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.SetResizePolicy( FIXED, ALL_DIMENSIONS );
 477       actor.SetPreferredSize( size.GetVectorXY() );
 478     }
 479
 480     mActiveLayout->ApplyConstraints(actor, itemId, durationSeconds, mScrollPositionObject, Self() );
 481   }
 482
 483   // Refresh the new layout
 484   ItemRange range = GetItemRange(*mActiveLayout, targetSize, GetCurrentLayoutPosition(0), false/* don't reserve extra*/);
 485   AddActorsWithinRange( range, durationSeconds );
 486
 487   // Scroll to an appropriate layout position
 488
 489   bool scrollAnimationNeeded(false);
 490   float firstItemScrollPosition(0.0f);
 491
 492   float current = GetCurrentLayoutPosition(0);
 493   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 494   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 495
 496   if (current < minimum)
 497   {
 498     scrollAnimationNeeded = true;
 499     firstItemScrollPosition = minimum;
 500   }
 501   else if (mAnchoringEnabled)
 502   {
 503     scrollAnimationNeeded = true;
 504     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 505   }
 506
 507   if (scrollAnimationNeeded)
 508   {
 509     RemoveAnimation(mScrollAnimation);
 510     mScrollAnimation = Animation::New(durationSeconds);
 511     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 512     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 513     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnLayoutActivationScrollFinished);
 514     mScrollAnimation.Play();
 515   }
 516
 517   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 518   AnimateScrollOvershoot(0.0f);
 519   mScrollOvershoot = 0.0f;
 520
 521   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 522   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 523   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 524
 525   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 526
 527   CalculateDomainSize(targetSize);
 528 }
 529
 530 void ItemView::DeactivateCurrentLayout()
 531 {
 532   if (mActiveLayout)
 533   {
 534     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 535     {
 536       Actor actor = iter->second;
 537       actor.RemoveConstraints();
 538     }
 539
 540     mActiveLayout = NULL;
 541   }
 542 }
 543
 544 void ItemView::OnRefreshNotification(PropertyNotification& source)
 545 {
 546   if(mRefreshEnabled || mScrollAnimation)
 547   {
 548     // Only refresh the cache during normal scrolling
 549     DoRefresh(GetCurrentLayoutPosition(0), true);
 550   }
 551 }
 552
 553 void ItemView::Refresh()
 554 {
 555   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 556   {
 557     ReleaseActor( iter->first, iter->second );
 558   }
 559   mItemPool.clear();
 560
 561   DoRefresh(GetCurrentLayoutPosition(0), true);
 562 }
 563
 564 void ItemView::DoRefresh(float currentLayoutPosition, bool cacheExtra)
 565 {
 566   if (mActiveLayout)
 567   {
 568     ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, currentLayoutPosition, cacheExtra/*reserve extra*/);
 569     RemoveActorsOutsideRange( range );
 570     AddActorsWithinRange( range, 0.0f/*immediate*/ );
 571
 572     mScrollUpdatedSignal.Emit( Vector3(0.0f, currentLayoutPosition, 0.0f) );
 573   }
 574 }
 575
 576 void ItemView::SetMinimumSwipeSpeed(float speed)
 577 {
 578   mMinimumSwipeSpeed = speed;
 579 }
 580
 581 float ItemView::GetMinimumSwipeSpeed() const
 582 {
 583   return mMinimumSwipeSpeed;
 584 }
 585
 586 void ItemView::SetMinimumSwipeDistance(float distance)
 587 {
 588   mMinimumSwipeDistance = distance;
 589 }
 590
 591 float ItemView::GetMinimumSwipeDistance() const
 592 {
 593   return mMinimumSwipeDistance;
 594 }
 595
 596 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 597 {
 598   mMouseWheelScrollDistanceStep = step;
 599 }
 600
 601 float ItemView::GetMouseWheelScrollDistanceStep() const
 602 {
 603   return mMouseWheelScrollDistanceStep;
 604 }
 605
 606 void ItemView::SetAnchoring(bool enabled)
 607 {
 608   mAnchoringEnabled = enabled;
 609 }
 610
 611 bool ItemView::GetAnchoring() const
 612 {
 613   return mAnchoringEnabled;
 614 }
 615
 616 void ItemView::SetAnchoringDuration(float durationSeconds)
 617 {
 618   mAnchoringDuration = durationSeconds;
 619 }
 620
 621 float ItemView::GetAnchoringDuration() const
 622 {
 623   return mAnchoringDuration;
 624 }
 625
 626 void ItemView::SetRefreshInterval(float intervalLayoutPositions)
 627 {
 628   if( !Equals(mRefreshIntervalLayoutPositions, intervalLayoutPositions) )
 629   {
 630     mRefreshIntervalLayoutPositions = intervalLayoutPositions;
 631
 632     if(mRefreshNotification)
 633     {
 634       mScrollPositionObject.RemovePropertyNotification(mRefreshNotification);
 635     }
 636     mRefreshNotification = mScrollPositionObject.AddPropertyNotification( ScrollConnector::SCROLL_POSITION, StepCondition(mRefreshIntervalLayoutPositions, 0.0f) );
 637     mRefreshNotification.NotifySignal().Connect( this, &ItemView::OnRefreshNotification );
 638   }
 639 }
 640
 641 float ItemView::GetRefreshInterval() const
 642 {
 643   return mRefreshIntervalLayoutPositions;
 644 }
 645
 646 void ItemView::SetRefreshEnabled(bool enabled)
 647 {
 648   mRefreshEnabled = enabled;
 649 }
 650
 651 Actor ItemView::GetItem(unsigned int itemId) const
 652 {
 653   Actor actor;
 654
 655   ConstItemPoolIter iter = mItemPool.find( itemId );
 656   if( iter != mItemPool.end() )
 657   {
 658     actor = iter->second;
 659   }
 660
 661   return actor;
 662 }
 663
 664 unsigned int ItemView::GetItemId( Actor actor ) const
 665 {
 666   unsigned int itemId( 0 );
 667
 668   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 669   {
 670     if( iter->second == actor )
 671     {
 672       itemId = iter->first;
 673       break;
 674     }
 675   }
 676
 677   return itemId;
 678 }
 679
 680 void ItemView::InsertItem( Item newItem, float durationSeconds )
 681 {
 682   mAddingItems = true;
 683
 684   Actor displacedActor;
 685   ItemPoolIter afterDisplacedIter = mItemPool.end();
 686
 687   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 688   if( mItemPool.end() != foundIter )
 689   {
 690     SetupActor( newItem, durationSeconds );
 691     Self().Add( newItem.second );
 692
 693     displacedActor = foundIter->second;
 694     foundIter->second = newItem.second;
 695
 696     afterDisplacedIter = ++foundIter;
 697   }
 698   else
 699   {
 700     // Inserting before the existing item range?
 701     ItemPoolIter iter = mItemPool.begin();
 702     if( iter != mItemPool.end() &&
 703         iter->first > newItem.first )
 704     {
 705       displacedActor = iter->second;
 706       mItemPool.erase( iter++ ); // iter is still valid after the erase
 707
 708       afterDisplacedIter = iter;
 709     }
 710   }
 711
 712   if( displacedActor )
 713   {
 714     // Move the existing actors to make room
 715     for( ItemPoolIter iter = afterDisplacedIter; mItemPool.end() != iter; ++iter )
 716     {
 717       Actor temp = iter->second;
 718       iter->second = displacedActor;
 719       displacedActor = temp;
 720
 721       iter->second.RemoveConstraints();
 722       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 723     }
 724
 725     // Create last item
 726     ItemPool::reverse_iterator lastIter = mItemPool.rbegin();
 727     if ( lastIter != mItemPool.rend() )
 728     {
 729       ItemId lastId = lastIter->first;
 730       Item lastItem( lastId + 1, displacedActor );
 731       mItemPool.insert( lastItem );
 732
 733       lastItem.second.RemoveConstraints();
 734       mActiveLayout->ApplyConstraints( lastItem.second, lastItem.first, durationSeconds, mScrollPositionObject, Self() );
 735     }
 736   }
 737
 738   CalculateDomainSize(Self().GetCurrentSize());
 739
 740   mAddingItems = false;
 741 }
 742
 743 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 744 {
 745   mAddingItems = true;
 746
 747   // Insert from lowest id to highest
 748   std::set<Item> sortedItems;
 749   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 750   {
 751     sortedItems.insert( *iter );
 752   }
 753
 754   for( std::set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 755   {
 756     Self().Add( iter->second );
 757
 758     ItemPoolIter foundIter = mItemPool.find( iter->first );
 759     if( mItemPool.end() != foundIter )
 760     {
 761       Actor moveMe = foundIter->second;
 762       foundIter->second = iter->second;
 763
 764       // Move the existing actors to make room
 765       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 766       {
 767         Actor temp = iter->second;
 768         iter->second = moveMe;
 769         moveMe = temp;
 770       }
 771
 772       // Create last item
 773       ItemId lastId = mItemPool.rbegin()->first;
 774       Item lastItem( lastId + 1, moveMe );
 775       mItemPool.insert( lastItem );
 776     }
 777     else
 778     {
 779       mItemPool.insert( *iter );
 780     }
 781   }
 782
 783   // Relayout everything
 784   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 785   {
 786     // If newly inserted
 787     if( FindById( newItems, iter->first ) )
 788     {
 789       SetupActor( *iter, durationSeconds );
 790     }
 791     else
 792     {
 793       iter->second.RemoveConstraints();
 794       mActiveLayout->ApplyConstraints( iter->second, iter->first, durationSeconds, mScrollPositionObject, Self() );
 795     }
 796   }
 797
 798   CalculateDomainSize(Self().GetCurrentSize());
 799
 800   mAddingItems = false;
 801 }
 802
 803 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 804 {
 805   bool actorsReordered = RemoveActor( itemId );
 806   if( actorsReordered )
 807   {
 808     ReapplyAllConstraints( durationSeconds );
 809
 810     OnItemsRemoved();
 811   }
 812 }
 813
 814 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 815 {
 816   bool actorsReordered( false );
 817
 818   // Remove from highest id to lowest
 819   set<ItemId> sortedItems;
 820   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 821   {
 822     sortedItems.insert( *iter );
 823   }
 824
 825   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 826   {
 827     if( RemoveActor( *iter ) )
 828     {
 829       actorsReordered = true;
 830     }
 831   }
 832
 833   if( actorsReordered )
 834   {
 835     ReapplyAllConstraints( durationSeconds );
 836
 837     OnItemsRemoved();
 838   }
 839 }
 840
 841 bool ItemView::RemoveActor(unsigned int itemId)
 842 {
 843   bool reordered( false );
 844
 845   ItemPoolIter removeIter = mItemPool.find( itemId );
 846   if( removeIter != mItemPool.end() )
 847   {
 848     ReleaseActor(itemId, removeIter->second);
 849   }
 850   else
 851   {
 852     // Removing before the existing item range?
 853     ItemPoolIter iter = mItemPool.begin();
 854     if( iter != mItemPool.end() &&
 855         iter->first > itemId )
 856     {
 857       // In order to decrement the first visible item ID
 858       mItemPool.insert( Item(iter->first - 1, Actor()) );
 859
 860       removeIter = mItemPool.begin();
 861     }
 862   }
 863
 864   if( removeIter != mItemPool.end() )
 865   {
 866     reordered = true;
 867
 868     // Adjust the remaining item IDs, for example if item 2 is removed:
 869     //   Initial actors:     After insert:
 870     //     ID 1 - ActorA       ID 1 - ActorA
 871     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 872     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 873     //     ID 4 - ActorD
 874     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 875     {
 876       if( iter->first < mItemPool.rbegin()->first )
 877       {
 878         iter->second = mItemPool[ iter->first + 1 ];
 879       }
 880       else
 881       {
 882         mItemPool.erase( iter );
 883         break;
 884       }
 885     }
 886   }
 887
 888   return reordered;
 889 }
 890
 891 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 892 {
 893   mAddingItems = true;
 894
 895   SetupActor( replacementItem, durationSeconds );
 896   Self().Add( replacementItem.second );
 897
 898   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 899   if( mItemPool.end() != iter )
 900   {
 901     ReleaseActor(iter->first, iter->second);
 902     iter->second = replacementItem.second;
 903   }
 904   else
 905   {
 906     mItemPool.insert( replacementItem );
 907   }
 908
 909   CalculateDomainSize(Self().GetCurrentSize());
 910
 911   mAddingItems = false;
 912 }
 913
 914 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 915 {
 916   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 917   {
 918     ReplaceItem( *iter, durationSeconds );
 919   }
 920 }
 921
 922 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 923 {
 924   // Remove unwanted actors from the ItemView & ItemPool
 925   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 926   {
 927     unsigned int current = iter->first;
 928
 929     if( ! range.Within( current ) )
 930     {
 931       ReleaseActor(iter->first, iter->second);
 932
 933       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 934     }
 935     else
 936     {
 937       ++iter;
 938     }
 939   }
 940 }
 941
 942 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 943 {
 944   range.end = std::min(mItemFactory.GetNumberOfItems(), range.end);
 945
 946   // The order of addition depends on the scroll direction.
 947   if (mRefreshOrderHint)
 948   {
 949     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 950     {
 951       AddNewActor( itemId, durationSeconds );
 952     }
 953   }
 954   else
 955   {
 956     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 957     {
 958       AddNewActor( itemId-1, durationSeconds );
 959     }
 960   }
 961
 962   // Total number of items may change dynamically.
 963   // Always recalculate the domain size to reflect that.
 964   CalculateDomainSize(Self().GetCurrentSize());
 965 }
 966
 967 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
 968 {
 969   mAddingItems = true;
 970
 971   if( mItemPool.end() == mItemPool.find( itemId ) )
 972   {
 973     Actor actor = mItemFactory.NewItem( itemId );
 974
 975     if( actor )
 976     {
 977       Item newItem( itemId, actor );
 978
 979       mItemPool.insert( newItem );
 980
 981       SetupActor( newItem, durationSeconds );
 982       Self().Add( actor );
 983     }
 984   }
 985
 986   mAddingItems = false;
 987 }
 988
 989 void ItemView::SetupActor( Item item, float durationSeconds )
 990 {
 991   item.second.SetParentOrigin( mItemsParentOrigin );
 992   item.second.SetAnchorPoint( mItemsAnchorPoint );
 993
 994   if( mActiveLayout )
 995   {
 996     Vector3 size;
 997     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
 998     {
 999       item.second.SetResizePolicy( FIXED, ALL_DIMENSIONS );
1000       item.second.SetPreferredSize( size.GetVectorXY() );
1001     }
1002
1003     mActiveLayout->ApplyConstraints( item.second, item.first, durationSeconds, mScrollPositionObject, Self() );
1004   }
1005 }
1006
1007 void ItemView::ReleaseActor( ItemId item, Actor actor )
1008 {
1009   Self().Remove( actor );
1010   mItemFactory.ItemReleased(item, actor);
1011 }
1012
1013 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, float layoutPosition, bool reserveExtra)
1014 {
1015   unsigned int itemCount = mItemFactory.GetNumberOfItems();
1016
1017   ItemRange available(0u, itemCount);
1018
1019   ItemRange range = layout.GetItemsWithinArea( layoutPosition, layoutSize );
1020
1021   if (reserveExtra)
1022   {
1023     // Add the reserve items for scrolling
1024     unsigned int extra = layout.GetReserveItemCount(layoutSize);
1025     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
1026     range.end += extra;
1027   }
1028
1029   return range.Intersection(available);
1030 }
1031
1032 void ItemView::OnChildAdd(Actor& child)
1033 {
1034   if(!mAddingItems)
1035   {
1036     // We don't want to do this downcast check for any item added by ItemView itself.
1037     Dali::Toolkit::ScrollComponent scrollComponent = Dali::Toolkit::ScrollComponent::DownCast(child);
1038     if(scrollComponent)
1039     {
1040       // Set the scroll connector when scroll bar is being added
1041       scrollComponent.SetScrollConnector(mScrollConnector);
1042     }
1043   }
1044 }
1045
1046 bool ItemView::OnTouchEvent(const TouchEvent& event)
1047 {
1048   // Ignore events with multiple-touch points
1049   if (event.GetPointCount() != 1)
1050   {
1051     return false;
1052   }
1053
1054   if (event.GetPoint(0).state == TouchPoint::Down)
1055   {
1056     // Cancel ongoing scrolling etc.
1057     mGestureState = Gesture::Clear;
1058
1059     mScrollDistance = 0.0f;
1060     mScrollSpeed = 0.0f;
1061     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
1062
1063     mScrollOvershoot = 0.0f;
1064     AnimateScrollOvershoot(0.0f);
1065
1066     if(mScrollAnimation)
1067     {
1068       mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1069     }
1070
1071     RemoveAnimation(mScrollAnimation);
1072   }
1073
1074   return true; // consume since we're potentially scrolling
1075 }
1076
1077 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
1078 {
1079   // Respond the mouse wheel event to scroll
1080   if (mActiveLayout)
1081   {
1082     Actor self = Self();
1083     const Vector3 layoutSize = Self().GetCurrentSize();
1084     float layoutPositionDelta = GetCurrentLayoutPosition(0) - (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
1085     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1086
1087     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1088     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1089     mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1090     mRefreshEnabled = true;
1091   }
1092
1093   if (mMouseWheelEventFinishedTimer.IsRunning())
1094   {
1095     mMouseWheelEventFinishedTimer.Stop();
1096   }
1097
1098   mMouseWheelEventFinishedTimer.Start();
1099
1100   return true;
1101 }
1102
1103 bool ItemView::OnMouseWheelEventFinished()
1104 {
1105   if (mActiveLayout)
1106   {
1107     RemoveAnimation(mScrollAnimation);
1108
1109     // No more mouse wheel events coming. Do the anchoring if enabled.
1110     mScrollAnimation = DoAnchoring();
1111     if (mScrollAnimation)
1112     {
1113       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1114       mScrollAnimation.Play();
1115     }
1116     else
1117     {
1118       mScrollOvershoot = 0.0f;
1119       AnimateScrollOvershoot(0.0f);
1120
1121       mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1122     }
1123   }
1124
1125   return false;
1126 }
1127
1128 void ItemView::ReapplyAllConstraints( float durationSeconds )
1129 {
1130   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1131   {
1132     unsigned int id = iter->first;
1133     Actor actor = iter->second;
1134
1135     actor.RemoveConstraints();
1136     mActiveLayout->ApplyConstraints(actor, id, durationSeconds, mScrollPositionObject, Self());
1137   }
1138 }
1139
1140 void ItemView::OnItemsRemoved()
1141 {
1142   CalculateDomainSize(Self().GetCurrentSize());
1143
1144   // Adjust scroll-position after an item is removed
1145   if( mActiveLayout )
1146   {
1147     float firstItemScrollPosition = ClampFirstItemPosition(GetCurrentLayoutPosition(0), Self().GetCurrentSize(), *mActiveLayout);
1148
1149     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1150   }
1151 }
1152
1153 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1154 {
1155   Actor self = Self();
1156   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1157   float clamppedPosition = std::min(0.0f, std::max(minLayoutPosition, targetPosition));
1158   mScrollOvershoot = targetPosition - clamppedPosition;
1159   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1160
1161   return clamppedPosition;
1162 }
1163
1164 void ItemView::OnPan( const PanGesture& gesture )
1165 {
1166   Actor self = Self();
1167   const Vector3 layoutSize = Self().GetCurrentSize();
1168
1169   RemoveAnimation(mScrollAnimation);
1170
1171   // Short-circuit if there is no active layout
1172   if (!mActiveLayout)
1173   {
1174     mGestureState = Gesture::Clear;
1175     return;
1176   }
1177
1178   mGestureState = gesture.state;
1179
1180   switch (mGestureState)
1181   {
1182     case Gesture::Finished:
1183     {
1184       // Swipe Detection
1185       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1186           mScrollSpeed > mMinimumSwipeSpeed)
1187       {
1188         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1189
1190         mRefreshOrderHint = true;
1191
1192         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1193         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1194                                                                layoutSize,
1195                                                                *mActiveLayout);
1196
1197         if (mAnchoringEnabled)
1198         {
1199           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1200         }
1201
1202         RemoveAnimation(mScrollAnimation);
1203
1204         float flickAnimationDuration = Clamp( mActiveLayout->GetItemFlickAnimationDuration() * std::max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)))
1205                                        , DEFAULT_MINIMUM_SWIPE_DURATION, DEFAULT_MAXIMUM_SWIPE_DURATION);
1206
1207         mScrollAnimation = Animation::New(flickAnimationDuration);
1208         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1209         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1210         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1211
1212         mIsFlicking = true;
1213         // Check whether it has already scrolled to the end
1214         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1215         {
1216           AnimateScrollOvershoot(0.0f);
1217         }
1218       }
1219
1220       // Anchoring may be triggered when there was no swipe
1221       if (!mScrollAnimation)
1222       {
1223         mScrollAnimation = DoAnchoring();
1224       }
1225
1226       // Reset the overshoot if no scroll animation.
1227       if (!mScrollAnimation)
1228       {
1229         mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1230
1231         AnimateScrollOvershoot(0.0f, false);
1232       }
1233     }
1234     break;
1235
1236     case Gesture::Started: // Fall through
1237     {
1238       mTotalPanDisplacement = Vector2::ZERO;
1239       mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1240       mRefreshEnabled = true;
1241     }
1242
1243     case Gesture::Continuing:
1244     {
1245       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1246       mScrollSpeed = Clamp((gesture.GetSpeed() * gesture.GetSpeed() * mActiveLayout->GetFlickSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1247
1248       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1249       mRefreshOrderHint = mScrollDistance < 0.0f;
1250
1251       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1252
1253       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1254
1255       float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1256
1257       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1258       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1259
1260       if( (firstItemScrollPosition >= 0.0f && currentOvershoot < 1.0f) || (firstItemScrollPosition <= mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize) && currentOvershoot > -1.0f) )
1261       {
1262         mTotalPanDisplacement += gesture.displacement;
1263       }
1264
1265       mScrollOvershoot = CalculateScrollOvershoot();
1266       mScrollPositionObject.SetProperty( ScrollConnector::OVERSHOOT, mScrollOvershoot );
1267     }
1268     break;
1269
1270     case Gesture::Cancelled:
1271     {
1272       mScrollAnimation = DoAnchoring();
1273     }
1274     break;
1275
1276     default:
1277       break;
1278   }
1279
1280   if (mScrollAnimation)
1281   {
1282     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1283     mScrollAnimation.Play();
1284   }
1285 }
1286
1287 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1288 {
1289   OnPan(gesture);
1290   return true;
1291 }
1292
1293 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1294 {
1295   Actor nextFocusActor;
1296   if(mActiveLayout)
1297   {
1298     int nextItemID = 0;
1299     if(!actor || actor == this->Self())
1300     {
1301       nextFocusActor = GetItem(nextItemID);
1302     }
1303     else if(actor && actor.GetParent() == this->Self())
1304     {
1305       int itemID = GetItemId(actor);
1306       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1307       nextFocusActor = GetItem(nextItemID);
1308       if(nextFocusActor == actor)
1309       {
1310         // need to pass NULL actor back to focus manager
1311         nextFocusActor.Reset();
1312         return nextFocusActor;
1313       }
1314     }
1315     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1316     Vector3 layoutSize = Self().GetCurrentSize();
1317     if(!nextFocusActor)
1318     {
1319       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1320       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1321       nextItemID = viewableItems.begin;
1322       nextFocusActor = GetItem(nextItemID);
1323     }
1324   }
1325   return nextFocusActor;
1326 }
1327
1328 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1329 {
1330   // only in this function if our chosen focus actor was actually used
1331   if(commitedFocusableActor)
1332   {
1333     int nextItemID = GetItemId(commitedFocusableActor);
1334     float layoutPosition = GetCurrentLayoutPosition(0);
1335     Vector3 layoutSize = Self().GetCurrentSize();
1336
1337     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1338     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1339   }
1340 }
1341
1342 Animation ItemView::DoAnchoring()
1343 {
1344   Animation anchoringAnimation;
1345   Actor self = Self();
1346
1347   if (mActiveLayout && mAnchoringEnabled)
1348   {
1349     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1350
1351     anchoringAnimation = Animation::New(mAnchoringDuration);
1352     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1353     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1354     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1355     if(!mIsFlicking)
1356     {
1357       AnimateScrollOvershoot(0.0f);
1358     }
1359   }
1360
1361   return anchoringAnimation;
1362 }
1363
1364 void ItemView::OnScrollFinished(Animation& source)
1365 {
1366   Actor self = Self();
1367
1368   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1369
1370   mScrollCompletedSignal.Emit(GetCurrentScrollPosition());
1371
1372   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1373   {
1374     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1375   }
1376   else
1377   {
1378     // Reset the overshoot
1379     AnimateScrollOvershoot( 0.0f );
1380   }
1381   mIsFlicking = false;
1382
1383   mScrollOvershoot = 0.0f;
1384 }
1385
1386 void ItemView::OnLayoutActivationScrollFinished(Animation& source)
1387 {
1388   RemoveAnimation(mScrollAnimation);
1389   mRefreshEnabled = true;
1390   DoRefresh(GetCurrentLayoutPosition(0), true);
1391 }
1392
1393 void ItemView::OnOvershootOnFinished(Animation& animation)
1394 {
1395   mAnimatingOvershootOn = false;
1396   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1397   RemoveAnimation(mScrollOvershootAnimation);
1398   if(mAnimateOvershootOff)
1399   {
1400     AnimateScrollOvershoot(0.0f);
1401   }
1402 }
1403
1404 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1405 {
1406   Actor self = Self();
1407   const Vector3 layoutSize = Self().GetCurrentSize();
1408   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1409
1410   if(durationSeconds > 0.0f)
1411   {
1412     RemoveAnimation(mScrollAnimation);
1413     mScrollAnimation = Animation::New(durationSeconds);
1414     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1415     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1416     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1417     mScrollAnimation.Play();
1418   }
1419   else
1420   {
1421     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1422     AnimateScrollOvershoot(0.0f);
1423   }
1424
1425   mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1426   mRefreshEnabled = true;
1427 }
1428
1429 void ItemView::RemoveAnimation(Animation& animation)
1430 {
1431   if(animation)
1432   {
1433     // Cease animating, and reset handle.
1434     animation.Clear();
1435     animation.Reset();
1436   }
1437 }
1438
1439 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1440 {
1441   Actor self = Self();
1442
1443   Vector3 firstItemPosition(Vector3::ZERO);
1444   Vector3 lastItemPosition(Vector3::ZERO);
1445
1446   if(mActiveLayout)
1447   {
1448     firstItemPosition = mActiveLayout->GetItemPosition( 0,0,layoutSize );
1449
1450     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1451     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1452     lastItemPosition = mActiveLayout->GetItemPosition( fabs(minLayoutPosition),fabs(minLayoutPosition),layoutSize );
1453
1454     float domainSize;
1455
1456     if(IsHorizontal(mActiveLayout->GetOrientation()))
1457     {
1458       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1459       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1460       domainSize = fabs(firstItemPosition.x - lastItemPosition.x);
1461     }
1462     else
1463     {
1464       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1465       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.y, 0.0f));
1466       domainSize = fabs(firstItemPosition.y - lastItemPosition.y);
1467     }
1468
1469     mScrollConnector.SetScrollDomain(minLayoutPosition, 0.0f, domainSize);
1470
1471     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1472     self.SetProperty(mPropertyCanScrollVertical, isLayoutScrollable);
1473     self.SetProperty(mPropertyCanScrollHorizontal, false);
1474   }
1475 }
1476
1477 Vector3 ItemView::GetDomainSize() const
1478 {
1479   Actor self = Self();
1480
1481   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1482   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
1483
1484   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1485 }
1486
1487 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1488 {
1489   Actor self = Self();
1490
1491   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1492   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1493   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1494
1495   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1496 }
1497
1498 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1499 {
1500   Vector3 firstItemPosition( mActiveLayout->GetItemPosition(0, layoutPosition, layoutSize ) );
1501   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1502 }
1503
1504 Vector3 ItemView::GetCurrentScrollPosition() const
1505 {
1506   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1507   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1508 }
1509
1510 void ItemView::AddOverlay(Actor actor)
1511 {
1512   Self().Add(actor);
1513 }
1514
1515 void ItemView::RemoveOverlay(Actor actor)
1516 {
1517   Self().Remove(actor);
1518 }
1519
1520 void ItemView::ScrollTo(const Vector3& position, float duration)
1521 {
1522   Actor self = Self();
1523   const Vector3 layoutSize = Self().GetCurrentSize();
1524
1525   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1526
1527   if(duration > 0.0f)
1528   {
1529     RemoveAnimation(mScrollAnimation);
1530     mScrollAnimation = Animation::New(duration);
1531     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1532     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1533     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1534     mScrollAnimation.Play();
1535   }
1536   else
1537   {
1538     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1539     AnimateScrollOvershoot(0.0f);
1540   }
1541
1542   mScrollStartedSignal.Emit(GetCurrentScrollPosition());
1543   mRefreshEnabled = true;
1544 }
1545
1546 void ItemView::SetOvershootEffectColor( const Vector4& color )
1547 {
1548   mOvershootEffectColor = color;
1549   if( mOvershootOverlay )
1550   {
1551     mOvershootOverlay.SetColor( color );
1552   }
1553 }
1554
1555 void ItemView::SetOvershootEnabled( bool enable )
1556 {
1557   Actor self = Self();
1558   if( enable )
1559   {
1560     Property::Index effectOvershootPropertyIndex = Property::INVALID_INDEX;
1561     mOvershootOverlay = CreateBouncingEffectActor( effectOvershootPropertyIndex );
1562     mOvershootOverlay.SetColor(mOvershootEffectColor);
1563     mOvershootOverlay.SetParentOrigin(ParentOrigin::TOP_LEFT);
1564     mOvershootOverlay.SetAnchorPoint(AnchorPoint::TOP_LEFT);
1565     mOvershootOverlay.SetDrawMode(DrawMode::OVERLAY);
1566     self.Add(mOvershootOverlay);
1567
1568     Constraint constraint = Constraint::New<Vector3>( Actor::Property::SIZE,
1569                                                       ParentSource( mPropertyScrollDirection ),
1570                                                       Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1571                                                       ParentSource( Actor::Property::SIZE ),
1572                                                       OvershootOverlaySizeConstraint() );
1573     mOvershootOverlay.ApplyConstraint(constraint);
1574     mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.width, OVERSHOOT_BOUNCE_ACTOR_DEFAULT_SIZE.height);
1575
1576     constraint = Constraint::New<Quaternion>( Actor::Property::ORIENTATION,
1577                                               ParentSource( mPropertyScrollDirection ),
1578                                               Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1579                                               OvershootOverlayRotationConstraint() );
1580     mOvershootOverlay.ApplyConstraint(constraint);
1581
1582     constraint = Constraint::New<Vector3>( Actor::Property::POSITION,
1583                                            ParentSource( Actor::Property::SIZE ),
1584                                            ParentSource( mPropertyScrollDirection ),
1585                                            Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1586                                            OvershootOverlayPositionConstraint() );
1587     mOvershootOverlay.ApplyConstraint(constraint);
1588
1589     constraint = Constraint::New<bool>( Actor::Property::VISIBLE,
1590                                         ParentSource( mPropertyCanScrollVertical ),
1591                                         OvershootOverlayVisibilityConstraint() );
1592     mOvershootOverlay.ApplyConstraint(constraint);
1593
1594     constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1595                                          Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1596                                          EqualToConstraint() );
1597     mOvershootOverlay.ApplyConstraint(constraint);
1598   }
1599   else
1600   {
1601     if( mOvershootOverlay )
1602     {
1603       self.Remove(mOvershootOverlay);
1604       mOvershootOverlay.Reset();
1605     }
1606   }
1607 }
1608
1609 float ItemView::CalculateScrollOvershoot()
1610 {
1611   float overshoot = 0.0f;
1612
1613   if(mActiveLayout)
1614   {
1615     // The overshoot must be calculated from the accumulated pan gesture displacement
1616     // since the pan gesture starts.
1617     Actor self = Self();
1618     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1619     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1620     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1621     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1622     float clamppedPosition = std::min(0.0f, std::max(minLayoutPosition, positionDelta));
1623     overshoot = positionDelta - clamppedPosition;
1624   }
1625
1626   return overshoot > 0.0f ? std::min(overshoot, 1.0f) : std::max(overshoot, -1.0f);
1627 }
1628
1629 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1630 {
1631   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1632
1633   // make sure we animate back if needed
1634   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1635
1636   if( mAnimatingOvershootOn )
1637   {
1638     // animating on, do not allow animate off
1639     return;
1640   }
1641
1642   if(mOvershootAnimationSpeed > Math::MACHINE_EPSILON_0)
1643   {
1644     float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1645     float duration = mOvershootOverlay.GetCurrentSize().height * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot)) / mOvershootAnimationSpeed;
1646
1647     RemoveAnimation(mScrollOvershootAnimation);
1648     mScrollOvershootAnimation = Animation::New(duration);
1649     mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1650     mScrollOvershootAnimation.AnimateTo( Property(mScrollPositionObject, ScrollConnector::OVERSHOOT), overshootAmount, TimePeriod(0.0f, duration) );
1651     mScrollOvershootAnimation.Play();
1652
1653     mAnimatingOvershootOn = animatingOn;
1654   }
1655   else
1656   {
1657     mScrollPositionObject.SetProperty( ScrollConnector::OVERSHOOT, overshootAmount );
1658   }
1659 }
1660
1661 void ItemView::SetItemsParentOrigin( const Vector3& parentOrigin )
1662 {
1663   if( parentOrigin != mItemsParentOrigin )
1664   {
1665     mItemsParentOrigin = parentOrigin;
1666     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1667     {
1668       iter->second.SetParentOrigin(parentOrigin);
1669     }
1670   }
1671 }
1672
1673 Vector3 ItemView::GetItemsParentOrigin() const
1674 {
1675   return mItemsParentOrigin;
1676 }
1677
1678 void ItemView::SetItemsAnchorPoint( const Vector3& anchorPoint )
1679 {
1680   if( anchorPoint != mItemsAnchorPoint )
1681   {
1682     mItemsAnchorPoint = anchorPoint;
1683     for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1684     {
1685       iter->second.SetAnchorPoint(anchorPoint);
1686     }
1687   }
1688 }
1689
1690 Vector3 ItemView::GetItemsAnchorPoint() const
1691 {
1692   return mItemsAnchorPoint;
1693 }
1694
1695 void ItemView::GetItemsRange(ItemRange& range)
1696 {
1697   if( !mItemPool.empty() )
1698   {
1699     range.begin = mItemPool.begin()->first;
1700     range.end = mItemPool.rbegin()->first + 1;
1701   }
1702   else
1703   {
1704     range.begin = 0;
1705     range.end = 0;
1706   }
1707 }
1708
1709 void ItemView::OnScrollPositionChanged( float position )
1710 {
1711   // Cancel scroll animation to prevent any fighting of setting the scroll position property.
1712   RemoveAnimation(mScrollAnimation);
1713
1714   // Refresh the cache immediately when the scroll position is changed.
1715   DoRefresh(position, false); // No need to cache extra items.
1716 }
1717
1718 } // namespace Internal
1719
1720 } // namespace Toolkit
1721
1722 } // namespace Dali