cosTheta;
  87 }
  88
  89 // Overshoot overlay constraints
  90
  91 struct OvershootOverlaySizeConstraint
  92 {
  93   Vector3 operator()(const Vector3& current,
  94                      const PropertyInput& parentScrollDirectionProperty,
  95                      const PropertyInput& parentOvershootProperty,
  96                      const PropertyInput& parentSizeProperty)
  97   {
  98     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
  99     const Vector3 parentSize = parentSizeProperty.GetVector3();
 100     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 101
 102     float overlayWidth;
 103
 104     if(Toolkit::IsVertical(parentOrientation))
 105     {
 106       overlayWidth = fabsf(parentScrollDirection.y) > Math::MACHINE_EPSILON_1 ? parentSize.x : parentSize.y;
 107     }
 108     else
 109     {
 110       overlayWidth = fabsf(parentScrollDirection.x) > Math::MACHINE_EPSILON_1 ? parentSize.y : parentSize.x;
 111     }
 112
 113     float overlayHeight = (overlayWidth > OVERSHOOT_BOUNCE_ACTOR_RESIZE_THRESHOLD) ? OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height : OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height*0.5f;
 114
 115     return Vector3( overlayWidth, overlayHeight, current.depth );
 116   }
 117 };
 118
 119 struct OvershootOverlayRotationConstraint
 120 {
 121   Quaternion operator()(const Quaternion& current,
 122                         const PropertyInput& parentScrollDirectionProperty,
 123                         const PropertyInput& parentOvershootProperty)
 124   {
 125     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 126     const float parentOvershoot = parentOvershootProperty.GetFloat();
 127     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 128
 129     float multiplier = 0;
 130     if(Toolkit::IsVertical(parentOrientation))
 131     {
 132       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 133       {
 134         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 135             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 136         {
 137           multiplier = 0.5f;
 138         }
 139         else
 140         {
 141           multiplier = 1.5f;
 142         }
 143       }
 144       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 145             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 146       {
 147         multiplier = 0.0f;
 148       }
 149       else
 150       {
 151         multiplier = 1.0f;
 152       }
 153     }
 154     else
 155     {
 156       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 157       {
 158         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot > Math::MACHINE_EPSILON_0)
 159             ||(parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot < Math::MACHINE_EPSILON_0) )
 160         {
 161           multiplier = 1.0f;
 162         }
 163         else
 164         {
 165           multiplier = 0.0f;
 166         }
 167       }
 168       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 169             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 170       {
 171         multiplier = 1.5f;
 172       }
 173       else
 174       {
 175         multiplier = 0.5f;
 176       }
 177     }
 178
 179     Quaternion rotation( Radian( multiplier * Math::PI ), Vector3::ZAXIS );
 180
 181     return rotation;
 182   }
 183 };
 184
 185 struct OvershootOverlayPositionConstraint
 186 {
 187   Vector3 operator()(const Vector3&    current,
 188                      const PropertyInput& parentSizeProperty,
 189                      const PropertyInput& parentScrollDirectionProperty,
 190                      const PropertyInput& parentOvershootProperty)
 191   {
 192     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 193     const float parentOvershoot = parentOvershootProperty.GetFloat();
 194     const Vector3 parentSize = parentSizeProperty.GetVector3();
 195     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 196
 197     Vector3 relativeOffset;
 198
 199     if(Toolkit::IsVertical(parentOrientation))
 200     {
 201       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 202       {
 203         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 204             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 205         {
 206           relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 207         }
 208         else
 209         {
 210           relativeOffset =Vector3(0.0f, 1.0f, 0.0f);
 211         }
 212       }
 213       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 214             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 215       {
 216         relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 217       }
 218       else
 219       {
 220         relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 221       }
 222     }
 223     else
 224     {
 225       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 226       {
 227         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot < Math::MACHINE_EPSILON_0)
 228             || (parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot > Math::MACHINE_EPSILON_0) )
 229         {
 230           relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 231         }
 232         else
 233         {
 234           relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 235         }
 236       }
 237       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 238             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 239       {
 240         relativeOffset = Vector3(0.0f, 1.0f, 0.0f);
 241       }
 242       else
 243       {
 244         relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 245       }
 246     }
 247
 248     return relativeOffset * parentSize;
 249
 250   }
 251 };
 252
 253 struct OvershootOverlayVisibilityConstraint
 254 {
 255   bool operator()(const bool& current,
 256                   const PropertyInput& parentLayoutScrollableProperty)
 257   {
 258     const bool parentLayoutScrollable = parentLayoutScrollableProperty.GetBoolean();
 259
 260     return parentLayoutScrollable;
 261   }
 262 };
 263
 264 /**
 265  * Relative position Constraint
 266  * Generates the relative position value of the item view based on the layout position,
 267  * and it's relation to the layout domain. This is a value from 0.0f to 1.0f in each axis.
 268  */
 269 Vector3 RelativePositionConstraint(const Vector3& current,
 270                                    const PropertyInput& scrollPositionProperty,
 271                                    const PropertyInput& scrollMinProperty,
 272                                    const PropertyInput& scrollMaxProperty,
 273                                    const PropertyInput& layoutSizeProperty)
 274 {
 275   const Vector3& position = Vector3(0.0f, scrollPositionProperty.GetFloat(), 0.0f);
 276   const Vector3& min = scrollMinProperty.GetVector3();
 277   const Vector3& max = scrollMaxProperty.GetVector3();
 278
 279   Vector3 relativePosition;
 280   Vector3 domainSize = max - min;
 281
 282   relativePosition.x = fabsf(domainSize.x) > Math::MACHINE_EPSILON_1 ? ((min.x - position.x) / fabsf(domainSize.x)) : 0.0f;
 283   relativePosition.y = fabsf(domainSize.y) > Math::MACHINE_EPSILON_1 ? ((min.y - position.y) / fabsf(domainSize.y)) : 0.0f;
 284
 285   return relativePosition;
 286 }
 287
 288 } // unnamed namespace
 289
 290 namespace Dali
 291 {
 292
 293 namespace Toolkit
 294 {
 295
 296 namespace Internal
 297 {
 298
 299 namespace // unnamed namespace
 300 {
 301
 302 bool FindById( const ItemContainer& items, ItemId id )
 303 {
 304   for( ConstItemIter iter = items.begin(); items.end() != iter; ++iter )
 305   {
 306     if( iter->first == id )
 307     {
 308       return true;
 309     }
 310   }
 311
 312   return false;
 313 }
 314
 315 } // unnamed namespace
 316
 317 Dali::Toolkit::ItemView ItemView::New(ItemFactory& factory)
 318 {
 319   // Create the implementation
 320   ItemViewPtr itemView(new ItemView(factory));
 321
 322   // Pass ownership to CustomActor via derived handle
 323   Dali::Toolkit::ItemView handle(*itemView);
 324
 325   // Second-phase init of the implementation
 326   // This can only be done after the CustomActor connection has been made...
 327   itemView->Initialize();
 328
 329   return handle;
 330 }
 331
 332 ItemView::ItemView(ItemFactory& factory)
 333 : Scrollable(),
 334   mItemFactory(factory),
 335   mActiveLayout(NULL),
 336   mAnimatingOvershootOn(false),
 337   mAnimateOvershootOff(false),
 338   mAnchoringEnabled(true),
 339   mAnchoringDuration(DEFAULT_ANCHORING_DURATION),
 340   mRefreshIntervalLayoutPositions(0.0f),
 341   mRefreshOrderHint(true/*Refresh item 0 first*/),
 342   mMinimumSwipeSpeed(DEFAULT_MINIMUM_SWIPE_SPEED),
 343   mMinimumSwipeDistance(DEFAULT_MINIMUM_SWIPE_DISTANCE),
 344   mMouseWheelScrollDistanceStep(0.0f),
 345   mScrollDistance(0.0f),
 346   mScrollSpeed(0.0f),
 347   mTotalPanDisplacement(Vector2::ZERO),
 348   mScrollOvershoot(0.0f),
 349   mIsFlicking(false),
 350   mGestureState(Gesture::Clear),
 351   mAddingItems(false),
 352   mPropertyPosition(Property::INVALID_INDEX),
 353   mPropertyMinimumLayoutPosition(Property::INVALID_INDEX),
 354   mPropertyScrollSpeed(Property::INVALID_INDEX),
 355   mRefreshEnabled(true),
 356   mItemsParentOrigin( ParentOrigin::CENTER),
 357   mItemsAnchorPoint( AnchorPoint::CENTER)
 358 {
 359   SetRequiresMouseWheelEvents(true);
 360   SetKeyboardNavigationSupport(true);
 361 }
 362
 363 void ItemView::OnInitialize()
 364 {
 365   Actor self = Self();
 366
 367   // Disable size negotiation for item views
 368   self.SetRelayoutEnabled( false );
 369
 370   mScrollConnector = Dali::Toolkit::ScrollConnector::New();
 371   mScrollPositionObject = mScrollConnector.GetScrollPositionObject();
 372   mScrollConnector.ScrollPositionChangedSignal().Connect( this, &ItemView::OnScrollPositionChanged );
 373
 374   mPropertyMinimumLayoutPosition = self.RegisterProperty(MINIMUM_LAYOUT_POSITION_PROPERTY_NAME, 0.0f);
 375   mPropertyPosition = self.RegisterProperty(POSITION_PROPERTY_NAME, 0.0f);
 376   mPropertyScrollSpeed = self.RegisterProperty(SCROLL_SPEED_PROPERTY_NAME, 0.0f);
 377
 378   EnableScrollComponent(Toolkit::Scrollable::OvershootIndicator);
 379
 380   Constraint constraint = Constraint::New<Vector3>(Toolkit::Scrollable::Property::SCROLL_RELATIVE_POSITION,
 381                                                    LocalSource(mPropertyPosition),
 382                                                    LocalSource(Toolkit::Scrollable::Property::SCROLL_POSITION_MIN),
 383                                                    LocalSource(Toolkit::Scrollable::Property::SCROLL_POSITION_MAX),
 384                                                    LocalSource(Actor::Property::SIZE),
 385                                                    RelativePositionConstraint);
 386   self.ApplyConstraint(constraint);
 387
 388   Vector2 stageSize = Stage::GetCurrent().GetSize();
 389   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 390
 391   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 392
 393   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 394   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 395
 396   SetRefreshInterval(DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS);
 397 }
 398
 399 ItemView::~ItemView()
 400 {
 401 }
 402
 403 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 404 {
 405   return mScrollConnector;
 406 }
 407
 408 unsigned int ItemView::GetLayoutCount() const
 409 {
 410   return mLayouts.size();
 411 }
 412
 413 void ItemView::AddLayout(ItemLayout& layout)
 414 {
 415   mLayouts.push_back(ItemLayoutPtr(&layout));
 416 }
 417
 418 void ItemView::RemoveLayout(unsigned int layoutIndex)
 419 {
 420   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 421
 422   if (mActiveLayout == mLayouts[layoutIndex].Get())
 423   {
 424     mActiveLayout = NULL;
 425   }
 426
 427   mLayouts.erase(mLayouts.begin() + layoutIndex);
 428 }
 429
 430 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 431 {
 432   return mLayouts[layoutIndex];
 433 }
 434
 435 ItemLayoutPtr ItemView::GetActiveLayout() const
 436 {
 437   return ItemLayoutPtr(mActiveLayout);
 438 }
 439
 440 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 441 {
 442   return mScrollConnector.GetScrollPosition() + static_cast<float>( itemId );
 443 }
 444
 445 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 446 {
 447   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 448
 449   mRefreshEnabled = false;
 450
 451   Actor self = Self();
 452
 453   // The ItemView size should match the active layout size
 454   self.SetSize(targetSize);
 455   mActiveLayoutTargetSize = targetSize;
 456
 457   // Switch to the new layout
 458   mActiveLayout = mLayouts[layoutIndex].Get();
 459
 460   // Move the items to the new layout positions...
 461
 462   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 463   {
 464     unsigned int itemId = iter->first;
 465     Actor actor = iter->second;
 466
 467     // Remove constraints from previous layout
 468     actor.RemoveConstraints();
 469
 470     Vector3 size;
 471     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 472     {
 473       // resize immediately
 474       actor.SetResizePolicy( FIXED, ALL_DIMENSIONS );
 475       actor.SetPreferredSize( size.GetVectorXY() );
 476     }
 477
 478     mActiveLayout->ApplyConstraints(actor, itemId, durationSeconds, mScrollPositionObject, Self() );
 479   }
 480
 481   // Refresh the new layout
 482   ItemRange range = GetItemRange(*mActiveLayout, targetSize, GetCurrentLayoutPosition(0), false/* don't reserve extra*/);
 483   AddActorsWithinRange( range, durationSeconds );
 484
 485   // Scroll to an appropriate layout position
 486
 487   bool scrollAnimationNeeded(false);
 488   float firstItemScrollPosition(0.0f);
 489
 490   float current = GetCurrentLayoutPosition(0);
 491   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 492   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 493
 494   if (current < minimum)
 495   {
 496     scrollAnimationNeeded = true;
 497     firstItemScrollPosition = minimum;
 498   }
 499   else if (mAnchoringEnabled)
 500   {
 501     scrollAnimationNeeded = true;
 502     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 503   }
 504
 505   if (scrollAnimationNeeded)
 506   {
 507     RemoveAnimation(mScrollAnimation);
 508     mScrollAnimation = Animation::New(durationSeconds);
 509     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 510     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 511     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnLayoutActivationScrollFinished);
 512     mScrollAnimation.Play();
 513   }
 514
 515   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 516   AnimateScrollOvershoot(0.0f);
 517   mScrollOvershoot = 0.0f;
 518
 519   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 520   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 521   self.SetProperty(Toolkit::Scrollable::Property::SCROLL_DIRECTION, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 522
 523   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 524
 525   CalculateDomainSize(targetSize);
 526 }
 527
 528 void ItemView::DeactivateCurrentLayout()
 529 {
 530   if (mActiveLayout)
 531   {
 532     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 533     {
 534       Actor actor = iter->second;
 535       actor.RemoveConstraints();
 536     }
 537
 538     mActiveLayout = NULL;
 539   }
 540 }
 541
 542 void ItemView::OnRefreshNotification(PropertyNotification& source)
 543 {
 544   if(mRefreshEnabled || mScrollAnimation)
 545   {
 546     // Only refresh the cache during normal scrolling
 547     DoRefresh(GetCurrentLayoutPosition(0), true);
 548   }
 549 }
 550
 551 void ItemView::Refresh()
 552 {
 553   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 554   {
 555     ReleaseActor( iter->first, iter->second );
 556   }
 557   mItemPool.clear();
 558
 559   DoRefresh(GetCurrentLayoutPosition(0), true);
 560 }
 561
 562 void ItemView::DoRefresh(float currentLayoutPosition, bool cacheExtra)
 563 {
 564   if (mActiveLayout)
 565   {
 566     ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, currentLayoutPosition, cacheExtra/*reserve extra*/);
 567     RemoveActorsOutsideRange( range );
 568     AddActorsWithinRange( range, 0.0f/*immediate*/ );
 569
 570     mScrollUpdatedSignal.Emit( Vector3(0.0f, currentLayoutPosition, 0.0f) );
 571   }
 572 }
 573
 574 void ItemView::SetMinimumSwipeSpeed(float speed)
 575 {
 576   mMinimumSwipeSpeed = speed;
 577 }
 578
 579 float ItemView::GetMinimumSwipeSpeed() const
 580 {
 581   return mMinimumSwipeSpeed;
 582 }
 583
 584 void ItemView::SetMinimumSwipeDistance(float distance)
 585 {
 586   mMinimumSwipeDistance = distance;
 587 }
 588
 589 float ItemView::GetMinimumSwipeDistance() const
 590 {
 591   return mMinimumSwipeDistance;
 592 }
 593
 594 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 595 {
 596   mMouseWheelScrollDistanceStep = step;
 597 }
 598
 599 float ItemView::GetMouseWheelScrollDistanceStep() const
 600 {
 601   return mMouseWheelScrollDistanceStep;
 602 }
 603
 604 void ItemView::SetAnchoring(bool enabled)
 605 {
 606   mAnchoringEnabled = enabled;
 607 }
 608
 609 bool ItemView::GetAnchoring() const
 610 {
 611   return mAnchoringEnabled;
 612 }
 613
 614 void ItemView::SetAnchoringDuration(float durationSeconds)
 615 {
 616   mAnchoringDuration = durationSeconds;
 617 }
 618
 619 float ItemView::GetAnchoringDuration() const
 620 {
 621   return mAnchoringDuration;
 622 }
 623
 624 void ItemView::SetRefreshInterval(float intervalLayoutPositions)
 625 {
 626   if( !Equals(mRefreshIntervalLayoutPositions, intervalLayoutPositions) )
 627   {
 628     mRefreshIntervalLayoutPositions = intervalLayoutPositions;
 629
 630     if(mRefreshNotification)
 631     {
 632       mScrollPositionObject.RemovePropertyNotification(mRefreshNotification);
 633     }
 634     mRefreshNotification = mScrollPositionObject.AddPropertyNotification( ScrollConnector::SCROLL_POSITION, StepCondition(mRefreshIntervalLayoutPositions, 0.0f) );
 635     mRefreshNotification.NotifySignal().Connect( this, &ItemView::OnRefreshNotification );
 636   }
 637 }
 638
 639 float ItemView::GetRefreshInterval() const
 640 {
 641   return mRefreshIntervalLayoutPositions;
 642 }
 643
 644 void ItemView::SetRefreshEnabled(bool enabled)
 645 {
 646   mRefreshEnabled = enabled;
 647 }
 648
 649 Actor ItemView::GetItem(unsigned int itemId) const
 650 {
 651   Actor actor;
 652
 653   ConstItemPoolIter iter = mItemPool.find( itemId );
 654   if( iter != mItemPool.end() )
 655   {
 656     actor = iter->second;
 657   }
 658
 659   return actor;
 660 }
 661
 662 unsigned int ItemView::GetItemId( Actor actor ) const
 663 {
 664   unsigned int itemId( 0 );
 665
 666   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 667   {
 668     if( iter->second == actor )
 669     {
 670       itemId = iter->first;
 671       break;
 672     }
 673   }
 674
 675   return itemId;
 676 }
 677
 678 void ItemView::InsertItem( Item newItem, float durationSeconds )
 679 {
 680   mAddingItems = true;
 681
 682   Actor displacedActor;
 683   ItemPoolIter afterDisplacedIter = mItemPool.end();
 684
 685   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 686   if( mItemPool.end() != foundIter )
 687   {
 688     SetupActor( newItem, durationSeconds );
 689     Self().Add( newItem.second );
 690
 691     displacedActor = foundIter->second;
 692     foundIter->second = newItem.second;
 693
 694     afterDisplacedIter = ++foundIter;
 695   }
 696   else
 697   {
 698     // Inserting before the existing item range?
 699     ItemPoolIter iter = mItemPool.begin();
 700     if( iter != mItemPool.end() &&
 701         iter->first > newItem.first )
 702     {
 703       displacedActor = iter->second;
 704       mItemPool.erase( iter++ ); // iter is still valid after the erase
 705
 706       afterDisplacedIter = iter;
 707     }
 708   }
 709
 710   if( displacedActor )
 711   {
 712     // Move the existing actors to make room
 713     for( ItemPoolIter iter = afterDisplacedIter; mItemPool.end() != iter; ++iter )
 714     {
 715       Actor temp = iter->second;
 716       iter->second = displacedActor;
 717       displacedActor = temp;
 718
 719       iter->second.RemoveConstraints();
 720       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 721     }
 722
 723     // Create last item
 724     ItemPool::reverse_iterator lastIter = mItemPool.rbegin();
 725     if ( lastIter != mItemPool.rend() )
 726     {
 727       ItemId lastId = lastIter->first;
 728       Item lastItem( lastId + 1, displacedActor );
 729       mItemPool.insert( lastItem );
 730
 731       lastItem.second.RemoveConstraints();
 732       mActiveLayout->ApplyConstraints( lastItem.second, lastItem.first, durationSeconds, mScrollPositionObject, Self() );
 733     }
 734   }
 735
 736   CalculateDomainSize(Self().GetCurrentSize());
 737
 738   mAddingItems = false;
 739 }
 740
 741 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 742 {
 743   mAddingItems = true;
 744
 745   // Insert from lowest id to highest
 746   std::set<Item> sortedItems;
 747   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 748   {
 749     sortedItems.insert( *iter );
 750   }
 751
 752   for( std::set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 753   {
 754     Self().Add( iter->second );
 755
 756     ItemPoolIter foundIter = mItemPool.find( iter->first );
 757     if( mItemPool.end() != foundIter )
 758     {
 759       Actor moveMe = foundIter->second;
 760       foundIter->second = iter->second;
 761
 762       // Move the existing actors to make room
 763       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 764       {
 765         Actor temp = iter->second;
 766         iter->second = moveMe;
 767         moveMe = temp;
 768       }
 769
 770       // Create last item
 771       ItemId lastId = mItemPool.rbegin()->first;
 772       Item lastItem( lastId + 1, moveMe );
 773       mItemPool.insert( lastItem );
 774     }
 775     else
 776     {
 777       mItemPool.insert( *iter );
 778     }
 779   }
 780
 781   // Relayout everything
 782   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 783   {
 784     // If newly inserted
 785     if( FindById( newItems, iter->first ) )
 786     {
 787       SetupActor( *iter, durationSeconds );
 788     }
 789     else
 790     {
 791       iter->second.RemoveConstraints();
 792       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 793     }
 794   }
 795
 796   CalculateDomainSize(Self().GetCurrentSize());
 797
 798   mAddingItems = false;
 799 }
 800
 801 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 802 {
 803   bool actorsReordered = RemoveActor( itemId );
 804   if( actorsReordered )
 805   {
 806     ReapplyAllConstraints( durationSeconds );
 807
 808     OnItemsRemoved();
 809   }
 810 }
 811
 812 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 813 {
 814   bool actorsReordered( false );
 815
 816   // Remove from highest id to lowest
 817   set<ItemId> sortedItems;
 818   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 819   {
 820     sortedItems.insert( *iter );
 821   }
 822
 823   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 824   {
 825     if( RemoveActor( *iter ) )
 826     {
 827       actorsReordered = true;
 828     }
 829   }
 830
 831   if( actorsReordered )
 832   {
 833     ReapplyAllConstraints( durationSeconds );
 834
 835     OnItemsRemoved();
 836   }
 837 }
 838
 839 bool ItemView::RemoveActor(unsigned int itemId)
 840 {
 841   bool reordered( false );
 842
 843   ItemPoolIter removeIter = mItemPool.find( itemId );
 844   if( removeIter != mItemPool.end() )
 845   {
 846     ReleaseActor(itemId, removeIter->second);
 847   }
 848   else
 849   {
 850     // Removing before the existing item range?
 851     ItemPoolIter iter = mItemPool.begin();
 852     if( iter != mItemPool.end() &&
 853         iter->first > itemId )
 854     {
 855       // In order to decrement the first visible item ID
 856       mItemPool.insert( Item(iter->first - 1, Actor()) );
 857
 858       removeIter = mItemPool.begin();
 859     }
 860   }
 861
 862   if( removeIter != mItemPool.end() )
 863   {
 864     reordered = true;
 865
 866     // Adjust the remaining item IDs, for example if item 2 is removed:
 867     //   Initial actors:     After insert:
 868     //     ID 1 - ActorA       ID 1 - ActorA
 869     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 870     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 871     //     ID 4 - ActorD
 872     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 873     {
 874       if( iter->first < mItemPool.rbegin()->first )
 875       {
 876         iter->second = mItemPool[ iter->first + 1 ];
 877       }
 878       else
 879       {
 880         mItemPool.erase( iter );
 881         break;
 882       }
 883     }
 884   }
 885
 886   return reordered;
 887 }
 888
 889 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 890 {
 891   mAddingItems = true;
 892
 893   SetupActor( replacementItem, durationSeconds );
 894   Self().Add( replacementItem.second );
 895
 896   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 897   if( mItemPool.end() != iter )
 898   {
 899     ReleaseActor(iter->first, iter->second);
 900     iter->second = replacementItem.second;
 901   }
 902   else
 903   {
 904     mItemPool.insert( replacementItem );
 905   }
 906
 907   CalculateDomainSize(Self().GetCurrentSize());
 908
 909   mAddingItems = false;
 910 }
 911
 912 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 913 {
 914   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 915   {
 916     ReplaceItem( *iter, durationSeconds );
 917   }
 918 }
 919
 920 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 921 {
 922   // Remove unwanted actors from the ItemView & ItemPool
 923   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 924   {
 925     unsigned int current = iter->first;
 926
 927     if( ! range.Within( current ) )
 928     {
 929       ReleaseActor(iter->first, iter->second);
 930
 931       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 932     }
 933     else
 934     {
 935       ++iter;
 936     }
 937   }
 938 }
 939
 940 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 941 {
 942   range.end = std::min(mItemFactory.GetNumberOfItems(), range.end);
 943
 944   // The order of addition depends on the scroll direction.
 945   if (mRefreshOrderHint)
 946   {
 947     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 948     {
 949       AddNewActor( itemId, durationSeconds );
 950     }
 951   }
 952   else
 953   {
 954     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 955     {
 956       AddNewActor( itemId-1, durationSeconds );
 957     }
 958   }
 959
 960   // Total number of items may change dynamically.
 961   // Always recalculate the domain size to reflect that.
 962   CalculateDomainSize(Self().GetCurrentSize());
 963 }
 964
 965 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
 966 {
 967   mAddingItems = true;
 968
 969   if( mItemPool.end() == mItemPool.find( itemId ) )
 970   {
 971     Actor actor = mItemFactory.NewItem( itemId );
 972
 973     if( actor )
 974     {
 975       Item newItem( itemId, actor );
 976
 977       mItemPool.insert( newItem );
 978
 979       SetupActor( newItem, durationSeconds );
 980       Self().Add( actor );
 981     }
 982   }
 983
 984   mAddingItems = false;
 985 }
 986
 987 void ItemView::SetupActor( Item item, float durationSeconds )
 988 {
 989   item.second.SetParentOrigin( mItemsParentOrigin );
 990   item.second.SetAnchorPoint( mItemsAnchorPoint );
 991
 992   if( mActiveLayout )
 993   {
 994     Vector3 size;
 995     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
 996     {
 997       item.second.SetResizePolicy( FIXED, ALL_DIMENSIONS );
 998       item.second.SetPreferredSize( size.GetVectorXY() );
 999     }
1000
1001     mActiveLayout->ApplyConstraints( item.second, item.first, durationSeconds, mScrollPositionObject, Self() );
1002   }
1003 }
1004
1005 void ItemView::ReleaseActor( ItemId item, Actor actor )
1006 {
1007   Self().Remove( actor );
1008   mItemFactory.ItemReleased(item, actor);
1009 }
1010
1011 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, float layoutPosition, bool reserveExtra)
1012 {
1013   unsigned int itemCount = mItemFactory.GetNumberOfItems();
1014
1015   ItemRange available(0u, itemCount);
1016
1017   ItemRange range = layout.GetItemsWithinArea( layoutPosition, layoutSize );
1018
1019   if (reserveExtra)
1020   {
1021     // Add the reserve items for scrolling
1022     unsigned int extra = layout.GetReserveItemCount(layoutSize);
1023     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
1024     range.end += extra;
1025   }
1026
1027   return range.Intersection(available);
1028 }
1029
1030 void ItemView::OnChildAdd(Actor& child)
1031 {
1032   if(!mAddingItems)
1033   {
1034     // We don't want to do this downcast check for any item added by ItemView itself.
1035     Dali::Toolkit::ScrollComponent scrollComponent = Dali::Toolkit::ScrollComponent::DownCast(child);
1036     if(scrollComponent)
1037     {
1038       // Set the scroll connector when scroll bar is being added
1039       scrollComponent.SetScrollConnector(mScrollConnector);
1040     }
1041   }
1042 }
1043
1044 bool ItemView::OnTouchEvent(const TouchEvent& event)
1045 {
1046   // Ignore events with multiple-touch points
1047   if (event.GetPointCount() != 1)
1048   {
1049     return false;
1050   }
1051
1052   if (event.GetPoint(0).state == TouchPoint::Down)
1053   {
1054     // Cancel ongoing scrolling etc.
1055     mGestureState = Gesture::Clear;
1056
1057     mScrollDistance = 0.0f;
1058     mScrollSpeed = 0.0f;
1059     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
1060
1061     mScrollOvershoot = 0.0f;
1062     AnimateScrollOvershoot(0.0f);
1063
1064     if(mScrollAnimation)
1065     {
1066       mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1067     }
1068
1069     RemoveAnimation(mScrollAnimation);
1070   }
1071
1072   return true; // consume since we're potentially scrolling
1073 }
1074
1075 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
1076 {
1077   // Respond the mouse wheel event to scroll
1078   if (mActiveLayout)
1079   {
1080     Actor self = Self();
1081     const Vector3 layoutSize = Self().GetCurrentSize();
1082     float layoutPositionDelta = GetCurrentLayoutPosition(0) - (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
1083     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1084
1085     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1086     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1087     mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1088     mRefreshEnabled = true;
1089   }
1090
1091   if (mMouseWheelEventFinishedTimer.IsRunning())
1092   {
1093     mMouseWheelEventFinishedTimer.Stop();
1094   }
1095
1096   mMouseWheelEventFinishedTimer.Start();
1097
1098   return true;
1099 }
1100
1101 bool ItemView::OnMouseWheelEventFinished()
1102 {
1103   if (mActiveLayout)
1104   {
1105     RemoveAnimation(mScrollAnimation);
1106
1107     // No more mouse wheel events coming. Do the anchoring if enabled.
1108     mScrollAnimation = DoAnchoring();
1109     if (mScrollAnimation)
1110     {
1111       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1112       mScrollAnimation.Play();
1113     }
1114     else
1115     {
1116       mScrollOvershoot = 0.0f;
1117       AnimateScrollOvershoot(0.0f);
1118
1119       mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1120     }
1121   }
1122
1123   return false;
1124 }
1125
1126 void ItemView::ReapplyAllConstraints( float durationSeconds )
1127 {
1128   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1129   {
1130     unsigned int id = iter->first;
1131     Actor actor = iter->second;
1132
1133     actor.RemoveConstraints();
1134     mActiveLayout->ApplyConstraints(actor, id, durationSeconds, mScrollPositionObject, Self());
1135   }
1136 }
1137
1138 void ItemView::OnItemsRemoved()
1139 {
1140   CalculateDomainSize(Self().GetCurrentSize());
1141
1142   // Adjust scroll-position after an item is removed
1143   if( mActiveLayout )
1144   {
1145     float firstItemScrollPosition = ClampFirstItemPosition(GetCurrentLayoutPosition(0), Self().GetCurrentSize(), *mActiveLayout);
1146
1147     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1148   }
1149 }
1150
1151 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1152 {
1153   Actor self = Self();
1154   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1155   float clamppedPosition = std::min(0.0f, std::max(minLayoutPosition, targetPosition));
1156   mScrollOvershoot = targetPosition - clamppedPosition;
1157   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1158
1159   return clamppedPosition;
1160 }
1161
1162 void ItemView::OnPan( const PanGesture& gesture )
1163 {
1164   Actor self = Self();
1165   const Vector3 layoutSize = Self().GetCurrentSize();
1166
1167   RemoveAnimation(mScrollAnimation);
1168
1169   // Short-circuit if there is no active layout
1170   if (!mActiveLayout)
1171   {
1172     mGestureState = Gesture::Clear;
1173     return;
1174   }
1175
1176   mGestureState = gesture.state;
1177
1178   switch (mGestureState)
1179   {
1180     case Gesture::Finished:
1181     {
1182       // Swipe Detection
1183       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1184           mScrollSpeed > mMinimumSwipeSpeed)
1185       {
1186         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1187
1188         mRefreshOrderHint = true;
1189
1190         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1191         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1192                                                                layoutSize,
1193                                                                *mActiveLayout);
1194
1195         if (mAnchoringEnabled)
1196         {
1197           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1198         }
1199
1200         RemoveAnimation(mScrollAnimation);
1201
1202         float flickAnimationDuration = Clamp( mActiveLayout->GetItemFlickAnimationDuration() * std::max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)))
1203                                        , DEFAULT_MINIMUM_SWIPE_DURATION, DEFAULT_MAXIMUM_SWIPE_DURATION);
1204
1205         mScrollAnimation = Animation::New(flickAnimationDuration);
1206         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1207         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1208         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1209
1210         mIsFlicking = true;
1211         // Check whether it has already scrolled to the end
1212         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1213         {
1214           AnimateScrollOvershoot(0.0f);
1215         }
1216       }
1217
1218       // Anchoring may be triggered when there was no swipe
1219       if (!mScrollAnimation)
1220       {
1221         mScrollAnimation = DoAnchoring();
1222       }
1223
1224       // Reset the overshoot if no scroll animation.
1225       if (!mScrollAnimation)
1226       {
1227         mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1228
1229         AnimateScrollOvershoot(0.0f, false);
1230       }
1231     }
1232     break;
1233
1234     case Gesture::Started: // Fall through
1235     {
1236       mTotalPanDisplacement = Vector2::ZERO;
1237       mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1238       mRefreshEnabled = true;
1239     }
1240
1241     case Gesture::Continuing:
1242     {
1243       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1244       mScrollSpeed = Clamp((gesture.GetSpeed() * gesture.GetSpeed() * mActiveLayout->GetFlickSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1245
1246       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1247       mRefreshOrderHint = mScrollDistance < 0.0f;
1248
1249       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1250
1251       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1252
1253       float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1254
1255       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1256       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1257
1258       if( (firstItemScrollPosition >= 0.0f && currentOvershoot < 1.0f) || (firstItemScrollPosition <= mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize) && currentOvershoot > -1.0f) )
1259       {
1260         mTotalPanDisplacement += gesture.displacement;
1261       }
1262
1263       mScrollOvershoot = CalculateScrollOvershoot();
1264       mScrollPositionObject.SetProperty( ScrollConnector::OVERSHOOT, mScrollOvershoot );
1265     }
1266     break;
1267
1268     case Gesture::Cancelled:
1269     {
1270       mScrollAnimation = DoAnchoring();
1271     }
1272     break;
1273
1274     default:
1275       break;
1276   }
1277
1278   if (mScrollAnimation)
1279   {
1280     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1281     mScrollAnimation.Play();
1282   }
1283 }
1284
1285 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1286 {
1287   OnPan(gesture);
1288   return true;
1289 }
1290
1291 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1292 {
1293   Actor nextFocusActor;
1294   if(mActiveLayout)
1295   {
1296     int nextItemID = 0;
1297     if(!actor || actor == this->Self())
1298     {
1299       nextFocusActor = GetItem(nextItemID);
1300     }
1301     else if(actor && actor.GetParent() == this->Self())
1302     {
1303       int itemID = GetItemId(actor);
1304       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1305       nextFocusActor = GetItem(nextItemID);
1306       if(nextFocusActor == actor)
1307       {
1308         // need to pass NULL actor back to focus manager
1309         nextFocusActor.Reset();
1310         return nextFocusActor;
1311       }
1312     }
1313     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1314     Vector3 layoutSize = Self().GetCurrentSize();
1315     if(!nextFocusActor)
1316     {
1317       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1318       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1319       nextItemID = viewableItems.begin;
1320       nextFocusActor = GetItem(nextItemID);
1321     }
1322   }
1323   return nextFocusActor;
1324 }
1325
1326 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1327 {
1328   // only in this function if our chosen focus actor was actually used
1329   if(commitedFocusableActor)
1330   {
1331     int nextItemID = GetItemId(commitedFocusableActor);
1332     float layoutPosition = GetCurrentLayoutPosition(0);
1333     Vector3 layoutSize = Self().GetCurrentSize();
1334
1335     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1336     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1337   }
1338 }
1339
1340 Animation ItemView::DoAnchoring()
1341 {
1342   Animation anchoringAnimation;
1343   Actor self = Self();
1344
1345   if (mActiveLayout && mAnchoringEnabled)
1346   {
1347     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1348
1349     anchoringAnimation = Animation::New(mAnchoringDuration);
1350     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1351     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1352     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1353     if(!mIsFlicking)
1354     {
1355       AnimateScrollOvershoot(0.0f);
1356     }
1357   }
1358
1359   return anchoringAnimation;
1360 }
1361
1362 void ItemView::OnScrollFinished(Animation& source)
1363 {
1364   Actor self = Self();
1365
1366   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1367
1368   mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1369
1370   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1371   {
1372     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1373   }
1374   else
1375   {
1376     // Reset the overshoot
1377     AnimateScrollOvershoot( 0.0f );
1378   }
1379   mIsFlicking = false;
1380
1381   mScrollOvershoot = 0.0f;
1382 }
1383
1384 void ItemView::OnLayoutActivationScrollFinished(Animation& source)
1385 {
1386   RemoveAnimation(mScrollAnimation);
1387   mRefreshEnabled = true;
1388   DoRefresh(GetCurrentLayoutPosition(0), true);
1389 }
1390
1391 void ItemView::OnOvershootOnFinished(Animation& animation)
1392 {
1393   mAnimatingOvershootOn = false;
1394   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1395   RemoveAnimation(mScrollOvershootAnimation);
1396   if(mAnimateOvershootOff)
1397   {
1398     AnimateScrollOvershoot(0.0f);
1399   }
1400 }
1401
1402 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1403 {
1404   Actor self = Self();
1405   const Vector3 layoutSize = Self().GetCurrentSize();
1406   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1407
1408   if(durationSeconds > 0.0f)
1409   {
1410     RemoveAnimation(mScrollAnimation);
1411     mScrollAnimation = Animation::New(durationSeconds);
1412     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1413     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1414     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1415     mScrollAnimation.Play();
1416   }
1417   else
1418   {
1419     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1420     AnimateScrollOvershoot(0.0f);
1421   }
1422
1423   mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1424   mRefreshEnabled = true;
1425 }
1426
1427 void ItemView::RemoveAnimation(Animation& animation)
1428 {
1429   if(animation)
1430   {
1431     // Cease animating, and reset handle.
1432     animation.Clear();
1433     animation.Reset();
1434   }
1435 }
1436
1437 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1438 {
1439   Actor self = Self();
1440
1441   Vector3 firstItemPosition(Vector3::ZERO);
1442   Vector3 lastItemPosition(Vector3::ZERO);
1443
1444   if(mActiveLayout)
1445   {
1446     firstItemPosition = mActiveLayout->GetItemPosition( 0,0,layoutSize );
1447
1448     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1449     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1450     lastItemPosition = mActiveLayout->GetItemPosition( fabs(minLayoutPosition),fabs(minLayoutPosition),layoutSize );
1451
1452     float domainSize;
1453
1454     if(IsHorizontal(mActiveLayout->GetOrientation()))
1455     {
1456       self.SetProperty(Toolkit::Scrollable::Property::SCROLL_POSITION_MIN, Vector3(0.0f, firstItemPosition.x, 0.0f));
1457       self.SetProperty(Toolkit::Scrollable::Property::SCROLL_POSITION_MAX, Vector3(0.0f, lastItemPosition.x, 0.0f));
1458       domainSize = fabs(firstItemPosition.x - lastItemPosition.x);
1459     }
1460     else
1461     {
1462       self.SetProperty(Toolkit::Scrollable::Property::SCROLL_POSITION_MIN, Vector3(0.0f, firstItemPosition.y, 0.0f));
1463       self.SetProperty(Toolkit::Scrollable::Property::SCROLL_POSITION_MAX, Vector3(0.0f, lastItemPosition.y, 0.0f));
1464       domainSize = fabs(firstItemPosition.y - lastItemPosition.y);
1465     }
1466
1467     mScrollConnector.SetScrollDomain(minLayoutPosition, 0.0f, domainSize);
1468
1469     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1470     self.SetProperty(Toolkit::Scrollable::Property::CAN_SCROLL_VERTICAL, isLayoutScrollable);
1471     self.SetProperty(Toolkit::Scrollable::Property::CAN_SCROLL_HORIZONTAL, false);
1472   }
1473 }
1474
1475 Vector3 ItemView::GetDomainSize() const
1476 {
1477   Actor self = Self();
1478
1479   float minScrollPosition = self.GetProperty<float>(Toolkit::Scrollable::Property::SCROLL_POSITION_MIN);
1480   float maxScrollPosition = self.GetProperty<float>(Toolkit::Scrollable::Property::SCROLL_POSITION_MAX);
1481
1482   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1483 }
1484
1485 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1486 {
1487   Actor self = Self();
1488
1489   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1490   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1491   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1492
1493   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1494 }
1495
1496 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1497 {
1498   Vector3 firstItemPosition( mActiveLayout->GetItemPosition(0, layoutPosition, layoutSize ) );
1499   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1500 }
1501
1502 Vector3 ItemView::GetCurrentScrollPosition() const
1503 {
1504   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1505   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1506 }
1507
1508 void ItemView::AddOverlay(Actor actor)
1509 {
1510   Self().Add(actor);
1511 }
1512
1513 void ItemView::RemoveOverlay(Actor actor)
1514 {
1515   Self().Remove(actor);
1516 }
1517
1518 void ItemView::ScrollTo(const Vector3& position, float duration)
1519 {
1520   Actor self = Self();
1521   const Vector3 layoutSize = Self().GetCurrentSize();
1522
1523   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1524
1525   if(duration > 0.0f)
1526   {
1527     RemoveAnimation(mScrollAnimation);
1528     mScrollAnimation = Animation::New(duration);
1529     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1530     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1531     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1532     mScrollAnimation.Play();
1533   }
1534   else
1535   {
1536     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1537     AnimateScrollOvershoot(0.0f);
1538   }
1539
1540   mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1541   mRefreshEnabled = true;
1542 }
1543
1544 void ItemView::SetOvershootEffectColor( const Vector4& color )
1545 {
1546   mOvershootEffectColor = color;
1547   if( mOvershootOverlay )
1548   {
1549     mOvershootOverlay.SetColor( color );
1550   }
1551 }
1552
1553 void ItemView::SetOvershootEnabled( bool enable )
1554 {
1555   Actor self = Self();
1556   if( enable )
1557   {
1558     Property::Index effectOvershootPropertyIndex = Property::INVALID_INDEX;
1559     mOvershootOverlay = CreateBouncingEffectActor( effectOvershootPropertyIndex );
1560     mOvershootOverlay.SetColor(mOvershootEffectColor);
1561     mOvershootOverlay.SetParentOrigin(ParentOrigin::TOP_LEFT);
1562     mOvershootOverlay.SetAnchorPoint(AnchorPoint::TOP_LEFT);
1563     mOvershootOverlay.SetDrawMode(DrawMode::OVERLAY);
1564     self.Add(mOvershootOverlay);
1565
1566     Constraint constraint = Constraint::New<Vector3>( Actor::Property::SIZE,
1567                                                       ParentSource( Toolkit::Scrollable::Property::SCROLL_DIRECTION ),
1568                                                       Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1569                                                       ParentSource( Actor::Property::SIZE ),
1570                                                       OvershootOverlaySizeConstraint() );
1571     mOvershootOverlay.ApplyConstraint(constraint);
1572     mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.width, OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height);
1573
1574     constraint = Constraint::New<Quaternion>( Actor::Property::ORIENTATION,
1575                                               ParentSource( Toolkit::Scrollable::Property::SCROLL_DIRECTION ),
1576                                               Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1577                                               OvershootOverlayRotationConstraint() );
1578     mOvershootOverlay.ApplyConstraint(constraint);
1579
1580     constraint = Constraint::New<Vector3>( Actor::Property::POSITION,
1581                                            ParentSource( Actor::Property::SIZE ),
1582                                            ParentSource( Toolkit::Scrollable::Property::SCROLL_DIRECTION ),
1583                                            Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1584                                            OvershootOverlayPositionConstraint() );
1585     mOvershootOverlay.ApplyConstraint(constraint);
1586
1587     constraint = Constraint::New<bool>( Actor::Property::VISIBLE,
1588                                         ParentSource( Toolkit::Scrollable::Property::CAN_SCROLL_VERTICAL ),
1589                                         OvershootOverlayVisibilityConstraint() );
1590     mOvershootOverlay.ApplyConstraint(constraint);
1591
1592     constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1593                                          Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1594                                          EqualToConstraint() );
1595     mOvershootOverlay.ApplyConstraint(constraint);
1596   }
1597   else
1598   {
1599     if( mOvershootOverlay )
1600     {
1601       self.Remove(mOvershootOverlay);
1602       mOvershootOverlay.Reset();
1603     }
1604   }
1605 }
1606
1607 float ItemView::CalculateScrollOvershoot()
1608 {
1609   float overshoot = 0.0f;
1610
1611   if(mActiveLayout)
1612   {
1613     // The overshoot must be calculated from the accumulated pan gesture displacement
1614     // since the pan gesture starts.
1615     Actor self = Self();
1616     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1617     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1618     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1619     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1620     float clamppedPosition = std::min(0.0f, std::max(minLayoutPosition, positionDelta));
1621     overshoot = positionDelta - clamppedPosition;
1622   }
1623
1624   return overshoot > 0.0f ? std::min(overshoot, 1.0f) : std::max(overshoot, -1.0f);
1625 }
1626
1627 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1628 {
1629   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1630
1631   // make sure we animate back if needed
1632   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1633
1634   if( mAnimatingOvershootOn )
1635   {
1636     // animating on, do not allow animate off
1637     return;
1638   }
1639
1640   if(mOvershootAnimationSpeed > Math::MACHINE_EPSILON_0)
1641   {
1642     float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1643     float duration = mOvershootOverlay.GetCurrentSize().height * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot)) / mOvershootAnimationSpeed;
1644
1645     RemoveAnimation(mScrollOvershootAnimation);
1646     mScrollOvershootAnimation = Animation::New(duration);
1647     mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1648     mScrollOvershootAnimation.AnimateTo( Property(mScrollPositionObject, ScrollConnector::OVERSHOOT), overshootAmount, TimePeriod(0.0f, duration) );
1649     mScrollOvershootAnimation.Play();
1650
1651     mAnimatingOvershootOn = animatingOn;
1652   }
1653   else
1654   {
1655     mScrollPositionObject.SetProperty( ScrollConnector::OVERSHOOT, overshootAmount );
1656   }
1657 }
1658
1659 void ItemView::SetItemsParentOrigin( const Vector3& parentOrigin )
1660 {
1661   if( parentOrigin != mItemsParentOrigin )
1662   {
1663     mItemsParentOrigin = parentOrigin;
1664     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1665     {
1666       iter->second.SetParentOrigin(parentOrigin);
1667     }
1668   }
1669 }
1670
1671 Vector3 ItemView::GetItemsParentOrigin() const
1672 {
1673   return mItemsParentOrigin;
1674 }
1675
1676 void ItemView::SetItemsAnchorPoint( const Vector3& anchorPoint )
1677 {
1678   if( anchorPoint != mItemsAnchorPoint )
1679   {
1680     mItemsAnchorPoint = anchorPoint;
1681     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1682     {
1683       iter->second.SetAnchorPoint(anchorPoint);
1684     }
1685   }
1686 }
1687
1688 Vector3 ItemView::GetItemsAnchorPoint() const
1689 {
1690   return mItemsAnchorPoint;
1691 }
1692
1693 void ItemView::GetItemsRange(ItemRange& range)
1694 {
1695   if( !mItemPool.empty() )
1696   {
1697     range.begin = mItemPool.begin()->first;
1698     range.end = mItemPool.rbegin()->first + 1;
1699   }
1700   else
1701   {
1702     range.begin = 0;
1703     range.end = 0;
1704   }
1705 }
1706
1707 void ItemView::OnScrollPositionChanged( float position )
1708 {
1709   // Cancel scroll animation to prevent any fighting of setting the scroll position property.
1710   RemoveAnimation(mScrollAnimation);
1711
1712   // Refresh the cache immediately when the scroll position is changed.
1713   DoRefresh(position, false); // No need to cache extra items.
1714 }
1715
1716 } // namespace Internal
1717
1718 } // namespace Toolkit
1719
1720 } // namespace Dali