sliders: implement color coding for clarity

app/node/color/ociogradingtransformlinear/ociogradingtransformlinear.cpp

@@ -42,10 +42,13 @@ OCIOGradingTransformLinearNode::OCIOGradingTransformLinearNode()
 {
   AddInput(kContrastInput, NodeValue::kVec4, QVector4D{1.0, 1.0, 1.0, 1.0});
   SetInputProperty(kContrastInput, QStringLiteral("min"), QVector4D{0.001f, 0.001f, 0.001f, 0.001f});
+  SetVec4InputColors(kContrastInput);
 
   AddInput(kOffsetInput, NodeValue::kVec4, QVector4D{0.0, 0.0, 0.0, 0.0});
+  SetVec4InputColors(kOffsetInput);
 
   AddInput(kExposureInput, NodeValue::kVec4, QVector4D{0.0, 0.0, 0.0, 0.0});
+  SetVec4InputColors(kExposureInput);
 
   AddInput(kSaturationInput, NodeValue::kFloat, 1.0);
   SetInputProperty(kSaturationInput, QStringLiteral("min"), 0.0);
@@ -124,4 +127,12 @@ void OCIOGradingTransformLinearNode::ConfigChanged()
   GenerateProcessor();
 }
 
+void OCIOGradingTransformLinearNode::SetVec4InputColors(const QString &input)
+{
+  SetInputProperty(input, QStringLiteral("color0"), QColor(255, 0, 0).name());
+  SetInputProperty(input, QStringLiteral("color1"), QColor(0, 255, 0).name());
+  SetInputProperty(input, QStringLiteral("color2"), QColor(0, 0, 255).name());
+  SetInputProperty(input, QStringLiteral("color3"), QColor(192, 192, 192).name());
+}
+
 }

app/node/color/ociogradingtransformlinear/ociogradingtransformlinear.h

@@ -55,6 +55,9 @@ class OCIOGradingTransformLinearNode : public OCIOBaseNode
 protected slots:
   virtual void ConfigChanged() override;
 
+private:
+  void SetVec4InputColors(const QString &input);
+
 };
 
 } // olive

app/widget/nodeparamview/nodeparamviewwidgetbridge.cpp

@@ -654,6 +654,23 @@ void NodeParamViewWidgetBridge::SetProperty(const QString &key, const QVariant &
       }
 
       UpdateWidgetValues();
+    } else if (key.startsWith(QStringLiteral("color"))) {
+      QColor c(value.toString());
+
+      int tracks = NodeValue::get_number_of_keyframe_tracks(data_type);
+
+      if (key.size() == 5) {
+        // Set for all tracks
+        for (int i=0; i<tracks; i++) {
+          static_cast<SliderBase*>(widgets_.at(i))->SetColor(c);
+        }
+      } else {
+        bool ok;
+        int element = key.mid(5).toInt(&ok);
+        if (ok && element >= 0 && element < tracks) {
+          static_cast<SliderBase*>(widgets_.at(element))->SetColor(c);
+        }
+      }
     }
   }
 

app/widget/slider/base/sliderbase.h

@@ -55,6 +55,11 @@ public:
     UpdateLabel();
   }
 
+  void SetColor(const QColor &c)
+  {
+    label_->SetColor(c);
+  }
+
 public slots:
   void ShowEditor();
 

app/widget/slider/base/sliderlabel.cpp

@@ -27,7 +27,8 @@
 namespace olive {
 
 SliderLabel::SliderLabel(QWidget *parent) :
-  QLabel(parent)
+  QLabel(parent),
+  override_color_enabled_(false)
 {
   QPalette p = palette();
 
@@ -52,6 +53,26 @@ SliderLabel::SliderLabel(QWidget *parent) :
   setContextMenuPolicy(Qt::CustomContextMenu);
 }
 
+void SliderLabel::SetColor(const QColor &c)
+{
+  // Prevent infinite loop in changeEvent when we set the stylesheet
+  override_color_enabled_ = false;
+  override_color_ = c;
+
+  // Different colors will look different depending on the theme (light/dark mode). We abstract
+  // that away here so that other classes can simply choose a color and we will handle making it
+  // more legible based on the background
+  QColor adjusted;
+  if (palette().window().color().lightness() < 128) {
+    adjusted = override_color_.lighter(150);
+  } else {
+    adjusted = override_color_.darker(150);
+  }
+
+  setStyleSheet(QStringLiteral("color: %1").arg(adjusted.name()));
+  override_color_enabled_ = true;
+}
+
 void SliderLabel::mousePressEvent(QMouseEvent *e)
 {
   if (e->button() == Qt::LeftButton) {
@@ -81,4 +102,13 @@ void SliderLabel::focusInEvent(QFocusEvent *event)
   }
 }
 
+void SliderLabel::changeEvent(QEvent *event)
+{
+  QWidget::changeEvent(event);
+
+  if (override_color_enabled_ && event->type() == QEvent::StyleChange) {
+    SetColor(override_color_);
+  }
+}
+
 }

app/widget/slider/base/sliderlabel.h

@@ -33,6 +33,8 @@ class SliderLabel : public QLabel
 public:
   SliderLabel(QWidget* parent);
 
+  void SetColor(const QColor &c);
+
 protected:
   virtual void mousePressEvent(QMouseEvent *e) override;
 
@@ -40,6 +42,8 @@ protected:
 
   virtual void focusInEvent(QFocusEvent *event) override;
 
+  virtual void changeEvent(QEvent *event) override;
+
 signals:
   void LabelPressed();
 
@@ -51,6 +55,10 @@ signals:
 
   void ChangeSliderType();
 
+private:
+  bool override_color_enabled_;
+  QColor override_color_;
+
 };
 
 }