skins2: rework image control (scale while preserving aspect ratio)

 - implement mouseOver (forgotten in prior commit)
 - picture rescaled only when size changed (better performance)
 - some cosmetics

modules/gui/skins2/controls/ctrl_image.cpp

@@ -38,7 +38,8 @@ CtrlImage::CtrlImage( intf_thread_t *pIntf, GenericBitmap &rBitmap,
                       const UString &rHelp, VarBool *pVisible, bool art ):
     CtrlFlat( pIntf, rHelp, pVisible ),
     m_pBitmap( &rBitmap ), m_pOriginalBitmap( &rBitmap ),
-    m_rCommand( rCommand ), m_resizeMethod( resizeMethod ), m_art( art )
+    m_rCommand( rCommand ), m_resizeMethod( resizeMethod ), m_art( art ),
+    m_x( 0 ), m_y( 0 )
 {
     // Create an initial unscaled image in the buffer
     m_pImage = OSFactory::instance( pIntf )->createOSGraphics(
@@ -94,32 +95,47 @@ void CtrlImage::handleEvent( EvtGeneric &rEvent )
 
 bool CtrlImage::mouseOver( int x, int y ) const
 {
-    if( m_resizeMethod == kMosaic &&
-        x >= 0 && x < getPosition()->getWidth() &&
+    if( x >= 0 && x < getPosition()->getWidth() &&
         y >= 0 && y < getPosition()->getHeight() )
     {
-        // In mosaic mode, convert the coordinates to make them fit to the
-        // size of the original image
+        // convert the coordinates to make them fit to the
+        // size of the original image if needed
+        switch( m_resizeMethod )
+        {
+        case kMosaic:
             x %= m_pImage->getWidth();
             y %= m_pImage->getHeight();
+            break;
+
+        case kScaleAndRatioPreserved:
+            x -= m_x;
+            y -= m_y;
+            break;
+
+        case kScale:
+            break;
         }
         return m_pImage->hit( x, y );
+    }
+
+    return false;
 }
 
 
 void CtrlImage::draw( OSGraphics &rImage, int xDest, int yDest )
 {
     const Position *pPos = getPosition();
-    if( pPos )
-    {
+    if( !pPos )
+        return;
+
     int width = pPos->getWidth();
     int height = pPos->getHeight();
+    if( width <= 0 || height <= 0 )
+        return;
 
     if( m_resizeMethod == kScale )
     {
         // Use scaling method
-            if( width > 0 && height > 0 )
-            {
         if( width != m_pImage->getWidth() ||
             height != m_pImage->getHeight() )
         {
@@ -132,7 +148,6 @@ void CtrlImage::draw( OSGraphics &rImage, int xDest, int yDest )
         }
         rImage.drawGraphics( *m_pImage, 0, 0, xDest, yDest );
     }
-        }
     else if( m_resizeMethod == kMosaic )
     {
         // Use mosaic method
@@ -155,42 +170,47 @@ void CtrlImage::draw( OSGraphics &rImage, int xDest, int yDest )
     }
     else if( m_resizeMethod == kScaleAndRatioPreserved )
     {
-            int width = pPos->getWidth();
-            int height = pPos->getHeight();
-
-            int w = m_pBitmap->getWidth();
-            int h = m_pBitmap->getHeight();
-
-            int scaled_height = width * h / w;
-            int scaled_width  = height * w / h;
+        int w0 = m_pBitmap->getWidth();
+        int h0 = m_pBitmap->getHeight();
 
-            int x, y;
+        int scaled_height = width * h0 / w0;
+        int scaled_width  = height * w0 / h0;
 
+        // new image scaled with aspect ratio preserved
+        // and centered inside the control boundaries
+        int w, h;
         if( scaled_height > height )
         {
-                width = scaled_width;
-                x = ( pPos->getWidth() - width ) / 2;
-                y = 0;
+            w = scaled_width;
+            h = height;
+            m_x = ( width - w ) / 2;
+            m_y = 0;
         }
         else
         {
-                height = scaled_height;
-                x =  0;
-                y = ( pPos->getHeight() - height ) / 2;
+            w = width;
+            h = scaled_height;
+            m_x = 0;
+            m_y = ( height - h ) / 2;
         }
 
+        // rescale the image if size changed
+        if( w != m_pImage->getWidth() ||
+            h != m_pImage->getHeight() )
+        {
             OSFactory *pOsFactory = OSFactory::instance( getIntf() );
-            // Rescale the image with the actual size of the control
-            ScaledBitmap bmp( getIntf(), *m_pBitmap, width, height );
+            ScaledBitmap bmp( getIntf(), *m_pBitmap, w, h );
             delete m_pImage;
-            m_pImage = pOsFactory->createOSGraphics( width, height );
+            m_pImage = pOsFactory->createOSGraphics( w, h );
             m_pImage->drawBitmap( bmp, 0, 0 );
-
-            rImage.drawGraphics( *m_pImage, 0, 0, xDest + x, yDest + y );
         }
+
+        // draw the scaled image at offset (m_x, m_y) from control origin
+        rImage.drawGraphics( *m_pImage, 0, 0, xDest + m_x, yDest + m_y );
     }
 }
 
+
 void CtrlImage::onUpdate( Subject<VarString> &rVariable, void* arg )
 {
     VlcProc *pVlcProc = VlcProc::instance( getIntf() );

modules/gui/skins2/controls/ctrl_image.hpp

@@ -78,6 +78,9 @@ private:
     resize_t m_resizeMethod;
     /// does the image get updated as art
     bool m_art;
+    /// offset for image inside the control
+    int m_x;
+    int m_y;
 
     /// Method called when the observed variable is modified
     virtual void onUpdate( Subject<VarString> &rVariable, void* );