skins2: implement art display in image controls

This patch gives skins developpers the possibility to display the art file
 associated to the current input in an image control.

It features the following :
    - a new 'art' boolean parameter is added for the Image control (skin.dtd)
    - when set to true, the skin engine will reuse this control to display
      the current art file
    - in addition to 'scale' and 'mosaic', the resize parameter can now accept
      a new 'scale2' value, that respects the original aspect ratio of art files

modules/gui/skins2/Modules.am

@@ -107,6 +107,8 @@ SOURCES_skins2 = \
 	src/dialogs.hpp \
 	src/file_bitmap.cpp \
 	src/file_bitmap.hpp \
+	src/art_bitmap.cpp \
+	src/art_bitmap.hpp \
 	src/ft2_bitmap.cpp \
 	src/ft2_bitmap.hpp \
 	src/ft2_font.cpp \
@@ -178,6 +180,8 @@ SOURCES_skins2 = \
 	utils/var_percent.hpp \
 	utils/var_text.cpp \
 	utils/var_text.hpp \
+	utils/var_string.cpp \
+	utils/var_string.hpp \
 	utils/var_tree.cpp \
 	utils/var_tree.hpp \
 	\

modules/gui/skins2/controls/ctrl_image.cpp

@@ -27,26 +27,47 @@
 #include "../events/evt_generic.hpp"
 #include "../src/os_factory.hpp"
 #include "../src/os_graphics.hpp"
+#include "../src/vlcproc.hpp"
 #include "../src/scaled_bitmap.hpp"
+#include "../src/art_bitmap.hpp"
 #include "../utils/position.hpp"
 
 
-CtrlImage::CtrlImage( intf_thread_t *pIntf, const GenericBitmap &rBitmap,
+CtrlImage::CtrlImage( intf_thread_t *pIntf, GenericBitmap &rBitmap,
                       CmdGeneric &rCommand, resize_t resizeMethod,
-                      const UString &rHelp, VarBool *pVisible ):
-    CtrlFlat( pIntf, rHelp, pVisible ), m_rBitmap( rBitmap ),
-    m_rCommand( rCommand ), m_resizeMethod( resizeMethod )
+                      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 )
 {
     // Create an initial unscaled image in the buffer
     m_pImage = OSFactory::instance( pIntf )->createOSGraphics(
                                     rBitmap.getWidth(), rBitmap.getHeight() );
-    m_pImage->drawBitmap( m_rBitmap );
+    m_pImage->drawBitmap( *m_pBitmap );
+
+    // Observe the variable
+    if( m_art )
+    {
+        VlcProc *pVlcProc = VlcProc::instance( getIntf() );
+        pVlcProc->getStreamArtVar().addObserver( this );
+
+        ArtBitmap::initArtBitmap( getIntf() );
+    }
+
 }
 
 
 CtrlImage::~CtrlImage()
 {
     delete m_pImage;
+
+    if( m_art )
+    {
+        VlcProc *pVlcProc = VlcProc::instance( getIntf() );
+        pVlcProc->getStreamArtVar().delObserver( this );
+
+        ArtBitmap::freeArtBitmap( );
+    }
 }
 
 
@@ -104,7 +125,7 @@ void CtrlImage::draw( OSGraphics &rImage, int xDest, int yDest )
                 {
                     OSFactory *pOsFactory = OSFactory::instance( getIntf() );
                     // Rescale the image with the actual size of the control
-                    ScaledBitmap bmp( getIntf(), m_rBitmap, width, height );
+                    ScaledBitmap bmp( getIntf(), *m_pBitmap, width, height );
                     delete m_pImage;
                     m_pImage = pOsFactory->createOSGraphics( width, height );
                     m_pImage->drawBitmap( bmp, 0, 0 );
@@ -112,7 +133,7 @@ void CtrlImage::draw( OSGraphics &rImage, int xDest, int yDest )
                 rImage.drawGraphics( *m_pImage, 0, 0, xDest, yDest );
             }
         }
-        else
+        else if( m_resizeMethod == kMosaic )
         {
             // Use mosaic method
             while( width > 0 )
@@ -132,6 +153,68 @@ void CtrlImage::draw( OSGraphics &rImage, int xDest, int yDest )
                 width -= m_pImage->getWidth();
             }
         }
+        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 x, y;
+
+            if( scaled_height > height )
+            {
+                width = scaled_width;
+                x = ( pPos->getWidth() - width ) / 2;
+                y = 0;
+            }
+            else
+            {
+                height = scaled_height;
+                x =  0;
+                y = ( pPos->getHeight() - height ) / 2;
+            }
+
+            OSFactory *pOsFactory = OSFactory::instance( getIntf() );
+            // Rescale the image with the actual size of the control
+            ScaledBitmap bmp( getIntf(), *m_pBitmap, width, height );
+            delete m_pImage;
+            m_pImage = pOsFactory->createOSGraphics( width, height );
+            m_pImage->drawBitmap( bmp, 0, 0 );
+
+            rImage.drawGraphics( *m_pImage, 0, 0, xDest + x, yDest + y );
+        }
+    }
+}
+
+void CtrlImage::onUpdate( Subject<VarString> &rVariable, void* arg )
+{
+    VlcProc *pVlcProc = VlcProc::instance( getIntf() );
+
+    if( &rVariable == &pVlcProc->getStreamArtVar() )
+    {
+        string str = ((VarString&)rVariable).get();
+        GenericBitmap* pArt = (GenericBitmap*) ArtBitmap::getArtBitmap( str );
+
+        m_pBitmap = pArt ? pArt : m_pOriginalBitmap;
+
+        msg_Dbg( getIntf(), "art file %s to be displayed (wxh = %ix%i)",
+                            str.c_str(),
+                            m_pBitmap->getWidth(),
+                            m_pBitmap->getHeight() );
+
+        delete m_pImage;
+        m_pImage = OSFactory::instance( getIntf() )->createOSGraphics(
+                                        m_pBitmap->getWidth(),
+                                        m_pBitmap->getHeight() );
+        m_pImage->drawBitmap( *m_pBitmap );
+
+        notifyLayout();
     }
 }
 
+

modules/gui/skins2/controls/ctrl_image.hpp

@@ -26,28 +26,31 @@
 #define CTRL_IMAGE_HPP
 
 #include "../commands/cmd_generic.hpp"
+#include "../utils/observer.hpp"
 #include "ctrl_flat.hpp"
 
 class GenericBitmap;
 class OSGraphics;
 class CmdGeneric;
+class VarString;
 
 
 /// Control image
-class CtrlImage: public CtrlFlat
+class CtrlImage: public CtrlFlat, public Observer<VarString>
 {
 public:
     /// Resize methods
     enum resize_t
     {
-        kMosaic,  // Repeat the base image in a mosaic
-        kScale    // Scale the base image
+        kMosaic,                // Repeat the base image in a mosaic
+        kScale,                 // Scale the base image
+        kScaleAndRatioPreserved // Scale image (aspect ratio preserved)
     };
 
     // Create an image with the given bitmap (which is NOT copied)
-    CtrlImage( intf_thread_t *pIntf, const GenericBitmap &rBitmap,
+    CtrlImage( intf_thread_t *pIntf, GenericBitmap &rBitmap,
                CmdGeneric &rCommand, resize_t resizeMethod,
-               const UString &rHelp, VarBool *pVisible );
+               const UString &rHelp, VarBool *pVisible, bool art );
     virtual ~CtrlImage();
 
     /// Handle an event on the control
@@ -64,13 +67,22 @@ public:
 
 private:
     /// Bitmap
-    const GenericBitmap &m_rBitmap;
+    GenericBitmap* m_pBitmap;
+    /// original Bitmap
+    GenericBitmap* m_pOriginalBitmap;
     /// Buffer to stored the rendered bitmap
     OSGraphics *m_pImage;
     /// Command triggered by a double-click on the image
     CmdGeneric &m_rCommand;
     /// Resize method
     resize_t m_resizeMethod;
+    /// does the image get updated as art
+    bool m_art;
+
+    /// Method called when the observed variable is modified
+    virtual void onUpdate( Subject<VarString> &rVariable, void* );
+
+
 };
 
 #endif

modules/gui/skins2/parser/builder.cpp

@@ -574,9 +574,12 @@ void Builder::addImage( const BuilderData::Image &rData )
     VarBool *pVisible = pInterpreter->getVarBool( rData.m_visible, m_pTheme );
 
     CtrlImage::resize_t resizeMethod =
-        (rData.m_resize == "scale" ? CtrlImage::kScale : CtrlImage::kMosaic);
+        rData.m_resize == "scale"  ? CtrlImage::kScale :
+        rData.m_resize == "mosaic" ? CtrlImage::kMosaic :
+                                     CtrlImage::kScaleAndRatioPreserved;
     CtrlImage *pImage = new CtrlImage( getIntf(), *pBmp, *pCommand,
-        resizeMethod, UString( getIntf(), rData.m_help.c_str() ), pVisible );
+        resizeMethod, UString( getIntf(), rData.m_help.c_str() ), pVisible,
+        rData.m_art );
     m_pTheme->m_controls[rData.m_id] = CtrlGenericPtr( pImage );
 
     // Compute the position of the control

modules/gui/skins2/parser/builder_data.def

@@ -11,7 +11,7 @@ Layout id:string width:int height:int minWidth:int maxWidth:int minHeight:int ma
 Anchor xPos:int yPos:int leftTop:string range:int priority:int points:string layoutId:string
 Button id:string xPos:int yPos:int leftTop:string rightBottom:string xKeepRatio:bool yKeepRatio:bool visible:string upId:string downId:string overId:string actionId:string tooltip:string help:string layer:int windowId:string layoutId:string panelId:string
 Checkbox id:string xPos:int yPos:int leftTop:string rightBottom:string xKeepRatio:bool yKeepRatio:bool visible:string up1Id:string down1Id:string over1Id:string up2Id:string down2Id:string over2Id:string state:string action1:string action2:string tooltip1:string tooltip2:string help:string layer:int windowId:string layoutId:string panelId:string
-Image id:string xPos:int yPos:int leftTop:string rightBottom:string xKeepRatio:bool yKeepRatio:bool visible:string bmpId:string actionId:string action2Id:string resize:string help:string layer:int windowId:string layoutId:string panelId:string
+Image id:string xPos:int yPos:int leftTop:string rightBottom:string xKeepRatio:bool yKeepRatio:bool visible:string bmpId:string actionId:string action2Id:string resize:string help:string art:bool layer:int windowId:string layoutId:string panelId:string
 IniFile id:string file:string
 Panel id:string xPos:int yPos:int leftTop:string rightBottom:string xKeepRatio:bool yKeepRatio:bool width:int height:int layer:int windowId:string layoutId:string panelId:string
 Text id:string xPos:int yPos:int visible:string fontId:string text:string width:int leftTop:string rightBottom:string xKeepRatio:bool yKeepRatio:bool color:uint32_t scrolling:string alignment:string help:string layer:int windowId:string layoutId:string panelId:string

modules/gui/skins2/parser/builder_data.hpp

@@ -267,8 +267,8 @@ m_id( id ), m_xPos( xPos ), m_yPos( yPos ), m_leftTop( leftTop ), m_rightBottom(
     /// Type definition
     struct Image
     {
-        Image( const string & id, int xPos, int yPos, const string & leftTop, const string & rightBottom, bool xKeepRatio, bool yKeepRatio, const string & visible, const string & bmpId, const string & actionId, const string & action2Id, const string & resize, const string & help, int layer, const string & windowId, const string & layoutId, const string & panelId ):
-m_id( id ), m_xPos( xPos ), m_yPos( yPos ), m_leftTop( leftTop ), m_rightBottom( rightBottom ), m_xKeepRatio( xKeepRatio ), m_yKeepRatio( yKeepRatio ), m_visible( visible ), m_bmpId( bmpId ), m_actionId( actionId ), m_action2Id( action2Id ), m_resize( resize ), m_help( help ), m_layer( layer ), m_windowId( windowId ), m_layoutId( layoutId ), m_panelId( panelId ) {}
+        Image( const string & id, int xPos, int yPos, const string & leftTop, const string & rightBottom, bool xKeepRatio, bool yKeepRatio, const string & visible, const string & bmpId, const string & actionId, const string & action2Id, const string & resize, const string & help, bool art, int layer, const string & windowId, const string & layoutId, const string & panelId ):
+m_id( id ), m_xPos( xPos ), m_yPos( yPos ), m_leftTop( leftTop ), m_rightBottom( rightBottom ), m_xKeepRatio( xKeepRatio ), m_yKeepRatio( yKeepRatio ), m_visible( visible ), m_bmpId( bmpId ), m_actionId( actionId ), m_action2Id( action2Id ), m_resize( resize ), m_help( help ), m_art( art ), m_layer( layer ), m_windowId( windowId ), m_layoutId( layoutId ), m_panelId( panelId ) {}
 
         string m_id;
         int m_xPos;
@@ -283,6 +283,7 @@ m_id( id ), m_xPos( xPos ), m_yPos( yPos ), m_leftTop( leftTop ), m_rightBottom(
         string m_action2Id;
         string m_resize;
         string m_help;
+        bool   m_art;
         int m_layer;
         string m_windowId;
         string m_layoutId;

modules/gui/skins2/parser/skin_parser.cpp

@@ -288,6 +288,7 @@ void SkinParser::handleBeginElement( const string &rName, AttrList_t &attr )
         DefaultAttr( attr, "action2", "none" );
         DefaultAttr( attr, "resize", "mosaic" );
         DefaultAttr( attr, "help", "" );
+        DefaultAttr( attr, "art", "false" );
 
         const BuilderData::Image imageData( uniqueId( attr["id"] ),
                 atoi( attr["x"] ) + m_xOffset, atoi( attr["y"] ) + m_yOffset,
@@ -295,7 +296,8 @@ void SkinParser::handleBeginElement( const string &rName, AttrList_t &attr )
                 convertBoolean( attr["xkeepratio"] ),
                 convertBoolean( attr["ykeepratio"] ), attr["visible"],
                 attr["image"], attr["action"], attr["action2"], attr["resize"],
-                attr["help"], m_curLayer, m_curWindowId, m_curLayoutId,
+                attr["help"], convertBoolean( attr["art"] ),
+                m_curLayer, m_curWindowId, m_curLayoutId,
                 m_panelStack.back() );
         m_curLayer++;
         m_pData->m_listImage.push_back( imageData );

modules/gui/skins2/src/art_bitmap.cpp

+/*****************************************************************************
+ * art_bitmap.cpp
+ *****************************************************************************
+ * Copyright (C) 2010 the VideoLAN team
+ * $Id$
+ *
+ * Author: Erwan Tulou      <erwan10@vidoelan.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "art_bitmap.hpp"
+#include <vlc_image.h>
+
+
+// static variables
+intf_thread_t*    ArtBitmap::m_pIntf = NULL;
+image_handler_t*  ArtBitmap::m_pImageHandler = NULL;
+list<ArtBitmap*>  ArtBitmap::m_listBitmap;
+
+ArtBitmap::ArtBitmap( string uriName ):
+    FileBitmap( m_pIntf, m_pImageHandler, uriName, -1 ), m_uriName( uriName )
+{
+}
+
+void ArtBitmap::initArtBitmap( intf_thread_t* pIntf )
+{
+    if( m_pIntf )
+        return;
+
+    // retain reference to skins interface
+    m_pIntf = pIntf;
+
+    // initialize handler
+    m_pImageHandler = image_HandlerCreate( pIntf );
+
+    if( !m_pImageHandler )
+        msg_Err( m_pIntf, "initialization of art bitmaps failed" );
+}
+
+
+ArtBitmap* ArtBitmap::getArtBitmap( string uriName )
+{
+    if( !m_pImageHandler )
+        return NULL;
+
+    // check whether art is already loaded
+    list<ArtBitmap*>::const_iterator it;
+    for( it = m_listBitmap.begin(); it != m_listBitmap.end(); ++it )
+    {
+        if( (*it)->getUriName() == uriName )
+            return *it;
+    }
+
+    // create and retain a new ArtBitmap since uri if not yet known
+    ArtBitmap* pArt = new ArtBitmap( uriName );
+    if( pArt && pArt->getWidth() && pArt->getHeight() )
+    {
+        m_listBitmap.push_back( pArt );
+        return pArt;
+    }
+    else
+    {
+        delete pArt;
+        return NULL;
+    }
+}
+
+void ArtBitmap::freeArtBitmap( )
+{
+    m_pIntf = NULL;
+
+    if( m_pImageHandler )
+    {
+        image_HandlerDelete( m_pImageHandler );
+        m_pImageHandler = NULL;
+    }
+
+    m_listBitmap.clear();
+}

modules/gui/skins2/src/art_bitmap.hpp

+/*****************************************************************************
+ * art_bitmap.hpp
+ *****************************************************************************
+ * Copyright (C) 2010 the VideoLAN team
+ * $Id$
+ *
+ * Author: Erwan Tulou      <erwan10@vidoelan.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifndef ART_BITMAP_HPP
+#define ART_BITMAP_HPP
+
+#include "file_bitmap.hpp"
+#include <string>
+#include <list>
+
+
+/// Class for art bitmaps
+class ArtBitmap: public FileBitmap
+{
+public:
+
+    static ArtBitmap* getArtBitmap( string uriName );
+    static void initArtBitmap( intf_thread_t* pIntf );
+    static void freeArtBitmap( );
+
+    string getUriName() { return m_uriName; }
+
+protected:
+
+    /// Constructor/destructor
+    ArtBitmap( string uriName );
+    virtual ~ArtBitmap() {}
+
+    /// skins2 interface
+    static intf_thread_t *m_pIntf;
+
+    /// Image handler (used to load art files)
+    static image_handler_t *m_pImageHandler;
+
+    // keep a cache of art already open
+    static list<ArtBitmap*> m_listBitmap;
+
+private:
+
+    // uriName
+    string m_uriName;
+
+};
+
+
+#endif

modules/gui/skins2/src/vlcproc.cpp

@@ -50,6 +50,7 @@
 #include "../commands/cmd_audio.hpp"
 #include "../commands/cmd_callbacks.hpp"
 #include "../utils/var_bool.hpp"
+#include "../utils/var_string.hpp"
 #include <sstream>
 
 #include <assert.h>
@@ -129,6 +130,8 @@ VlcProc::VlcProc( intf_thread_t *pIntf ): SkinObject( pIntf ),
     pVarManager->registerVar( m_cVarStreamBitRate, "bitrate" );
     m_cVarStreamSampleRate = VariablePtr( new VarText( getIntf(), false ) );
     pVarManager->registerVar( m_cVarStreamSampleRate, "samplerate" );
+    m_cVarStreamArt = VariablePtr( new VarString( getIntf() ) );
+    pVarManager->registerVar( m_cVarStreamArt, "streamArt" );
 
     // Register the equalizer bands
     for( int i = 0; i < EqualizerBands::kNbBands; i++)
@@ -430,6 +433,7 @@ int VlcProc::onGenericCallback( vlc_object_t *pObj, const char *pVariable,
 #define SET_BOOL(m,v)         ((VarBoolImpl*)(m).get())->set(v)
 #define SET_STREAMTIME(m,v,b) ((StreamTime*)(m).get())->set(v,b)
 #define SET_TEXT(m,v)         ((VarText*)(m).get())->set(v)
+#define SET_STRING(m,v)       ((VarString*)(m).get())->set(v)
 #define SET_VOLUME(m,v,b)     ((Volume*)(m).get())->set(v,b)
 
 void VlcProc::on_item_current_changed( vlc_object_t* p_obj, vlc_value_t newVal )
@@ -446,6 +450,11 @@ void VlcProc::on_item_current_changed( vlc_object_t* p_obj, vlc_value_t newVal )
     SET_TEXT( m_cVarStreamURI, UString( getIntf(), psz_uri ) );
     free( psz_uri );
 
+    // Update art uri
+    char *psz_art = input_item_GetArtURL( p_item );
+    SET_STRING( m_cVarStreamArt, string( psz_art ? psz_art : "" ) );
+    free( psz_art );
+
     // Update playtree
     getPlaytreeVar().onUpdateCurrent( true );
 }
@@ -767,4 +776,5 @@ void VlcProc::setFullscreenVar( bool b_fullscreen )
 #undef  SET_BOOL
 #undef  SET_STREAMTIME
 #undef  SET_TEXT
+#undef  SET_STRING
 #undef  SET_VOLUME

modules/gui/skins2/src/vlcproc.hpp

@@ -36,6 +36,7 @@
 #include "../vars/volume.hpp"
 #include "../utils/position.hpp"
 #include "../utils/var_text.hpp"
+#include "../utils/var_string.hpp"
 #include "../commands/cmd_generic.hpp"
 #include "../controls/ctrl_video.hpp"
 
@@ -81,6 +82,10 @@ public:
     VarText &getStreamSampleRateVar()
         { return *((VarText*)(m_cVarStreamSampleRate.get())); }
 
+    /// Getter for the stream Art url variable
+    VarString &getStreamArtVar()
+       { return *((VarString*)(m_cVarStreamArt.get())); }
+
     /// Getter/Setter for the fullscreen variable
     VarBool &getFullscreenVar() { return *((VarBool*)(m_cVarFullscreen.get())); }
     void setFullscreenVar( bool );
@@ -128,6 +133,7 @@ private:
     VariablePtr m_cVarStreamURI;
     VariablePtr m_cVarStreamBitRate;
     VariablePtr m_cVarStreamSampleRate;
+    VariablePtr m_cVarStreamArt;
     /// Variable for the "mute" state
     VariablePtr m_cVarMute;
     /// Variables related to the input

modules/gui/skins2/utils/var_string.cpp

+/*****************************************************************************
+ * var_string.cpp
+ *****************************************************************************
+ * Copyright (C) 2010 the VideoLAN team
+ * $Id$
+ *
+ * Author: Erwan Tulou      <erwan10 aT videolan DoT org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include "var_string.hpp"
+
+
+const string VarString::m_type = "string";
+
+
+void VarString::set( string str )
+{
+    // If the value has changed, notify the observers
+    if( m_value != str )
+    {
+        m_value = str;
+        notify( NULL );
+    }
+}
+

modules/gui/skins2/utils/var_string.hpp

+/*****************************************************************************
+ * var_string.hpp
+ *****************************************************************************
+ * Copyright (C) 2010 the VideoLAN team
+ * $Id$
+ *
+ * Author: Erwan Tulou      <erwan10 aT videolan DoT org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifndef VAR_STRING
+#define VAR_STRING
+
+#include "variable.hpp"
+#include "observer.hpp"
+
+class VarString;
+
+
+/// String variable
+class VarString: public Variable, public Subject<VarString>
+{
+public:
+    VarString( intf_thread_t *pIntf ): Variable( pIntf ), m_value( string("tit") ) { }
+    virtual ~VarString() { }
+
+    /// Get the variable type
+    virtual const string &getType() const { return m_type; }
+
+    /// Set the internal value
+    virtual void set( string str );
+    virtual string get() const { return m_value; }
+
+private:
+    /// Variable type
+    static const string m_type;
+    /// string value
+    string m_value;
+};
+
+#endif

share/skins2/skin.dtd

@@ -140,6 +140,7 @@
         action2     CDATA   "none"
         resize      CDATA   "mosaic"
         help        CDATA   ""
+        art         CDATA   "false"
     >
 <!ELEMENT Button EMPTY>
     <!ATTLIST Button