Fixed for single line text updates
[platform/core/uifw/dali-toolkit.git] / dali-toolkit / internal / text / text-controller-impl.cpp
index c7adc7b..532afed 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,7 +55,6 @@ struct SelectionBoxInfo
 const float MAX_FLOAT = std::numeric_limits<float>::max();
 const float MIN_FLOAT = std::numeric_limits<float>::min();
 const Dali::Toolkit::Text::CharacterDirection LTR = false; ///< Left To Right direction
-const uint32_t STAR = 0x2A;
 
 } // namespace
 
@@ -71,6 +70,8 @@ namespace Text
 EventData::EventData( DecoratorPtr decorator )
 : mDecorator( decorator ),
   mImfManager(),
+  mPlaceholderFont( NULL ),
+  mPlaceholderText(),
   mPlaceholderTextActive(),
   mPlaceholderTextInactive(),
   mPlaceholderTextColor( 0.8f, 0.8f, 0.8f, 0.8f ),
@@ -84,6 +85,8 @@ EventData::EventData( DecoratorPtr decorator )
   mPreEditStartPosition( 0u ),
   mPreEditLength( 0u ),
   mCursorHookPositionX( 0.f ),
+  mDoubleTapAction( Controller::NoTextTap::NO_ACTION ),
+  mLongPressAction( Controller::NoTextTap::SHOW_SELECTION_POPUP ),
   mIsShowingPlaceholderText( false ),
   mPreEditFlag( false ),
   mDecoratorUpdated( false ),
@@ -97,12 +100,14 @@ EventData::EventData( DecoratorPtr decorator )
   mUpdateLeftSelectionPosition( false ),
   mUpdateRightSelectionPosition( false ),
   mIsLeftHandleSelected( false ),
+  mIsRightHandleSelected( false ),
   mUpdateHighlightBox( false ),
   mScrollAfterUpdatePosition( false ),
   mScrollAfterDelete( false ),
   mAllTextSelected( false ),
   mUpdateInputStyle( false ),
-  mPasswordInput( false )
+  mPasswordInput( false ),
+  mIsPlaceholderPixelSize( false )
 {
   mImfManager = ImfManager::Get();
 }
@@ -227,10 +232,25 @@ bool Controller::Impl::ProcessInputEvents()
 
       if( mEventData->mScrollAfterUpdatePosition && ( mEventData->mIsLeftHandleSelected ? mEventData->mUpdateLeftSelectionPosition : mEventData->mUpdateRightSelectionPosition ) )
       {
-        CursorInfo& info = mEventData->mIsLeftHandleSelected ? leftHandleInfo : rightHandleInfo;
+        if( mEventData->mIsLeftHandleSelected && mEventData->mIsRightHandleSelected )
+        {
+          CursorInfo& infoLeft = leftHandleInfo;
+
+          const Vector2 currentCursorPositionLeft( infoLeft.primaryPosition.x, infoLeft.lineOffset );
+          ScrollToMakePositionVisible( currentCursorPositionLeft, infoLeft.lineHeight );
+
+          CursorInfo& infoRight = rightHandleInfo;
 
-        const Vector2 currentCursorPosition( info.primaryPosition.x, info.lineOffset );
-        ScrollToMakePositionVisible( currentCursorPosition, info.lineHeight );
+          const Vector2 currentCursorPositionRight( infoRight.primaryPosition.x, infoRight.lineOffset );
+          ScrollToMakePositionVisible( currentCursorPositionRight, infoRight.lineHeight );
+        }
+        else
+        {
+          CursorInfo& info = mEventData->mIsLeftHandleSelected ? leftHandleInfo : rightHandleInfo;
+
+          const Vector2 currentCursorPosition( info.primaryPosition.x, info.lineOffset );
+          ScrollToMakePositionVisible( currentCursorPosition, info.lineHeight );
+        }
       }
     }
 
@@ -261,6 +281,8 @@ bool Controller::Impl::ProcessInputEvents()
       mEventData->mUpdateLeftSelectionPosition = false;
       mEventData->mUpdateRightSelectionPosition = false;
       mEventData->mUpdateHighlightBox = false;
+      mEventData->mIsLeftHandleSelected = false;
+      mEventData->mIsRightHandleSelected = false;
     }
 
     mEventData->mScrollAfterUpdatePosition = false;
@@ -769,24 +791,16 @@ bool Controller::Impl::UpdateModel( OperationsMask operationsRequired )
     return false;
   }
 
-  Vector<Character> utf32CharactersStar;
-  const Length characterCount = mModel->mLogicalModel->mText.Count();
-  const bool isPasswordInput = ( mEventData != NULL && mEventData->mPasswordInput &&
-        !mEventData->mIsShowingPlaceholderText && characterCount > 0 );
-
-  if (isPasswordInput)
+  Vector<Character>& srcCharacters = mModel->mLogicalModel->mText;
+  Vector<Character> displayCharacters;
+  bool useHiddenText = false;
+  if ( mHiddenInput && mEventData != NULL && !mEventData->mIsShowingPlaceholderText)
   {
-    utf32CharactersStar.Resize( characterCount );
-
-    uint32_t* begin = utf32CharactersStar.Begin();
-    uint32_t* end = begin + characterCount;
-    while ( begin < end )
-    {
-      *begin++ = STAR;
-    }
+    mHiddenInput->Substitute( srcCharacters,displayCharacters );
+    useHiddenText = true;
   }
 
-  Vector<Character>& utf32Characters = isPasswordInput ? utf32CharactersStar : mModel->mLogicalModel->mText;
+  Vector<Character>& utf32Characters = useHiddenText ? displayCharacters : srcCharacters;
   const Length numberOfCharacters = utf32Characters.Count();
 
   // Index to the first character of the first paragraph to be updated.
@@ -872,8 +886,19 @@ bool Controller::Impl::UpdateModel( OperationsMask operationsRequired )
       // Get the default font's description.
       TextAbstraction::FontDescription defaultFontDescription;
       TextAbstraction::PointSize26Dot6 defaultPointSize = TextAbstraction::FontClient::DEFAULT_POINT_SIZE;
-      if( NULL != mFontDefaults )
+
+      if( IsShowingPlaceholderText() && ( NULL != mEventData->mPlaceholderFont ) )
       {
+        // If the placeholder font is set specifically, only placeholder font is changed.
+        defaultFontDescription = mEventData->mPlaceholderFont->mFontDescription;
+        if( mEventData->mPlaceholderFont->sizeDefined )
+        {
+          defaultPointSize = mEventData->mPlaceholderFont->mDefaultPointSize * 64u;
+        }
+      }
+      else if( NULL != mFontDefaults )
+      {
+        // Set the normal font and the placeholder font.
         defaultFontDescription = mFontDefaults->mFontDescription;
         defaultPointSize = mFontDefaults->mDefaultPointSize * 64u;
       }
@@ -1151,29 +1176,30 @@ void Controller::Impl::OnCursorKeyEvent( const Event& event )
     }
 
     const LineIndex lineIndex = mModel->mVisualModel->GetLineOfCharacter( characterIndex );
+    const LineIndex previousLineIndex = ( lineIndex > 0 ? lineIndex - 1u : lineIndex );
 
-    if( lineIndex > 0u )
-    {
-      // Retrieve the cursor position info.
-      CursorInfo cursorInfo;
-      GetCursorPosition( mEventData->mPrimaryCursorPosition,
-                         cursorInfo );
+    // Retrieve the cursor position info.
+    CursorInfo cursorInfo;
+    GetCursorPosition( mEventData->mPrimaryCursorPosition,
+                       cursorInfo );
 
-      // Get the line above.
-      const LineRun& line = *( mModel->mVisualModel->mLines.Begin() + ( lineIndex - 1u ) );
+    // Get the line above.
+    const LineRun& line = *( mModel->mVisualModel->mLines.Begin() + previousLineIndex );
 
-      // Get the next hit 'y' point.
-      const float hitPointY = cursorInfo.lineOffset - 0.5f * ( line.ascender - line.descender );
+    // Get the next hit 'y' point.
+    const float hitPointY = cursorInfo.lineOffset - 0.5f * ( line.ascender - line.descender );
 
-      // Use the cursor hook position 'x' and the next hit 'y' position to calculate the new cursor index.
-      mEventData->mPrimaryCursorPosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
-                                                                        mModel->mLogicalModel,
-                                                                        mMetrics,
-                                                                        mEventData->mCursorHookPositionX,
-                                                                        hitPointY );
-    }
+    // Use the cursor hook position 'x' and the next hit 'y' position to calculate the new cursor index.
+    bool matchedCharacter = false;
+    mEventData->mPrimaryCursorPosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
+                                                                      mModel->mLogicalModel,
+                                                                      mMetrics,
+                                                                      mEventData->mCursorHookPositionX,
+                                                                      hitPointY,
+                                                                      CharacterHitTest::TAP,
+                                                                      matchedCharacter );
   }
-  else if(   Dali::DALI_KEY_CURSOR_DOWN == keyCode )
+  else if( Dali::DALI_KEY_CURSOR_DOWN == keyCode )
   {
     // Get first the line index of the current cursor position index.
     CharacterIndex characterIndex = 0u;
@@ -1199,11 +1225,14 @@ void Controller::Impl::OnCursorKeyEvent( const Event& event )
       const float hitPointY = cursorInfo.lineOffset + cursorInfo.lineHeight + 0.5f * ( line.ascender - line.descender );
 
       // Use the cursor hook position 'x' and the next hit 'y' position to calculate the new cursor index.
+      bool matchedCharacter = false;
       mEventData->mPrimaryCursorPosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
                                                                         mModel->mLogicalModel,
                                                                         mMetrics,
                                                                         mEventData->mCursorHookPositionX,
-                                                                        hitPointY );
+                                                                        hitPointY,
+                                                                        CharacterHitTest::TAP,
+                                                                        matchedCharacter );
     }
   }
 
@@ -1229,11 +1258,15 @@ void Controller::Impl::OnTapEvent( const Event& event )
         // Keep the tap 'x' position. Used to move the cursor.
         mEventData->mCursorHookPositionX = xPosition;
 
+        // Whether to touch point hits on a glyph.
+        bool matchedCharacter = false;
         mEventData->mPrimaryCursorPosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
                                                                           mModel->mLogicalModel,
                                                                           mMetrics,
                                                                           xPosition,
-                                                                          yPosition );
+                                                                          yPosition,
+                                                                          CharacterHitTest::TAP,
+                                                                          matchedCharacter );
 
         // When the cursor position is changing, delay cursor blinking
         mEventData->mDecorator->DelayCursorBlink();
@@ -1255,6 +1288,20 @@ void Controller::Impl::OnTapEvent( const Event& event )
         mEventData->mImfManager.NotifyCursorPosition();
       }
     }
+    else if( 2u == tapCount )
+    {
+      if( mEventData->mSelectionEnabled )
+      {
+        // Convert from control's coords to text's coords.
+        const float xPosition = event.p2.mFloat - mModel->mScrollPosition.x;
+        const float yPosition = event.p3.mFloat - mModel->mScrollPosition.y;
+
+        // Calculates the logical position from the x,y coords.
+        RepositionSelectionHandles( xPosition,
+                                    yPosition,
+                                    mEventData->mDoubleTapAction );
+      }
+    }
   }
 }
 
@@ -1325,12 +1372,26 @@ void Controller::Impl::OnLongPressEvent( const Event& event )
 {
   DALI_LOG_INFO( gLogFilter, Debug::General, "Controller::OnLongPressEvent\n" );
 
-  if( EventData::EDITING == mEventData->mState )
+  if( !IsShowingRealText() && ( EventData::EDITING == mEventData->mState ) )
   {
-    ChangeState ( EventData::EDITING_WITH_POPUP );
+    ChangeState( EventData::EDITING_WITH_POPUP );
     mEventData->mDecoratorUpdated = true;
     mEventData->mUpdateInputStyle = true;
   }
+  else
+  {
+    if( mEventData->mSelectionEnabled )
+    {
+      // Convert from control's coords to text's coords.
+      const float xPosition = event.p2.mFloat - mModel->mScrollPosition.x;
+      const float yPosition = event.p3.mFloat - mModel->mScrollPosition.y;
+
+      // Calculates the logical position from the x,y coords.
+      RepositionSelectionHandles( xPosition,
+                                  yPosition,
+                                  mEventData->mLongPressAction );
+    }
+  }
 }
 
 void Controller::Impl::OnHandleEvent( const Event& event )
@@ -1352,11 +1413,14 @@ void Controller::Impl::OnHandleEvent( const Event& event )
     const float yPosition = event.p3.mFloat - mModel->mScrollPosition.y;
 
     // Need to calculate the handle's new position.
+    bool matchedCharacter = false;
     const CharacterIndex handleNewPosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
                                                                           mModel->mLogicalModel,
                                                                           mMetrics,
                                                                           xPosition,
-                                                                          yPosition );
+                                                                          yPosition,
+                                                                          CharacterHitTest::SCROLL,
+                                                                          matchedCharacter );
 
     if( Event::GRAB_HANDLE_EVENT == event.type )
     {
@@ -1393,6 +1457,7 @@ void Controller::Impl::OnHandleEvent( const Event& event )
 
       // Will define the order to scroll the text to match the handle position.
       mEventData->mIsLeftHandleSelected = true;
+      mEventData->mIsRightHandleSelected = false;
     }
     else if( Event::RIGHT_SELECTION_HANDLE_EVENT == event.type )
     {
@@ -1413,6 +1478,7 @@ void Controller::Impl::OnHandleEvent( const Event& event )
 
       // Will define the order to scroll the text to match the handle position.
       mEventData->mIsLeftHandleSelected = false;
+      mEventData->mIsRightHandleSelected = true;
     }
   } // end ( HANDLE_PRESSED == state )
   else if( ( HANDLE_RELEASED == state ) ||
@@ -1425,11 +1491,14 @@ void Controller::Impl::OnHandleEvent( const Event& event )
       const float xPosition = event.p2.mFloat - mModel->mScrollPosition.x;
       const float yPosition = event.p3.mFloat - mModel->mScrollPosition.y;
 
+      bool matchedCharacter = false;
       handlePosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
                                                     mModel->mLogicalModel,
                                                     mMetrics,
                                                     xPosition,
-                                                    yPosition );
+                                                    yPosition,
+                                                    CharacterHitTest::SCROLL,
+                                                    matchedCharacter );
     }
 
     if( Event::GRAB_HANDLE_EVENT == event.type )
@@ -1541,11 +1610,14 @@ void Controller::Impl::OnHandleEvent( const Event& event )
 
       // Get the new handle position.
       // The grab handle's position is in decorator's coords. Need to transforms to text's coords.
+      bool matchedCharacter = false;
       const CharacterIndex handlePosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
                                                                          mModel->mLogicalModel,
                                                                          mMetrics,
                                                                          position.x - mModel->mScrollPosition.x,
-                                                                         position.y - mModel->mScrollPosition.y );
+                                                                         position.y - mModel->mScrollPosition.y,
+                                                                         CharacterHitTest::SCROLL,
+                                                                         matchedCharacter );
 
       if( mEventData->mPrimaryCursorPosition != handlePosition )
       {
@@ -1582,11 +1654,14 @@ void Controller::Impl::OnHandleEvent( const Event& event )
 
       // Get the new handle position.
       // The selection handle's position is in decorator's coords. Need to transform to text's coords.
+      bool matchedCharacter = false;
       const CharacterIndex handlePosition = Text::GetClosestCursorIndex( mModel->mVisualModel,
                                                                          mModel->mLogicalModel,
                                                                          mMetrics,
                                                                          position.x - mModel->mScrollPosition.x,
-                                                                         position.y - mModel->mScrollPosition.y );
+                                                                         position.y - mModel->mScrollPosition.y,
+                                                                         CharacterHitTest::SCROLL,
+                                                                         matchedCharacter );
 
       if( leftSelectionHandleEvent )
       {
@@ -1639,7 +1714,8 @@ void Controller::Impl::OnSelectEvent( const Event& event )
 
     // Calculates the logical position from the x,y coords.
     RepositionSelectionHandles( xPosition,
-                                yPosition );
+                                yPosition,
+                                Controller::NoTextTap::HIGHLIGHT );
   }
 }
 
@@ -1713,8 +1789,18 @@ void Controller::Impl::RetrieveSelection( std::string& selectedText, bool delete
       mModel->mLogicalModel->UpdateTextStyleRuns( startOfSelectedText, -static_cast<int>( lengthOfSelectedText ) );
 
       // Mark the paragraphs to be updated.
-      mTextUpdateInfo.mCharacterIndex = startOfSelectedText;
-      mTextUpdateInfo.mNumberOfCharactersToRemove = lengthOfSelectedText;
+      if( Layout::Engine::SINGLE_LINE_BOX == mLayoutEngine.GetLayout() )
+      {
+        mTextUpdateInfo.mCharacterIndex = 0;
+        mTextUpdateInfo.mNumberOfCharactersToRemove = mTextUpdateInfo.mPreviousNumberOfCharacters;
+        mTextUpdateInfo.mNumberOfCharactersToAdd = mTextUpdateInfo.mPreviousNumberOfCharacters - lengthOfSelectedText;
+        mTextUpdateInfo.mClearAll = true;
+      }
+      else
+      {
+        mTextUpdateInfo.mCharacterIndex = startOfSelectedText;
+        mTextUpdateInfo.mNumberOfCharactersToRemove = lengthOfSelectedText;
+      }
 
       // Delete text between handles
       Vector<Character>::Iterator first = utf32Characters.Begin() + startOfSelectedText;
@@ -1964,15 +2050,15 @@ void Controller::Impl::RepositionSelectionHandles()
     // Whether to retrieve the next line.
     if( index == lastGlyphOfLine )
     {
-      // Retrieve the next line.
-      ++lineRun;
-
-      // Get the last glyph of the new line.
-      lastGlyphOfLine = lineRun->glyphRun.glyphIndex + lineRun->glyphRun.numberOfGlyphs - 1u;
-
       ++lineIndex;
       if( lineIndex < firstLineIndex + numberOfLines )
       {
+        // Retrieve the next line.
+        ++lineRun;
+
+        // Get the last glyph of the new line.
+        lastGlyphOfLine = lineRun->glyphRun.glyphIndex + lineRun->glyphRun.numberOfGlyphs - 1u;
+
         // Keep the offset and height of the current selection box.
         const float currentLineOffset = selectionBoxInfo->lineOffset;
         const float currentLineHeight = selectionBoxInfo->lineHeight;
@@ -2170,7 +2256,7 @@ void Controller::Impl::RepositionSelectionHandles()
   mEventData->mDecoratorUpdated = true;
 }
 
-void Controller::Impl::RepositionSelectionHandles( float visualX, float visualY )
+void Controller::Impl::RepositionSelectionHandles( float visualX, float visualY, Controller::NoTextTap::Action action )
 {
   if( NULL == mEventData )
   {
@@ -2196,16 +2282,18 @@ void Controller::Impl::RepositionSelectionHandles( float visualX, float visualY
   // Find which word was selected
   CharacterIndex selectionStart( 0 );
   CharacterIndex selectionEnd( 0 );
-  const bool indicesFound = FindSelectionIndices( mModel->mVisualModel,
+  CharacterIndex noTextHitIndex( 0 );
+  const bool characterHit = FindSelectionIndices( mModel->mVisualModel,
                                                   mModel->mLogicalModel,
                                                   mMetrics,
                                                   visualX,
                                                   visualY,
                                                   selectionStart,
-                                                  selectionEnd );
+                                                  selectionEnd,
+                                                  noTextHitIndex );
   DALI_LOG_INFO( gLogFilter, Debug::Verbose, "%p selectionStart %d selectionEnd %d\n", this, selectionStart, selectionEnd );
 
-  if( indicesFound )
+  if( characterHit || ( Controller::NoTextTap::HIGHLIGHT == action ) )
   {
     ChangeState( EventData::SELECTING );
 
@@ -2216,14 +2304,30 @@ void Controller::Impl::RepositionSelectionHandles( float visualX, float visualY
     mEventData->mUpdateRightSelectionPosition = true;
     mEventData->mUpdateHighlightBox = true;
 
+    // It may happen an IMF commit event arrives before the selection event
+    // if the IMF manager is in pre-edit state. The commit event will set the
+    // mEventData->mUpdateCursorPosition flag to true. If it's not set back
+    // to false, the highlight box won't be updated.
+    mEventData->mUpdateCursorPosition = false;
+
     mEventData->mScrollAfterUpdatePosition = ( mEventData->mLeftSelectionPosition != mEventData->mRightSelectionPosition );
   }
-  else
+  else if( Controller::NoTextTap::SHOW_SELECTION_POPUP == action )
   {
     // Nothing to select. i.e. a white space, out of bounds
-    ChangeState( EventData::EDITING );
+    ChangeState( EventData::EDITING_WITH_POPUP );
 
-    mEventData->mPrimaryCursorPosition = selectionEnd;
+    mEventData->mPrimaryCursorPosition = noTextHitIndex;
+
+    mEventData->mUpdateCursorPosition = true;
+    mEventData->mUpdateGrabHandlePosition = true;
+    mEventData->mScrollAfterUpdatePosition = true;
+    mEventData->mUpdateInputStyle = true;
+  }
+  else if( Controller::NoTextTap::NO_ACTION == action )
+  {
+    // Nothing to select. i.e. a white space, out of bounds
+    mEventData->mPrimaryCursorPosition = noTextHitIndex;
 
     mEventData->mUpdateCursorPosition = true;
     mEventData->mUpdateGrabHandlePosition = true;
@@ -2527,13 +2631,18 @@ void Controller::Impl::GetCursorPosition( CharacterIndex logical,
     return;
   }
 
-  Text::GetCursorPosition( mModel->mVisualModel,
-                           mModel->mLogicalModel,
-                           mMetrics,
-                           logical,
+  const bool isMultiLine = ( Layout::Engine::MULTI_LINE_BOX == mLayoutEngine.GetLayout() );
+  GetCursorPositionParameters parameters;
+  parameters.visualModel = mModel->mVisualModel;
+  parameters.logicalModel = mModel->mLogicalModel;
+  parameters.metrics = mMetrics;
+  parameters.logical = logical;
+  parameters.isMultiline = isMultiLine;
+
+  Text::GetCursorPosition( parameters,
                            cursorInfo );
 
-  if( Layout::Engine::MULTI_LINE_BOX == mLayoutEngine.GetLayout() )
+  if( isMultiLine )
   {
     // If the text is editable and multi-line, the cursor position after a white space shouldn't exceed the boundaries of the text control.
 
@@ -2614,6 +2723,8 @@ void Controller::Impl::UpdateCursorPosition( const CursorInfo& cursorInfo )
 
   const Vector2 cursorPosition = cursorInfo.primaryPosition + mModel->mScrollPosition;
 
+  mEventData->mDecorator->SetGlyphOffset( PRIMARY_CURSOR, cursorInfo.glyphOffset );
+
   // Sets the cursor position.
   mEventData->mDecorator->SetPosition( PRIMARY_CURSOR,
                                        cursorPosition.x,
@@ -2749,13 +2860,16 @@ void Controller::Impl::ScrollToMakePositionVisible( const Vector2& position, flo
     mModel->mScrollPosition.x = mModel->mVisualModel->mControlSize.width - positionEndX;
   }
 
-  if( decoratorPositionBeginY < 0.f )
-  {
-    mModel->mScrollPosition.y = -position.y;
-  }
-  else if( decoratorPositionEndY > mModel->mVisualModel->mControlSize.height )
+  if( Layout::Engine::MULTI_LINE_BOX == mLayoutEngine.GetLayout() )
   {
-    mModel->mScrollPosition.y = mModel->mVisualModel->mControlSize.height - positionEndY;
+    if( decoratorPositionBeginY < 0.f )
+    {
+      mModel->mScrollPosition.y = -position.y;
+    }
+    else if( decoratorPositionEndY > mModel->mVisualModel->mControlSize.height )
+    {
+      mModel->mScrollPosition.y = mModel->mVisualModel->mControlSize.height - positionEndY;
+    }
   }
 }
 
@@ -2764,9 +2878,20 @@ void Controller::Impl::ScrollTextToMatchCursor( const CursorInfo& cursorInfo )
   // Get the current cursor position in decorator coords.
   const Vector2& currentCursorPosition = mEventData->mDecorator->GetPosition( PRIMARY_CURSOR );
 
+  const LineIndex lineIndex = mModel->mVisualModel->GetLineOfCharacter( mEventData->mPrimaryCursorPosition  );
+
+
+
   // Calculate the offset to match the cursor position before the character was deleted.
   mModel->mScrollPosition.x = currentCursorPosition.x - cursorInfo.primaryPosition.x;
-  mModel->mScrollPosition.y = currentCursorPosition.y - cursorInfo.lineOffset;
+
+  //If text control has more than two lines and current line index is not last, calculate scrollpositionY
+  if( mModel->mVisualModel->mLines.Count() > 1u && lineIndex != mModel->mVisualModel->mLines.Count() -1u )
+  {
+    const float currentCursorGlyphOffset = mEventData->mDecorator->GetGlyphOffset( PRIMARY_CURSOR );
+    mModel->mScrollPosition.y = currentCursorPosition.y - cursorInfo.lineOffset - currentCursorGlyphOffset;
+  }
+
 
   ClampHorizontalScroll( mModel->mVisualModel->GetLayoutSize() );
   ClampVerticalScroll( mModel->mVisualModel->GetLayoutSize() );