Index: sources/gui/qml/compounds/ValueAdjuster.qml
===================================================================
diff -u -rea4de12b2c7d6306a9cb89ff23eb95ccd25077a1 -r56817942c7534dc34c2b0bce640534fa51671086
--- sources/gui/qml/compounds/ValueAdjuster.qml	(.../ValueAdjuster.qml)	(revision ea4de12b2c7d6306a9cb89ff23eb95ccd25077a1)
+++ sources/gui/qml/compounds/ValueAdjuster.qml	(.../ValueAdjuster.qml)	(revision 56817942c7534dc34c2b0bce640534fa51671086)
@@ -20,54 +20,44 @@
 import QtQuick.Controls 2.2
 
 Item { id: _root
-    property real   decimal     : 0
-    property real   minimum     : 0
-    property real   maximum     : 0
-    property real   value       : 0
-    property real  defaultValue : 0
-    property real   step        : 0
-
-    property bool   active      : false
+    property string extraText   : ""
+    property alias  value       : _rangedValue.rawValue
+    property alias  minimum     : _rangedValue.rawMin
+    property alias  maximum     : _rangedValue.rawMax
+    property alias  step        : _rangedValue.rawStep
+    property alias  decimal     : _rangedValue.precision
+    property alias  canOff      : _rangedValue.canOff
+    property real   defaultValue: 0
+    property bool   isActive    : false
     property bool   editable    : true
+    property bool   canRefresh  : false
+    property alias  textColor   : _text.color
+    property bool   grabbed     : false
 
-    property bool canIncrement  : active ? value < maximum : true
-    property bool canDecrement  : active ? allowOff ? value > 0 :
-                                                      value > minimum : true
+    signal didChange        (real vValue)
+    signal didActiveChange  (bool vState)
 
-    property bool allowOff      : false
+    onIsActiveChanged             : {
+        if ( canRefresh )   { canRefresh = false; return    }
 
-    // fix floating-point precision issue
-    readonly property real stepVal  : Math.round(step       * 100) / 100
-    readonly property real minVal   : Math.round(minimum    * 100) / 100
-    readonly property real val      : Math.round(value      * 100) / 100
+        if ( isActive )     { didChange(_root.defaultValue) }
+    }
 
-    onActiveChanged             : if ( active ) { _root.value = _root.defaultValue }
+    function refresh()      { canRefresh    = true          }
 
-    function clear() { _root.active = false }
+    function clear()        { didActiveChange(false)        }
 
-    function increment() {
-        if ( ! active )     { active = true                                 }
-        else {
-            if ( allowOff ) { value = val < minVal ? minVal : val + stepVal }
-            else            { value += stepVal                              }
-        }
+    RangedValue { id: _rangedValue
+        objectName: "_rangedValue"
     }
 
-    function decrement() {
-        if ( ! active )     { active = true                             }
-        else {
-            if ( allowOff ) { value = val > minVal ? val - stepVal : 0  }
-            else            { value -= stepVal                          }
-        }
-    }
-
     Text { id: _text
         anchors.centerIn: parent
-        text            : _root.active ? _root.allowOff ? _root.value === 0 ?
-                                                              "OFF" :
-                                                              _root.value.toFixed( _root.decimal ) :
+        text            : _root.isActive ? _root.canOff ? _root.value === 0 ?
+                                                          qsTr("OFF") :
+                                                          _root.value.toFixed( _root.decimal ) :
                                         _root.value.toFixed( _root.decimal ) : Variables.emptyEntry
-        color           : Colors.offWhite
+        color           : _rangedValue.isValueInRange || ! _root.isActive ? Colors.offWhite : Colors.red
         font.pixelSize  : Fonts.fontPixelValueControl
     }
 
@@ -112,48 +102,43 @@
         }
 
         MouseArea { id: _sliderMouseArea
-            property bool grabbed: false
 
             anchors.fill        : parent
             pressAndHoldInterval: 0
+            drag.axis           : Drag.XAxis      // only horizontal
 
             onClicked: {
-                if ( _root.editable ) {
-                    active  = true
-                    focus   = true
-                }
+                if ( _root.editable ) { didActiveChange(true); focus = true }
 
                 _slider.opacity = 0
             }
 
             onReleased: {
-                _sliderMouseArea.grabbed = true
-.                grabbed = false
+                _root.grabbed = false
                 _slider.opacity = 0
             }
 
             onPressAndHold: {
-                if ( _root.editable ) {
-                    active  = true
-                    focus   = true
-                }
+                if ( _root.editable ) { didActiveChange(true); focus = true }
 
-                _sliderMouseArea.grabbed = true
+                _root.grabbed = true
             }
 
             onPositionChanged: {
-                if (grabbed) {
+                if (_root.grabbed) {
                     if ( _slider.opacity === 0 ) { _animator.start() }
 
-                    _slider.pos = Math.max(0, Math.min(1, mouse.x / parent.width))
-                    let raw =  _slider.from + _slider.pos * (_slider.to - _slider.from)
-                    let stepped = Math.round((raw - _slider.from) / _root.step) * _root.step + _slider.from
-                    _root.value = stepped
+                    if (_root.step != 0) {
+                        _slider.pos = Math.max(0, Math.min(1, mouse.x / parent.width))
+                        let raw =  _slider.from + _slider.pos * (_slider.to - _slider.from)
+                        let stepped = Math.round((raw - _slider.from) / _root.step) * _root.step + _slider.from
+                        didChange(stepped)
+                    }
                 }
             }
 
             onExited: {
-                if ( ! _sliderMouseArea.grabbed ) {
+                if ( ! _root.grabbed ) {
                     _animator.stop()
                     _slider.opacity = 0
                 }
@@ -165,7 +150,7 @@
             from    : 0
             to      : 1
             duration: 350
-            running : _sliderMouseArea.grabbed
+            running : _root.grabbed
         }
 
         Behavior on opacity { NumberAnimation { duration: 200 } }
@@ -178,11 +163,15 @@
             leftMargin      : Variables.defaultMargin
         }
         iconSize                : Variables.circleButtonDefaultDiameter
-        enabled                 : _root.canDecrement
+        enabled                 : _rangedValue.canDecrement
         visible                 : _root.editable
         iconImageSource         : enabled ? "qrc:/images/iArrowLeft" :
                                             "qrc:/images/iArrowLeftDisabled"
-        onClicked               : decrement()
+        onClicked               : {
+            if ( ! isActive ) { didActiveChange(true); return }
+
+            didChange(_rangedValue.decrementedValue())
+        }
     }
 
     IconButton { id: _rightArrow
@@ -192,10 +181,14 @@
             rightMargin     : Variables.defaultMargin
         }
         iconSize                : Variables.circleButtonDefaultDiameter
-        enabled                 : _root.canIncrement
+        enabled                 : _rangedValue.canIncrement
         visible                 : _root.editable
         iconImageSource         : enabled ? "qrc:/images/iArrowRight" :
                                             "qrc:/images/iArrowRightDisabled"
-        onClicked               : increment()
+        onClicked               : {
+            if ( ! isActive ) { didActiveChange(true); return }
+
+            didChange(_rangedValue.incrementedValue())
+        }
     }
 }