added UI messages with gauge bars for variable values (partially addresses #631)

src/common/PaletteHandler.cxx

@@ -144,11 +144,10 @@ void PaletteHandler::changeAdjustable(bool increase)
 
     *myAdjustables[myCurrentAdjustable].value = scaleFrom100(newVal);
 
-    ostringstream buf;
+    ostringstream msg, val;
-    buf << "Custom '" << myAdjustables[myCurrentAdjustable].name
+    msg << "Palette " << myAdjustables[myCurrentAdjustable].name;
-        << "' set to " << newVal << "%";
+    val << newVal << "%";
-
+    myOSystem.frameBuffer().showMessage(msg.str(), val.str(), newVal);
-    myOSystem.frameBuffer().showMessage(buf.str());
     setPalette();
   }
 }
@@ -179,11 +178,11 @@ void PaletteHandler::changeColorPhaseShift(bool increase)
     generateCustomPalette(timing);
     setPalette(SETTING_CUSTOM);
 
-    ostringstream ss;
+    ostringstream val;
-    ss << "Color phase shift at "
+    val << std::fixed << std::setprecision(1) << newPhase << DEGREE;
-      << std::fixed << std::setprecision(1) << newPhase << DEGREE;
+    myOSystem.frameBuffer().showMessage("Palette phase shift", val.str(), newPhase,
-
+                                        (isNTSC ? DEF_NTSC_SHIFT : DEF_PAL_SHIFT) - MAX_SHIFT,
-    myOSystem.frameBuffer().showMessage(ss.str());
+                                        (isNTSC ? DEF_NTSC_SHIFT : DEF_PAL_SHIFT) + MAX_SHIFT);
   }
 }
 

src/common/SoundSDL2.cxx

@@ -217,7 +217,6 @@ void SoundSDL2::setVolume(uInt32 percent)
 void SoundSDL2::adjustVolume(Int8 direction)
 {
   ostringstream strval;
-  string message;
 
   Int32 percent = myVolume;
 
@@ -225,9 +224,7 @@ void SoundSDL2::adjustVolume(Int8 direction)
     percent -= 2;
   else if(direction == 1)
     percent += 2;
-
+  percent = BSPF::clamp(percent, 0, 100);
-  if((percent < 0) || (percent > 100))
-    return;
 
   setVolume(percent);
 
@@ -241,11 +238,8 @@ void SoundSDL2::adjustVolume(Int8 direction)
   }
 
   // Now show an onscreen message
-  strval << percent;
+  strval << percent << "%";
-  message = "Volume set to ";
+  myOSystem.frameBuffer().showMessage("Volume", strval.str(), percent);
-  message += strval.str();
-
-  myOSystem.frameBuffer().showMessage(message);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/common/tv_filters/NTSCFilter.cxx

@@ -112,40 +112,24 @@ string NTSCFilter::setPreviousAdjustable()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-string NTSCFilter::increaseAdjustable()
+void NTSCFilter::changeAdjustable(bool increase, string& text, string& valueText, Int32& value)
 {
   //if(myPreset != Preset::CUSTOM)
   //  return "'Custom' TV mode not selected";
 
-  uInt32 newval = scaleTo100(*ourCustomAdjustables[myCurrentAdjustable].value);
+  value = scaleTo100(*ourCustomAdjustables[myCurrentAdjustable].value);
-  newval += 2;  if(newval > 100) newval = 100;
+  value = BSPF::clamp(value + (increase ? 2 : -2), 0, 100);
-  *ourCustomAdjustables[myCurrentAdjustable].value = scaleFrom100(newval);
 
-  ostringstream buf;
+  *ourCustomAdjustables[myCurrentAdjustable].value = scaleFrom100(value);
-  buf << "Custom '" << ourCustomAdjustables[myCurrentAdjustable].type
-      << "' set to " << newval << "%";
 
   setPreset(myPreset);
-  return buf.str();
-}
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+  ostringstream msg, val;
-string NTSCFilter::decreaseAdjustable()
+  msg << "Custom " << ourCustomAdjustables[myCurrentAdjustable].type;
-{
+  val << value << "%";
-  //if(myPreset != Preset::CUSTOM)
-  //  return "'Custom' TV mode not selected";
 
-  uInt32 newval = scaleTo100(*ourCustomAdjustables[myCurrentAdjustable].value);
+  text = msg.str();
-  if(newval < 2) newval = 0;
+  valueText = val.str();
-  else           newval -= 2;
-  *ourCustomAdjustables[myCurrentAdjustable].value = scaleFrom100(newval);
-
-  ostringstream buf;
-  buf << "Custom '" << ourCustomAdjustables[myCurrentAdjustable].type
-      << "' set to " << newval << "%";
-
-  setPreset(myPreset);
-  return buf.str();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/common/tv_filters/NTSCFilter.hxx

@@ -92,8 +92,7 @@ class NTSCFilter
     // only 4 combinations are necessary
     string setNextAdjustable();
     string setPreviousAdjustable();
-    string increaseAdjustable();
+    void changeAdjustable(bool increase, string& text, string& valueText, Int32& value);
-    string decreaseAdjustable();
 
     // Load and save NTSC-related settings
     void loadConfig(const Settings& settings);

src/emucore/Console.cxx

@@ -349,14 +349,14 @@ bool Console::load(Serializer& in)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Console::toggleFormat(int direction)
+void Console::selectFormat(bool next)
 {
   string saveformat, message;
   uInt32 format = myCurrentFormat;
 
-  if(direction == 1)
+  if(next)
     format = (myCurrentFormat + 1) % 7;
-  else if(direction == -1)
+  else
     format = myCurrentFormat > 0 ? (myCurrentFormat - 1) : 6;
 
   setFormat(format);
@@ -521,39 +521,20 @@ void Console::togglePhosphor()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Console::changePhosphor(int direction)
+void Console::changePhosphor(bool increase)
 {
   int blend = BSPF::stringToInt(myProperties.get(PropType::Display_PPBlend));
 
-  if(direction == +1)       // increase blend
+  if(increase)      // increase blend
-  {
+    blend += 2;
-    if(blend >= 100)
+  else              // decrease blend
-    {
+    blend -= 2;
-      myOSystem.frameBuffer().showMessage("Phosphor blend at maximum");
+  blend = BSPF::clamp(blend, 0, 100);
-      myOSystem.frameBuffer().tiaSurface().enablePhosphor(true, 100);
-      return;
-    }
-    else
-      blend = std::min(blend+2, 100);
-  }
-  else if(direction == -1)  // decrease blend
-  {
-    if(blend <= 2)
-    {
-      myOSystem.frameBuffer().showMessage("Phosphor blend at minimum");
-      myOSystem.frameBuffer().tiaSurface().enablePhosphor(true, 0);
-      return;
-    }
-    else
-      blend = std::max(blend-2, 0);
-  }
-  else
-    return;
 
   ostringstream val;
   val << blend;
   myProperties.set(PropType::Display_PPBlend, val.str());
-  myOSystem.frameBuffer().showMessage("Phosphor blend " + val.str());
+  myOSystem.frameBuffer().showMessage("Phosphor blend", val.str() + "%", blend);
   myOSystem.frameBuffer().tiaSurface().enablePhosphor(true, blend);
 }
 
@@ -631,45 +612,25 @@ void Console::fry() const
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Console::changeVerticalCenter(int direction)
+void Console::changeVerticalCenter(bool increase)
 {
   Int32 vcenter = myTIA->vcenter();
 
-  if(direction == +1)       // increase vcenter
+  if(increase)      // increase vcenter
-  {
-    if(vcenter >= myTIA->maxVcenter())
-    {
-      myOSystem.frameBuffer().showMessage("V-Center at maximum");
-      return;
-    }
     ++vcenter;
-  }
+  else              // decrease vcenter
-  else if(direction == -1)  // decrease vcenter
-  {
-    if (vcenter <= myTIA->minVcenter())
-    {
-      myOSystem.frameBuffer().showMessage("V-Center at minimum");
-      return;
-    }
     --vcenter;
-  }
+  vcenter = BSPF::clamp(vcenter, myTIA->minVcenter(), myTIA->maxVcenter());
-  else
-    return;
 
-  ostringstream ss;
+  ostringstream ss, val;
   ss << vcenter;
 
   myProperties.set(PropType::Display_VCenter, ss.str());
   if (vcenter != myTIA->vcenter()) myTIA->setVcenter(vcenter);
 
-  ss.str("");
+  val << (vcenter ? vcenter > 0 ? "+" : "" : " ") << vcenter << "px";
-  ss << "V-Center ";
+  myOSystem.frameBuffer().showMessage("V-Center", val.str(), vcenter,
-  if (!vcenter)
+                                      myTIA->minVcenter(), myTIA->maxVcenter());
-    ss << "default";
-  else
-    ss << (vcenter > 0 ? "+" : "") << vcenter << "px";
-
-  myOSystem.frameBuffer().showMessage(ss.str());
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -682,30 +643,15 @@ void Console::updateVcenter(Int32 vcenter)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Console::changeScanlineAdjust(int direction)
+void Console::changeScanlineAdjust(bool increase)
 {
   Int32 newAdjustVSize = myTIA->adjustVSize();
 
-  if (direction != -1 && direction != +1) return;
+  if(increase)      // increase scanline adjustment
-
-  if(direction == +1)       // increase scanline adjustment
-  {
-    if (newAdjustVSize >= 5)
-    {
-      myOSystem.frameBuffer().showMessage("V-Size at maximum");
-      return;
-    }
     newAdjustVSize++;
-  }
+  else              // decrease scanline adjustment
-  else if(direction == -1)  // decrease scanline adjustment
-  {
-    if (newAdjustVSize <= -5)
-    {
-      myOSystem.frameBuffer().showMessage("V-Size at minimum");
-      return;
-    }
     newAdjustVSize--;
-  }
+  newAdjustVSize = BSPF::clamp(newAdjustVSize, -5, 5);
 
   if (newAdjustVSize != myTIA->adjustVSize()) {
       myTIA->setAdjustVSize(newAdjustVSize);
@@ -713,15 +659,10 @@ void Console::changeScanlineAdjust(int direction)
       initializeVideo();
   }
 
-  ostringstream ss;
+  ostringstream val;
 
-  ss << "V-Size ";
+  val << (newAdjustVSize ? newAdjustVSize > 0 ? "+" : "" : " ") << newAdjustVSize << "%";
-  if (!newAdjustVSize)
+  myOSystem.frameBuffer().showMessage("V-Size", val.str(), newAdjustVSize, -5, 5);
-    ss << "default";
-  else
-    ss << (newAdjustVSize > 0 ? "+" : "") << newAdjustVSize << "%";
-
-  myOSystem.frameBuffer().showMessage(ss.str());
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/Console.hxx

@@ -189,9 +189,9 @@ class Console : public Serializable, public ConsoleIO
     /**
       Toggle between NTSC/PAL/SECAM (and variants) display format.
 
-      @param direction +1 indicates increase, -1 indicates decrease.
+      @param next  Select next if true, else previous
     */
-    void toggleFormat(int direction = 1);
+    void selectFormat(bool next = true);
 
     /**
       Set NTSC/PAL/SECAM (and variants) display format.
@@ -222,9 +222,9 @@ class Console : public Serializable, public ConsoleIO
     /**
       Change the "Display.PPBlend" variable.
 
-      @param direction +1 indicates increase, -1 indicates decrease.
+      @param increase  Increase if true, else decrease
     */
-    void changePhosphor(int direction);
+    void changePhosphor(bool increase = true);
 
     /**
       Toggles the PAL color-loss effect.
@@ -257,18 +257,18 @@ class Console : public Serializable, public ConsoleIO
     /**
       Change the "Display.VCenter" variable.
 
-      @param direction +1 indicates increase, -1 indicates decrease.
+      @param increase  Increase if true, else decrease
     */
-    void changeVerticalCenter(int direction);
+    void changeVerticalCenter(bool increase = true);
 
     /**
       Change the "TIA scanline adjust" variable.
       Note that there are currently two of these (NTSC and PAL).  The currently
       active mode will determine which one is used.
 
-      @param direction +1 indicates increase, -1 indicates decrease.
+      @param increase  Increase if true, else decrease
     */
-    void changeScanlineAdjust(int direction);
+    void changeScanlineAdjust(bool increase = true);
 
     /**
       Returns the current framerate.

src/emucore/EventHandler.cxx

@@ -413,27 +413,27 @@ void EventHandler::handleEvent(Event::Type event, Int32 value, bool repeated)
       return;
 
     case Event::VidmodeDecrease:
-      if(pressed) myOSystem.frameBuffer().changeVidMode(-1);
+      if(pressed) myOSystem.frameBuffer().selectVidMode(false);
       return;
 
     case Event::VidmodeIncrease:
-      if(pressed) myOSystem.frameBuffer().changeVidMode(+1);
+      if(pressed) myOSystem.frameBuffer().selectVidMode(true);
       return;
 
     case Event::VCenterDecrease:
-      if (pressed) myOSystem.console().changeVerticalCenter(-1);
+      if (pressed) myOSystem.console().changeVerticalCenter(false);
       return;
 
     case Event::VCenterIncrease:
-      if (pressed) myOSystem.console().changeVerticalCenter(+1);
+      if (pressed) myOSystem.console().changeVerticalCenter(true);
       return;
 
     case Event::ScanlineAdjustDecrease:
-      if (pressed) myOSystem.console().changeScanlineAdjust(-1);
+      if (pressed) myOSystem.console().changeScanlineAdjust(false);
       return;
 
     case Event::ScanlineAdjustIncrease:
-      if (pressed) myOSystem.console().changeScanlineAdjust(+1);
+      if (pressed) myOSystem.console().changeScanlineAdjust(true);
       return;
 
     case Event::PreviousPaletteAttribute:
@@ -457,11 +457,11 @@ void EventHandler::handleEvent(Event::Type event, Int32 value, bool repeated)
       return;
 
     case Event::OverscanDecrease:
-      if (pressed) myOSystem.frameBuffer().changeOverscan(-1);
+      if (pressed) myOSystem.frameBuffer().changeOverscan(false);
       return;
 
     case Event::OverscanIncrease:
-      if (pressed) myOSystem.frameBuffer().changeOverscan(1);
+      if (pressed) myOSystem.frameBuffer().changeOverscan(true);
       return;
 
     case Event::PreviousVideoMode:
@@ -525,27 +525,33 @@ void EventHandler::handleEvent(Event::Type event, Int32 value, bool repeated)
     case Event::DecreaseAttribute:
       if (pressed)
       {
+        string text, valueText;
+        Int32 newVal;
+
         myOSystem.frameBuffer().tiaSurface().setNTSC(NTSCFilter::Preset::CUSTOM);
-        myOSystem.frameBuffer().showMessage(
+        myOSystem.frameBuffer().tiaSurface().ntsc().changeAdjustable(false, text, valueText, newVal);
-          myOSystem.frameBuffer().tiaSurface().ntsc().decreaseAdjustable());
+        myOSystem.frameBuffer().showMessage(text, valueText, newVal);
       }
       return;
 
     case Event::IncreaseAttribute:
       if (pressed)
       {
+        string text, valueText;
+        Int32 newVal;
+
         myOSystem.frameBuffer().tiaSurface().setNTSC(NTSCFilter::Preset::CUSTOM);
-        myOSystem.frameBuffer().showMessage(
+        myOSystem.frameBuffer().tiaSurface().ntsc().changeAdjustable(true, text, valueText, newVal);
-          myOSystem.frameBuffer().tiaSurface().ntsc().increaseAdjustable());
+        myOSystem.frameBuffer().showMessage(text, valueText, newVal);
       }
       return;
 
     case Event::PhosphorDecrease:
-      if (pressed) myOSystem.console().changePhosphor(-1);
+      if (pressed) myOSystem.console().changePhosphor(false);
       return;
 
     case Event::PhosphorIncrease:
-      if (pressed) myOSystem.console().changePhosphor(1);
+      if (pressed) myOSystem.console().changePhosphor(true);
       return;
 
     case Event::TogglePhosphor:
@@ -603,11 +609,11 @@ void EventHandler::handleEvent(Event::Type event, Int32 value, bool repeated)
       return;
 
     case Event::FormatDecrease:
-      if (pressed) myOSystem.console().toggleFormat(-1);
+      if (pressed) myOSystem.console().selectFormat(false);
       return;
 
     case Event::FormatIncrease:
-      if (pressed) myOSystem.console().toggleFormat(1);
+      if (pressed) myOSystem.console().selectFormat(true);
       return;
 
     case Event::ToggleGrabMouse:

src/emucore/FrameBuffer.cxx

@@ -309,7 +309,12 @@ FBInitStatus FrameBuffer::createDisplay(const string& title, BufferType type,
   }
 
   if(!myMsg.surface)
-    myMsg.surface = allocateSurface(font().getMaxCharWidth() * 56, font().getFontHeight() * 1.5);
+  {
+    const int fontWidth = font().getMaxCharWidth(),
+              HBORDER = fontWidth * 1.25 / 2.0;
+    myMsg.surface = allocateSurface(fontWidth * MESSAGE_WIDTH + HBORDER * 2,
+                                    font().getFontHeight() * 1.5);
+  }
 #endif
 
   // Print initial usage message, but only print it later if the status has changed
@@ -500,19 +505,62 @@ void FrameBuffer::showMessage(const string& message, MessagePosition position,
   const int VBORDER = fontHeight / 4;
   const int HBORDER = fontWidth * 1.25 / 2.0;
 
-  // Precompute the message coordinates
+  myMsg.counter = uInt32(myOSystem.frameRate()) * 2; // Show message for 2 seconds
-  myMsg.text    = message;
+  if(myMsg.counter == 0)
-  myMsg.counter = uInt32(myOSystem.frameRate()) << 1; // Show message for 2 seconds
+    myMsg.counter = 120;
-  if(myMsg.counter == 0)  myMsg.counter = 60;
-  myMsg.color   = kBtnTextColor;
 
-  myMsg.w = font().getStringWidth(myMsg.text) + HBORDER * 2;
+  // Precompute the message coordinates
-  myMsg.h = fontHeight + VBORDER * 2;
+  myMsg.text      = message;
+  myMsg.color     = kBtnTextColor;
+  myMsg.showGauge = false;
+  myMsg.w         = font().getStringWidth(myMsg.text) + HBORDER * 2;
+  myMsg.h         = fontHeight + VBORDER * 2;
+  myMsg.position  = position;
+  myMsg.enabled   = true;
+
+  myMsg.surface->setSrcSize(myMsg.w, myMsg.h);
+  myMsg.surface->setDstSize(myMsg.w * hidpiScaleFactor(), myMsg.h * hidpiScaleFactor());
+#endif
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void FrameBuffer::showMessage(const string& message, const string& valueText,
+                              float value, float minValue, float maxValue)
+{
+#ifdef GUI_SUPPORT
+  // Only show messages if they've been enabled
+  if(myMsg.surface == nullptr || !myOSystem.settings().getBool("uimessages"))
+    return;
+
+  const int fontWidth  = font().getMaxCharWidth(),
+            fontHeight = font().getFontHeight();
+  const int VBORDER = fontHeight / 4;
+  const int HBORDER = fontWidth * 1.25 / 2.0;
+
+  myMsg.counter = uInt32(myOSystem.frameRate()) * 5; // Show message for 5 seconds
+  if(myMsg.counter == 0)
+    myMsg.counter = 120;
+
+  // Precompute the message coordinates
+  myMsg.text       = message;
+  myMsg.color      = kBtnTextColor;
+  myMsg.showGauge  = true;
+  if(maxValue - minValue != 0)
+    myMsg.value = (value - minValue) / (maxValue - minValue) * 100.F;
+  else
+    myMsg.value = 100.F;
+  myMsg.valueText  = valueText;
+  myMsg.w          = std::min(fontWidth * MESSAGE_WIDTH,
+                       font().getStringWidth(myMsg.text)
+                         + fontWidth * (GAUGEBAR_WIDTH + 2)
+                         + font().getStringWidth(myMsg.valueText))
+                     + HBORDER * 2;
+  myMsg.h          = fontHeight + VBORDER * 2;
+  myMsg.position   = MessagePosition::BottomCenter;
+  myMsg.enabled    = true;
 
   myMsg.surface->setSrcSize(myMsg.w, myMsg.h);
   myMsg.surface->setDstSize(myMsg.w * hidpiScaleFactor(), myMsg.h * hidpiScaleFactor());
-  myMsg.position = position;
-  myMsg.enabled = true;
 #endif
 }
 
@@ -631,6 +679,7 @@ inline bool FrameBuffer::drawMessage()
             fontHeight = font().getFontHeight();
   const int VBORDER = fontHeight / 4;
   const int HBORDER = fontWidth * 1.25 / 2.0;
+  constexpr int BORDER = 1;
 
   switch(myMsg.position)
   {
@@ -681,10 +730,44 @@ inline bool FrameBuffer::drawMessage()
   }
 
   myMsg.surface->setDstPos(myMsg.x + myImageRect.x(), myMsg.y + myImageRect.y());
-  myMsg.surface->fillRect(1, 1, myMsg.w - 2, myMsg.h - 2, kBtnColor);
+  myMsg.surface->fillRect(0, 0, myMsg.w, myMsg.h, kColor);
-  myMsg.surface->frameRect(0, 0, myMsg.w, myMsg.h, kColor);
+  myMsg.surface->fillRect(BORDER, BORDER, myMsg.w - BORDER * 2, myMsg.h - BORDER * 2, kBtnColor);
   myMsg.surface->drawString(font(), myMsg.text, HBORDER, VBORDER,
                             myMsg.w, myMsg.color);
+
+  if(myMsg.showGauge)
+  {
+    constexpr int NUM_TICKMARKS = 4;
+    // limit gauge bar width if texts are too long
+    const int swidth = std::min(fontWidth * GAUGEBAR_WIDTH,
+                                fontWidth * (MESSAGE_WIDTH - 2)
+                                - font().getStringWidth(myMsg.text)
+                                - font().getStringWidth(myMsg.valueText));
+    const int bwidth = swidth * myMsg.value / 100.F;
+    const int bheight = fontHeight >> 1;
+    const int x = HBORDER + font().getStringWidth(myMsg.text) + fontWidth;
+    // align bar with bottom of text
+    const int y = VBORDER + font().desc().ascent - bheight;
+
+    // draw bar gauge
+    myMsg.surface->fillRect(x - BORDER, y, swidth + BORDER * 2, bheight, kSliderBGColor);
+    myMsg.surface->fillRect(x, y + BORDER, bwidth, bheight - BORDER * 2, kSliderColor);
+    // draw tickmark in the middle of the bar
+    for(int i = 1; i < NUM_TICKMARKS; ++i)
+    {
+      ColorId color;
+      int xt = x + swidth * i / NUM_TICKMARKS;
+      if(bwidth < xt - x)
+        color = kCheckColor; // kSliderColor;
+      else
+        color = kSliderBGColor;
+      myMsg.surface->vLine(xt, y + bheight / 2, y + bheight - 1, color);
+    }
+    // draw value text
+    myMsg.surface->drawString(font(), myMsg.valueText,
+                              x + swidth + fontWidth, VBORDER,
+                              myMsg.w, myMsg.color);
+  }
   myMsg.surface->render();
   myMsg.counter--;
 #endif
@@ -900,12 +983,12 @@ void FrameBuffer::toggleFullscreen()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void FrameBuffer::changeOverscan(int direction)
+void FrameBuffer::changeOverscan(bool increase)
 {
   if (fullScreen())
   {
     int oldOverscan = myOSystem.settings().getInt("tia.fs_overscan");
-    int overscan = BSPF::clamp(oldOverscan + direction, 0, 10);
+    int overscan = BSPF::clamp(oldOverscan + (increase ? 1 : -1), 0, 10);
 
     if (overscan != oldOverscan)
     {
@@ -914,14 +997,15 @@ void FrameBuffer::changeOverscan(int direction)
       // issue a complete framebuffer re-initialization
       myOSystem.createFrameBuffer();
     }
-    ostringstream msg;
+
-    msg << "Overscan at " << overscan << "%";
+    ostringstream val;
-    showMessage(msg.str());
+    val << (overscan ? overscan > 0 ? "+" : "" : " ") << overscan << "%";
+    myOSystem.frameBuffer().showMessage("Overscan", val.str(), overscan, 0, 10);
   }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool FrameBuffer::changeVidMode(int direction)
+bool FrameBuffer::selectVidMode(bool next)
 {
   EventHandlerState state = myOSystem.eventHandler().state();
   bool tiaMode = (state != EventHandlerState::DEBUGGER &&
@@ -931,12 +1015,10 @@ bool FrameBuffer::changeVidMode(int direction)
   if(!tiaMode)
     return false;
 
-  if(direction == +1)
+  if(next)
     myCurrentModeList->next();
-  else if(direction == -1)
-    myCurrentModeList->previous();
   else
-    return false;
+    myCurrentModeList->previous();
 
   saveCurrentWindowPosition();
 
@@ -956,7 +1038,7 @@ bool FrameBuffer::changeVidMode(int direction)
     myTIASurface->initialize(myOSystem.console(), mode);
 
     resetSurfaces();
-    showMessage(mode.description);
+    showMessage("Zoom", mode.description, mode.zoom, supportedTIAMinZoom(), myTIAMaxZoom);
     myOSystem.sound().mute(oldMuteState);
 
     if(fullScreen())
@@ -1077,7 +1159,7 @@ void FrameBuffer::setAvailableVidModes(uInt32 baseWidth, uInt32 baseHeight)
     for(float zoom = minZoom; zoom <= myTIAMaxZoom; zoom += ZOOM_STEPS)
     {
       ostringstream desc;
-      desc << "Zoom " << zoom << "x";
+      desc << (zoom * 100) << "%";
 
       VideoMode mode(baseWidth*zoom, baseHeight*zoom, baseWidth*zoom, baseHeight*zoom,
                      VideoMode::Stretch::Fill, 1.0, desc.str(), zoom);

src/emucore/FrameBuffer.hxx

@@ -147,6 +147,17 @@ class FrameBuffer
     void showMessage(const string& message,
                      MessagePosition position = MessagePosition::BottomCenter,
                      bool force = false);
+    /**
+      Shows a message with a bar gauge onscreen.
+
+      @param message    The message to be shown
+      @param valueText  The value of the bar gauge as text
+      @param value      The bar gauge percentage
+      @param minValue   The minimal value of the bar gauge
+      @param maxValue   The maximal value of the bar gauge
+    */
+    void showMessage(const string& message, const string& valueText,
+                     float value, float minValue = 0.F, float maxValue = 100.F);
 
     /**
       Toggles showing or hiding framerate statistics.
@@ -251,10 +262,10 @@ class FrameBuffer
 
     /**
       Changes the fullscreen overscan.
-        direction = -1 means less overscan
+
-        direction = +1 means more overscan
+      @param increase  Increase if true, else decrease
     */
-    void changeOverscan(int direction);
+    void changeOverscan(bool increase = true);
 
     /**
       This method is called when the user wants to switch to the next
@@ -264,9 +275,9 @@ class FrameBuffer
         direction = -1 means go to the next lower video mode
         direction = +1 means go to the next higher video mode
 
-      @param direction  Described above
+      @param next  Select next if true, else previous
     */
-    bool changeVidMode(int direction);
+    bool selectVidMode(bool next = true);
 
     /**
       Sets the state of the cursor (hidden or grabbed) based on the
@@ -502,6 +513,11 @@ class FrameBuffer
     OSystem& myOSystem;
 
   private:
+    // Maximum message width [chars]
+    static constexpr int MESSAGE_WIDTH = 56;
+    // Maximum gauge bar width [chars]
+    static constexpr int GAUGEBAR_WIDTH = 30;
+
     /**
       Draw pending messages.
 
@@ -648,6 +664,9 @@ class FrameBuffer
       ColorId color{kNone};
       shared_ptr<FBSurface> surface;
       bool enabled{false};
+      bool showGauge{false};
+      float value{0.0F};
+      string valueText;
     };
     Message myMsg;
     Message myStatsMsg;

src/emucore/TIASurface.cxx

@@ -231,21 +231,11 @@ void TIASurface::setScanlineIntensity(int amount)
   ostringstream buf;
   uInt32 intensity = enableScanlines(amount);
 
-  if(intensity == 0)
-    buf << "Scanlines disabled";
-  else
-  {
-    buf << "Scanline intensity at ";
-    if(intensity < 100)
-      buf << intensity << "%";
-    else
-      buf << "maximum";
-  }
   myOSystem.settings().setValue("tv.scanlines", intensity);
-
   enableNTSC(ntscEnabled());
 
-  myFB.showMessage(buf.str());
+  buf << intensity << "%";
+  myFB.showMessage("Scanline intensity", buf.str(), intensity);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/gui/CommandDialog.cxx

@@ -199,7 +199,7 @@ void CommandDialog::handleCommand(CommandSender* sender, int cmd,
 
     // Column 3
     case kFormatCmd:
-      instance().console().toggleFormat();
+      instance().console().selectFormat();
       updateTVFormat();
       break;
 

src/gui/MinUICommandDialog.cxx

@@ -217,7 +217,7 @@ void MinUICommandDialog::handleCommand(CommandSender* sender, int cmd,
 
     // Column 3
     case kFormatCmd:
-      instance().console().toggleFormat();
+      instance().console().selectFormat();
       updateTVFormat();
       break;