[ui] GraphEditor: Move ChoiceParam control to its own file

Start modularization of attribute controls for better readability
and maintenance.
Make Choice control independent from the MeshroomUI API.

meshroom/ui/qml/GraphEditor/AttributeControls/Choice.qml

@@ -0,0 +1,34 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+
+import MaterialIcons
+import Controls
+
+/**
+ * A combobox-type control with a single current `value` and a list of possible `values`.
+ * Provides filtering capabilities and support for custom values (i.e: `value` not in `values`).
+ */
+RowLayout {
+    id: root
+
+    required property var value
+    required property var values
+
+    signal editingFinished(var value)
+
+    FilterComboBox {
+        id: comboBox
+
+        Layout.fillWidth: true
+        sourceModel: root.values
+        inputValue: root.value
+        onEditingFinished: value => root.editingFinished(value)
+    }
+
+    MaterialLabel {
+        visible: !comboBox.validValue
+        text: MaterialIcons.warning
+        ToolTip.text: "Custom value detected"
+    }
+}

meshroom/ui/qml/GraphEditor/AttributeItemDelegate.qml

@@ -6,6 +6,7 @@ import QtQuick.Dialogs
 import MaterialIcons 2.2
 import Utils 1.0
 import Controls 1.0
+import "AttributeControls" as AttributeControls
 
 /**
  * Instantiate a control to visualize and edit an Attribute based on its type.
@@ -208,7 +209,7 @@ RowLayout {
                 case "PushButtonParam":
                     return pushButtonComponent
                 case "ChoiceParam":
-                    return attribute.desc.exclusive ? comboBoxComponent : multiChoiceComponent
+                    return attribute.desc.exclusive ? choiceComponent : multiChoiceComponent
                 case "IntParam": return sliderComponent
                 case "FloatParam":
                     if (attribute.desc.semantic === 'color/hue')
@@ -469,26 +470,15 @@ RowLayout {
         }
 
         Component {
-            id: comboBoxComponent
+            id: choiceComponent
 
-            RowLayout {
-                FilterComboBox {
-                    id: comboBox
-
-                    Layout.fillWidth: true
-
-                    enabled: root.editable
-                    sourceModel: attribute.values
-                    inputValue: attribute.value
+            AttributeControls.Choice {
+                value: root.attribute.value
+                values: root.attribute.values
+                enabled: root.editable
 
-                    onEditingFinished: (value) => {
-                        _reconstruction.setAttribute(attribute, value)
-                    }
-                }
-                MaterialLabel {
-                    visible: !comboBox.validValue
-                    text: MaterialIcons.warning
-                    ToolTip.text: "Custom value detected"
+                onEditingFinished: (value) => {
+                    _reconstruction.setAttribute(root.attribute, value)
                 }
             }
         }