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   RegisterCommonProperties();
 366
 367   Actor self = Self();
 368
 369   // Disable size negotiation for item views
 370   self.SetRelayoutEnabled( false );
 371
 372   mScrollConnector = Dali::Toolkit::ScrollConnector::New();
 373   mScrollPositionObject = mScrollConnector.GetScrollPositionObject();
 374   mScrollConnector.ScrollPositionChangedSignal().Connect( this, &ItemView::OnScrollPositionChanged );
 375
 376   mPropertyMinimumLayoutPosition = self.RegisterProperty(MINIMUM_LAYOUT_POSITION_PROPERTY_NAME, 0.0f);
 377   mPropertyPosition = self.RegisterProperty(POSITION_PROPERTY_NAME, 0.0f);
 378   mPropertyScrollSpeed = self.RegisterProperty(SCROLL_SPEED_PROPERTY_NAME, 0.0f);
 379
 380   EnableScrollComponent(Toolkit::Scrollable::OvershootIndicator);
 381
 382   Constraint constraint = Constraint::New<Vector3>(mPropertyRelativePosition,
 383                                                    LocalSource(mPropertyPosition),
 384                                                    LocalSource(mPropertyPositionMin),
 385                                                    LocalSource(mPropertyPositionMax),
 386                                                    LocalSource(Actor::Property::SIZE),
 387                                                    RelativePositionConstraint);
 388   self.ApplyConstraint(constraint);
 389
 390   Vector2 stageSize = Stage::GetCurrent().GetSize();
 391   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 392
 393   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 394
 395   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 396   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 397
 398   SetRefreshInterval(DEFAULT_REFRESH_INTERVAL_LAYOUT_POSITIONS);
 399 }
 400
 401 ItemView::~ItemView()
 402 {
 403 }
 404
 405 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 406 {
 407   return mScrollConnector;
 408 }
 409
 410 unsigned int ItemView::GetLayoutCount() const
 411 {
 412   return mLayouts.size();
 413 }
 414
 415 void ItemView::AddLayout(ItemLayout& layout)
 416 {
 417   mLayouts.push_back(ItemLayoutPtr(&layout));
 418 }
 419
 420 void ItemView::RemoveLayout(unsigned int layoutIndex)
 421 {
 422   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 423
 424   if (mActiveLayout == mLayouts[layoutIndex].Get())
 425   {
 426     mActiveLayout = NULL;
 427   }
 428
 429   mLayouts.erase(mLayouts.begin() + layoutIndex);
 430 }
 431
 432 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 433 {
 434   return mLayouts[layoutIndex];
 435 }
 436
 437 ItemLayoutPtr ItemView::GetActiveLayout() const
 438 {
 439   return ItemLayoutPtr(mActiveLayout);
 440 }
 441
 442 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 443 {
 444   return mScrollConnector.GetScrollPosition() + static_cast<float>( itemId );
 445 }
 446
 447 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 448 {
 449   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 450
 451   mRefreshEnabled = false;
 452
 453   Actor self = Self();
 454
 455   // The ItemView size should match the active layout size
 456   self.SetSize(targetSize);
 457   mActiveLayoutTargetSize = targetSize;
 458
 459   // Switch to the new layout
 460   mActiveLayout = mLayouts[layoutIndex].Get();
 461
 462   // Move the items to the new layout positions...
 463
 464   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 465   {
 466     unsigned int itemId = iter->first;
 467     Actor actor = iter->second;
 468
 469     // Remove constraints from previous layout
 470     actor.RemoveConstraints();
 471
 472     Vector3 size;
 473     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 474     {
 475       // resize immediately
 476       actor.SetSize( size.GetVectorXY() );
 477     }
 478
 479     mActiveLayout->ApplyConstraints(actor, itemId, durationSeconds, mScrollPositionObject, Self() );
 480   }
 481
 482   // Refresh the new layout
 483   ItemRange range = GetItemRange(*mActiveLayout, targetSize, GetCurrentLayoutPosition(0), false/* don't reserve extra*/);
 484   AddActorsWithinRange( range, durationSeconds );
 485
 486   // Scroll to an appropriate layout position
 487
 488   bool scrollAnimationNeeded(false);
 489   float firstItemScrollPosition(0.0f);
 490
 491   float current = GetCurrentLayoutPosition(0);
 492   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 493   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 494
 495   if (current < minimum)
 496   {
 497     scrollAnimationNeeded = true;
 498     firstItemScrollPosition = minimum;
 499   }
 500   else if (mAnchoringEnabled)
 501   {
 502     scrollAnimationNeeded = true;
 503     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 504   }
 505
 506   if (scrollAnimationNeeded)
 507   {
 508     RemoveAnimation(mScrollAnimation);
 509     mScrollAnimation = Animation::New(durationSeconds);
 510     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 511     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 512     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnLayoutActivationScrollFinished);
 513     mScrollAnimation.Play();
 514   }
 515
 516   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 517   AnimateScrollOvershoot(0.0f);
 518   mScrollOvershoot = 0.0f;
 519
 520   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 521   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 522   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 523
 524   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 525
 526   CalculateDomainSize(targetSize);
 527 }
 528
 529 void ItemView::DeactivateCurrentLayout()
 530 {
 531   if (mActiveLayout)
 532   {
 533     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 534     {
 535       Actor actor = iter->second;
 536       actor.RemoveConstraints();
 537     }
 538
 539     mActiveLayout = NULL;
 540   }
 541 }
 542
 543 void ItemView::OnRefreshNotification(PropertyNotification& source)
 544 {
 545   if(mRefreshEnabled || mScrollAnimation)
 546   {
 547     // Only refresh the cache during normal scrolling
 548     DoRefresh(GetCurrentLayoutPosition(0), true);
 549   }
 550 }
 551
 552 void ItemView::Refresh()
 553 {
 554   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 555   {
 556     ReleaseActor( iter->first, iter->second );
 557   }
 558   mItemPool.clear();
 559
 560   DoRefresh(GetCurrentLayoutPosition(0), true);
 561 }
 562
 563 void ItemView::DoRefresh(float currentLayoutPosition, bool cacheExtra)
 564 {
 565   if (mActiveLayout)
 566   {
 567     ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, currentLayoutPosition, cacheExtra/*reserve extra*/);
 568     RemoveActorsOutsideRange( range );
 569     AddActorsWithinRange( range, 0.0f/*immediate*/ );
 570
 571     mScrollUpdatedSignal.Emit( Vector3(0.0f, currentLayoutPosition, 0.0f) );
 572   }
 573 }
 574
 575 void ItemView::SetMinimumSwipeSpeed(float speed)
 576 {
 577   mMinimumSwipeSpeed = speed;
 578 }
 579
 580 float ItemView::GetMinimumSwipeSpeed() const
 581 {
 582   return mMinimumSwipeSpeed;
 583 }
 584
 585 void ItemView::SetMinimumSwipeDistance(float distance)
 586 {
 587   mMinimumSwipeDistance = distance;
 588 }
 589
 590 float ItemView::GetMinimumSwipeDistance() const
 591 {
 592   return mMinimumSwipeDistance;
 593 }
 594
 595 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 596 {
 597   mMouseWheelScrollDistanceStep = step;
 598 }
 599
 600 float ItemView::GetMouseWheelScrollDistanceStep() const
 601 {
 602   return mMouseWheelScrollDistanceStep;
 603 }
 604
 605 void ItemView::SetAnchoring(bool enabled)
 606 {
 607   mAnchoringEnabled = enabled;
 608 }
 609
 610 bool ItemView::GetAnchoring() const
 611 {
 612   return mAnchoringEnabled;
 613 }
 614
 615 void ItemView::SetAnchoringDuration(float durationSeconds)
 616 {
 617   mAnchoringDuration = durationSeconds;
 618 }
 619
 620 float ItemView::GetAnchoringDuration() const
 621 {
 622   return mAnchoringDuration;
 623 }
 624
 625 void ItemView::SetRefreshInterval(float intervalLayoutPositions)
 626 {
 627   if( !Equals(mRefreshIntervalLayoutPositions, intervalLayoutPositions) )
 628   {
 629     mRefreshIntervalLayoutPositions = intervalLayoutPositions;
 630
 631     if(mRefreshNotification)
 632     {
 633       mScrollPositionObject.RemovePropertyNotification(mRefreshNotification);
 634     }
 635     mRefreshNotification = mScrollPositionObject.AddPropertyNotification( ScrollConnector::SCROLL_POSITION, StepCondition(mRefreshIntervalLayoutPositions, 0.0f) );
 636     mRefreshNotification.NotifySignal().Connect( this, &ItemView::OnRefreshNotification );
 637   }
 638 }
 639
 640 float ItemView::GetRefreshInterval() const
 641 {
 642   return mRefreshIntervalLayoutPositions;
 643 }
 644
 645 void ItemView::SetRefreshEnabled(bool enabled)
 646 {
 647   mRefreshEnabled = enabled;
 648 }
 649
 650 Actor ItemView::GetItem(unsigned int itemId) const
 651 {
 652   Actor actor;
 653
 654   ConstItemPoolIter iter = mItemPool.find( itemId );
 655   if( iter != mItemPool.end() )
 656   {
 657     actor = iter->second;
 658   }
 659
 660   return actor;
 661 }
 662
 663 unsigned int ItemView::GetItemId( Actor actor ) const
 664 {
 665   unsigned int itemId( 0 );
 666
 667   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 668   {
 669     if( iter->second == actor )
 670     {
 671       itemId = iter->first;
 672       break;
 673     }
 674   }
 675
 676   return itemId;
 677 }
 678
 679 void ItemView::InsertItem( Item newItem, float durationSeconds )
 680 {
 681   mAddingItems = true;
 682
 683   Actor displacedActor;
 684   ItemPoolIter afterDisplacedIter = mItemPool.end();
 685
 686   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 687   if( mItemPool.end() != foundIter )
 688   {
 689     SetupActor( newItem, durationSeconds );
 690     Self().Add( newItem.second );
 691
 692     displacedActor = foundIter->second;
 693     foundIter->second = newItem.second;
 694
 695     afterDisplacedIter = ++foundIter;
 696   }
 697   else
 698   {
 699     // Inserting before the existing item range?
 700     ItemPoolIter iter = mItemPool.begin();
 701     if( iter != mItemPool.end() &&
 702         iter->first > newItem.first )
 703     {
 704       displacedActor = iter->second;
 705       mItemPool.erase( iter++ ); // iter is still valid after the erase
 706
 707       afterDisplacedIter = iter;
 708     }
 709   }
 710
 711   if( displacedActor )
 712   {
 713     // Move the existing actors to make room
 714     for( ItemPoolIter iter = afterDisplacedIter; mItemPool.end() != iter; ++iter )
 715     {
 716       Actor temp = iter->second;
 717       iter->second = displacedActor;
 718       displacedActor = temp;
 719
 720       iter->second.RemoveConstraints();
 721       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 722     }
 723
 724     // Create last item
 725     ItemPool::reverse_iterator lastIter = mItemPool.rbegin();
 726     if ( lastIter != mItemPool.rend() )
 727     {
 728       ItemId lastId = lastIter->first;
 729       Item lastItem( lastId + 1, displacedActor );
 730       mItemPool.insert( lastItem );
 731
 732       lastItem.second.RemoveConstraints();
 733       mActiveLayout->ApplyConstraints( lastItem.second, lastItem.first, durationSeconds, mScrollPositionObject, Self() );
 734     }
 735   }
 736
 737   CalculateDomainSize(Self().GetCurrentSize());
 738
 739   mAddingItems = false;
 740 }
 741
 742 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 743 {
 744   mAddingItems = true;
 745
 746   // Insert from lowest id to highest
 747   std::set<Item> sortedItems;
 748   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 749   {
 750     sortedItems.insert( *iter );
 751   }
 752
 753   for( std::set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 754   {
 755     Self().Add( iter->second );
 756
 757     ItemPoolIter foundIter = mItemPool.find( iter->first );
 758     if( mItemPool.end() != foundIter )
 759     {
 760       Actor moveMe = foundIter->second;
 761       foundIter->second = iter->second;
 762
 763       // Move the existing actors to make room
 764       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 765       {
 766         Actor temp = iter->second;
 767         iter->second = moveMe;
 768         moveMe = temp;
 769       }
 770
 771       // Create last item
 772       ItemId lastId = mItemPool.rbegin()->first;
 773       Item lastItem( lastId + 1, moveMe );
 774       mItemPool.insert( lastItem );
 775     }
 776     else
 777     {
 778       mItemPool.insert( *iter );
 779     }
 780   }
 781
 782   // Relayout everything
 783   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 784   {
 785     // If newly inserted
 786     if( FindById( newItems, iter->first ) )
 787     {
 788       SetupActor( *iter, durationSeconds );
 789     }
 790     else
 791     {
 792       iter->second.RemoveConstraints();
 793       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 794     }
 795   }
 796
 797   CalculateDomainSize(Self().GetCurrentSize());
 798
 799   mAddingItems = false;
 800 }
 801
 802 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 803 {
 804   bool actorsReordered = RemoveActor( itemId );
 805   if( actorsReordered )
 806   {
 807     ReapplyAllConstraints( durationSeconds );
 808
 809     OnItemsRemoved();
 810   }
 811 }
 812
 813 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 814 {
 815   bool actorsReordered( false );
 816
 817   // Remove from highest id to lowest
 818   set<ItemId> sortedItems;
 819   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 820   {
 821     sortedItems.insert( *iter );
 822   }
 823
 824   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 825   {
 826     if( RemoveActor( *iter ) )
 827     {
 828       actorsReordered = true;
 829     }
 830   }
 831
 832   if( actorsReordered )
 833   {
 834     ReapplyAllConstraints( durationSeconds );
 835
 836     OnItemsRemoved();
 837   }
 838 }
 839
 840 bool ItemView::RemoveActor(unsigned int itemId)
 841 {
 842   bool reordered( false );
 843
 844   ItemPoolIter removeIter = mItemPool.find( itemId );
 845   if( removeIter != mItemPool.end() )
 846   {
 847     ReleaseActor(itemId, removeIter->second);
 848   }
 849   else
 850   {
 851     // Removing before the existing item range?
 852     ItemPoolIter iter = mItemPool.begin();
 853     if( iter != mItemPool.end() &&
 854         iter->first > itemId )
 855     {
 856       // In order to decrement the first visible item ID
 857       mItemPool.insert( Item(iter->first - 1, Actor()) );
 858
 859       removeIter = mItemPool.begin();
 860     }
 861   }
 862
 863   if( removeIter != mItemPool.end() )
 864   {
 865     reordered = true;
 866
 867     // Adjust the remaining item IDs, for example if item 2 is removed:
 868     //   Initial actors:     After insert:
 869     //     ID 1 - ActorA       ID 1 - ActorA
 870     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 871     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 872     //     ID 4 - ActorD
 873     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 874     {
 875       if( iter->first < mItemPool.rbegin()->first )
 876       {
 877         iter->second = mItemPool[ iter->first + 1 ];
 878       }
 879       else
 880       {
 881         mItemPool.erase( iter );
 882         break;
 883       }
 884     }
 885   }
 886
 887   return reordered;
 888 }
 889
 890 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 891 {
 892   mAddingItems = true;
 893
 894   SetupActor( replacementItem, durationSeconds );
 895   Self().Add( replacementItem.second );
 896
 897   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 898   if( mItemPool.end() != iter )
 899   {
 900     ReleaseActor(iter->first, iter->second);
 901     iter->second = replacementItem.second;
 902   }
 903   else
 904   {
 905     mItemPool.insert( replacementItem );
 906   }
 907
 908   CalculateDomainSize(Self().GetCurrentSize());
 909
 910   mAddingItems = false;
 911 }
 912
 913 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 914 {
 915   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 916   {
 917     ReplaceItem( *iter, durationSeconds );
 918   }
 919 }
 920
 921 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 922 {
 923   // Remove unwanted actors from the ItemView & ItemPool
 924   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 925   {
 926     unsigned int current = iter->first;
 927
 928     if( ! range.Within( current ) )
 929     {
 930       ReleaseActor(iter->first, iter->second);
 931
 932       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 933     }
 934     else
 935     {
 936       ++iter;
 937     }
 938   }
 939 }
 940
 941 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 942 {
 943   range.end = std::min(mItemFactory.GetNumberOfItems(), range.end);
 944
 945   // The order of addition depends on the scroll direction.
 946   if (mRefreshOrderHint)
 947   {
 948     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 949     {
 950       AddNewActor( itemId, durationSeconds );
 951     }
 952   }
 953   else
 954   {
 955     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 956     {
 957       AddNewActor( itemId-1, durationSeconds );
 958     }
 959   }
 960
 961   // Total number of items may change dynamically.
 962   // Always recalculate the domain size to reflect that.
 963   CalculateDomainSize(Self().GetCurrentSize());
 964 }
 965
 966 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
 967 {
 968   mAddingItems = true;
 969
 970   if( mItemPool.end() == mItemPool.find( itemId ) )
 971   {
 972     Actor actor = mItemFactory.NewItem( itemId );
 973
 974     if( actor )
 975     {
 976       Item newItem( itemId, actor );
 977
 978       mItemPool.insert( newItem );
 979
 980       SetupActor( newItem, durationSeconds );
 981       Self().Add( actor );
 982     }
 983   }
 984
 985   mAddingItems = false;
 986 }
 987
 988 void ItemView::SetupActor( Item item, float durationSeconds )
 989 {
 990   item.second.SetParentOrigin( mItemsParentOrigin );
 991   item.second.SetAnchorPoint( mItemsAnchorPoint );
 992
 993   if( mActiveLayout )
 994   {
 995     Vector3 size;
 996     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
 997     {
 998       item.second.SetSize( 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(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1457       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1458       domainSize = fabs(firstItemPosition.x - lastItemPosition.x);
1459     }
1460     else
1461     {
1462       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1463       self.SetProperty(mPropertyPositionMax, 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(mPropertyCanScrollVertical, isLayoutScrollable);
1471     self.SetProperty(mPropertyCanScrollHorizontal, false);
1472   }
1473 }
1474
1475 Vector3 ItemView::GetDomainSize() const
1476 {
1477   Actor self = Self();
1478
1479   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1480   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
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( mPropertyScrollDirection ),
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( mPropertyScrollDirection ),
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( mPropertyScrollDirection ),
1583                                            Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1584                                            OvershootOverlayPositionConstraint() );
1585     mOvershootOverlay.ApplyConstraint(constraint);
1586
1587     constraint = Constraint::New<bool>( Actor::Property::VISIBLE,
1588                                         ParentSource( mPropertyCanScrollVertical ),
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