+/*
+ * Copyright (c) 2020 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.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// CLASS HEADER
+#include <dali-toolkit/internal/text/text-controller-relayouter.h>
+
+// EXTERNAL INCLUDES
+#include <limits>
+#include <dali/integration-api/debug.h>
+
+// INTERNAL INCLUDES
+#include <dali-toolkit/internal/text/layouts/layout-parameters.h>
+#include <dali-toolkit/internal/text/text-controller-impl.h>
+
+namespace
+{
+
+#if defined(DEBUG_ENABLED)
+Debug::Filter* gLogFilter = Debug::Filter::New(Debug::NoLogging, true, "LOG_TEXT_CONTROLS");
+#endif
+
+constexpr float MAX_FLOAT = std::numeric_limits<float>::max();
+
+float ConvertToEven( float value )
+{
+ int intValue(static_cast<int>( value ));
+ return static_cast<float>( intValue + ( intValue & 1 ) );
+}
+
+} // namespace
+
+namespace Dali
+{
+
+namespace Toolkit
+{
+
+namespace Text
+{
+
+Vector3 Controller::Relayouter::GetNaturalSize(Controller& controller)
+{
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "-->Controller::GetNaturalSize\n" );
+ Vector3 naturalSize;
+
+ // Make sure the model is up-to-date before layouting
+ controller.ProcessModifyEvents();
+
+ Controller::Impl& impl = *controller.mImpl;
+ ModelPtr& model = impl.mModel;
+ VisualModelPtr& visualModel = model->mVisualModel;
+ if( impl.mRecalculateNaturalSize )
+ {
+ // Operations that can be done only once until the text changes.
+ const OperationsMask onlyOnceOperations = static_cast<OperationsMask>( CONVERT_TO_UTF32 |
+ GET_SCRIPTS |
+ VALIDATE_FONTS |
+ GET_LINE_BREAKS |
+ BIDI_INFO |
+ SHAPE_TEXT |
+ GET_GLYPH_METRICS );
+
+ // Set the update info to relayout the whole text.
+ TextUpdateInfo& textUpdateInfo = impl.mTextUpdateInfo;
+ textUpdateInfo.mParagraphCharacterIndex = 0u;
+ textUpdateInfo.mRequestedNumberOfCharacters = model->mLogicalModel->mText.Count();
+
+ // Make sure the model is up-to-date before layouting
+ impl.UpdateModel( onlyOnceOperations );
+
+ // Get a reference to the pending operations member
+ OperationsMask& operationsPending = impl.mOperationsPending;
+
+ // Layout the text for the new width.
+ operationsPending = static_cast<OperationsMask>( operationsPending | LAYOUT | REORDER );
+
+ // Store the actual control's size to restore later.
+ const Size actualControlSize = visualModel->mControlSize;
+
+ DoRelayout( controller,
+ Size( MAX_FLOAT, MAX_FLOAT ),
+ static_cast<OperationsMask>( onlyOnceOperations |
+ LAYOUT | REORDER ),
+ naturalSize.GetVectorXY() );
+
+ // Do not do again the only once operations.
+ operationsPending = static_cast<OperationsMask>( operationsPending & ~onlyOnceOperations );
+
+ // Do the size related operations again.
+ const OperationsMask sizeOperations = static_cast<OperationsMask>( LAYOUT |
+ ALIGN |
+ REORDER );
+ operationsPending = static_cast<OperationsMask>( operationsPending | sizeOperations );
+
+ // Stores the natural size to avoid recalculate it again
+ // unless the text/style changes.
+ visualModel->SetNaturalSize( naturalSize.GetVectorXY() );
+
+ impl.mRecalculateNaturalSize = false;
+
+ // Clear the update info. This info will be set the next time the text is updated.
+ textUpdateInfo.Clear();
+ textUpdateInfo.mClearAll = true;
+
+ // Restore the actual control's size.
+ visualModel->mControlSize = actualControlSize;
+
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::GetNaturalSize calculated %f,%f,%f\n", naturalSize.x, naturalSize.y, naturalSize.z );
+ }
+ else
+ {
+ naturalSize = visualModel->GetNaturalSize();
+
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::GetNaturalSize cached %f,%f,%f\n", naturalSize.x, naturalSize.y, naturalSize.z );
+ }
+
+ naturalSize.x = ConvertToEven( naturalSize.x );
+ naturalSize.y = ConvertToEven( naturalSize.y );
+
+ return naturalSize;
+}
+
+bool Controller::Relayouter::CheckForTextFit(Controller& controller, float pointSize, const Size& layoutSize)
+{
+ Size textSize;
+ Controller::Impl& impl = *controller.mImpl;
+ TextUpdateInfo& textUpdateInfo = impl.mTextUpdateInfo;
+ impl.mFontDefaults->mFitPointSize = pointSize;
+ impl.mFontDefaults->sizeDefined = true;
+ controller.ClearFontData();
+
+ // Operations that can be done only once until the text changes.
+ const OperationsMask onlyOnceOperations = static_cast<OperationsMask>( CONVERT_TO_UTF32 |
+ GET_SCRIPTS |
+ VALIDATE_FONTS |
+ GET_LINE_BREAKS |
+ BIDI_INFO |
+ SHAPE_TEXT|
+ GET_GLYPH_METRICS );
+
+ textUpdateInfo.mParagraphCharacterIndex = 0u;
+ textUpdateInfo.mRequestedNumberOfCharacters = impl.mModel->mLogicalModel->mText.Count();
+
+ // Make sure the model is up-to-date before layouting
+ impl.UpdateModel( onlyOnceOperations );
+
+ DoRelayout( controller,
+ Size( layoutSize.width, MAX_FLOAT ),
+ static_cast<OperationsMask>( onlyOnceOperations | LAYOUT),
+ textSize);
+
+ // Clear the update info. This info will be set the next time the text is updated.
+ textUpdateInfo.Clear();
+ textUpdateInfo.mClearAll = true;
+
+ if( textSize.width > layoutSize.width || textSize.height > layoutSize.height )
+ {
+ return false;
+ }
+ return true;
+}
+
+float Controller::Relayouter::GetHeightForWidth(Controller& controller, float width)
+{
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "-->Controller::GetHeightForWidth %p width %f\n", &controller, width );
+ // Make sure the model is up-to-date before layouting
+ controller.ProcessModifyEvents();
+
+ Controller::Impl& impl = *controller.mImpl;
+ ModelPtr& model = impl.mModel;
+ VisualModelPtr& visualModel = model->mVisualModel;
+ TextUpdateInfo& textUpdateInfo = impl.mTextUpdateInfo;
+
+ Size layoutSize;
+ if( fabsf( width - visualModel->mControlSize.width ) > Math::MACHINE_EPSILON_1000 ||
+ textUpdateInfo.mFullRelayoutNeeded ||
+ textUpdateInfo.mClearAll )
+ {
+ // Operations that can be done only once until the text changes.
+ const OperationsMask onlyOnceOperations = static_cast<OperationsMask>( CONVERT_TO_UTF32 |
+ GET_SCRIPTS |
+ VALIDATE_FONTS |
+ GET_LINE_BREAKS |
+ BIDI_INFO |
+ SHAPE_TEXT |
+ GET_GLYPH_METRICS );
+
+ // Set the update info to relayout the whole text.
+ textUpdateInfo.mParagraphCharacterIndex = 0u;
+ textUpdateInfo.mRequestedNumberOfCharacters = model->mLogicalModel->mText.Count();
+
+ // Make sure the model is up-to-date before layouting
+ impl.UpdateModel( onlyOnceOperations );
+
+ // Get a reference to the pending operations member
+ OperationsMask& operationsPending = impl.mOperationsPending;
+
+ // Layout the text for the new width.
+ operationsPending = static_cast<OperationsMask>( operationsPending | LAYOUT );
+
+ // Store the actual control's width.
+ const float actualControlWidth = visualModel->mControlSize.width;
+
+ DoRelayout( controller,
+ Size( width, MAX_FLOAT ),
+ static_cast<OperationsMask>( onlyOnceOperations |
+ LAYOUT ),
+ layoutSize );
+
+ // Do not do again the only once operations.
+ operationsPending = static_cast<OperationsMask>( operationsPending & ~onlyOnceOperations );
+
+ // Do the size related operations again.
+ const OperationsMask sizeOperations = static_cast<OperationsMask>( LAYOUT |
+ ALIGN |
+ REORDER );
+
+ operationsPending = static_cast<OperationsMask>( operationsPending | sizeOperations );
+
+ // Clear the update info. This info will be set the next time the text is updated.
+ textUpdateInfo.Clear();
+ textUpdateInfo.mClearAll = true;
+
+ // Restore the actual control's width.
+ visualModel->mControlSize.width = actualControlWidth;
+
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::GetHeightForWidth calculated %f\n", layoutSize.height );
+ }
+ else
+ {
+ layoutSize = visualModel->GetLayoutSize();
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::GetHeightForWidth cached %f\n", layoutSize.height );
+ }
+
+ return layoutSize.height;
+}
+
+Controller::UpdateTextType Controller::Relayouter::Relayout(Controller& controller, const Size& size, Dali::LayoutDirection::Type layoutDirection)
+{
+ Controller::Impl& impl = *controller.mImpl;
+ ModelPtr& model = impl.mModel;
+ VisualModelPtr& visualModel = model->mVisualModel;
+ TextUpdateInfo& textUpdateInfo = impl.mTextUpdateInfo;
+
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "-->Controller::Relayout %p size %f,%f, autoScroll[%s]\n", &controller, size.width, size.height, impl.mIsAutoScrollEnabled ?"true":"false" );
+
+ UpdateTextType updateTextType = NONE_UPDATED;
+
+ if( ( size.width < Math::MACHINE_EPSILON_1000 ) || ( size.height < Math::MACHINE_EPSILON_1000 ) )
+ {
+ if( 0u != visualModel->mGlyphPositions.Count() )
+ {
+ visualModel->mGlyphPositions.Clear();
+ updateTextType = MODEL_UPDATED;
+ }
+
+ // Clear the update info. This info will be set the next time the text is updated.
+ textUpdateInfo.Clear();
+
+ // Not worth to relayout if width or height is equal to zero.
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::Relayout (skipped)\n" );
+
+ return updateTextType;
+ }
+
+ // Whether a new size has been set.
+ const bool newSize = ( size != visualModel->mControlSize );
+
+ // Get a reference to the pending operations member
+ OperationsMask& operationsPending = impl.mOperationsPending;
+
+ if( newSize )
+ {
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "new size (previous size %f,%f)\n", visualModel->mControlSize.width, visualModel->mControlSize.height );
+
+ if( ( 0 == textUpdateInfo.mNumberOfCharactersToAdd ) &&
+ ( 0 == textUpdateInfo.mPreviousNumberOfCharacters ) &&
+ ( ( visualModel->mControlSize.width < Math::MACHINE_EPSILON_1000 ) || ( visualModel->mControlSize.height < Math::MACHINE_EPSILON_1000 ) ) )
+ {
+ textUpdateInfo.mNumberOfCharactersToAdd = model->mLogicalModel->mText.Count();
+ }
+
+ // Layout operations that need to be done if the size changes.
+ operationsPending = static_cast<OperationsMask>( operationsPending |
+ LAYOUT |
+ ALIGN |
+ UPDATE_LAYOUT_SIZE |
+ REORDER );
+ // Set the update info to relayout the whole text.
+ textUpdateInfo.mFullRelayoutNeeded = true;
+ textUpdateInfo.mCharacterIndex = 0u;
+
+ // Store the size used to layout the text.
+ visualModel->mControlSize = size;
+ }
+
+ // Whether there are modify events.
+ if( 0u != impl.mModifyEvents.Count() )
+ {
+ // Style operations that need to be done if the text is modified.
+ operationsPending = static_cast<OperationsMask>( operationsPending | COLOR );
+ }
+
+ // Set the update info to elide the text.
+ if( model->mElideEnabled ||
+ ( ( NULL != impl.mEventData ) && impl.mEventData->mIsPlaceholderElideEnabled ) )
+ {
+ // Update Text layout for applying elided
+ operationsPending = static_cast<OperationsMask>( operationsPending |
+ ALIGN |
+ LAYOUT |
+ UPDATE_LAYOUT_SIZE |
+ REORDER );
+ textUpdateInfo.mFullRelayoutNeeded = true;
+ textUpdateInfo.mCharacterIndex = 0u;
+ }
+
+ if( model->mMatchSystemLanguageDirection && impl.mLayoutDirection != layoutDirection )
+ {
+ // Clear the update info. This info will be set the next time the text is updated.
+ textUpdateInfo.mClearAll = true;
+ // Apply modifications to the model
+ // Shape the text again is needed because characters like '()[]{}' have to be mirrored and the glyphs generated again.
+ operationsPending = static_cast<OperationsMask>( operationsPending |
+ GET_GLYPH_METRICS |
+ SHAPE_TEXT |
+ UPDATE_DIRECTION |
+ LAYOUT |
+ BIDI_INFO |
+ REORDER );
+ impl.mLayoutDirection = layoutDirection;
+ }
+
+ // Make sure the model is up-to-date before layouting.
+ controller.ProcessModifyEvents();
+ bool updated = impl.UpdateModel( operationsPending );
+
+ // Layout the text.
+ Size layoutSize;
+ updated = DoRelayout( controller, size, operationsPending, layoutSize ) || updated;
+
+
+ if( updated )
+ {
+ updateTextType = MODEL_UPDATED;
+ }
+
+ // Do not re-do any operation until something changes.
+ operationsPending = NO_OPERATION;
+ model->mScrollPositionLast = model->mScrollPosition;
+
+ // Whether the text control is editable
+ const bool isEditable = NULL != impl.mEventData;
+
+ // Keep the current offset as it will be used to update the decorator's positions (if the size changes).
+ Vector2 offset;
+ if( newSize && isEditable )
+ {
+ offset = model->mScrollPosition;
+ }
+
+ if( !isEditable || !controller.IsMultiLineEnabled() )
+ {
+ // After doing the text layout, the vertical offset to place the actor in the desired position can be calculated.
+ controller.CalculateVerticalOffset( size );
+ }
+
+ if( isEditable )
+ {
+ if( newSize )
+ {
+ // If there is a new size, the scroll position needs to be clamped.
+ impl.ClampHorizontalScroll( layoutSize );
+
+ // Update the decorator's positions is needed if there is a new size.
+ impl.mEventData->mDecorator->UpdatePositions( model->mScrollPosition - offset );
+ }
+
+ // Move the cursor, grab handle etc.
+ if( impl.ProcessInputEvents() )
+ {
+ updateTextType = static_cast<UpdateTextType>( updateTextType | DECORATOR_UPDATED );
+ }
+ }
+
+ // Clear the update info. This info will be set the next time the text is updated.
+ textUpdateInfo.Clear();
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::Relayout\n" );
+
+ return updateTextType;
+}
+
+bool Controller::Relayouter::DoRelayout(Controller& controller, const Size& size, OperationsMask operationsRequired, Size& layoutSize )
+{
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "-->Controller::DoRelayout %p size %f,%f\n", &controller, size.width, size.height );
+ bool viewUpdated( false );
+
+ Controller::Impl& impl = *controller.mImpl;
+
+ // Calculate the operations to be done.
+ const OperationsMask operations = static_cast<OperationsMask>( impl.mOperationsPending & operationsRequired );
+
+ TextUpdateInfo& textUpdateInfo = impl.mTextUpdateInfo;
+ const CharacterIndex startIndex = textUpdateInfo.mParagraphCharacterIndex;
+ const Length requestedNumberOfCharacters = textUpdateInfo.mRequestedNumberOfCharacters;
+
+ // Get the current layout size.
+ VisualModelPtr& visualModel = impl.mModel->mVisualModel;
+ layoutSize = visualModel->GetLayoutSize();
+
+ if( NO_OPERATION != ( LAYOUT & operations ) )
+ {
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "-->Controller::DoRelayout LAYOUT & operations\n");
+
+ // Some vectors with data needed to layout and reorder may be void
+ // after the first time the text has been laid out.
+ // Fill the vectors again.
+
+ // Calculate the number of glyphs to layout.
+ const Vector<GlyphIndex>& charactersToGlyph = visualModel->mCharactersToGlyph;
+ const Vector<Length>& glyphsPerCharacter = visualModel->mGlyphsPerCharacter;
+ const GlyphIndex* const charactersToGlyphBuffer = charactersToGlyph.Begin();
+ const Length* const glyphsPerCharacterBuffer = glyphsPerCharacter.Begin();
+
+ const CharacterIndex lastIndex = startIndex + ( ( requestedNumberOfCharacters > 0u ) ? requestedNumberOfCharacters - 1u : 0u );
+ const GlyphIndex startGlyphIndex = textUpdateInfo.mStartGlyphIndex;
+
+ // Make sure the index is not out of bound
+ if ( charactersToGlyph.Count() != glyphsPerCharacter.Count() ||
+ requestedNumberOfCharacters > charactersToGlyph.Count() ||
+ ( lastIndex > charactersToGlyph.Count() && charactersToGlyph.Count() > 0u ) )
+ {
+ std::string currentText;
+ controller.GetText( currentText );
+
+ DALI_LOG_ERROR( "Controller::DoRelayout: Attempting to access invalid buffer\n" );
+ DALI_LOG_ERROR( "Current text is: %s\n", currentText.c_str() );
+ DALI_LOG_ERROR( "startIndex: %u, lastIndex: %u, requestedNumberOfCharacters: %u, charactersToGlyph.Count = %lu, glyphsPerCharacter.Count = %lu\n", startIndex, lastIndex, requestedNumberOfCharacters, charactersToGlyph.Count(), glyphsPerCharacter.Count());
+
+ return false;
+ }
+
+ const Length numberOfGlyphs = ( requestedNumberOfCharacters > 0u ) ? *( charactersToGlyphBuffer + lastIndex ) + *( glyphsPerCharacterBuffer + lastIndex ) - startGlyphIndex : 0u;
+ const Length totalNumberOfGlyphs = visualModel->mGlyphs.Count();
+
+ if( 0u == totalNumberOfGlyphs )
+ {
+ if( NO_OPERATION != ( UPDATE_LAYOUT_SIZE & operations ) )
+ {
+ visualModel->SetLayoutSize( Size::ZERO );
+ }
+
+ // Nothing else to do if there is no glyphs.
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::DoRelayout no glyphs, view updated true\n" );
+ return true;
+ }
+
+ // Set the layout parameters.
+ Layout::Parameters layoutParameters( size, impl.mModel);
+
+ // Resize the vector of positions to have the same size than the vector of glyphs.
+ Vector<Vector2>& glyphPositions = visualModel->mGlyphPositions;
+ glyphPositions.Resize( totalNumberOfGlyphs );
+
+ // Whether the last character is a new paragraph character.
+ const Character* const textBuffer = impl.mModel->mLogicalModel->mText.Begin();
+ textUpdateInfo.mIsLastCharacterNewParagraph = TextAbstraction::IsNewParagraph( *( textBuffer + ( impl.mModel->mLogicalModel->mText.Count() - 1u ) ) );
+ layoutParameters.isLastNewParagraph = textUpdateInfo.mIsLastCharacterNewParagraph;
+
+ // The initial glyph and the number of glyphs to layout.
+ layoutParameters.startGlyphIndex = startGlyphIndex;
+ layoutParameters.numberOfGlyphs = numberOfGlyphs;
+ layoutParameters.startLineIndex = textUpdateInfo.mStartLineIndex;
+ layoutParameters.estimatedNumberOfLines = textUpdateInfo.mEstimatedNumberOfLines;
+
+ // Update the ellipsis
+ bool elideTextEnabled = impl.mModel->mElideEnabled;
+
+ if( NULL != impl.mEventData )
+ {
+ if( impl.mEventData->mPlaceholderEllipsisFlag && impl.IsShowingPlaceholderText() )
+ {
+ elideTextEnabled = impl.mEventData->mIsPlaceholderElideEnabled;
+ }
+ else if( EventData::INACTIVE != impl.mEventData->mState )
+ {
+ // Disable ellipsis when editing
+ elideTextEnabled = false;
+ }
+
+ // Reset the scroll position in inactive state
+ if( elideTextEnabled && ( impl.mEventData->mState == EventData::INACTIVE ) )
+ {
+ controller.ResetScrollPosition();
+ }
+ }
+
+ // Update the visual model.
+ bool isAutoScrollEnabled = impl.mIsAutoScrollEnabled;
+ Size newLayoutSize;
+ viewUpdated = impl.mLayoutEngine.LayoutText( layoutParameters,
+ newLayoutSize,
+ elideTextEnabled,
+ isAutoScrollEnabled );
+ impl.mIsAutoScrollEnabled = isAutoScrollEnabled;
+
+ viewUpdated = viewUpdated || ( newLayoutSize != layoutSize );
+
+ if( viewUpdated )
+ {
+ layoutSize = newLayoutSize;
+
+ if( NO_OPERATION != ( UPDATE_DIRECTION & operations ) )
+ {
+ impl.mIsTextDirectionRTL = false;
+ }
+
+ if ( ( NO_OPERATION != ( UPDATE_DIRECTION & operations ) ) && !visualModel->mLines.Empty() )
+ {
+ impl.mIsTextDirectionRTL = visualModel->mLines[0u].direction;
+ }
+
+ // Sets the layout size.
+ if( NO_OPERATION != ( UPDATE_LAYOUT_SIZE & operations ) )
+ {
+ visualModel->SetLayoutSize( layoutSize );
+ }
+ } // view updated
+ }
+
+ if( NO_OPERATION != ( ALIGN & operations ) )
+ {
+ // The laid-out lines.
+ Vector<LineRun>& lines = visualModel->mLines;
+
+ CharacterIndex alignStartIndex = startIndex;
+ Length alignRequestedNumberOfCharacters = requestedNumberOfCharacters;
+
+ // the whole text needs to be full aligned.
+ // If you do not do a full aligned, only the last line of the multiline input is aligned.
+ if( impl.mEventData && impl.mEventData->mUpdateAlignment )
+ {
+ alignStartIndex = 0u;
+ alignRequestedNumberOfCharacters = impl.mModel->mLogicalModel->mText.Count();
+ impl.mEventData->mUpdateAlignment = false;
+ }
+
+ // Need to align with the control's size as the text may contain lines
+ // starting either with left to right text or right to left.
+ impl.mLayoutEngine.Align( size,
+ alignStartIndex,
+ alignRequestedNumberOfCharacters,
+ impl.mModel->mHorizontalAlignment,
+ lines,
+ impl.mModel->mAlignmentOffset,
+ impl.mLayoutDirection,
+ impl.mModel->mMatchSystemLanguageDirection );
+
+ viewUpdated = true;
+ }
+#if defined(DEBUG_ENABLED)
+ std::string currentText;
+ controller.GetText( currentText );
+ DALI_LOG_INFO( gLogFilter, Debug::Concise, "Controller::DoRelayout [%p] mImpl->mIsTextDirectionRTL[%s] [%s]\n", &controller, (impl.mIsTextDirectionRTL)?"true":"false", currentText.c_str() );
+#endif
+ DALI_LOG_INFO( gLogFilter, Debug::Verbose, "<--Controller::DoRelayout, view updated %s\n", ( viewUpdated ? "true" : "false" ) );
+ return viewUpdated;
+}
+
+void Controller::Relayouter::CalculateVerticalOffset(Controller& controller, const Size& controlSize)
+{
+ Controller::Impl& impl = *controller.mImpl;
+ ModelPtr& model = impl.mModel;
+ Size layoutSize = model->mVisualModel->GetLayoutSize();
+
+ if( fabsf( layoutSize.height ) < Math::MACHINE_EPSILON_1000 )
+ {
+ // Get the line height of the default font.
+ layoutSize.height = impl.GetDefaultFontLineHeight();
+ }
+
+ switch( model->mVerticalAlignment )
+ {
+ case VerticalAlignment::TOP:
+ {
+ model->mScrollPosition.y = 0.f;
+ break;
+ }
+ case VerticalAlignment::CENTER:
+ {
+ model->mScrollPosition.y = floorf( 0.5f * ( controlSize.height - layoutSize.height ) ); // try to avoid pixel alignment.
+ break;
+ }
+ case VerticalAlignment::BOTTOM:
+ {
+ model->mScrollPosition.y = controlSize.height - layoutSize.height;
+ break;
+ }
+ }
+}
+
+} // namespace Text
+
+} // namespace Toolkit
+
+} // namespace Dali