AYON: Tools enhancements (#5753)

* moved universal 'TreeView' to utils

* use 'TreeView' in folders widget

* propagate 'set_deselectable' in 'FoldersWidget'

* propagate more public functionality of 'FoldersWidget'

* fix 'set_name_filer' typo

* rename 'get_current_project_name' to 'get_selected_project_name'

* added signals to task and project widgets

* implemented more helper methods in hierarchy model

* added more information to 'FolderItem'

* add empty line after docstring

* fix expected selection of folders in loader

* keep only 'double_clicked' signal

* pass full mouse event to signal

openpype/tools/utils/views.py

@@ -1,4 +1,6 @@
 from openpype.resources import get_image_path
+from openpype.tools.flickcharm import FlickCharm
+
 from qtpy import QtWidgets, QtCore, QtGui, QtSvg
 
 
@@ -57,3 +59,63 @@ class TreeViewSpinner(QtWidgets.QTreeView):
             self.paint_empty(event)
         else:
             super(TreeViewSpinner, self).paintEvent(event)
+
+
+class TreeView(QtWidgets.QTreeView):
+    """Ultimate TreeView with flick charm and double click signals.
+
+    Tree view have deselectable mode, which allows to deselect items by
+    clicking on item area without any items.
+
+    Todos:
+        Add refresh animation.
+    """
+
+    double_clicked = QtCore.Signal(QtGui.QMouseEvent)
+
+    def __init__(self, *args, **kwargs):
+        super(TreeView, self).__init__(*args, **kwargs)
+        self._deselectable = False
+
+        self._flick_charm_activated = False
+        self._flick_charm = FlickCharm(parent=self)
+        self._before_flick_scroll_mode = None
+
+    def is_deselectable(self):
+        return self._deselectable
+
+    def set_deselectable(self, deselectable):
+        self._deselectable = deselectable
+
+    deselectable = property(is_deselectable, set_deselectable)
+
+    def mousePressEvent(self, event):
+        if self._deselectable:
+            index = self.indexAt(event.pos())
+            if not index.isValid():
+                # clear the selection
+                self.clearSelection()
+                # clear the current index
+                self.setCurrentIndex(QtCore.QModelIndex())
+        super(TreeView, self).mousePressEvent(event)
+
+    def mouseDoubleClickEvent(self, event):
+        self.double_clicked.emit(event)
+
+        return super(TreeView, self).mouseDoubleClickEvent(event)
+
+    def activate_flick_charm(self):
+        if self._flick_charm_activated:
+            return
+        self._flick_charm_activated = True
+        self._before_flick_scroll_mode = self.verticalScrollMode()
+        self._flick_charm.activateOn(self)
+        self.setVerticalScrollMode(QtWidgets.QAbstractItemView.ScrollPerPixel)
+
+    def deactivate_flick_charm(self):
+        if not self._flick_charm_activated:
+            return
+        self._flick_charm_activated = False
+        self._flick_charm.deactivateFrom(self)
+        if self._before_flick_scroll_mode is not None:
+            self.setVerticalScrollMode(self._before_flick_scroll_mode)