Restore increased range for volume effect, only limit the visible range in timeline

Related to #770

data/effects/README

@@ -50,6 +50,11 @@ The rest:
         - tag "comment": (optional) description of the parameter (support HTML formatting) (not yet supported by all widgets)
         - attribute "name": MLT filter parameter name
         - attribute "paramprefix": a string to be prepended to the parameter value before passing it to MLT
+        - attribute "suffix": a string to be appended to the parameter (for UI display only)
+        - attribute "min": the minimal accepted value
+        - attribute "max": the maximal accepted value
+        - attribute "visualmin": the minimal value displayed in timeline keyframes (can be > than min)
+        - attribute "visualmax": the maximal value displayed in timeline keyframes (can be < than max)
         - attribute "default": initial value, format depends on parameter type
         - attribute "optional": if it is set, it means that this parameter can have an empty value. So then loading a project, don't set its value to default
         - attribute "type": widget (GUI) to use

data/effects/volume.xml

@@ -3,7 +3,7 @@
 	<name>Volume (keyframable)</name>
 	<description>Adjust audio volume with keyframes</description>
 	<author>Dan Dennedy</author>
-	<parameter type="animated" name="level" default="0" max="50" min="-50" suffix="dB" scale="-1">
+	<parameter type="animated" name="level" default="0" max="50" min="-100" visualmax="50" visualmin="-50" suffix="dB" scale="-1">
 		<name>Gain</name>
 	</parameter>
 </effect>

src/assets/keyframes/model/keyframemodel.cpp

@@ -298,8 +298,12 @@ bool KeyframeModel::updateKeyframe(int pos, double newVal)
 {
     GenTime Pos(pos, pCore->getCurrentFps());
     if (auto ptr = m_model.lock()) {
-        double min = ptr->data(m_index, AssetParameterModel::MinRole).toDouble();
-        double max = ptr->data(m_index, AssetParameterModel::MaxRole).toDouble();
+        double min = ptr->data(m_index, AssetParameterModel::VisualMinRole).toDouble();
+        double max = ptr->data(m_index, AssetParameterModel::VisualMaxRole).toDouble();
+        if (qFuzzyIsNull(min) && qFuzzyIsNull(max)) {
+            min = ptr->data(m_index, AssetParameterModel::MinRole).toDouble();
+            max = ptr->data(m_index, AssetParameterModel::MaxRole).toDouble();
+        }
         double factor = ptr->data(m_index, AssetParameterModel::FactorRole).toDouble();
         double norm = ptr->data(m_index, AssetParameterModel::DefaultRole).toDouble();
         int logRole = ptr->data(m_index, AssetParameterModel::ScaleRole).toInt();
@@ -454,8 +458,12 @@ QVariant KeyframeModel::data(const QModelIndex &index, int role) const
         double val = it->second.second.toDouble();
         if (auto ptr = m_model.lock()) {
             Q_ASSERT(m_index.isValid());
-            double min = ptr->data(m_index, AssetParameterModel::MinRole).toDouble();
-            double max = ptr->data(m_index, AssetParameterModel::MaxRole).toDouble();
+            double min = ptr->data(m_index, AssetParameterModel::VisualMinRole).toDouble();
+            double max = ptr->data(m_index, AssetParameterModel::VisualMaxRole).toDouble();
+            if (qFuzzyIsNull(min) && qFuzzyIsNull(max)) {
+                min = ptr->data(m_index, AssetParameterModel::MinRole).toDouble();
+                max = ptr->data(m_index, AssetParameterModel::MaxRole).toDouble();
+            }
             double factor = ptr->data(m_index, AssetParameterModel::FactorRole).toDouble();
             double norm = ptr->data(m_index, AssetParameterModel::DefaultRole).toDouble();
             int logRole = ptr->data(m_index, AssetParameterModel::ScaleRole).toInt();
@@ -890,8 +898,12 @@ QVariant KeyframeModel::updateInterpolated(const QVariant &interpValue, double v
 QVariant KeyframeModel::getNormalizedValue(double newVal) const
 {
     if (auto ptr = m_model.lock()) {
-        double min = ptr->data(m_index, AssetParameterModel::MinRole).toDouble();
-        double max = ptr->data(m_index, AssetParameterModel::MaxRole).toDouble();
+        double min = ptr->data(m_index, AssetParameterModel::VisualMinRole).toDouble();
+        double max = ptr->data(m_index, AssetParameterModel::VisualMaxRole).toDouble();
+        if (qFuzzyIsNull(min) && qFuzzyIsNull(max)) {
+            min = ptr->data(m_index, AssetParameterModel::MinRole).toDouble();
+            max = ptr->data(m_index, AssetParameterModel::MaxRole).toDouble();
+        }
         double factor = ptr->data(m_index, AssetParameterModel::FactorRole).toDouble();
         double norm = ptr->data(m_index, AssetParameterModel::DefaultRole).toDouble();
         int logRole = ptr->data(m_index, AssetParameterModel::ScaleRole).toInt();

src/assets/model/assetparametermodel.cpp

@@ -440,6 +440,10 @@ QVariant AssetParameterModel::data(const QModelIndex &index, int role) const
         return parseAttribute(m_ownerId, QStringLiteral("decimals"), element);
     case OddRole:
         return element.attribute(QStringLiteral("odd")) == QLatin1String("1");
+    case VisualMinRole:
+        return parseAttribute(m_ownerId, QStringLiteral("visualmin"), element);
+    case VisualMaxRole:
+        return parseAttribute(m_ownerId, QStringLiteral("visualmax"), element);
     case DefaultRole:
         return parseAttribute(m_ownerId, QStringLiteral("default"), element);
     case FilterRole:

src/assets/model/assetparametermodel.hpp

@@ -91,6 +91,8 @@ public:
         CommentRole,
         AlternateNameRole,
         MinRole,
+        VisualMinRole,
+        VisualMaxRole,
         MaxRole,
         DefaultRole,
         SuffixRole,