Text Layout - Ellipsis the text when exceeds the boundaries of the box.

[platform/core/uifw/dali-toolkit.git] / dali-toolkit / internal / text / text-view.cpp

diff --git a/dali-toolkit/internal/text/text-view.cpp b/dali-toolkit/internal/text/text-view.cpp
index 61073fe..e7bd262 100644 (file)
--- a/dali-toolkit/internal/text/text-view.cpp
+++ b/dali-toolkit/internal/text/text-view.cpp
@@ -20,6 +20,7 @@
 
 // EXTERNAL INCLUDES
 #include <dali/public-api/math/vector2.h>
+#include <dali/public-api/text-abstraction/font-client.h>
 
 namespace Dali
 {
@@ -33,12 +34,15 @@ namespace Text
 struct View::Impl
 {
   VisualModelPtr mVisualModel;
+  TextAbstraction::FontClient mFontClient; ///< Handle to the font client.
 };
 
 View::View()
 : mImpl( NULL )
 {
   mImpl = new View::Impl();
+
+  mImpl->mFontClient = TextAbstraction::FontClient::Get();
 }
 
 View::~View()
@@ -51,6 +55,139 @@ void View::SetVisualModel( VisualModelPtr visualModel )
   mImpl->mVisualModel = visualModel;
 }
 
+Length View::GetGlyphs( GlyphInfo* glyphs,
+                        Vector2* glyphPositions,
+                        GlyphIndex glyphIndex,
+                        Length numberOfGlyphs ) const
+{
+  Length numberOfLaidOutGlyphs = 0u;
+
+  if( mImpl->mVisualModel )
+  {
+    // If ellipsis is enabled, the number of glyphs the layout engine has laid out may be less than 'numberOfGlyphs'.
+    // Check the last laid out line to know if the layout engine elided some text.
+
+    const Length numberOfLines = mImpl->mVisualModel->GetNumberOfLines();
+    if( numberOfLines > 0u )
+    {
+      const LineRun& lastLine = *( mImpl->mVisualModel->mLines.Begin() + ( numberOfLines - 1u ) );
+
+      // If ellipsis is enabled, calculate the number of laid out glyphs.
+      // Otherwise use the given number of glyphs.
+      if( lastLine.ellipsis )
+      {
+        numberOfLaidOutGlyphs = lastLine.glyphIndex + lastLine.numberOfGlyphs;
+      }
+      else
+      {
+        numberOfLaidOutGlyphs = numberOfGlyphs;
+      }
+
+      // Retrieve from the visual model the glyphs and positions.
+      mImpl->mVisualModel->GetGlyphs( glyphs,
+                                      glyphIndex,
+                                      numberOfLaidOutGlyphs );
+
+      mImpl->mVisualModel->GetGlyphPositions( glyphPositions,
+                                              glyphIndex,
+                                              numberOfLaidOutGlyphs );
+
+      if( 1u == numberOfLaidOutGlyphs )
+      {
+        // not a point try to do ellipsis with only one laid out character.
+        return numberOfLaidOutGlyphs;
+      }
+
+      if( lastLine.ellipsis )
+      {
+        // firstPenX, penY and firstPenSet are used to position the ellipsis glyph if needed.
+        float firstPenX = 0.f; // Used if rtl text is elided.
+        float penY = 0.f;
+        bool firstPenSet = false;
+
+        // Add the ellipsis glyph.
+        bool inserted = false;
+        float removedGlypsWidth = 0.f;
+        Length numberOfRemovedGlyphs = 0u;
+        GlyphIndex index = numberOfLaidOutGlyphs - 1u;
+
+        // The ellipsis glyph has to fit in the place where the last glyph(s) is(are) removed.
+        while( !inserted )
+        {
+          const GlyphInfo& glyphToRemove = *( glyphs + index );
+
+          // Need to reshape the glyph as the font may be different in size.
+          const GlyphInfo& ellipsisGlyph = mImpl->mFontClient.GetEllipsisGlyph( mImpl->mFontClient.GetPointSize( glyphToRemove.fontId ) );
+
+          if( !firstPenSet )
+          {
+            const Vector2& position = *( glyphPositions + index );
+
+            // Calculates the penY of the current line. It will be used to position the ellipsis glyph.
+            penY = position.y + glyphToRemove.yBearing;
+
+            // Calculates the first penX which will be used if rtl text is elided.
+            firstPenX = position.x - glyphToRemove.xBearing;
+            if( firstPenX < -ellipsisGlyph.xBearing )
+            {
+              // Avoids to exceed the bounding box when rtl text is elided.
+              firstPenX = -ellipsisGlyph.xBearing;
+            }
+
+            removedGlypsWidth = -ellipsisGlyph.xBearing;
+
+            firstPenSet = true;
+          }
+
+          removedGlypsWidth += std::min( glyphToRemove.advance, ( glyphToRemove.xBearing + glyphToRemove.width ) );
+
+          // Calculate the width of the ellipsis glyph and check if it fits.
+          const float ellipsisGlyphWidth = ellipsisGlyph.width + ellipsisGlyph.xBearing;
+          if( ellipsisGlyphWidth < removedGlypsWidth )
+          {
+            GlyphInfo& glyphInfo = *( glyphs + index );
+            Vector2& position = *( glyphPositions + index );
+            position.x -= glyphInfo.xBearing;
+
+            // Replace the glyph by the ellipsis glyph.
+            glyphInfo = ellipsisGlyph;
+
+            // Change the 'x' and 'y' position of the ellipsis glyph.
+
+            if( position.x > firstPenX )
+            {
+              position.x = firstPenX + removedGlypsWidth - ellipsisGlyphWidth;
+            }
+
+            position.x += ellipsisGlyph.xBearing;
+            position.y = penY - ellipsisGlyph.yBearing;
+
+            inserted = true;
+          }
+          else
+          {
+            if( index > 0u )
+            {
+              --index;
+            }
+            else
+            {
+              // No space for the ellipsis.
+              inserted = true;
+            }
+            ++numberOfRemovedGlyphs;
+          }
+        }
+
+        // 'Removes' all the glyphs after the ellipsis glyph.
+        numberOfLaidOutGlyphs -= numberOfRemovedGlyphs;
+      }
+    }
+  }
+
+  return numberOfLaidOutGlyphs;
+}
+
 const Vector4& View::GetTextColor() const
 {
   if ( mImpl->mVisualModel )
@@ -128,26 +265,6 @@ Length View::GetNumberOfGlyphs() const
   return 0;
 }
 
-void View::GetGlyphs( GlyphInfo* glyphs,
-                      GlyphIndex glyphIndex,
-                      Length numberOfGlyphs ) const
-{
-  if( mImpl->mVisualModel )
-  {
-    mImpl->mVisualModel->GetGlyphs( glyphs, glyphIndex, numberOfGlyphs );
-  }
-}
-
-void View::GetGlyphPositions( Vector2* glyphPositions,
-                              GlyphIndex glyphIndex,
-                              Length numberOfGlyphs ) const
-{
-  if( mImpl->mVisualModel )
-  {
-    mImpl->mVisualModel->GetGlyphPositions( glyphPositions, glyphIndex, numberOfGlyphs );
-  }
-}
-
 } // namespace Text
 
 } // namespace Toolkit