Convert text drawing and measurement to use Core Text API.

Contributed by Elizabeth Irizarry of Adobe with some modifications
by Neil Hodgson.

1 files changed, 56 insertions, 94 deletions

diff --git a/cocoa/QuartzTextLayout.h b/cocoa/QuartzTextLayout.h
index 64bf492d4..033ac98fb 100644
--- a/cocoa/QuartzTextLayout.h
+++ b/cocoa/QuartzTextLayout.h
@@ -15,127 +15,89 @@
 
 #include "QuartzTextStyle.h"
 
+
 class QuartzTextLayout
 {
 public:
     /** Create a text layout for drawing on the specified context. */
-    QuartzTextLayout( CGContextRef context ) : layout( NULL ), unicode_string( NULL ), unicode_length( 0 )
+    QuartzTextLayout( CGContextRef context )
     {
-        OSStatus err = ATSUCreateTextLayout( &layout );
-        if (0 != err)
-                layout = NULL;
-
+		mString = NULL;
+		mLine = NULL;
         setContext(context);
-
-        ATSUAttributeTag tag = kATSULineLayoutOptionsTag;
-        ByteCount size = sizeof( ATSLineLayoutOptions );
-        ATSLineLayoutOptions rendering = kATSLineUseDeviceMetrics; //| kATSLineFractDisable | kATSLineUseQDRendering
-        ATSUAttributeValuePtr valuePtr = &rendering;
-        err = ATSUSetLayoutControls( layout, 1, &tag, &size, &valuePtr );
     }
 
     ~QuartzTextLayout()
     {
-        if (NULL != layout)
-            ATSUDisposeTextLayout( layout );
-        layout = NULL;
-
-        if ( unicode_string != NULL )
-        {
-            delete[] unicode_string;
-            unicode_string = NULL;
-            unicode_length = 0;
-        }
-    }
-
-    /** Assign a string to the text layout object. */
-    // TODO: Create a UTF8 version
-    // TODO: Optimise the ASCII version by not copying so much
-    OSStatus setText( const UInt8* buffer, size_t byteLength, CFStringEncoding encoding )
-    {
-        if (NULL == layout)
-                return -1;
-        CFStringRef str = CFStringCreateWithBytes( NULL, buffer, byteLength, encoding, false );
-        if (!str)
-            return -1;
-
-        unicode_length = CFStringGetLength( str );
-        if (unicode_string)
-            delete[] unicode_string;
-        unicode_string = new UniChar[ unicode_length ];
-        CFStringGetCharacters( str, CFRangeMake( 0, unicode_length ), unicode_string );
-
-        CFRelease( str );
-        str = NULL;
-
-        OSStatus err;
-        err = ATSUSetTextPointerLocation( layout, unicode_string, kATSUFromTextBeginning, kATSUToTextEnd, unicode_length );
-        if( err != noErr ) return err;
-
-        // Turn on the default font fallbacks
-        return ATSUSetTransientFontMatching( layout, true );
+		if ( mString != NULL )
+		{
+			CFRelease(mString);
+			mString = NULL;
+		}
+		if ( mLine != NULL )
+		{
+			CFRelease(mLine);
+			mLine = NULL;
+		}	
     }
 
     inline void setText( const UInt8* buffer, size_t byteLength, const QuartzTextStyle& r )
     {
-        this->setText( buffer, byteLength, kCFStringEncodingUTF8 );
-        ATSUSetRunStyle( layout, r.getATSUStyle(), 0, unicode_length );
-    }
-
-    /** Apply the specified text style on the entire range of text. */
-    void setStyle( const QuartzTextStyle& style )
-    {
-        ATSUSetRunStyle( layout, style.getATSUStyle(), kATSUFromTextBeginning, kATSUToTextEnd );
+		CFStringRef str = CFStringCreateWithBytes( NULL, buffer, byteLength, kCFStringEncodingUTF8, false );
+        if (!str)
+            return;
+		
+		CFMutableDictionaryRef stringAttribs = r.getCTStyle();
+		
+		if (mString != NULL)
+			CFRelease(mString);
+		mString = ::CFAttributedStringCreate(NULL, str, stringAttribs);
+		
+		if (mLine != NULL)
+			CFRelease(mLine);
+		mLine = ::CTLineCreateWithAttributedString(mString);
+		
+		CFRelease( str );
     }
 
-    /** Draw the text layout into the current CGContext at the specified position, flipping the CGContext's Y axis if required.
+    /** Draw the text layout into the current CGContext at the specified position.
     * @param x The x axis position to draw the baseline in the current CGContext.
-    * @param y The y axis position to draw the baseline in the current CGContext.
-    * @param flipTextYAxis If true, the CGContext's Y axis will be flipped before drawing the text, and restored afterwards. Use this when drawing in an HIView's CGContext, where the origin is the top left corner. */
-    void draw( float x, float y, bool flipTextYAxis = false )
+    * @param y The y axis position to draw the baseline in the current CGContext. */
+    void draw( float x, float y )
     {
-        if (NULL == layout || 0 == unicode_length)
-                return;
-        if ( flipTextYAxis )
-        {
-            CGContextSaveGState( gc );
-            CGContextScaleCTM( gc, 1.0, -1.0 );
-            y = -y;
-        }
-        
-        OSStatus err;
-        err = ATSUDrawText( layout, kATSUFromTextBeginning, kATSUToTextEnd, X2Fix( x ), X2Fix( y ) );
-
-        if ( flipTextYAxis ) CGContextRestoreGState( gc );
+		if (mLine == NULL)
+			return;
+		
+		::CGContextSetTextMatrix(gc, CGAffineTransformMakeScale(1.0, -1.0));
+		
+		// Set the text drawing position.
+		::CGContextSetTextPosition(gc, x, y);
+		
+		// And finally, draw!
+		::CTLineDraw(mLine, gc);
     }
-
-    /** Sets a single text layout control on the ATSUTextLayout object.
-    * @param tag The control to set.
-    * @param size The size of the parameter pointed to by value.
-    * @param value A pointer to the new value for the control.
-    */
-    void setControl( ATSUAttributeTag tag, ByteCount size, ATSUAttributeValuePtr value )
-    {
-        ATSUSetLayoutControls( layout, 1, &tag, &size, &value );
+	
+	float MeasureStringWidth()
+	{		
+		if (mLine == NULL)
+			return 0.0f;
+		
+		return ::CTLineGetTypographicBounds(mLine, NULL, NULL, NULL);
+	}
+	
+    CTLineRef getCTLine() {
+        return mLine;
     }
-
-    ATSUTextLayout getLayout() {
-        return layout;
-    }
-
-    inline CFIndex getLength() const { return unicode_length; }
+	
     inline void setContext (CGContextRef context)
     {
         gc = context;
-        if (NULL != layout)
-            setControl( kATSUCGContextTag, sizeof( gc ), &gc );
     }
 
 private:
-    ATSUTextLayout layout;
-    UniChar* unicode_string;
-    int unicode_length;
     CGContextRef gc;
+	CFAttributedStringRef mString;
+	CTLineRef mLine;
 };
 
 #endif