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   mPropertyOvershoot = self.RegisterProperty(OVERSHOOT_PROPERTY_NAME, 0.0f);
 443
 444   ApplyOvershootOverlayConstraints();
 445
 446   Constraint constraint = Constraint::New<Vector3>(mPropertyRelativePosition,
 447                                                    LocalSource(mPropertyPosition),
 448                                                    LocalSource(mPropertyPositionMin),
 449                                                    LocalSource(mPropertyPositionMax),
 450                                                    LocalSource(Actor::SIZE),
 451                                                    RelativePositionConstraint);
 452   self.ApplyConstraint(constraint);
 453
 454   Vector2 stageSize = Stage::GetCurrent().GetSize();
 455   mMouseWheelScrollDistanceStep = stageSize.y * DEFAULT_MOUSE_WHEEL_SCROLL_DISTANCE_STEP_PROPORTION;
 456
 457   EnableGestureDetection(Gesture::Type(Gesture::Pan));
 458
 459   mMouseWheelEventFinishedTimer = Timer::New( MOUSE_WHEEL_EVENT_FINISHED_TIME_OUT );
 460   mMouseWheelEventFinishedTimer.TickSignal().Connect( this, &ItemView::OnMouseWheelEventFinished );
 461 }
 462
 463 ItemView::~ItemView()
 464 {
 465 }
 466
 467 Dali::Toolkit::ScrollConnector ItemView::GetScrollConnector() const
 468 {
 469   return mScrollConnector;
 470 }
 471
 472 unsigned int ItemView::GetLayoutCount() const
 473 {
 474   return mLayouts.size();
 475 }
 476
 477 void ItemView::AddLayout(ItemLayout& layout)
 478 {
 479   mLayouts.push_back(ItemLayoutPtr(&layout));
 480 }
 481
 482 void ItemView::RemoveLayout(unsigned int layoutIndex)
 483 {
 484   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 485
 486   if (mActiveLayout == mLayouts[layoutIndex].Get())
 487   {
 488     mActiveLayout = NULL;
 489   }
 490
 491   mLayouts.erase(mLayouts.begin() + layoutIndex);
 492 }
 493
 494 ItemLayoutPtr ItemView::GetLayout(unsigned int layoutIndex) const
 495 {
 496   return mLayouts[layoutIndex];
 497 }
 498
 499 ItemLayoutPtr ItemView::GetActiveLayout() const
 500 {
 501   return ItemLayoutPtr(mActiveLayout);
 502 }
 503
 504 float ItemView::GetCurrentLayoutPosition(unsigned int itemId) const
 505 {
 506   return mScrollPositionObject.GetProperty<float>( ScrollConnector::SCROLL_POSITION ) + static_cast<float>( itemId );
 507 }
 508
 509 void ItemView::ActivateLayout(unsigned int layoutIndex, const Vector3& targetSize, float durationSeconds)
 510 {
 511   DALI_ASSERT_ALWAYS(layoutIndex < mLayouts.size());
 512
 513   Actor self = Self();
 514
 515   // The ItemView size should match the active layout size
 516   self.SetSize(targetSize);
 517   mActiveLayoutTargetSize = targetSize;
 518
 519   // Switch to the new layout
 520   mActiveLayout = mLayouts[layoutIndex].Get();
 521
 522   // Move the items to the new layout positions...
 523
 524   bool resizeAnimationNeeded(false);
 525
 526   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 527   {
 528     unsigned int itemId = iter->first;
 529     Actor actor = iter->second;
 530
 531     // Remove constraints from previous layout
 532     actor.RemoveConstraints();
 533
 534     Vector3 size;
 535     if(mActiveLayout->GetItemSize(itemId, targetSize, size))
 536     {
 537       if( durationSeconds > 0.0f )
 538       {
 539         // Use a size animation
 540         if (!resizeAnimationNeeded)
 541         {
 542           resizeAnimationNeeded = true;
 543           RemoveAnimation(mResizeAnimation);
 544           mResizeAnimation = Animation::New(durationSeconds);
 545         }
 546
 547         // The layout provides its own resize animation
 548         mActiveLayout->GetResizeAnimation(mResizeAnimation, actor, size, durationSeconds);
 549       }
 550       else
 551       {
 552         // resize immediately
 553         actor.SetSize(size);
 554       }
 555     }
 556
 557     ApplyConstraints(actor, *mActiveLayout, itemId, durationSeconds);
 558   }
 559
 560   if (resizeAnimationNeeded)
 561   {
 562     mResizeAnimation.Play();
 563   }
 564
 565   // Refresh the new layout
 566   ItemRange range = GetItemRange(*mActiveLayout, targetSize, true/*reserve extra*/);
 567   AddActorsWithinRange( range, durationSeconds );
 568
 569   // Scroll to an appropriate layout position
 570
 571   bool scrollAnimationNeeded(false);
 572   float firstItemScrollPosition(0.0f);
 573
 574   float current = GetCurrentLayoutPosition(0);
 575   float minimum = ClampFirstItemPosition(current, targetSize, *mActiveLayout);
 576   self.SetProperty(mPropertyPosition, GetScrollPosition(current, targetSize));
 577
 578   if (current < minimum)
 579   {
 580     scrollAnimationNeeded = true;
 581     firstItemScrollPosition = minimum;
 582   }
 583   else if (mAnchoringEnabled)
 584   {
 585     scrollAnimationNeeded = true;
 586     firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(current);
 587   }
 588
 589   if (scrollAnimationNeeded)
 590   {
 591     RemoveAnimation(mScrollAnimation);
 592     mScrollAnimation = Animation::New(mAnchoringDuration);
 593     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
 594     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, targetSize), AlphaFunctions::EaseOut );
 595     mScrollAnimation.Play();
 596   }
 597
 598   self.SetProperty(mPropertyMinimumLayoutPosition, mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize));
 599   AnimateScrollOvershoot(0.0f);
 600   mScrollOvershoot = 0.0f;
 601
 602   Radian scrollDirection(mActiveLayout->GetScrollDirection());
 603   float orientation = static_cast<float>(mActiveLayout->GetOrientation());
 604   self.SetProperty(mPropertyScrollDirection, Vector3(sinf(scrollDirection), cosf(scrollDirection), orientation));
 605
 606   self.SetProperty(mPropertyScrollSpeed, mScrollSpeed);
 607
 608   CalculateDomainSize(targetSize);
 609 }
 610
 611 void ItemView::DeactivateCurrentLayout()
 612 {
 613   if (mActiveLayout)
 614   {
 615     for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 616     {
 617       Actor actor = iter->second;
 618       actor.RemoveConstraints();
 619     }
 620
 621     mActiveLayout = NULL;
 622   }
 623
 624   CancelRefreshTimer();
 625 }
 626
 627 void ItemView::SetDefaultAlphaFunction(AlphaFunction func)
 628 {
 629   mDefaultAlphaFunction = func;
 630 }
 631
 632 AlphaFunction ItemView::GetDefaultAlphaFunction() const
 633 {
 634   return mDefaultAlphaFunction;
 635 }
 636
 637 bool ItemView::OnRefreshTick()
 638 {
 639   // Short-circuit if there is no active layout
 640   if (!mActiveLayout)
 641   {
 642     return false;
 643   }
 644
 645   ItemRange range = GetItemRange(*mActiveLayout, mActiveLayoutTargetSize, true/*reserve extra*/);
 646
 647   RemoveActorsOutsideRange( range );
 648
 649   AddActorsWithinRange( range, 0.0f/*immediate*/ );
 650
 651   // Keep refreshing whilst the layout is moving
 652   return mScrollAnimation || (mGestureState == Gesture::Started || mGestureState == Gesture::Continuing);
 653 }
 654
 655 void ItemView::SetMinimumSwipeSpeed(float speed)
 656 {
 657   mMinimumSwipeSpeed = speed;
 658 }
 659
 660 float ItemView::GetMinimumSwipeSpeed() const
 661 {
 662   return mMinimumSwipeSpeed;
 663 }
 664
 665 void ItemView::SetMinimumSwipeDistance(float distance)
 666 {
 667   mMinimumSwipeDistance = distance;
 668 }
 669
 670 float ItemView::GetMinimumSwipeDistance() const
 671 {
 672   return mMinimumSwipeDistance;
 673 }
 674
 675 void ItemView::SetMouseWheelScrollDistanceStep(float step)
 676 {
 677   mMouseWheelScrollDistanceStep = step;
 678 }
 679
 680 float ItemView::GetMouseWheelScrollDistanceStep() const
 681 {
 682   return mMouseWheelScrollDistanceStep;
 683 }
 684
 685 void ItemView::SetAnchoring(bool enabled)
 686 {
 687   mAnchoringEnabled = enabled;
 688 }
 689
 690 bool ItemView::GetAnchoring() const
 691 {
 692   return mAnchoringEnabled;
 693 }
 694
 695 void ItemView::SetAnchoringDuration(float durationSeconds)
 696 {
 697   mAnchoringDuration = durationSeconds;
 698 }
 699
 700 float ItemView::GetAnchoringDuration() const
 701 {
 702   return mAnchoringDuration;
 703 }
 704
 705 void ItemView::SetRefreshInterval(unsigned int intervalMilliseconds)
 706 {
 707   mRefreshIntervalMilliseconds = intervalMilliseconds;
 708 }
 709
 710 unsigned int ItemView::GetRefreshInterval() const
 711 {
 712   return mRefreshIntervalMilliseconds;
 713 }
 714
 715 Actor ItemView::GetItem(unsigned int itemId) const
 716 {
 717   Actor actor;
 718
 719   ConstItemPoolIter iter = mItemPool.find( itemId );
 720   if( iter != mItemPool.end() )
 721   {
 722     actor = iter->second;
 723   }
 724
 725   return actor;
 726 }
 727
 728 unsigned int ItemView::GetItemId( Actor actor ) const
 729 {
 730   unsigned int itemId( 0 );
 731
 732   for ( ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter )
 733   {
 734     if( iter->second == actor )
 735     {
 736       itemId = iter->first;
 737       break;
 738     }
 739   }
 740
 741   return itemId;
 742 }
 743
 744 void ItemView::InsertItem( Item newItem, float durationSeconds )
 745 {
 746   SetupActor( newItem, durationSeconds );
 747   Self().Add( newItem.second );
 748
 749   ItemPoolIter foundIter = mItemPool.find( newItem.first );
 750   if( mItemPool.end() != foundIter )
 751   {
 752     Actor moveMe = foundIter->second;
 753     foundIter->second = newItem.second;
 754
 755     // Move the existing actors to make room
 756     for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 757     {
 758       Actor temp = iter->second;
 759       iter->second = moveMe;
 760       moveMe = temp;
 761
 762       iter->second.RemoveConstraints();
 763       ApplyConstraints( iter->second, *mActiveLayout, iter->first, durationSeconds );
 764     }
 765
 766     // Create last item
 767     ItemId lastId = mItemPool.rbegin()->first;
 768     Item lastItem( lastId + 1, moveMe );
 769     mItemPool.insert( lastItem );
 770
 771     lastItem.second.RemoveConstraints();
 772     ApplyConstraints( lastItem.second, *mActiveLayout, lastItem.first, durationSeconds );
 773   }
 774   else
 775   {
 776     mItemPool.insert( newItem );
 777   }
 778 }
 779
 780 void ItemView::InsertItems( const ItemContainer& newItems, float durationSeconds )
 781 {
 782   // Insert from lowest id to highest
 783   set<Item> sortedItems;
 784   for( ConstItemIter iter = newItems.begin(); newItems.end() != iter; ++iter )
 785   {
 786     sortedItems.insert( *iter );
 787   }
 788
 789   for( set<Item>::iterator iter = sortedItems.begin(); sortedItems.end() != iter; ++iter )
 790   {
 791     Self().Add( iter->second );
 792
 793     cout << "inserting item: " << iter->first << endl;
 794
 795     ItemPoolIter foundIter = mItemPool.find( iter->first );
 796     if( mItemPool.end() != foundIter )
 797     {
 798       Actor moveMe = foundIter->second;
 799       foundIter->second = iter->second;
 800
 801       // Move the existing actors to make room
 802       for( ItemPoolIter iter = ++foundIter; mItemPool.end() != iter; ++iter )
 803       {
 804         Actor temp = iter->second;
 805         iter->second = moveMe;
 806         moveMe = temp;
 807       }
 808
 809       // Create last item
 810       ItemId lastId = mItemPool.rbegin()->first;
 811       Item lastItem( lastId + 1, moveMe );
 812       mItemPool.insert( lastItem );
 813     }
 814     else
 815     {
 816       mItemPool.insert( *iter );
 817     }
 818   }
 819
 820   // Relayout everything
 821   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
 822   {
 823     // If newly inserted
 824     if( FindById( newItems, iter->first ) )
 825     {
 826       SetupActor( *iter, durationSeconds );
 827     }
 828     else
 829     {
 830       iter->second.RemoveConstraints();
 831       ApplyConstraints( iter->second, *mActiveLayout, iter->first, durationSeconds );
 832     }
 833   }
 834 }
 835
 836 void ItemView::RemoveItem( unsigned int itemId, float durationSeconds )
 837 {
 838   bool actorRemoved = RemoveActor( itemId );
 839   if( actorRemoved )
 840   {
 841     ReapplyAllConstraints( durationSeconds );
 842   }
 843 }
 844
 845 void ItemView::RemoveItems( const ItemIdContainer& itemIds, float durationSeconds )
 846 {
 847   bool actorRemoved( false );
 848
 849   // Remove from highest id to lowest
 850   set<ItemId> sortedItems;
 851   for( ConstItemIdIter iter = itemIds.begin(); itemIds.end() != iter; ++iter )
 852   {
 853     sortedItems.insert( *iter );
 854   }
 855
 856   for( set<ItemId>::reverse_iterator iter = sortedItems.rbegin(); sortedItems.rend() != iter; ++iter )
 857   {
 858     if( RemoveActor( *iter ) )
 859     {
 860       actorRemoved = true;
 861     }
 862   }
 863
 864   if( actorRemoved )
 865   {
 866     ReapplyAllConstraints( durationSeconds );
 867   }
 868 }
 869
 870 bool ItemView::RemoveActor(unsigned int itemId)
 871 {
 872   bool removed( false );
 873
 874   const ItemPoolIter removeIter = mItemPool.find( itemId );
 875
 876   if( removeIter != mItemPool.end() )
 877   {
 878     Self().Remove( removeIter->second );
 879     removed = true;
 880
 881     // Adjust the remaining item IDs, for example if item 2 is removed:
 882     //   Initial actors:     After insert:
 883     //     ID 1 - ActorA       ID 1 - ActorA
 884     //     ID 2 - ActorB       ID 2 - ActorC (previously ID 3)
 885     //     ID 3 - ActorC       ID 3 - ActorB (previously ID 4)
 886     //     ID 4 - ActorD
 887     for (ItemPoolIter iter = removeIter; iter != mItemPool.end(); ++iter)
 888     {
 889       if( iter->first < mItemPool.rbegin()->first )
 890       {
 891         iter->second = mItemPool[ iter->first + 1 ];
 892       }
 893       else
 894       {
 895         mItemPool.erase( iter );
 896         break;
 897       }
 898     }
 899   }
 900
 901   return removed;
 902 }
 903
 904 void ItemView::ReplaceItem( Item replacementItem, float durationSeconds )
 905 {
 906   SetupActor( replacementItem, durationSeconds );
 907   Self().Add( replacementItem.second );
 908
 909   const ItemPoolIter iter = mItemPool.find( replacementItem.first );
 910   if( mItemPool.end() != iter )
 911   {
 912     Self().Remove( iter->second );
 913     iter->second = replacementItem.second;
 914   }
 915   else
 916   {
 917     mItemPool.insert( replacementItem );
 918   }
 919 }
 920
 921 void ItemView::ReplaceItems( const ItemContainer& replacementItems, float durationSeconds )
 922 {
 923   for( ConstItemIter iter = replacementItems.begin(); replacementItems.end() != iter; ++iter )
 924   {
 925     ReplaceItem( *iter, durationSeconds );
 926   }
 927 }
 928
 929 void ItemView::RemoveActorsOutsideRange( ItemRange range )
 930 {
 931   // Remove unwanted actors from the ItemView & ItemPool
 932   for (ItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); )
 933   {
 934     unsigned int current = iter->first;
 935
 936     if( ! range.Within( current ) )
 937     {
 938       Self().Remove( iter->second );
 939
 940       mItemPool.erase( iter++ ); // erase invalidates the return value of post-increment; iter remains valid
 941     }
 942     else
 943     {
 944       ++iter;
 945     }
 946   }
 947 }
 948
 949 void ItemView::AddActorsWithinRange( ItemRange range, float durationSeconds )
 950 {
 951   range.end = min(mItemFactory.GetNumberOfItems(), range.end);
 952
 953   // The order of addition depends on the scroll direction.
 954   if (mRefreshOrderHint)
 955   {
 956     for (unsigned int itemId = range.begin; itemId < range.end; ++itemId)
 957     {
 958       AddNewActor( itemId, durationSeconds );
 959     }
 960   }
 961   else
 962   {
 963     for (unsigned int itemId = range.end; itemId > range.begin; --itemId)
 964     {
 965       AddNewActor( itemId-1, durationSeconds );
 966     }
 967   }
 968 }
 969
 970 void ItemView::AddNewActor( unsigned int itemId, float durationSeconds )
 971 {
 972   if( mItemPool.end() == mItemPool.find( itemId ) )
 973   {
 974     Actor actor = mItemFactory.NewItem( itemId );
 975
 976     if( actor )
 977     {
 978       Item newItem( itemId, actor );
 979
 980       mItemPool.insert( newItem );
 981
 982       SetupActor( newItem, durationSeconds );
 983       Self().Add( actor );
 984     }
 985   }
 986 }
 987
 988 void ItemView::SetupActor( Item item, float durationSeconds )
 989 {
 990   item.second.SetParentOrigin( ParentOrigin::CENTER );
 991   item.second.SetAnchorPoint( AnchorPoint::CENTER );
 992
 993   if( mActiveLayout )
 994   {
 995     Vector3 size;
 996     if( mActiveLayout->GetItemSize( item.first, mActiveLayoutTargetSize, size ) )
 997     {
 998       item.second.SetSize( size );
 999     }
1000
1001     ApplyConstraints( item.second, *mActiveLayout, item.first, durationSeconds );
1002   }
1003 }
1004
1005 ItemRange ItemView::GetItemRange(ItemLayout& layout, const Vector3& layoutSize, bool reserveExtra)
1006 {
1007   unsigned int itemCount = mItemFactory.GetNumberOfItems();
1008
1009   ItemRange available(0u, itemCount);
1010
1011   ItemRange range = layout.GetItemsWithinArea( GetCurrentLayoutPosition(0), layoutSize );
1012
1013   if (reserveExtra)
1014   {
1015     // Add the reserve items for scrolling
1016     unsigned int extra = layout.GetReserveItemCount(layoutSize);
1017     range.begin = (range.begin >= extra) ? (range.begin - extra) : 0u;
1018     range.end += extra;
1019   }
1020
1021   return range.Intersection(available);
1022 }
1023
1024 bool ItemView::OnTouchEvent(const TouchEvent& event)
1025 {
1026   // Ignore events with multiple-touch points
1027   if (event.GetPointCount() != 1)
1028   {
1029     return false;
1030   }
1031
1032   if (event.GetPoint(0).state == TouchPoint::Down)
1033   {
1034     // Cancel ongoing scrolling etc.
1035     mGestureState = Gesture::Clear;
1036
1037     mScrollDistance = 0.0f;
1038     mScrollSpeed = 0.0f;
1039     Self().SetProperty(mPropertyScrollSpeed, mScrollSpeed);
1040
1041     mScrollOvershoot = 0.0f;
1042     AnimateScrollOvershoot(0.0f);
1043
1044     mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1045
1046     RemoveAnimation(mScrollAnimation);
1047   }
1048
1049   return true; // consume since we're potentially scrolling
1050 }
1051
1052 bool ItemView::OnMouseWheelEvent(const MouseWheelEvent& event)
1053 {
1054   // Respond the mouse wheel event to scroll
1055   if (mActiveLayout)
1056   {
1057     Actor self = Self();
1058     const Vector3 layoutSize = Self().GetCurrentSize();
1059     float layoutPositionDelta = GetCurrentLayoutPosition(0) + (event.z * mMouseWheelScrollDistanceStep * mActiveLayout->GetScrollSpeedFactor());
1060     float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1061
1062     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1063     self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1064     mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1065     StartRefreshTimer();
1066   }
1067
1068   if (mMouseWheelEventFinishedTimer.IsRunning())
1069   {
1070     mMouseWheelEventFinishedTimer.Stop();
1071   }
1072
1073   mMouseWheelEventFinishedTimer.Start();
1074
1075   return true;
1076 }
1077
1078 bool ItemView::OnMouseWheelEventFinished()
1079 {
1080   if (mActiveLayout)
1081   {
1082     RemoveAnimation(mScrollAnimation);
1083
1084     // No more mouse wheel events coming. Do the anchoring if enabled.
1085     mScrollAnimation = DoAnchoring();
1086     if (mScrollAnimation)
1087     {
1088       StartRefreshTimer();
1089
1090       mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1091       mScrollAnimation.Play();
1092     }
1093     else
1094     {
1095       mScrollOvershoot = 0.0f;
1096       AnimateScrollOvershoot(0.0f);
1097
1098       mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1099     }
1100   }
1101
1102   return false;
1103 }
1104
1105 void ItemView::ApplyConstraints(Actor& actor, ItemLayout& layout, unsigned int itemId, float duration)
1106 {
1107   ItemLayout::Vector3Function positionConstraint;
1108   if (layout.GetPositionConstraint(itemId, positionConstraint))
1109   {
1110     WrappedVector3Constraint wrapped(positionConstraint, itemId);
1111
1112     Constraint constraint = Constraint::New<Vector3>( Actor::POSITION,
1113                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1114                                                       ParentSource( mPropertyScrollSpeed ),
1115                                                       ParentSource( Actor::SIZE ),
1116                                                       wrapped );
1117     constraint.SetApplyTime(duration);
1118     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1119
1120     actor.ApplyConstraint(constraint);
1121   }
1122
1123   ItemLayout::QuaternionFunction rotationConstraint;
1124   if (layout.GetRotationConstraint(itemId, rotationConstraint))
1125   {
1126     WrappedQuaternionConstraint wrapped(rotationConstraint, itemId);
1127
1128     Constraint constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1129                                                          Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1130                                                          ParentSource( mPropertyScrollSpeed ),
1131                                                          ParentSource( Actor::SIZE ),
1132                                                          wrapped );
1133     constraint.SetApplyTime(duration);
1134     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1135
1136     actor.ApplyConstraint(constraint);
1137   }
1138
1139   ItemLayout::Vector3Function scaleConstraint;
1140   if (layout.GetScaleConstraint(itemId, scaleConstraint))
1141   {
1142     WrappedVector3Constraint wrapped(scaleConstraint, itemId);
1143
1144     Constraint constraint = Constraint::New<Vector3>( Actor::SCALE,
1145                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1146                                                       ParentSource( mPropertyScrollSpeed ),
1147                                                       ParentSource( Actor::SIZE ),
1148                                                       wrapped );
1149     constraint.SetApplyTime(duration);
1150     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1151
1152     actor.ApplyConstraint(constraint);
1153   }
1154
1155   ItemLayout::Vector4Function colorConstraint;
1156   if (layout.GetColorConstraint(itemId, colorConstraint))
1157   {
1158     WrappedVector4Constraint wrapped(colorConstraint, itemId);
1159
1160     Constraint constraint = Constraint::New<Vector4>( Actor::COLOR,
1161                                                       Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1162                                                       ParentSource( mPropertyScrollSpeed ),
1163                                                       ParentSource( Actor::SIZE ),
1164                                                       wrapped );
1165     constraint.SetApplyTime(duration);
1166     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1167
1168     // Release color constraints slowly; this allows ItemView to co-exist with ImageActor fade-in
1169     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1170     constraint.SetRemoveAction(Dali::Constraint::Discard);
1171
1172     actor.ApplyConstraint(constraint);
1173   }
1174
1175   ItemLayout::BoolFunction visibilityConstraint;
1176   if (layout.GetVisibilityConstraint(itemId, visibilityConstraint))
1177   {
1178     WrappedBoolConstraint wrapped(visibilityConstraint, itemId);
1179
1180     Constraint constraint = Constraint::New<bool>( Actor::VISIBLE,
1181                                                    Source( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ),
1182                                                    ParentSource( mPropertyScrollSpeed ),
1183                                                    ParentSource( Actor::SIZE ),
1184                                                    wrapped );
1185     constraint.SetApplyTime(duration);
1186     constraint.SetAlphaFunction(mDefaultAlphaFunction);
1187
1188     // Release visibility constraints the same time as the color constraint
1189     constraint.SetRemoveTime(DEFAULT_COLOR_VISIBILITY_REMOVE_TIME);
1190     constraint.SetRemoveAction(Dali::Constraint::Discard);
1191
1192     actor.ApplyConstraint(constraint);
1193   }
1194 }
1195
1196 void ItemView::ReapplyAllConstraints( float durationSeconds )
1197 {
1198   for (ConstItemPoolIter iter = mItemPool.begin(); iter != mItemPool.end(); ++iter)
1199   {
1200     unsigned int id = iter->first;
1201     Actor actor = iter->second;
1202
1203     actor.RemoveConstraints();
1204     ApplyConstraints(actor, *mActiveLayout, id, durationSeconds);
1205   }
1206
1207   CalculateDomainSize(Self().GetCurrentSize());
1208 }
1209
1210 float ItemView::ClampFirstItemPosition(float targetPosition, const Vector3& targetSize, ItemLayout& layout)
1211 {
1212   Actor self = Self();
1213   float minLayoutPosition = layout.GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), targetSize);
1214   float clamppedPosition = min(0.0f, max(minLayoutPosition, targetPosition));
1215   mScrollOvershoot = targetPosition - clamppedPosition;
1216   self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1217
1218   return clamppedPosition;
1219 }
1220
1221 void ItemView::OnPan(PanGesture gesture)
1222 {
1223   Actor self = Self();
1224   const Vector3 layoutSize = Self().GetCurrentSize();
1225
1226   RemoveAnimation(mScrollAnimation);
1227
1228   // Short-circuit if there is no active layout
1229   if (!mActiveLayout)
1230   {
1231     mGestureState = Gesture::Clear;
1232     return;
1233   }
1234
1235   mGestureState = gesture.state;
1236
1237   switch (mGestureState)
1238   {
1239     case Gesture::Finished:
1240     {
1241       // Swipe Detection
1242       if (fabsf(mScrollDistance) > mMinimumSwipeDistance &&
1243           mScrollSpeed > mMinimumSwipeSpeed)
1244       {
1245         float direction = (mScrollDistance < 0.0f) ? -1.0f : 1.0f;
1246
1247         mRefreshOrderHint = true;
1248
1249         float currentLayoutPosition = GetCurrentLayoutPosition(0);
1250         float firstItemScrollPosition = ClampFirstItemPosition(currentLayoutPosition + mScrollSpeed * direction,
1251                                                                layoutSize,
1252                                                                *mActiveLayout);
1253
1254         if (mAnchoringEnabled)
1255         {
1256           firstItemScrollPosition = mActiveLayout->GetClosestAnchorPosition(firstItemScrollPosition);
1257         }
1258
1259         RemoveAnimation(mScrollAnimation);
1260
1261         float flickAnimationDuration = mActiveLayout->GetItemFlickAnimationDuration() * max(1.0f, fabsf(firstItemScrollPosition - GetCurrentLayoutPosition(0)));
1262         mScrollAnimation = Animation::New(flickAnimationDuration);
1263         mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1264         mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1265         mScrollAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1266
1267         mIsFlicking = true;
1268         // Check whether it has already scrolled to the end
1269         if(fabs(currentLayoutPosition - firstItemScrollPosition) > Math::MACHINE_EPSILON_0)
1270         {
1271           AnimateScrollOvershoot(0.0f);
1272         }
1273       }
1274
1275       // Anchoring may be triggered when there was no swipe
1276       if (!mScrollAnimation)
1277       {
1278         mScrollAnimation = DoAnchoring();
1279       }
1280
1281       // Reset the overshoot if no scroll animation.
1282       if (!mScrollAnimation)
1283       {
1284         mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1285
1286         AnimateScrollOvershoot(0.0f, false);
1287       }
1288     }
1289     break;
1290
1291     case Gesture::Started: // Fall through
1292     {
1293       mTotalPanDisplacement = Vector2::ZERO;
1294     }
1295
1296     case Gesture::Continuing:
1297     {
1298       mScrollDistance = CalculateScrollDistance(gesture.displacement, *mActiveLayout);
1299       mScrollSpeed = Clamp((gesture.GetSpeed() * mActiveLayout->GetScrollSpeedFactor() * MILLISECONDS_PER_SECONDS), 0.0f, mActiveLayout->GetMaximumSwipeSpeed());
1300
1301       // Refresh order depends on the direction of the scroll; negative is towards the last item.
1302       mRefreshOrderHint = mScrollDistance < 0.0f;
1303
1304       RemoveAnimation(mScrollSpeedAnimation);
1305       mScrollSpeedAnimation = Animation::New(0.3f);
1306       mScrollSpeedAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), mScrollSpeed, AlphaFunctions::Linear );
1307       mScrollSpeedAnimation.Play();
1308
1309       float layoutPositionDelta = GetCurrentLayoutPosition(0) + (mScrollDistance * mActiveLayout->GetScrollSpeedFactor());
1310
1311       float firstItemScrollPosition = ClampFirstItemPosition(layoutPositionDelta, layoutSize, *mActiveLayout);
1312
1313       mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1314       self.SetProperty(mPropertyPosition, GetScrollPosition(firstItemScrollPosition, layoutSize));
1315       mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1316
1317       mTotalPanDisplacement += gesture.displacement;
1318       mScrollOvershoot = layoutPositionDelta - firstItemScrollPosition;
1319       if( mScrollOvershoot > Math::MACHINE_EPSILON_1 )
1320       {
1321         AnimateScrollOvershoot(1.0f);
1322       }
1323       else if( mScrollOvershoot < -Math::MACHINE_EPSILON_1 )
1324       {
1325         AnimateScrollOvershoot(-1.0f);
1326       }
1327       else
1328       {
1329         AnimateScrollOvershoot(0.0f);
1330       }
1331
1332       StartRefreshTimer();
1333     }
1334     break;
1335
1336     case Gesture::Cancelled:
1337     {
1338       mScrollAnimation = DoAnchoring();
1339     }
1340     break;
1341
1342     default:
1343       break;
1344   }
1345
1346   if (mScrollAnimation)
1347   {
1348     StartRefreshTimer();
1349
1350     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1351     mScrollAnimation.Play();
1352   }
1353 }
1354
1355 bool ItemView::OnAccessibilityPan(PanGesture gesture)
1356 {
1357   OnPan(gesture);
1358   return true;
1359 }
1360
1361 Actor ItemView::GetNextKeyboardFocusableActor(Actor actor, Control::KeyboardFocusNavigationDirection direction, bool loopEnabled)
1362 {
1363   Actor nextFocusActor;
1364   if(mActiveLayout)
1365   {
1366     int nextItemID = 0;
1367     if(!actor || actor == this->Self())
1368     {
1369       nextFocusActor = GetItem(nextItemID);
1370     }
1371     else if(actor && actor.GetParent() == this->Self())
1372     {
1373       int itemID = GetItemId(actor);
1374       nextItemID = mActiveLayout->GetNextFocusItemID(itemID, mItemFactory.GetNumberOfItems(), direction, loopEnabled);
1375       nextFocusActor = GetItem(nextItemID);
1376       if(nextFocusActor == actor)
1377       {
1378         // need to pass NULL actor back to focus manager
1379         nextFocusActor.Reset();
1380         return nextFocusActor;
1381       }
1382     }
1383     float layoutPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1384     Vector3 layoutSize = Self().GetCurrentSize();
1385     if(!nextFocusActor)
1386     {
1387       // likely the current item is not buffered, so not in our item pool, probably best to get first viewable item
1388       ItemRange viewableItems = mActiveLayout->GetItemsWithinArea(layoutPosition, layoutSize);
1389       nextItemID = viewableItems.begin;
1390       nextFocusActor = GetItem(nextItemID);
1391     }
1392   }
1393   return nextFocusActor;
1394 }
1395
1396 void ItemView::OnKeyboardFocusChangeCommitted(Actor commitedFocusableActor)
1397 {
1398   // only in this function if our chosen focus actor was actually used
1399   if(commitedFocusableActor)
1400   {
1401     int nextItemID = GetItemId(commitedFocusableActor);
1402     float layoutPosition = GetCurrentLayoutPosition(0);
1403     Vector3 layoutSize = Self().GetCurrentSize();
1404     Vector3 focusItemPosition = Vector3::ZERO;
1405     ItemLayout::Vector3Function itemPositionConstraint;
1406     if (mActiveLayout->GetPositionConstraint(nextItemID, itemPositionConstraint))
1407     {
1408       focusItemPosition = itemPositionConstraint(Vector3::ZERO, layoutPosition + nextItemID, 0.0f, layoutSize);
1409     }
1410
1411     float scrollTo = mActiveLayout->GetClosestOnScreenLayoutPosition(nextItemID, layoutPosition, layoutSize);
1412     ScrollTo(Vector3(0.0f, scrollTo, 0.0f), DEFAULT_KEYBOARD_FOCUS_SCROLL_DURATION);
1413   }
1414 }
1415
1416 Animation ItemView::DoAnchoring()
1417 {
1418   Animation anchoringAnimation;
1419   Actor self = Self();
1420
1421   if (mActiveLayout && mAnchoringEnabled)
1422   {
1423     float anchorPosition = mActiveLayout->GetClosestAnchorPosition( GetCurrentLayoutPosition(0) );
1424
1425     anchoringAnimation = Animation::New(mAnchoringDuration);
1426     anchoringAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), anchorPosition, AlphaFunctions::EaseOut );
1427     anchoringAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(anchorPosition, self.GetCurrentSize()), AlphaFunctions::EaseOut );
1428     anchoringAnimation.AnimateTo( Property(self, mPropertyScrollSpeed), 0.0f, AlphaFunctions::EaseOut );
1429     if(!mIsFlicking)
1430     {
1431       AnimateScrollOvershoot(0.0f);
1432     }
1433   }
1434
1435   return anchoringAnimation;
1436 }
1437
1438 void ItemView::OnScrollFinished(Animation& source)
1439 {
1440   Actor self = Self();
1441
1442   RemoveAnimation(mScrollAnimation); // mScrollAnimation is used to query whether we're scrolling
1443
1444   mScrollCompletedSignalV2.Emit(GetCurrentScrollPosition());
1445
1446   if(mIsFlicking && fabsf(mScrollOvershoot) > Math::MACHINE_EPSILON_1)
1447   {
1448     AnimateScrollOvershoot( mScrollOvershoot > 0.0f ? 1.0f : -1.0f, true);
1449   }
1450   else
1451   {
1452     // Reset the overshoot
1453     AnimateScrollOvershoot( 0.0f );
1454   }
1455   mIsFlicking = false;
1456
1457   mScrollOvershoot = 0.0f;
1458 }
1459
1460 void ItemView::OnOvershootOnFinished(Animation& animation)
1461 {
1462   mAnimatingOvershootOn = false;
1463   mScrollOvershootAnimation.FinishedSignal().Disconnect(this, &ItemView::OnOvershootOnFinished);
1464   RemoveAnimation(mScrollOvershootAnimation);
1465   if(mAnimateOvershootOff)
1466   {
1467     AnimateScrollOvershoot(0.0f);
1468   }
1469 }
1470
1471 void ItemView::StartRefreshTimer()
1472 {
1473   if (!mRefreshTimer)
1474   {
1475     mRefreshTimer = Timer::New( mRefreshIntervalMilliseconds );
1476     mRefreshTimer.TickSignal().Connect( this, &ItemView::OnRefreshTick );
1477   }
1478
1479   if (!mRefreshTimer.IsRunning())
1480   {
1481     mRefreshTimer.Start();
1482   }
1483 }
1484
1485 void ItemView::CancelRefreshTimer()
1486 {
1487   if (mRefreshTimer)
1488   {
1489     mRefreshTimer.Stop();
1490   }
1491 }
1492
1493 void ItemView::ScrollToItem(unsigned int itemId, float durationSeconds)
1494 {
1495   Actor self = Self();
1496   const Vector3 layoutSize = Self().GetCurrentSize();
1497   float firstItemScrollPosition = ClampFirstItemPosition(mActiveLayout->GetItemScrollToPosition(itemId), layoutSize, *mActiveLayout);
1498
1499   StartRefreshTimer();
1500
1501   if(durationSeconds > 0.0f)
1502   {
1503     RemoveAnimation(mScrollAnimation);
1504     mScrollAnimation = Animation::New(durationSeconds);
1505     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1506     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1507     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1508     mScrollAnimation.Play();
1509   }
1510   else
1511   {
1512     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1513     AnimateScrollOvershoot(0.0f);
1514   }
1515
1516   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1517 }
1518
1519 void ItemView::RemoveAnimation(Animation& animation)
1520 {
1521   if(animation)
1522   {
1523     // Cease animating, and reset handle.
1524     animation.Clear();
1525     animation.Reset();
1526   }
1527 }
1528
1529 void ItemView::CalculateDomainSize(const Vector3& layoutSize)
1530 {
1531   Actor self = Self();
1532
1533   Vector3 firstItemPosition(Vector3::ZERO);
1534   Vector3 lastItemPosition(Vector3::ZERO);
1535
1536   if(mActiveLayout)
1537   {
1538     ItemLayout::Vector3Function firstItemPositionConstraint;
1539     if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1540     {
1541       firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, 0, 0.0f, layoutSize);
1542     }
1543
1544     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), layoutSize);
1545     ItemLayout::Vector3Function lastItemPositionConstraint;
1546     if (mActiveLayout->GetPositionConstraint(fabs(minLayoutPosition), lastItemPositionConstraint))
1547     {
1548       lastItemPosition = lastItemPositionConstraint(Vector3::ZERO, fabs(minLayoutPosition), 0.0f, layoutSize);
1549     }
1550
1551     if(IsHorizontal(mActiveLayout->GetOrientation()))
1552     {
1553       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.x, 0.0f));
1554       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.x, 0.0f));
1555     }
1556     else
1557     {
1558       self.SetProperty(mPropertyPositionMin, Vector3(0.0f, firstItemPosition.y, 0.0f));
1559       self.SetProperty(mPropertyPositionMax, Vector3(0.0f, lastItemPosition.y, 0.0f));
1560     }
1561
1562     bool isLayoutScrollable = IsLayoutScrollable(layoutSize);
1563     self.SetProperty(mPropertyCanScrollVertical, isLayoutScrollable);
1564     self.SetProperty(mPropertyCanScrollHorizontal, false);
1565   }
1566 }
1567
1568 Vector3 ItemView::GetDomainSize() const
1569 {
1570   Actor self = Self();
1571
1572   float minScrollPosition = self.GetProperty<float>(mPropertyPositionMin);
1573   float maxScrollPosition = self.GetProperty<float>(mPropertyPositionMax);
1574
1575   return Vector3(0.0f, fabs(maxScrollPosition - minScrollPosition), 0.0f);
1576 }
1577
1578 bool ItemView::IsLayoutScrollable(const Vector3& layoutSize)
1579 {
1580   Actor self = Self();
1581
1582   float currentLayoutPosition = ClampFirstItemPosition( GetCurrentLayoutPosition(0), layoutSize, *mActiveLayout );
1583   float forwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition + 1.0, layoutSize, *mActiveLayout);
1584   float backwardClampedPosition = ClampFirstItemPosition(currentLayoutPosition - 1.0, layoutSize, *mActiveLayout);
1585
1586   return (fabs(forwardClampedPosition - backwardClampedPosition) > Math::MACHINE_EPSILON_0);
1587 }
1588
1589 float ItemView::GetScrollPosition(float layoutPosition, const Vector3& layoutSize) const
1590 {
1591   Vector3 firstItemPosition(Vector3::ZERO);
1592   ItemLayout::Vector3Function firstItemPositionConstraint;
1593   if (mActiveLayout->GetPositionConstraint(0, firstItemPositionConstraint))
1594   {
1595     firstItemPosition = firstItemPositionConstraint(Vector3::ZERO, layoutPosition, 0.0f, layoutSize);
1596   }
1597
1598   return IsHorizontal(mActiveLayout->GetOrientation()) ? firstItemPosition.x: firstItemPosition.y;
1599 }
1600
1601 Vector3 ItemView::GetCurrentScrollPosition() const
1602 {
1603   float currentLayoutPosition = GetCurrentLayoutPosition(0);
1604   return Vector3(0.0f, GetScrollPosition(currentLayoutPosition, Self().GetCurrentSize()), 0.0f);
1605 }
1606
1607 void ItemView::AddOverlay(Actor actor)
1608 {
1609   Self().Add(actor);
1610 }
1611
1612 void ItemView::RemoveOverlay(Actor actor)
1613 {
1614   Self().Remove(actor);
1615 }
1616
1617 void ItemView::ScrollTo(const Vector3& position, float duration)
1618 {
1619   Actor self = Self();
1620   const Vector3 layoutSize = Self().GetCurrentSize();
1621
1622   float firstItemScrollPosition = ClampFirstItemPosition(position.y, layoutSize, *mActiveLayout);
1623
1624   StartRefreshTimer();
1625
1626   if(duration > 0.0f)
1627   {
1628     RemoveAnimation(mScrollAnimation);
1629     mScrollAnimation = Animation::New(duration);
1630     mScrollAnimation.AnimateTo( Property( mScrollPositionObject, ScrollConnector::SCROLL_POSITION ), firstItemScrollPosition, AlphaFunctions::EaseOut );
1631     mScrollAnimation.AnimateTo( Property(self, mPropertyPosition), GetScrollPosition(firstItemScrollPosition, layoutSize), AlphaFunctions::EaseOut );
1632     mScrollAnimation.FinishedSignal().Connect(this, &ItemView::OnScrollFinished);
1633     mScrollAnimation.Play();
1634   }
1635   else
1636   {
1637     mScrollPositionObject.SetProperty( ScrollConnector::SCROLL_POSITION, firstItemScrollPosition );
1638     AnimateScrollOvershoot(0.0f);
1639   }
1640
1641   mScrollStartedSignalV2.Emit(GetCurrentScrollPosition());
1642 }
1643
1644 void ItemView::ApplyOvershootOverlayConstraints()
1645 {
1646   Constraint constraint = Constraint::New<float>( Actor::SIZE_WIDTH,
1647                                                     ParentSource( mPropertyScrollDirection ),
1648                                                     ParentSource( mPropertyOvershoot ),
1649                                                     ParentSource( Actor::SIZE ),
1650                                                     OvershootOverlaySizeConstraint() );
1651   mOvershootOverlay.ApplyConstraint(constraint);
1652   mOvershootOverlay.SetSize(OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA.width, OVERSHOOT_BOUNCE_IMAGE_1_PIXEL_AREA.height);
1653
1654   constraint = Constraint::New<Quaternion>( Actor::ROTATION,
1655                                             ParentSource( mPropertyScrollDirection ),
1656                                             ParentSource( mPropertyOvershoot ),
1657                                             OvershootOverlayRotationConstraint() );
1658   mOvershootOverlay.ApplyConstraint(constraint);
1659
1660   constraint = Constraint::New<Vector3>( Actor::POSITION,
1661                                          ParentSource( Actor::SIZE ),
1662                                          ParentSource( mPropertyScrollDirection ),
1663                                          ParentSource( mPropertyOvershoot ),
1664                                          OvershootOverlayPositionConstraint() );
1665   mOvershootOverlay.ApplyConstraint(constraint);
1666
1667   constraint = Constraint::New<bool>( Actor::VISIBLE,
1668                                       ParentSource( mPropertyCanScrollVertical ),
1669                                       OvershootOverlayVisibilityConstraint() );
1670   mOvershootOverlay.ApplyConstraint(constraint);
1671
1672   int effectOvershootPropertyIndex = mOvershootEffect.GetPropertyIndex(mOvershootEffect.GetOvershootPropertyName());
1673   Actor self = Self();
1674   constraint = Constraint::New<float>( effectOvershootPropertyIndex,
1675                                        Source( self, mPropertyOvershoot ),
1676                                        EqualToConstraint() );
1677   mOvershootEffect.ApplyConstraint(constraint);
1678 }
1679
1680 float ItemView::CalculateScrollOvershoot()
1681 {
1682   float overshoot = 0.0f;
1683
1684   if(mActiveLayout)
1685   {
1686     // The overshoot must be calculated from the accumulated pan gesture displacement
1687     // since the pan gesture starts.
1688     Actor self = Self();
1689     float scrollDistance = CalculateScrollDistance(mTotalPanDisplacement, *mActiveLayout) * mActiveLayout->GetScrollSpeedFactor();
1690     float positionDelta = GetCurrentLayoutPosition(0) + scrollDistance;
1691     float minLayoutPosition = mActiveLayout->GetMinimumLayoutPosition(mItemFactory.GetNumberOfItems(), Self().GetCurrentSize());
1692     self.SetProperty(mPropertyMinimumLayoutPosition, minLayoutPosition);
1693     float clamppedPosition = min(0.0f, max(minLayoutPosition, positionDelta));
1694     overshoot = positionDelta - clamppedPosition;
1695   }
1696
1697   return overshoot;
1698 }
1699
1700 void ItemView::AnimateScrollOvershoot(float overshootAmount, bool animateBack)
1701 {
1702   bool animatingOn = fabsf(overshootAmount) > Math::MACHINE_EPSILON_1;
1703
1704   // make sure we animate back if needed
1705   mAnimateOvershootOff = animateBack || (!animatingOn && mAnimatingOvershootOn);
1706
1707   if( mAnimatingOvershootOn )
1708   {
1709     // animating on, do not allow animate off
1710     return;
1711   }
1712
1713   Actor self = Self();
1714   float currentOvershoot = self.GetProperty<float>(mPropertyOvershoot);
1715   float duration = DEFAULT_OVERSHOOT_ANIMATION_DURATION * (animatingOn ? (1.0f - fabsf(currentOvershoot)) : fabsf(currentOvershoot));
1716
1717   RemoveAnimation(mScrollOvershootAnimation);
1718   mScrollOvershootAnimation = Animation::New(duration);
1719   mScrollOvershootAnimation.FinishedSignal().Connect(this, &ItemView::OnOvershootOnFinished);
1720   mScrollOvershootAnimation.AnimateTo( Property(self, mPropertyOvershoot), overshootAmount, TimePeriod(0.0f, duration) );
1721   mScrollOvershootAnimation.Play();
1722
1723   mAnimatingOvershootOn = animatingOn;
1724 }
1725
1726 } // namespace Internal
1727
1728 } // namespace Toolkit
1729
1730 } // namespace Dali