Massage base dragging

- Make dragging nodes not conflict with dragging the base
- Make shift-drag do a rubber-band select
- Fix cursors
- Fix nodes dragging weirdly on scene transition
- De-hack nodes automatically deselecting on expand start

typetapper/hierarchy_graph_view.py

@@ -7,10 +7,10 @@ import random
 from threading import Lock
 import logging
 
-from PySide6.QtCore import QRectF, QPointF, QTimeLine, QEasingCurve, QMarginsF, QTimer, Qt
+from PySide6.QtCore import QRectF, QPointF, QTimeLine, QEasingCurve, QMarginsF, QTimer, Qt, QEvent
 from PySide6.QtGui import QColor, QFont, QBrush, QPainterPath, QPen
 from PySide6.QtWidgets import QGraphicsItem, QGraphicsRectItem, QGraphicsSimpleTextItem, QHBoxLayout, QGraphicsScene, \
-    QGraphicsEllipseItem
+    QGraphicsEllipseItem, QGraphicsSceneMouseEvent
 
 import networkx
 import pygraphviz
@@ -120,6 +120,8 @@ class HierarchicalGraphWidget(QZoomableDraggableGraphicsView):
         self._layout_animation.timeout.connect(self._iterate_layout)
         self._layout_animation_controller.setSingleShot(True)
         self._layout_animation_controller.timeout.connect(self._layout_animation.stop)
+        self.setDragMode(QZoomableDraggableGraphicsView.ScrollHandDrag)
+        self.viewport().setCursor(Qt.CursorShape.ArrowCursor)
 
         self._on_change_group(src='__init__')
 
@@ -572,17 +574,25 @@ class HierarchicalGraphWidget(QZoomableDraggableGraphicsView):
 
     def mousePressEvent(self, event):
         self._mouse_is_down = True
-        super().mousePressEvent(event)
+        if event.modifiers() & Qt.ShiftModifier == 0:
+            self.setDragMode(QZoomableDraggableGraphicsView.ScrollHandDrag)
+        else:
+            self.setDragMode(QZoomableDraggableGraphicsView.RubberBandDrag)
+            self.viewport().setCursor(Qt.CursorShape.CrossCursor)
+        super(QZoomableDraggableGraphicsView, self).mousePressEvent(event)  # lol. lmao even
 
     def mouseReleaseEvent(self, event):
         self._mouse_is_down = False
         if self.drop_target is not None:
             self.confirm_drop()
         super().mouseReleaseEvent(event)
+        self.viewport().setCursor(Qt.CursorShape.ArrowCursor)
 
     # objectcontainer event handlers
 
     def _on_change_group(self, focus=None, **kwargs):
+        self.scene().clearSelection()
+
         old_group = self._old_group
         self._old_group = self.current_group.am_obj
         self._layouts[old_group] = {qnode.model: qnode.center for qnode in self.qnodes}
@@ -597,8 +607,12 @@ class HierarchicalGraphWidget(QZoomableDraggableGraphicsView):
         if focus is None:
             focus = old_group
         if focus in self.ug_reverse:
-            self.qnodes[self.ug_reverse[focus]].setSelected(True)
-            self.centerOn(self.qnodes[self.ug_reverse[focus]].center)
+            qnode = self.qnodes[self.ug_reverse[focus]]
+            # deliver a bogus event - prevents the selected node from dragging to the origin
+            event = QGraphicsSceneMouseEvent(QEvent.GraphicsSceneMouseRelease)
+            qnode.mouseReleaseEvent(event)
+            qnode.setSelected(True)
+            self.centerOn(qnode.center)
 
     def _on_selection_changed(self, src=None, **kwargs):
         if src == 'qt':
@@ -710,6 +724,9 @@ class HGNode(AnimatableItem):
     # qt overrides
 
     def itemChange(self, change, value):
+        if change == QGraphicsItem.ItemPositionChange and self.exiting:
+            # refuse to move while exiting?
+            return self.pos()
         if change == QGraphicsItem.ItemPositionHasChanged:
             if not self.hgw._layout_event_occurring:
                 for edge in self.edges.values():
@@ -874,9 +891,10 @@ class PropChartHG(HGNode, PropChart):
 
     def begin_expand(self):
         if self.timeline.state() == QTimeLine.NotRunning:
-            # horrifying
-            QTimer.singleShot(10, lambda: self.hgw.begin_expand(self.model))
+            self.hgw.begin_expand(self.model)
             return True
+        else:
+            return False
 
     def paint(self, painter, option, widget=...):
         if self.isSelected():
@@ -1132,8 +1150,9 @@ class PlusButton(QGraphicsItem):
 
     def mousePressEvent(self, event):
         if self.callback():
-            event.ignore()
-        super().mousePressEvent(event)
+            event.accept()
+        else:
+            super().mousePressEvent(event)
 
     def hoverEnterEvent(self, event):
         self.object_bg.setBrush(PLUS_HOVERED_COLOR)