#!/usr/bin/env python3 #****************************************************************************** # treemodel.py, provides a class for the tree's data # # TreeLine, an information storage program # Copyright (C) 2022, Douglas W. Bell # # This is free software; you can redistribute it and/or modify it under the # terms of the GNU General Public License, either Version 2 or any later # version. This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY. See the included LICENSE file for details. #****************************************************************************** import json from PyQt5.QtCore import (QAbstractItemModel, QMimeData, QModelIndex, Qt, pyqtSignal) import undo import treestructure import globalref class TreeModel(QAbstractItemModel): """Class interfacing between the tree structure and the tree view. """ # first arg is set file modified, second is update trees in other views treeModified = pyqtSignal(bool, bool) def __init__(self, treeStructure, parent=None): """Initialize a TreeModel. Arguments: treeStructure -- a ref to the main tree structure parent -- optional QObject parent for the model """ super().__init__(parent) self.treeStructure = treeStructure def index(self, row, column, parentIndex): """Returns the index of a spot in the model based on the parent index. Uses createIndex() to generate the model indices. Arguments: row -- the row of the model node column -- the column (always 0 for now) parentIndex -- the parent's model index in the tree structure """ try: if not parentIndex.isValid(): node = self.treeStructure.childList[row] fakeSpot = list(self.treeStructure.spotRefs)[0] spot = node.matchedSpot(fakeSpot) return self.createIndex(row, column, spot) parentSpot = parentIndex.internalPointer() node = parentSpot.nodeRef.childList[row] return self.createIndex(row, column, node.matchedSpot(parentSpot)) except IndexError: return QModelIndex() def parent(self, index): """Returns the parent model index of the spot at the given index. Arguments: index -- the child model index """ try: parentSpot = index.internalPointer().parentSpot if parentSpot.parentSpot: return self.createIndex(parentSpot.row(), 0, parentSpot) except AttributeError: # attempt to fix an unreproducable bug deleting deep nodes pass return QModelIndex() def rowCount(self, parentIndex): """Returns the number of children for the spot at the given index. Arguments: parentIndex -- the parent model index """ try: parentSpot = parentIndex.internalPointer() return parentSpot.nodeRef.numChildren() except AttributeError: # top level if no parentIndex return len(self.treeStructure.childList) def columnCount(self, parentIndex): """The number of columns -- always 1 for now. """ return 1 def data(self, index, role=Qt.DisplayRole): """Return the output data for the node in the given role. Arguments: index -- the spot's model index role -- the type of data requested """ spot = index.internalPointer() if not spot: return None node = spot.nodeRef if role in (Qt.DisplayRole, Qt.EditRole): return node.title() if (role == Qt.DecorationRole and globalref.genOptions['ShowTreeIcons']): return globalref.treeIcons.getIcon(node.formatRef.iconName, True) return None def setData(self, index, value, role=Qt.EditRole): """Set node title after edit operation. Return True on success. Arguments: index -- the node's model index value -- the string result of the editing role -- the edit role of the data """ if role != Qt.EditRole: return super().setData(index, value, role) node = index.internalPointer().nodeRef dataUndo = undo.DataUndo(self.treeStructure.undoList, node) if node.setTitle(value): self.dataChanged.emit(index, index) self.treeModified.emit(True, False) return True self.treeStructure.undoList.removeLastUndo(dataUndo) return False def flags(self, index): """Return the flags for the node at the given index. Arguments: index -- the node's model index """ return (Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable | Qt.ItemIsDragEnabled | Qt.ItemIsDropEnabled) def mimeData(self, indexList): """Return a mime data object for the given node index branches. Arguments: indexList -- a list of node indexes to convert """ spots = [index.internalPointer() for index in indexList] # remove selections from the same branch TreeModel.storedDragSpots = [spot for spot in spots if spot.parentSpotSet(). isdisjoint(set(spots))] nodes = [spot.nodeRef for spot in TreeModel.storedDragSpots] TreeModel.storedDragModel = self struct = treestructure.TreeStructure(topNodes=nodes, addSpots=False) generics = {formatRef.genericType for formatRef in struct.treeFormats.values() if formatRef.genericType} for generic in generics: genericRef = self.treeStructure.treeFormats[generic] struct.treeFormats.addTypeIfMissing(genericRef) for formatRef in genericRef.derivedTypes: struct.treeFormats.addTypeIfMissing(formatRef) data = struct.fileData() dataStr = json.dumps(data, indent=0, sort_keys=True) mime = QMimeData() mime.setData('application/json', bytes(dataStr, encoding='utf-8')) return mime def mimeTypes(self): """Return a list of supported mime types for model objects. """ return ['application/json'] def supportedDropActions(self): """Return drop action enum values that are supported by this model. """ return Qt.CopyAction | Qt.MoveAction def dropMimeData(self, mimeData, dropAction, row, column, index): """Decode mime data and add as a child node to the given index. Return True if successful. Arguments: mimeData -- data for the node branch to be added dropAction -- a drop type enum value row -- a row number for the drop location column -- the column number for the drop location (normally 0) index -- the index of the parent node for the drop """ parent = (index.internalPointer().nodeRef if index.internalPointer() else self.treeStructure) isMove = (dropAction == Qt.MoveAction and TreeModel.storedDragModel == self) undoParents = [parent] if isMove: moveParents = {spot.parentSpot.nodeRef for spot in TreeModel.storedDragSpots} undoParents.extend(list(moveParents)) newStruct = treestructure.structFromMimeData(mimeData) # check for valid structure and no circular clone ref and not siblings: if newStruct and (not isMove or (not parent.uId in newStruct.nodeDict and (row >= 0 or {node.uId for node in parent.childList}. isdisjoint({node.uId for node in newStruct.childList})))): undo.ChildListUndo(self.treeStructure.undoList, undoParents, treeFormats=self.treeStructure.treeFormats) if isMove: for spot in TreeModel.storedDragSpots: self.treeStructure.deleteNodeSpot(spot) newStruct.replaceClonedBranches(self.treeStructure) else: newStruct.replaceDuplicateIds(self.treeStructure.nodeDict) self.treeStructure.addNodesFromStruct(newStruct, parent, row) return True return False