[ui] GraphEditor: add "Delete From Here" in node contextual menu

* ease the deletion of a branch from a given starting point
* accessible with alt+del on a node
* re-order menu to put the most destructive operation (Clear Data) at the very end

meshroom/ui/graph.py

@@ -390,6 +390,18 @@ class UIGraph(QObject):
     def removeNode(self, node):
         self.push(commands.RemoveNodeCommand(self._graph, node))
 
+    @Slot(Node)
+    def removeNodesFrom(self, startNode):
+        """
+        Remove all nodes starting from 'startNode' to graph leaves.
+        Args:
+            startNode (Node): the node to start from.
+        """
+        with self.groupedGraphModification("Remove Nodes from {}".format(startNode.name)):
+            # Perform nodes removal from leaves to start node so that edges
+            # can be re-created in correct order on redo.
+            [self.removeNode(node) for node in reversed(self._graph.nodesFromNode(startNode)[0])]
+
     @Slot(Attribute, Attribute)
     def addEdge(self, src, dst):
         if isinstance(dst, ListAttribute) and not isinstance(src, ListAttribute):

meshroom/ui/qml/GraphEditor/GraphEditor.qml

@@ -2,6 +2,7 @@ import QtQuick 2.7
 import QtQuick.Controls 2.3
 import QtQuick.Layouts 1.3
 import Controls 1.0
+import Utils 1.0
 import MaterialIcons 2.2
 
 /**
@@ -274,7 +275,7 @@ Item {
                 }
                 MenuSeparator {}
                 MenuItem {
-                    text: "Duplicate"
+                    text: "Duplicate Node"
                     onTriggered: duplicateNode(nodeMenu.currentNode, false)
                 }
                 MenuItem {
@@ -282,16 +283,23 @@ Item {
                     onTriggered: duplicateNode(nodeMenu.currentNode, true)
                 }
                 MenuSeparator {}
-                MenuItem {
-                    text: "Clear Data"
-                    enabled: !root.readOnly
-                    onTriggered: nodeMenu.currentNode.clearData()
-                }
                 MenuItem {
                     text: "Delete Node"
                     enabled: !root.readOnly
                     onTriggered: uigraph.removeNode(nodeMenu.currentNode)
                 }
+                MenuItem {
+                    text: "Delete From Here"
+                    enabled: !root.readOnly
+                    onTriggered: uigraph.removeNodesFrom(nodeMenu.currentNode)
+                }
+                MenuSeparator {}
+                MenuItem {
+                    text: "Clear Data"
+                    palette.text: Colors.red
+                    enabled: !root.readOnly
+                    onTriggered: nodeMenu.currentNode.clearData()
+                }
             }
 
             // Nodes
@@ -337,7 +345,12 @@ Item {
                     onEntered: uigraph.hoveredNode = node
                     onExited: uigraph.hoveredNode = null
 
-                    Keys.onDeletePressed: uigraph.removeNode(node)
+                    Keys.onDeletePressed: {
+                        if(event.modifiers == Qt.AltModifier)
+                            uigraph.removeNodesFrom(node)
+                        else
+                            uigraph.removeNode(node)
+                    }
 
                     Behavior on x {
                         enabled: animatePosition