[ui] Center pasted nodes in GraphEditor when it does not contain the mouse

When using the Edit > Paste menu, or when pressing Ctrl+V while the Graph
Editor has the focus but the mouse is not contained in it, there is no
current mouse position in the GraphEditor so the position that is provided
to the "pasteNodes" function is the last known mouse position, which is
oftentimes on the border of the GraphEditor.

This commit automatically sets the mouse's position to the center of
the GraphEditor, and "builds" the zone containing the pasted nodes around
it.

meshroom/ui/graph.py

@@ -789,8 +789,8 @@ class UIGraph(QObject):
             return json.dumps(selection, indent=4)
         return ''
 
-    @Slot(str, QPoint, result="QVariantList")
+    @Slot(str, QPoint, bool, result="QVariantList")
-    def pasteNodes(self, clipboardContent, position=None):
+    def pasteNodes(self, clipboardContent, position=None, centerPosition=False):
         """
         Parse the content of the clipboard to see whether it contains
         valid node descriptions. If that is the case, the nodes described
@@ -810,6 +810,8 @@ class UIGraph(QObject):
             clipboardContent (str): the string contained in the clipboard, that may or may not contain valid
                                     node information
             position (QPoint): the position of the mouse in the Graph Editor when the function was called
+            centerPosition (bool): whether the provided position is not the top-left corner of the pasting
+                                    zone, but its center
 
         Returns:
             list: the list of Node objects that were pasted and added to the graph
@@ -844,7 +846,9 @@ class UIGraph(QObject):
         # to the first node within that zone.
         firstNodePos = None
         minX = 0
+        maxX = 0
         minY = 0
+        maxY = 0
         for key in sorted(d):
             nodeType = d[key].get("nodeType", None)
             if not nodeType:
@@ -855,12 +859,18 @@ class UIGraph(QObject):
                 if not firstNodePos:
                     firstNodePos = pos
                     minX = pos[0]
+                    maxX = pos[0]
                     minY = pos[1]
+                    maxY = pos[1]
                 else:
                     if minX > pos[0]:
                         minX = pos[0]
+                    if maxX < pos[0]:
+                        maxX = pos[0]
                     if minY > pos[1]:
                         minY = pos[1]
+                    if maxY < pos[1]:
+                        maxY = pos[1]
 
         # Ensure there will not be an error if no node has a specified position
         if not firstNodePos:
@@ -869,6 +879,11 @@ class UIGraph(QObject):
         # Position of the first node within the zone
         position = Position(position.x + firstNodePos[0] - minX, position.y + firstNodePos[1] - minY)
 
+        if centerPosition: # Center the zone around the mouse's position (mouse's position might be artificial)
+            maxX = maxX + self.layout.nodeWidth  # maxX and maxY are the position of the furthest node's top-left corner
+            maxY = maxY + self.layout.nodeHeight  # We want the position of the furthest node's bottom-right corner
+            position = Position(position.x - ((maxX - minX) / 2), position.y - ((maxY - minY) / 2))
+
         finalPosition = None
         prevPosition = None
         positions = []

meshroom/ui/qml/GraphEditor/GraphEditor.qml

@@ -41,7 +41,6 @@ Item {
     clip: true
 
     SystemPalette { id: activePalette }
-    property point pastePosition
 
     /// Get node delegate for the given node object
     function nodeDelegate(node)
@@ -89,14 +88,22 @@ Item {
     /// Paste content of clipboard to graph editor and create new node if valid
     function pasteNodes()
     {
-        if (uigraph.hoveredNode != null) {
+        var finalPosition = undefined
-            var node = nodeDelegate(uigraph.hoveredNode)
+        var centerPosition = false
-            root.pastePosition = Qt.point(node.mousePosition.x + node.x, node.mousePosition.y + node.y)
+        if (mouseArea.containsMouse) {
+            if (uigraph.hoveredNode != null) {
+                var node = nodeDelegate(uigraph.hoveredNode)
+                finalPosition = Qt.point(node.mousePosition.x + node.x, node.mousePosition.y + node.y)
+            } else {
+                finalPosition = mapToItem(draggable, mouseArea.mouseX, mouseArea.mouseY)
+            }
         } else {
-            root.pastePosition = mapToItem(draggable, mouseArea.mouseX, mouseArea.mouseY)
+            finalPosition = getCenterPosition()
+            centerPosition = true
         }
+
         var copiedContent = Clipboard.getText()
-        var nodes = uigraph.pasteNodes(copiedContent, root.pastePosition)
+        var nodes = uigraph.pasteNodes(copiedContent, finalPosition, centerPosition)
         if (nodes.length > 0) {
             uigraph.clearNodeSelection()
             uigraph.selectedNode = nodes[0]
@@ -104,6 +111,12 @@ Item {
         }
     }
 
+    /// Get the coordinates of the point at the center of the GraphEditor
+    function getCenterPosition()
+    {
+        return mapToItem(draggable, mouseArea.width / 2, mouseArea.height / 2)
+    }
+
     Keys.onPressed: {
         if (event.key === Qt.Key_F)
             fit()