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 Flora License, Version 1.0 (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://floralicense.org/license/
   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 // CLASS HEADER
  18 #include <dali-toolkit/internal/controls/scrollable/item-view/item-view-impl.h>
  19
  20 // EXTERNAL INCLUDES
  21 #include <algorithm>
  22
  23 // INTERNAL INCLUDES
  24 #include <dali/public-api/events/mouse-wheel-event.h>
  25 #include <dali-toolkit/public-api/controls/scrollable/item-view/item-factory.h>
  26 #include <dali-toolkit/internal/controls/scrollable/scroll-connector-impl.h>
  27
  28 using namespace std;
  29 using namespace Dali;
  30
  31 namespace // unnamed namespace
  32 {
  33
  34 //Type registration
  35 TypeRegistration mType( typeid(Toolkit::ItemView), typeid(Toolkit::Scrollable), NULL );
  36
  37 const float DEFAULT_MINIMUM_SWIPE_SPEED = 1.0f;
  38 const float DEFAULT_MINIMUM_SWIPE_DISTANCE = 3.0f;
  39 const float DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION = 0.1f;
  40
  41 const int DEFAULT_REFRESH_INTERVAL_MILLISECONDS = 50; // 20 updates per second
  42 const int MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT = 500;  // 0.5 second
  43
  44 const float DEFAULT_ANCHORING_DURATION = 1.0f;  // 1 second
  45 const float DEFAULT_COLOR_VISIBILITY_REMOVE_TIME = 0.5f; // 0.5 second
  46
  47 const float MILLISECONDS_PER_SECONDS = 1000.0f;
  48
  49 const char* OVERSHOOT_OVERLAY_RIPPLE_IMAGE_PATH = DALI_IMAGE_DIR "overshoot_ripple.png";
  50 const Rect<int> OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA( 0, 0, 720, 58 );
  51 const Vector4 OVERSHOOT_OVERLAY_NINE_PATCH_BORDER(0.0f, 0.0f, 1.0f, 12.0f);
  52 const float MAXIMUM_OVERSHOOT_HEIGHT = 36.0f;  // 36 pixels
  53 const float DEFAULT_OVERSHOOT_ANIMATION_DURATION = 0.5f;  // 0.5 second
  54 const float DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION = 0.2f;
  55
  56 const string LAYOUT_POSITION_PROPERTY_NAME( "item-view-layout-position" );
  57 const string POSITION_PROPERTY_NAME( "item-view-position" );
  58 const string MINIMUM_LAYOUT_POSITION_PROPERTY_NAME( "item-view-minimum-layout-position" );
  59 const string SCROLL_SPEED_PROPERTY_NAME( "item-view-scroll-speed" );
  60 const string SCROLL_DIRECTION_PROPERTY_NAME( "item-view-scroll-direction" );
  61 const string OVERSHOOT_PROPERTY_NAME( "item-view-overshoot" );
  62
  63 // Functors which wrap constraint functions with stored item IDs
  64
  65 struct WrappedVector3Constraint
  66 {
  67   WrappedVector3Constraint(Toolkit::ItemLayout::Vector3Function wrapMe, unsigned int itemId)
  68   : mWrapMe(wrapMe),
  69     mItemId(itemId)
  70   {
  71   }
  72
  73   Vector3 operator()(const Vector3& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
  74   {
  75     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
  76
  77     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
  78   }
  79
  80   Toolkit::ItemLayout::Vector3Function mWrapMe;
  81   unsigned int mItemId;
  82 };
  83
  84 struct WrappedQuaternionConstraint
  85 {
  86   WrappedQuaternionConstraint(Toolkit::ItemLayout::QuaternionFunction wrapMe, unsigned int itemId)
  87   : mWrapMe(wrapMe),
  88     mItemId(itemId)
  89   {
  90   }
  91
  92   Quaternion operator()(const Quaternion& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
  93   {
  94     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
  95
  96     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
  97   }
  98
  99   Toolkit::ItemLayout::QuaternionFunction mWrapMe;
 100   unsigned int mItemId;
 101 };
 102
 103 struct WrappedVector4Constraint
 104 {
 105   WrappedVector4Constraint(Toolkit::ItemLayout::Vector4Function wrapMe, unsigned int itemId)
 106   : mWrapMe(wrapMe),
 107     mItemId(itemId)
 108   {
 109   }
 110
 111   Vector4 operator()(const Vector4& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
 112   {
 113     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 114
 115     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 116   }
 117
 118   Toolkit::ItemLayout::Vector4Function mWrapMe;
 119   unsigned int mItemId;
 120 };
 121
 122 struct WrappedBoolConstraint
 123 {
 124   WrappedBoolConstraint(Toolkit::ItemLayout::BoolFunction wrapMe, unsigned int itemId)
 125   : mWrapMe(wrapMe),
 126     mItemId(itemId)
 127   {
 128   }
 129
 130   bool operator()(const bool& current, const PropertyInput& layoutPosition, const PropertyInput& scrollSpeed, const PropertyInput& layoutSize)
 131   {
 132     float offsetLayoutPosition = layoutPosition.GetFloat() + static_cast<float>(mItemId);
 133
 134     return mWrapMe(current, offsetLayoutPosition, scrollSpeed.GetFloat(), layoutSize.GetVector3());
 135   }
 136
 137   Toolkit::ItemLayout::BoolFunction mWrapMe;
 138   unsigned int mItemId;
 139 };
 140
 141 /**
 142  * Local helper to convert pan distance (in actor coordinates) to the layout-specific scrolling direction
 143  */
 144 float CalculateScrollDistance(Vector2 panDistance, Toolkit::ItemLayout& layout)
 145 {
 146   Radian scrollDirection(layout.GetScrollDirection());
 147
 148   float cosTheta = cosf(scrollDirection);
 149   float sinTheta = sinf(scrollDirection);
 150
 151   return panDistance.x * sinTheta + panDistance.y * cosTheta;
 152 }
 153
 154 // Overshoot overlay constraints
 155
 156 struct OvershootOverlaySizeConstraint
 157 {
 158   float operator()(const float& current,
 159                      const PropertyInput& parentScrollDirectionProperty,
 160                      const PropertyInput& parentOvershootProperty,
 161                      const PropertyInput& parentSizeProperty)
 162   {
 163     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 164     const Vector3 parentSize = parentSizeProperty.GetVector3();
 165     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 166
 167     float overlayWidth;
 168
 169     if(Toolkit::IsVertical(parentOrientation))
 170     {
 171       overlayWidth = fabsf(parentScrollDirection.y) > Math::MACHINE_EPSILON_1 ? parentSize.x : parentSize.y;
 172     }
 173     else
 174     {
 175       overlayWidth = fabsf(parentScrollDirection.x) > Math::MACHINE_EPSILON_1 ? parentSize.y : parentSize.x;
 176     }
 177
 178     return overlayWidth;
 179   }
 180 };
 181
 182 struct OvershootOverlayRotationConstraint
 183 {
 184   Quaternion operator()(const Quaternion& current,
 185                         const PropertyInput& parentScrollDirectionProperty,
 186                         const PropertyInput& parentOvershootProperty)
 187   {
 188     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 189     const float parentOvershoot = parentOvershootProperty.GetFloat();
 190     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 191
 192     Quaternion rotation;
 193
 194     if(Toolkit::IsVertical(parentOrientation))
 195     {
 196       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 197       {
 198         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 199             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 200         {
 201           rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 202         }
 203         else
 204         {
 205           rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 206         }
 207       }
 208       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 209             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 210       {
 211         rotation = Quaternion(0.0f, Vector3::ZAXIS);
 212       }
 213       else
 214       {
 215         rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 216       }
 217     }
 218     else
 219     {
 220       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 221       {
 222         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot > Math::MACHINE_EPSILON_0)
 223             ||(parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot < Math::MACHINE_EPSILON_0) )
 224         {
 225           rotation = Quaternion(Math::PI, Vector3::ZAXIS);
 226         }
 227         else
 228         {
 229           rotation = Quaternion(0.0f, Vector3::ZAXIS);
 230         }
 231       }
 232       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 233             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 234       {
 235         rotation = Quaternion(1.5f * Math::PI, Vector3::ZAXIS);
 236       }
 237       else
 238       {
 239         rotation = Quaternion(0.5f * Math::PI, Vector3::ZAXIS);
 240       }
 241     }
 242
 243     return rotation;
 244   }
 245 };
 246
 247 struct OvershootOverlayPositionConstraint
 248 {
 249   Vector3 operator()(const Vector3&    current,
 250                      const PropertyInput& parentSizeProperty,
 251                      const PropertyInput& parentScrollDirectionProperty,
 252                      const PropertyInput& parentOvershootProperty)
 253   {
 254     const Vector3 parentScrollDirection = parentScrollDirectionProperty.GetVector3();
 255     const float parentOvershoot = parentOvershootProperty.GetFloat();
 256     const Vector3 parentSize = parentSizeProperty.GetVector3();
 257     const Toolkit::ControlOrientation::Type& parentOrientation = static_cast<Toolkit::ControlOrientation::Type>(parentScrollDirection.z);
 258
 259     Vector3 relativeOffset;
 260
 261     if(Toolkit::IsVertical(parentOrientation))
 262     {
 263       if(fabsf(parentScrollDirection.y) <= Math::MACHINE_EPSILON_1)
 264       {
 265         if( (parentOrientation == Toolkit::ControlOrientation::Up && parentOvershoot < Math::MACHINE_EPSILON_0)
 266             || (parentOrientation == Toolkit::ControlOrientation::Down && parentOvershoot > Math::MACHINE_EPSILON_0) )
 267         {
 268           relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 269         }
 270         else
 271         {
 272           relativeOffset =Vector3(0.0f, 1.0f, 0.0f);
 273         }
 274       }
 275       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.y > Math::MACHINE_EPSILON_0)
 276             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.y < Math::MACHINE_EPSILON_0) )
 277       {
 278         relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 279       }
 280       else
 281       {
 282         relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 283       }
 284     }
 285     else
 286     {
 287       if(fabsf(parentScrollDirection.x) <= Math::MACHINE_EPSILON_1)
 288       {
 289         if( (parentOrientation == Toolkit::ControlOrientation::Left && parentOvershoot < Math::MACHINE_EPSILON_0)
 290             || (parentOrientation == Toolkit::ControlOrientation::Right && parentOvershoot > Math::MACHINE_EPSILON_0) )
 291         {
 292           relativeOffset = Vector3(0.0f, 0.0f, 0.0f);
 293         }
 294         else
 295         {
 296           relativeOffset = Vector3(1.0f, 1.0f, 0.0f);
 297         }
 298       }
 299       else if( (parentOvershoot > Math::MACHINE_EPSILON_0 && parentScrollDirection.x > Math::MACHINE_EPSILON_0)
 300             || (parentOvershoot < Math::MACHINE_EPSILON_0 && parentScrollDirection.x < Math::MACHINE_EPSILON_0) )
 301       {
 302         relativeOffset = Vector3(0.0f, 1.0f, 0.0f);
 303       }
 304       else
 305       {
 306         relativeOffset = Vector3(1.0f, 0.0f, 0.0f);
 307       }
 308     }
 309
 310     return relativeOffset * parentSize;
 311
 312   }
 313 };
 314
 315 struct OvershootOverlayVisibilityConstraint
 316 {
 317   bool operator()(const bool& current,
 318                   const PropertyInput& parentLayoutScrollableProperty)
 319   {
 320     const bool parentLayoutScrollable = parentLayoutScrollableProperty.GetBoolean();
 321
 322     return parentLayoutScrollable;
 323   }
 324 };
 325
 326 /**
 327  * Relative position Constraint
 328  * Generates the relative position value of the item view based on the layout position,
 329  * and it's relation to the layout domain. This is a value from 0.0f to 1.0f in each axis.
 330  */
 331 Vector3 RelativePositionConstraint(const Vector3& current,
 332                                    const PropertyInput& scrollPositionProperty,
 333                                    const PropertyInput& scrollMinProperty,
 334                                    const PropertyInput& scrollMaxProperty,
 335                                    const PropertyInput& layoutSizeProperty)
 336 {
 337   const Vector3& position = Vector3(0.0f, scrollPositionProperty.GetFloat(), 0.0f);
 338   const Vector3& min = scrollMinProperty.GetVector3();
 339   const Vector3& max = scrollMaxProperty.GetVector3();
 340
 341   Vector3 relativePosition;
 342   Vector3 domainSize = max - min;
 343
 344   relativePosition.x = fabsf(domainSize.x) > Math::MACHINE_EPSILON_1 ? ((min.x - position.x) / fabsf(domainSize.x)) : 0.0f;
 345   relativePosition.y = fabsf(domainSize.y) > Math::MACHINE_EPSILON_1 ? ((min.y - position.y) / fabsf(domainSize.y)) : 0.0f;
 346
 347   return relativePosition;
 348 }
 349
 350 } // unnamed namespace
 351
 352 namespace Dali
 353 {
 354
 355 namespace Toolkit
 356 {
 357
 358 namespace Internal
 359 {
 360
 361 namespace // unnamed namespace
 362 {
 363
 364 bool FindById( const ItemContainer& items, ItemId id )
 365 {
 366   for( ConstItemIter iter = items.begin(); items.end() != iter; ++iter )
 367   {
 368     if( iter->first == id )
 369     {
 370       return true;
 371     }
 372   }
 373
 374   return false;
 375 }
 376
 377 } // unnamed namespace
 378
 379 Dali::Toolkit::ItemView ItemView::New(ItemFactory& factory)
 380 {
 381   // Create the implementation
 382   ItemViewPtr itemView(new ItemView(factory));
 383
 384   // Pass ownership to CustomActor via derived handle
 385   Dali::Toolkit::ItemView handle(*itemView);
 386
 387   // Second-phase init of the implementation
 388   // This can only be done after the CustomActor connection has been made...
 389   itemView->Initialize();
 390
 391   return handle;
 392 }
 393
 394 ItemView::ItemView(ItemFactory& factory)
 395 : Scrollable(),
 396   mItemFactory(factory),
 397   mActiveLayout(NULL),
 398   mDefaultAlphaFunction(Dali::Constraint::DEFAULT_ALPHA_FUNCTION),
 399   mAnimatingOvershootOn(false),
 400   mAnimateOvershootOff(false),
 401   mAnchoringEnabled(true),
 402   mAnchoringDuration(DEFAULT_ANCHORING_DURATION),
 403   mRefreshIntervalMilliseconds(DEFAULT_REFRESH_INTERVAL_MILLISECONDS),
 404   mRefreshOrderHint(true/*Refresh item 0 first*/),
 405   mMinimumSwipeSpeed(DEFAULT_MINIMUM_SWIPE_SPEED),
 406   mMinimumSwipeDistance(DEFAULT_MINIMUM_SWIPE_DISTANCE),
 407   mScrollDistance(0.0f),
 408   mScrollSpeed(0.0f),
 409   mTotalPanDisplacement(Vector2::ZERO),
 410   mScrollOvershoot(0.0f),
 411   mIsFlicking(false),
 412   mGestureState(Gesture::Clear)
 413 {
 414   SetRequiresMouseWheelEvents(true);
 415   SetKeyboardNavigationSupport(true);
 416 }
 417
 418 void ItemView::OnInitialize()
 419 {
 420   SetSizePolicy( Toolkit::Control::Fixed, Toolkit::Control::Fixed );
 421
 422   RegisterCommonProperties();
 423
 424   Actor self = Self();
 425
 426   mOvershootEffect = OvershootRippleEffect::New();
 427   Image overshootImage = Image::New( OVERSHOOT_OVERLAY_RIPPLE_IMAGE_PATH );
 428   mOvershootOverlay = ImageActor::New( overshootImage );
 429   mOvershootOverlay.SetParentOrigin(ParentOrigin::TOP_LEFT);
 430   mOvershootOverlay.SetAnchorPoint(AnchorPoint::TOP_LEFT);
 431   mOvershootOverlay.SetDrawMode(DrawMode::OVERLAY);
 432   mOvershootOverlay.SetShaderEffect(mOvershootEffect);
 433   mOvershootOverlay.SetPixelArea(OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA);
 434   self.Add(mOvershootOverlay);
 435
 436   mScrollConnector = Dali::Toolkit::ScrollConnector::New();
 437   mScrollPositionObject = mScrollConnector.GetScrollPositionObject();
 438
 439   mPropertyMinimumLayoutPosition = self.RegisterProperty(MINIMUM_LAYOUT_POSITION_PROPERTY_NAME, 0.0f);
 440   mPropertyPosition = self.RegisterProperty(POSITION_PROPERTY_NAME, 0.0f);
 441   mPropertyScrollSpeed = self.RegisterProperty(SCROLL_SPEED_PROPERTY_NAME, 0.0f);
 442
 443   ApplyOvershootOverlayConstraints();
 444
 445   Constraint constraint = Constraint::New<Vector3>(mPropertyRelativePosition,
 446                                                    LocalSource(mPropertyPosition),
 447                                                    LocalSource(mPropertyPositionMin),
 448                                                    LocalSource(mPropertyPositionMax),
 449                                                    LocalSource(Actor::SIZE),
 450                                                    RelativePositionConstraint);
 451   self.ApplyConstraint(constraint);
 452
 453   Vector2 stageSize = Stage::GetCurrent().GetSize();
 454   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 455
 456   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 457
 458   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 459   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 460 }
 461
 462 ItemView::~ItemView()
 463 {
 464 }
 465
 466 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 467 {
 468   return mScrollConnector;
 469 }
 470
 471 unsigned int ItemView::GetLayoutCount() const
 472 {
 473   return mLayouts.size();
 474 }
 475
 476 void ItemView::AddLayout(ItemLayout& layout)
 477 {
 478   mLayouts.push_back(ItemLayoutPtr(&layout));
 479 }
 480
 481 void ItemView::RemoveLayout(unsigned int layoutIndex)
 482 {
 483   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 484
 485   if (mActiveLayout == mLayouts[layoutIndex].Get())
 486   {
 487     mActiveLayout = NULL;
 488   }
 489
 490   mLayouts.erase(mLayouts.begin() + layoutIndex);
 491 }
 492
 493 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 494 {
 495   return mLayouts[layoutIndex];
 496 }
 497
 498 ItemLayoutPtr ItemView::GetActiveLayout() const
 499 {
 500   return ItemLayoutPtr(mActiveLayout);
 501 }
 502
 503 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 504 {
 505   return mScrollPositionObject.GetProperty<float>( ScrollConnector::SCROLL_POSITION ) + static_cast<float>( itemId );
 506 }
 507
 508 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 509 {
 510   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 511
 512   Actor self = Self();
 513
 514   // The ItemView size should match the active layout size
 515   self.SetSize(targetSize);
 516   mActiveLayoutTargetSize = targetSize;
 517
 518   // Switch to the new layout
 519   mActiveLayout = mLayouts[layoutIndex].Get();
 520
 521   // Move the items to the new layout positions...
 522
 523   bool resizeAnimationNeeded(false);
 524
 525   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 526   {
 527     unsigned int itemId = iter->first;
 528     Actor actor = iter->second;
 529
 530     // Remove constraints from previous layout
 531     actor.RemoveConstraints();
 532
 533     Vector3 size;
 534     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 535     {
 536       if( durationSeconds > 0.0f )
 537       {
 538         // Use a size animation
 539         if (!resizeAnimationNeeded)
 540         {
 541           resizeAnimationNeeded = true;
 542           RemoveAnimation(mResizeAnimation);
 543           mResizeAnimation = Animation::New(durationSeconds);
 544         }
 545
 546         // The layout provides its own resize animation
 547         mActiveLayout->GetResizeAnimation(mResizeAnimation, actor, size, durationSeconds);
 548       }
 549       else
 550       {
 551         // resize immediately
 552         actor.SetSize(size);
 553       }
 554     }
 555
 556     ApplyConstraints(actor, *mActiveLayout, itemId, durationSeconds);
 557   }
 558
 559   if (resizeAnimationNeeded)
 560   {
 561     mResizeAnimation.Play();
 562   }
 563
 564   // Refresh the new layout
 565   ItemRange range = GetItemRange(*mActiveLayout, targetSize, true/*reserve extra*/);
 566   AddActorsWithinRange( range, durationSeconds );
 567
 568   // Scroll to an appropriate layout position
 569
 570   bool scrollAnimationNeeded(false);
 571   float firstItemScrollPosition(0.0f);
 572
 573   float current = GetCurrentLayoutPosition(0);
 574   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 575   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 576
 577   if (current < minimum)
 578   {
 579     scrollAnimationNeeded = true;
 580     firstItemScrollPosition = minimum;
 581   }
 582   else if (mAnchoringEnabled)
 583   {
 584     scrollAnimationNeeded = true;
 585     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 586   }
 587
 588   if (scrollAnimationNeeded)
 589   {
 590     RemoveAnimation(mScrollAnimation);
 591     mScrollAnimation = Animation::New(mAnchoringDuration);
 592     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 593     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 594     mScrollAnimation.Play();
 595   }
 596
 597   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 598   AnimateScrollOvershoot(0.0f);
 599   mScrollOvershoot = 0.0f;
 600
 601   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 602   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 603   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 604
 605   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 606
 607   CalculateDomainSize(targetSize);
 608 }
 609
 610 void ItemView::DeactivateCurrentLayout()
 611 {
 612   if (mActiveLayout)
 613   {
 614     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 615     {
 616       Actor actor = iter->second;
 617       actor.RemoveConstraints();
 618     }
 619
 620     mActiveLayout = NULL;
 621   }
 622
 623   CancelRefreshTimer();
 624 }
 625
 626 void ItemView::SetDefaultAlphaFunction(AlphaFunction func)
 627 {
 628   mDefaultAlphaFunction = func;
 629 }
 630
 631 AlphaFunction ItemView::GetDefaultAlphaFunction() const
 632 {
 633   return mDefaultAlphaFunction;
 634 }
 635
 636 bool ItemView::OnRefreshTick()
 637 {
 638   // Short-circuit if there is no active layout
 639   if (!mActiveLayout)
 640   {
 641     return false;
 642   }
 643
 644   ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, true/*reserve extra*/);
 645
 646   RemoveActorsOutsideRange( range );
 647
 648   AddActorsWithinRange( range, 0.0f/*immediate*/ );
 649
 650   // Keep refreshing whilst the layout is moving
 651   return mScrollAnimation || (mGestureState == Gesture::Started || mGestureState == Gesture::Continuing);
 652 }
 653
 654 void ItemView::SetMinimumSwipeSpeed(float speed)
 655 {
 656   mMinimumSwipeSpeed = speed;
 657 }
 658
 659 float ItemView::GetMinimumSwipeSpeed() const
 660 {
 661   return mMinimumSwipeSpeed;
 662 }
 663
 664 void ItemView::SetMinimumSwipeDistance(float distance)
 665 {
 666   mMinimumSwipeDistance = distance;
 667 }
 668
 669 float ItemView::GetMinimumSwipeDistance() const
 670 {
 671   return mMinimumSwipeDistance;
 672 }
 673
 674 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 675 {
 676   mMouseWheelScrollDistanceStep = step;
 677 }
 678
 679 float ItemView::GetMouseWheelScrollDistanceStep() const
 680 {
 681   return mMouseWheelScrollDistanceStep;
 682 }
 683
 684 void ItemView::SetAnchoring(bool enabled)
 685 {
 686   mAnchoringEnabled = enabled;
 687 }
 688
 689 bool ItemView::GetAnchoring() const
 690 {
 691   return mAnchoringEnabled;
 692 }
 693
 694 void ItemView::SetAnchoringDuration(float durationSeconds)
 695 {
 696   mAnchoringDuration = durationSeconds;
 697 }
 698
 699 float ItemView::GetAnchoringDuration() const
 700 {
 701   return mAnchoringDuration;
 702 }
 703
 704 void ItemView::SetRefreshInterval(unsigned int intervalMilliseconds)
 705 {
 706   mRefreshIntervalMilliseconds = intervalMilliseconds;
 707 }
 708
 709 unsigned int ItemView::GetRefreshInterval() const
 710 {
 711   return mRefreshIntervalMilliseconds;
 712 }
 713
 714 Actor ItemView::GetItem(unsigned int itemId) const
 715 {
 716   Actor actor;
 717
 718   ConstItemPoolIter iter = mItemPool.find( itemId );
 719   if( iter != mItemPool.end() )
 720   {
 721     actor = iter->second;
 722   }
 723
 724   return actor;
 725 }
 726
 727 unsigned int ItemView::GetItemId( Actor actor ) const
 728 {
 729   unsigned int itemId( 0 );
 730
 731   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 732   {
 733     if( iter->second == actor )
 734     {
 735       itemId = iter->first;
 736       break;
 737     }
 738   }
 739
 740   return itemId;
 741 }
 742
 743 void ItemView::InsertItem( Item newItem, float durationSeconds )
 744 {
 745   SetupActor( newItem, durationSeconds );
 746   Self().Add( newItem.second );
 747
 748   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 749   if( mItemPool.end() != foundIter )
 750   {
 751     Actor moveMe = foundIter->second;
 752     foundIter->second = newItem.second;
 753
 754     // Move the existing actors to make room
 755     for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 756     {
 757       Actor temp = iter->second;
 758       iter->second = moveMe;
 759       moveMe = temp;
 760
 761       iter->second.RemoveConstraints();
 762       ApplyConstraints( iter->second, *mActiveLayout, iter->first, durationSeconds );
 763     }
 764
 765     // Create last item
 766     ItemId lastId = mItemPool.rbegin()->first;
 767     Item lastItem( lastId + 1, moveMe );
 768     mItemPool.insert( lastItem );
 769
 770     lastItem.second.RemoveConstraints();
 771     ApplyConstraints( lastItem.second, *mActiveLayout, lastItem.first, durationSeconds );
 772   }
 773   else
 774   {
 775     mItemPool.insert( newItem );
 776   }
 777 }
 778
 779 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 780 {
 781   // Insert from lowest id to highest
 782   set<Item> sortedItems;
 783   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 784   {
 785     sortedItems.insert( *iter );
 786   }
 787
 788   for( set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 789   {
 790     Self().Add( iter->second );
 791
 792     cout << "inserting item: " << iter->first << endl;
 793
 794     ItemPoolIter foundIter = mItemPool.find( iter->first );
 795     if( mItemPool.end() != foundIter )
 796     {
 797       Actor moveMe = foundIter->second;
 798       foundIter->second = iter->second;
 799
 800       // Move the existing actors to make room
 801       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 802       {
 803         Actor temp = iter->second;
 804         iter->second = moveMe;
 805         moveMe = temp;
 806       }
 807
 808       // Create last item
 809       ItemId lastId = mItemPool.rbegin()->first;
 810       Item lastItem( lastId + 1, moveMe );
 811       mItemPool.insert( lastItem );
 812     }
 813     else
 814     {
 815       mItemPool.insert( *iter );
 816     }
 817   }
 818
 819   // Relayout everything
 820   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 821   {
 822     // If newly inserted
 823     if( FindById( newItems, iter->first ) )
 824     {
 825       SetupActor( *iter, durationSeconds );
 826     }
 827     else
 828     {
 829       iter->second.RemoveConstraints();
 830       ApplyConstraints( iter->second, *mActiveLayout, iter->first, durationSeconds );
 831     }
 832   }
 833 }
 834
 835 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 836 {
 837   bool actorRemoved = RemoveActor( itemId );
 838   if( actorRemoved )
 839   {
 840     ReapplyAllConstraints( durationSeconds );
 841   }
 842 }
 843
 844 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 845 {
 846   bool actorRemoved( false );
 847
 848   // Remove from highest id to lowest
 849   set<ItemId> sortedItems;
 850   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 851   {
 852     sortedItems.insert( *iter );
 853   }
 854
 855   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 856   {
 857     if( RemoveActor( *iter ) )
 858     {
 859       actorRemoved = true;
 860     }
 861   }
 862
 863   if( actorRemoved )
 864   {
 865     ReapplyAllConstraints( durationSeconds );
 866   }
 867 }
 868
 869 bool ItemView::RemoveActor(unsigned int itemId)
 870 {
 871   bool removed( false );
 872
 873   const ItemPoolIter removeIter = mItemPool.find( itemId );
 874
 875   if( removeIter != mItemPool.end() )
 876   {
 877     Self().Remove( removeIter->second );
 878     removed = true;
 879
 880     // Adjust the remaining item IDs, for example if item 2 is removed:
 881     //   Initial actors:     After insert:
 882     //     ID 1 - ActorA       ID 1 - ActorA
 883     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 884     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 885     //     ID 4 - ActorD
 886     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 887     {
 888       if( iter->first < mItemPool.rbegin()->first )
 889       {
 890         iter->second = mItemPool[ iter->first + 1 ];
 891       }
 892       else
 893       {
 894         mItemPool.erase( iter );
 895         break;
 896       }
 897     }
 898   }
 899
 900   return removed;
 901 }
 902
 903 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 904 {
 905   SetupActor( replacementItem, durationSeconds );
 906   Self().Add( replacementItem.second );
 907
 908   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 909   if( mItemPool.end() != iter )
 910   {
 911     Self().Remove( iter->second );
 912     iter->second = replacementItem.second;
 913   }
 914   else
 915   {
 916     mItemPool.insert( replacementItem );
 917   }
 918 }
 919
 920 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 921 {
 922   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 923   {
 924     ReplaceItem( *iter, durationSeconds );
 925   }
 926 }
 927
 928 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 929 {
 930   // Remove unwanted actors from the ItemView & ItemPool
 931   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 932   {
 933     unsigned int current = iter->first;
 934
 935     if( ! range.Within( current ) )
 936     {
 937       Self().Remove( iter->second );
 938
 939       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 940     }
 941     else
 942     {
 943       ++iter;
 944     }
 945   }
 946 }
 947
 948 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 949 {
 950   range.end = min(mItemFactory.GetNumberOfItems(), range.end);
 951
 952   // The order of addition depends on the scroll direction.
 953   if (mRefreshOrderHint)
 954   {
 955     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 956     {
 957       AddNewActor( itemId, durationSeconds );
 958     }
 959   }
 960   else
 961   {
 962     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 963     {
 964       AddNewActor( itemId-1, durationSeconds );
 965     }
 966   }
 967 }
 968
 969 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
 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
 987 void ItemView::SetupActor( Item item, float durationSeconds )
 988 {
 989   item.second.SetParentOrigin( ParentOrigin::CENTER );
 990   item.second.SetAnchorPoint( AnchorPoint::CENTER );
 991
 992   if( mActiveLayout )
 993   {
 994     Vector3 size;
 995     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
 996     {
 997       item.second.SetSize( size );
 998     }
 999
1000     ApplyConstraints( item.second, *mActiveLayout, item.first, durationSeconds );
1001   }
1002 }
1003
1004 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, bool reserveExtra)
1005 {
1006   unsigned int itemCount = mItemFactory.GetNumberOfItems();
1007
1008   ItemRange available(0u, itemCount);
1009
1010   ItemRange range = layout.GetItemsWithinArea( GetCurrentLayoutPosition(0), layoutSize );
1011
1012   if (reserveExtra)
1013   {
1014     // Add the reserve items for scrolling
1015     unsigned int extra = layout.GetReserveItemCount(layoutSize);
1016     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
1017     range.end += extra;
1018   }
1019
1020   return range.Intersection(available);
1021 }
1022
1023 bool ItemView::OnTouchEvent(const TouchEvent& event)
1024 {
1025   // Ignore events with multiple-touch points
1026   if (event.GetPointCount() != 1)
1027   {
1028     return false;
1029   }
1030
1031   if (event.GetPoint(0).state == TouchPoint::Down)
1032   {
1033     // Cancel ongoing scrolling etc.
1034     mGestureState = Gesture::Clear;
1035
1036     mScrollDistance = 0.0f;
1037     mScrollSpeed = 0.0f;
1038     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
1039
1040     mScrollOvershoot = 0.0f;
1041     AnimateScrollOvershoot(0.0f);
1042
1043     mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1044
1045     RemoveAnimation(mScrollAnimation);
1046   }
1047
1048   return true; // consume since we're potentially scrolling
1049 }
1050
1051 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
1052 {
1053   // Respond the mouse wheel event to scroll
1054   if (mActiveLayout)
1055   {
1056     Actor self = Self();
1057     const Vector3 layoutSize = Self().GetCurrentSize();
1058     float layoutPositionDelta = GetCurrentLayoutPosition(0) + (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
1059     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1060
1061     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1062     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1063     mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1064     StartRefreshTimer();
1065   }
1066
1067   if (mMouseWheelEventFinishedTimer.IsRunning())
1068   {
1069     mMouseWheelEventFinishedTimer.Stop();
1070   }
1071
1072   mMouseWheelEventFinishedTimer.Start();
1073
1074   return true;
1075 }
1076
1077 bool ItemView::OnMouseWheelEventFinished()
1078 {
1079   if (mActiveLayout)
1080   {
1081     RemoveAnimation(mScrollAnimation);
1082
1083     // No more mouse wheel events coming. Do the anchoring if enabled.
1084     mScrollAnimation = DoAnchoring();
1085     if (mScrollAnimation)
1086     {
1087       StartRefreshTimer();
1088
1089       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1090       mScrollAnimation.Play();
1091     }
1092     else
1093     {
1094       mScrollOvershoot = 0.0f;
1095       AnimateScrollOvershoot(0.0f);
1096
1097       mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1098     }
1099   }
1100
1101   return false;
1102 }
1103
1104 void ItemView::ApplyConstraints(Actor& actor, ItemLayout& layout, unsigned int itemId, float duration)
1105 {
1106   ItemLayout::Vector3Function positionConstraint;
1107   if (layout.GetPositionConstraint(itemId, positionConstraint))
1108   {
1109     WrappedVector3Constraint wrapped(positionConstraint, itemId);
1110
1111     Constraint constraint = Constraint::New<Vector3>( Actor::POSITION,
1112                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1113                                                       ParentSource( mPropertyScrollSpeed ),
1114                                                       ParentSource( Actor::SIZE ),
1115                                                       wrapped );
1116     constraint.SetApplyTime(duration);
1117     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1118
1119     actor.ApplyConstraint(constraint);
1120   }
1121
1122   ItemLayout::QuaternionFunction rotationConstraint;
1123   if (layout.GetRotationConstraint(itemId, rotationConstraint))
1124   {
1125     WrappedQuaternionConstraint wrapped(rotationConstraint, itemId);
1126
1127     Constraint constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1128                                                          Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1129                                                          ParentSource( mPropertyScrollSpeed ),
1130                                                          ParentSource( Actor::SIZE ),
1131                                                          wrapped );
1132     constraint.SetApplyTime(duration);
1133     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1134
1135     actor.ApplyConstraint(constraint);
1136   }
1137
1138   ItemLayout::Vector3Function scaleConstraint;
1139   if (layout.GetScaleConstraint(itemId, scaleConstraint))
1140   {
1141     WrappedVector3Constraint wrapped(scaleConstraint, itemId);
1142
1143     Constraint constraint = Constraint::New<Vector3>( Actor::SCALE,
1144                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1145                                                       ParentSource( mPropertyScrollSpeed ),
1146                                                       ParentSource( Actor::SIZE ),
1147                                                       wrapped );
1148     constraint.SetApplyTime(duration);
1149     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1150
1151     actor.ApplyConstraint(constraint);
1152   }
1153
1154   ItemLayout::Vector4Function colorConstraint;
1155   if (layout.GetColorConstraint(itemId, colorConstraint))
1156   {
1157     WrappedVector4Constraint wrapped(colorConstraint, itemId);
1158
1159     Constraint constraint = Constraint::New<Vector4>( Actor::COLOR,
1160                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1161                                                       ParentSource( mPropertyScrollSpeed ),
1162                                                       ParentSource( Actor::SIZE ),
1163                                                       wrapped );
1164     constraint.SetApplyTime(duration);
1165     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1166
1167     // Release color constraints slowly; this allows ItemView to co-exist with ImageActor fade-in
1168     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1169     constraint.SetRemoveAction(Dali::Constraint::Discard);
1170
1171     actor.ApplyConstraint(constraint);
1172   }
1173
1174   ItemLayout::BoolFunction visibilityConstraint;
1175   if (layout.GetVisibilityConstraint(itemId, visibilityConstraint))
1176   {
1177     WrappedBoolConstraint wrapped(visibilityConstraint, itemId);
1178
1179     Constraint constraint = Constraint::New<bool>( Actor::VISIBLE,
1180                                                    Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1181                                                    ParentSource( mPropertyScrollSpeed ),
1182                                                    ParentSource( Actor::SIZE ),
1183                                                    wrapped );
1184     constraint.SetApplyTime(duration);
1185     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1186
1187     // Release visibility constraints the same time as the color constraint
1188     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1189     constraint.SetRemoveAction(Dali::Constraint::Discard);
1190
1191     actor.ApplyConstraint(constraint);
1192   }
1193 }
1194
1195 void ItemView::ReapplyAllConstraints( float durationSeconds )
1196 {
1197   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1198   {
1199     unsigned int id = iter->first;
1200     Actor actor = iter->second;
1201
1202     actor.RemoveConstraints();
1203     ApplyConstraints(actor, *mActiveLayout, id, durationSeconds);
1204   }
1205
1206   CalculateDomainSize(Self().GetCurrentSize());
1207 }
1208
1209 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1210 {
1211   Actor self = Self();
1212   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1213   float clamppedPosition = min(0.0f, max(minLayoutPosition, targetPosition));
1214   mScrollOvershoot = targetPosition - clamppedPosition;
1215   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1216
1217   return clamppedPosition;
1218 }
1219
1220 void ItemView::OnPan(PanGesture gesture)
1221 {
1222   Actor self = Self();
1223   const Vector3 layoutSize = Self().GetCurrentSize();
1224
1225   RemoveAnimation(mScrollAnimation);
1226
1227   // Short-circuit if there is no active layout
1228   if (!mActiveLayout)
1229   {
1230     mGestureState = Gesture::Clear;
1231     return;
1232   }
1233
1234   mGestureState = gesture.state;
1235
1236   switch (mGestureState)
1237   {
1238     case Gesture::Finished:
1239     {
1240       // Swipe Detection
1241       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1242           mScrollSpeed > mMinimumSwipeSpeed)
1243       {
1244         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1245
1246         mRefreshOrderHint = true;
1247
1248         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1249         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1250                                                                layoutSize,
1251                                                                *mActiveLayout);
1252
1253         if (mAnchoringEnabled)
1254         {
1255           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1256         }
1257
1258         RemoveAnimation(mScrollAnimation);
1259
1260         float flickAnimationDuration = mActiveLayout->GetItemFlickAnimationDuration() * max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)));
1261         mScrollAnimation = Animation::New(flickAnimationDuration);
1262         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1263         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1264         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1265
1266         mIsFlicking = true;
1267         // Check whether it has already scrolled to the end
1268         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1269         {
1270           AnimateScrollOvershoot(0.0f);
1271         }
1272       }
1273
1274       // Anchoring may be triggered when there was no swipe
1275       if (!mScrollAnimation)
1276       {
1277         mScrollAnimation = DoAnchoring();
1278       }
1279
1280       // Reset the overshoot if no scroll animation.
1281       if (!mScrollAnimation)
1282       {
1283         mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1284
1285         AnimateScrollOvershoot(0.0f, false);
1286       }
1287     }
1288     break;
1289
1290     case Gesture::Started: // Fall through
1291     {
1292       mTotalPanDisplacement = Vector2::ZERO;
1293     }
1294
1295     case Gesture::Continuing:
1296     {
1297       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1298       mScrollSpeed = Clamp((gesture.GetSpeed() * mActiveLayout->GetScrollSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1299
1300       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1301       mRefreshOrderHint = mScrollDistance < 0.0f;
1302
1303       RemoveAnimation(mScrollSpeedAnimation);
1304       mScrollSpeedAnimation = Animation::New(0.3f);
1305       mScrollSpeedAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), mScrollSpeed, AlphaFunctions::Linear );
1306       mScrollSpeedAnimation.Play();
1307
1308       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1309
1310       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1311
1312       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1313       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1314       mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1315
1316       mTotalPanDisplacement += gesture.displacement;
1317       mScrollOvershoot = layoutPositionDelta - firstItemScrollPosition;
1318       if( mScrollOvershoot > Math::MACHINE_EPSILON_1 )
1319       {
1320         AnimateScrollOvershoot(1.0f);
1321       }
1322       else if( mScrollOvershoot < -Math::MACHINE_EPSILON_1 )
1323       {
1324         AnimateScrollOvershoot(-1.0f);
1325       }
1326       else
1327       {
1328         AnimateScrollOvershoot(0.0f);
1329       }
1330
1331       StartRefreshTimer();
1332     }
1333     break;
1334
1335     case Gesture::Cancelled:
1336     {
1337       mScrollAnimation = DoAnchoring();
1338     }
1339     break;
1340
1341     default:
1342       break;
1343   }
1344
1345   if (mScrollAnimation)
1346   {
1347     StartRefreshTimer();
1348
1349     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1350     mScrollAnimation.Play();
1351   }
1352 }
1353
1354 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1355 {
1356   OnPan(gesture);
1357   return true;
1358 }
1359
1360 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1361 {
1362   Actor nextFocusActor;
1363   if(mActiveLayout)
1364   {
1365     int nextItemID = 0;
1366     if(!actor || actor == this->Self())
1367     {
1368       nextFocusActor = GetItem(nextItemID);
1369     }
1370     else if(actor && actor.GetParent() == this->Self())
1371     {
1372       int itemID = GetItemId(actor);
1373       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1374       nextFocusActor = GetItem(nextItemID);
1375       if(nextFocusActor == actor)
1376       {
1377         // need to pass NULL actor back to focus manager
1378         nextFocusActor.Reset();
1379         return nextFocusActor;
1380       }
1381     }
1382     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1383     Vector3 layoutSize = Self().GetCurrentSize();
1384     if(!nextFocusActor)
1385     {
1386       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1387       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1388       nextItemID = viewableItems.begin;
1389       nextFocusActor = GetItem(nextItemID);
1390     }
1391   }
1392   return nextFocusActor;
1393 }
1394
1395 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1396 {
1397   // only in this function if our chosen focus actor was actually used
1398   if(commitedFocusableActor)
1399   {
1400     int nextItemID = GetItemId(commitedFocusableActor);
1401     float layoutPosition = GetCurrentLayoutPosition(0);
1402     Vector3 layoutSize = Self().GetCurrentSize();
1403     Vector3 focusItemPosition = Vector3::ZERO;
1404     ItemLayout::Vector3Function itemPositionConstraint;
1405     if (mActiveLayout->GetPositionConstraint(nextItemID, itemPositionConstraint))
1406     {
1407       focusItemPosition = itemPositionConstraint(Vector3::ZERO, layoutPosition + nextItemID, 0.0f, layoutSize);
1408     }
1409
1410     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1411     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1412   }
1413 }
1414
1415 Animation ItemView::DoAnchoring()
1416 {
1417   Animation anchoringAnimation;
1418   Actor self = Self();
1419
1420   if (mActiveLayout && mAnchoringEnabled)
1421   {
1422     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1423
1424     anchoringAnimation = Animation::New(mAnchoringDuration);
1425     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1426     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1427     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1428     if(!mIsFlicking)
1429     {
1430       AnimateScrollOvershoot(0.0f);
1431     }
1432   }
1433
1434   return anchoringAnimation;
1435 }
1436
1437 void ItemView::OnScrollFinished(Animation& source)
1438 {
1439   Actor self = Self();
1440
1441   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1442
1443   mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1444
1445   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1446   {
1447     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1448   }
1449   else
1450   {
1451     // Reset the overshoot
1452     AnimateScrollOvershoot( 0.0f );
1453   }
1454   mIsFlicking = false;
1455
1456   mScrollOvershoot = 0.0f;
1457 }
1458
1459 void ItemView::OnOvershootOnFinished(Animation& animation)
1460 {
1461   mAnimatingOvershootOn = false;
1462   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1463   RemoveAnimation(mScrollOvershootAnimation);
1464   if(mAnimateOvershootOff)
1465   {
1466     AnimateScrollOvershoot(0.0f);
1467   }
1468 }
1469
1470 void ItemView::StartRefreshTimer()
1471 {
1472   if (!mRefreshTimer)
1473   {
1474     mRefreshTimer = Timer::New( mRefreshIntervalMilliseconds );
1475     mRefreshTimer.TickSignal().Connect( this, &ItemView::OnRefreshTick );
1476   }
1477
1478   if (!mRefreshTimer.IsRunning())
1479   {
1480     mRefreshTimer.Start();
1481   }
1482 }
1483
1484 void ItemView::CancelRefreshTimer()
1485 {
1486   if (mRefreshTimer)
1487   {
1488     mRefreshTimer.Stop();
1489   }
1490 }
1491
1492 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1493 {
1494   Actor self = Self();
1495   const Vector3 layoutSize = Self().GetCurrentSize();
1496   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1497
1498   StartRefreshTimer();
1499
1500   if(durationSeconds > 0.0f)
1501   {
1502     RemoveAnimation(mScrollAnimation);
1503     mScrollAnimation = Animation::New(durationSeconds);
1504     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1505     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1506     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1507     mScrollAnimation.Play();
1508   }
1509   else
1510   {
1511     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1512     AnimateScrollOvershoot(0.0f);
1513   }
1514
1515   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1516 }
1517
1518 void ItemView::RemoveAnimation(Animation& animation)
1519 {
1520   if(animation)
1521   {
1522     // Cease animating, and reset handle.
1523     animation.Clear();
1524     animation.Reset();
1525   }
1526 }
1527
1528 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1529 {
1530   Actor self = Self();
1531
1532   Vector3 firstItemPosition(Vector3::ZERO);
1533   Vector3 lastItemPosition(Vector3::ZERO);
1534
1535   if(mActiveLayout)
1536   {
1537     ItemLayout::Vector3Function firstItemPositionConstraint;
1538     if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1539     {
1540       firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, 0, 0.0f, layoutSize);
1541     }
1542
1543     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1544     ItemLayout::Vector3Function lastItemPositionConstraint;
1545     if (mActiveLayout->GetPositionConstraint(fabs(minLayoutPosition), lastItemPositionConstraint))
1546     {
1547       lastItemPosition = lastItemPositionConstraint(Vector3::ZERO, fabs(minLayoutPosition), 0.0f, layoutSize);
1548     }
1549
1550     if(IsHorizontal(mActiveLayout->GetOrientation()))
1551     {
1552       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1553       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1554     }
1555     else
1556     {
1557       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1558       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.y, 0.0f));
1559     }
1560
1561     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1562     self.SetProperty(mPropertyCanScrollVertical, isLayoutScrollable);
1563     self.SetProperty(mPropertyCanScrollHorizontal, false);
1564   }
1565 }
1566
1567 Vector3 ItemView::GetDomainSize() const
1568 {
1569   Actor self = Self();
1570
1571   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1572   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
1573
1574   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1575 }
1576
1577 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1578 {
1579   Actor self = Self();
1580
1581   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1582   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1583   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1584
1585   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1586 }
1587
1588 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1589 {
1590   Vector3 firstItemPosition(Vector3::ZERO);
1591   ItemLayout::Vector3Function firstItemPositionConstraint;
1592   if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1593   {
1594     firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, layoutPosition, 0.0f, layoutSize);
1595   }
1596
1597   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1598 }
1599
1600 Vector3 ItemView::GetCurrentScrollPosition() const
1601 {
1602   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1603   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1604 }
1605
1606 void ItemView::AddOverlay(Actor actor)
1607 {
1608   Self().Add(actor);
1609 }
1610
1611 void ItemView::RemoveOverlay(Actor actor)
1612 {
1613   Self().Remove(actor);
1614 }
1615
1616 void ItemView::ScrollTo(const Vector3& position, float duration)
1617 {
1618   Actor self = Self();
1619   const Vector3 layoutSize = Self().GetCurrentSize();
1620
1621   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1622
1623   StartRefreshTimer();
1624
1625   if(duration > 0.0f)
1626   {
1627     RemoveAnimation(mScrollAnimation);
1628     mScrollAnimation = Animation::New(duration);
1629     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1630     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1631     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1632     mScrollAnimation.Play();
1633   }
1634   else
1635   {
1636     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1637     AnimateScrollOvershoot(0.0f);
1638   }
1639
1640   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1641 }
1642
1643 void ItemView::ApplyOvershootOverlayConstraints()
1644 {
1645   Constraint constraint = Constraint::New<float>( Actor::SIZE_WIDTH,
1646                                                     ParentSource( mPropertyScrollDirection ),
1647                                                     Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1648                                                     ParentSource( Actor::SIZE ),
1649                                                     OvershootOverlaySizeConstraint() );
1650   mOvershootOverlay.ApplyConstraint(constraint);
1651   mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA.width, OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA.height);
1652
1653   constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1654                                             ParentSource( mPropertyScrollDirection ),
1655                                             Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1656                                             OvershootOverlayRotationConstraint() );
1657   mOvershootOverlay.ApplyConstraint(constraint);
1658
1659   constraint = Constraint::New<Vector3>( Actor::POSITION,
1660                                          ParentSource( Actor::SIZE ),
1661                                          ParentSource( mPropertyScrollDirection ),
1662                                          Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1663                                          OvershootOverlayPositionConstraint() );
1664   mOvershootOverlay.ApplyConstraint(constraint);
1665
1666   constraint = Constraint::New<bool>( Actor::VISIBLE,
1667                                       ParentSource( mPropertyCanScrollVertical ),
1668                                       OvershootOverlayVisibilityConstraint() );
1669   mOvershootOverlay.ApplyConstraint(constraint);
1670
1671   int effectOvershootPropertyIndex = mOvershootEffect.GetPropertyIndex(mOvershootEffect.GetOvershootPropertyName());
1672   Actor self = Self();
1673   constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1674                                        Source( mScrollPositionObject, ScrollConnector::OVERSHOOT ),
1675                                        EqualToConstraint() );
1676   mOvershootEffect.ApplyConstraint(constraint);
1677 }
1678
1679 float ItemView::CalculateScrollOvershoot()
1680 {
1681   float overshoot = 0.0f;
1682
1683   if(mActiveLayout)
1684   {
1685     // The overshoot must be calculated from the accumulated pan gesture displacement
1686     // since the pan gesture starts.
1687     Actor self = Self();
1688     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1689     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1690     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1691     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1692     float clamppedPosition = min(0.0f, max(minLayoutPosition, positionDelta));
1693     overshoot = positionDelta - clamppedPosition;
1694   }
1695
1696   return overshoot;
1697 }
1698
1699 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1700 {
1701   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1702
1703   // make sure we animate back if needed
1704   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1705
1706   if( mAnimatingOvershootOn )
1707   {
1708     // animating on, do not allow animate off
1709     return;
1710   }
1711
1712   Actor self = Self();
1713   float currentOvershoot = mScrollPositionObject.GetProperty<float>(ScrollConnector::OVERSHOOT);
1714   float duration = DEFAULT_OVERSHOOT_ANIMATION_DURATION * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot));
1715
1716   RemoveAnimation(mScrollOvershootAnimation);
1717   mScrollOvershootAnimation = Animation::New(duration);
1718   mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1719   mScrollOvershootAnimation.AnimateTo( Property(mScrollPositionObject, ScrollConnector::OVERSHOOT), overshootAmount, TimePeriod(0.0f, duration) );
1720   mScrollOvershootAnimation.Play();
1721
1722   mAnimatingOvershootOn = animatingOn;
1723 }
1724
1725 } // namespace Internal
1726
1727 } // namespace Toolkit
1728
1729 } // namespace Dali