added image navigation display

added keyboard image navigation (TODO: controller)

src/gui/LauncherDialog.cxx

@@ -879,6 +879,14 @@ void LauncherDialog::handleKeyDown(StellaKey key, StellaMod mod, bool repeated)
         reload();
         break;
 
+      case KBDK_LEFT:
+        myRomImageWidget->changeImage(-1);
+        break;
+
+      case KBDK_RIGHT:
+        myRomImageWidget->changeImage(1);
+        break;
+
       default:
         handled = false;
         break;

src/gui/RomImageWidget.cxx

@@ -33,7 +33,7 @@ RomImageWidget::RomImageWidget(GuiObject* boss, const GUI::Font& font,
   : Widget(boss, font, x, y, w, h),
     CommandSender(boss)
 {
-  _flags = Widget::FLAG_ENABLED;
+  _flags = Widget::FLAG_ENABLED | Widget::FLAG_TRACK_MOUSE;
   _bgcolor = kDlgColor;
   _bgcolorlo = kBGColorLo;
   myImageHeight = _h - labelHeight(font);
@@ -80,6 +80,19 @@ void RomImageWidget::reloadProperties(const FSNode& node)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void RomImageWidget::parseProperties(const FSNode& node)
 {
+  if(myNavSurface == nullptr)
+  {
+    // Create navigation surface
+    myNavSurface = instance().frameBuffer().allocateSurface(
+      _w, myImageHeight);
+
+    FBSurface::Attributes& attr = myNavSurface->attributes();
+
+    attr.blending = true;
+    attr.blendalpha = 60; 
+    myNavSurface->applyAttributes();
+  }                           
+
   // Check if a surface has ever been created; if so, we use it
   // The surface will always be the maximum size, but sometimes we'll
   // only draw certain parts of it
@@ -91,9 +104,12 @@ void RomImageWidget::parseProperties(const FSNode& node)
 
     dialog().addRenderCallback([this]() {
       if(mySurfaceIsValid)
+      {
         mySurface->render();
+        if(isHighlighted())
+          myNavSurface->render();
       }
-    );
+    });
   }
 
   // Initialize to empty properties entry
@@ -131,6 +147,17 @@ void RomImageWidget::parseProperties(const FSNode& node)
   setDirty();
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool RomImageWidget::changeImage(int direction)
+{
+  if(direction == -1 && myImageIdx)
+    return loadPng(myImageList[--myImageIdx].getPath());
+  else if(direction == 1 && myImageIdx < myImageList.size() - 1)
+    return loadPng(myImageList[++myImageIdx].getPath());
+
+  return false;
+}
+
 #ifdef PNG_SUPPORT
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool RomImageWidget::getImageList(const string& filename)
@@ -184,31 +211,19 @@ bool RomImageWidget::loadPng(const string& filename)
   }
   return false;
 }
-#endif
 
-#ifdef PNG_SUPPORT
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void RomImageWidget::handleMouseUp(int x, int y, MouseButton b, int clickCount)
 {
   if(isEnabled() && x >= 0 && x < _w && y >= 0 && y < myImageHeight)
-  {
+    changeImage(x < _w / 2 ? 1 : -1);
-    if(x < _w/2)
-    {
-      if(myImageIdx)
-      {
-        loadPng(myImageList[--myImageIdx].getPath());
-      }
-    }
-    else if(myImageIdx < myImageList.size() - 1)
-    {
-      loadPng(myImageList[++myImageIdx].getPath());
-    }
-  }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void RomImageWidget::handleMouseMoved(int x, int y)
 {
+  if(x < _w / 2 != myMouseX < _w / 2)
+    setDirty();
   myMouseX = x;
 }
 #endif
@@ -239,13 +254,8 @@ void RomImageWidget::drawWidget(bool hilite)
     // the dialog surface position into account
     const Common::Rect& s_dst = s.dstRect();
     mySurface->setDstPos(x + s_dst.x(), y + s_dst.y());
-  }
+
-  else if(mySurfaceErrorMsg != "")
+    // Draw the image label and counter
-  {
-    const uInt32 x = _x + ((_w - _font.getStringWidth(mySurfaceErrorMsg)) >> 1);
-    const uInt32 y = _y + ((yoff - _font.getLineHeight()) >> 1);
-    s.drawString(_font, mySurfaceErrorMsg, x, y, _w - 10, _textcolor);
-  }
     ostringstream buf;
     buf << myImageIdx + 1 << "/" << myImageList.size();
     const int yText = _y + myImageHeight + _font.getFontHeight() / 8;
@@ -256,15 +266,42 @@ void RomImageWidget::drawWidget(bool hilite)
     if(myImageList.size())
       s.drawString(_font, buf.str(), _x + _w - wText, yText, wText, _textcolor);
 
-#ifdef PNG_SUPPORT
+    // Draw the navigation arrows
-  if(isHighlighted())
+    const bool leftArrow = myMouseX < _w / 2;
+
+    myNavSurface->invalidate();
+    if(isHighlighted() &&
+      ((leftArrow && myImageIdx) || (!leftArrow && myImageIdx < myImageList.size() - 1)) || true)
     {
-    // TODO: need another surface
+      const int w = _w / 64;
-    const int xOfs = myMouseX < _w / 2 ? 10 : _w - 50;
+      const int w2 = 1; // w / 2;
+      const int ax = leftArrow ? _w / 12 - w / 2 : _w - _w / 12 - w / 2;
+      const int ay = myImageHeight >> 1;
+      const int dx = (_w / 32) * (leftArrow ? 1 : -1);
+      const int dy = myImageHeight / 16;
 
-    s.line(xOfs, _h / 2 - 10, xOfs + 20, _h / 2, kBtnTextColorHi);
+      for(int i = 0; i < w; ++i)
+      {
+        myNavSurface->line(ax + dx + i + w2, ay - dy, ax + i + w2, ay, kBGColor);
+        myNavSurface->line(ax + dx + i + w2, ay + dy, ax + i + w2, ay, kBGColor);
+        myNavSurface->line(ax + dx + i, ay - dy + w2, ax + i, ay + w2, kBGColor);
+        myNavSurface->line(ax + dx + i, ay + dy + w2, ax + i, ay + w2, kBGColor);
+        myNavSurface->line(ax + dx + i + w2, ay - dy + w2, ax + i + w2, ay + w2, kBGColor);
+        myNavSurface->line(ax + dx + i + w2, ay + dy + w2, ax + i + w2, ay + w2, kBGColor);
+      }
+      for(int i = 0; i < w; ++i)
+      {
+        myNavSurface->line(ax + dx + i, ay - dy, ax + i, ay, kColorInfo);
+        myNavSurface->line(ax + dx + i, ay + dy, ax + i, ay, kColorInfo);
+      }
+      myNavSurface->setDstRect(mySurface->dstRect());
+    }
+  }
+  else if(mySurfaceErrorMsg != "")
+  {
+    const uInt32 x = _x + ((_w - _font.getStringWidth(mySurfaceErrorMsg)) >> 1);
+    const uInt32 y = _y + ((yoff - _font.getLineHeight()) >> 1);
+    s.drawString(_font, mySurfaceErrorMsg, x, y, _w - 10, _textcolor);
   }
-#endif
-
   clearDirty();
 }

src/gui/RomImageWidget.hxx

@@ -39,6 +39,7 @@ class RomImageWidget : public Widget, public CommandSender
     void setProperties(const FSNode& node, const string& md5);
     void clearProperties();
     void reloadProperties(const FSNode& node);
+    bool changeImage(int direction = 1);
 
   protected:
     void drawWidget(bool hilite) override;
@@ -58,6 +59,9 @@ class RomImageWidget : public Widget, public CommandSender
     // Surface pointer holding the PNG image
     shared_ptr<FBSurface> mySurface;
 
+    // Surface pointer holding the navigation elements
+    shared_ptr<FBSurface> myNavSurface;
+
     // Whether the surface should be redrawn by drawWidget()
     bool mySurfaceIsValid{false};
 
@@ -70,7 +74,7 @@ class RomImageWidget : public Widget, public CommandSender
     // Indicates if an error occurred in creating/displaying the surface
     string mySurfaceErrorMsg;
 
-#ifdef PNG_SUPPORT
+    // Height of the image area
     int myImageHeight{0};
 
     // Contains the list of image names for the current ROM
@@ -84,7 +88,6 @@ class RomImageWidget : public Widget, public CommandSender
 
     // Label for the loaded image
     string myLabel;
-#endif
 
   private:
     // Following constructors and assignment operators not supported