Merge pull request #2 from Blakeinstein/master

[Important] Helper commit to help merge shape branch with master

4 files changed, 141 insertions, 9 deletions

diff --git a/src/main/python/utils/dialogs.py b/src/main/python/utils/dialogs.py
index e008aa5..3791599 100644
--- a/src/main/python/utils/dialogs.py
+++ b/src/main/python/utils/dialogs.py
@@ -99,4 +99,12 @@ def saveEvent(parent = None):
         if alert == QMessageBox.Save:
             if not parent.saveProject(): #the parent's saveProject method is called which returns false if saving was cancelled by the user
                 return False
-    return True
\ No newline at end of file
+    return True
+
+def showUndoDialog(undoView, parent):
+    dialogBox = QDialog(parent)
+    dialogBox.resize(400, 400)
+    layout = QFormLayout(dialogBox)
+    layout.addWidget(undoView)
+    dialogBox.setWindowTitle("Undo Stack")
+    dialogBox.show()
\ No newline at end of file
diff --git a/src/main/python/utils/fileWindow.py b/src/main/python/utils/fileWindow.py
index e549568..8f2fd32 100644
--- a/src/main/python/utils/fileWindow.py
+++ b/src/main/python/utils/fileWindow.py
@@ -18,6 +18,7 @@ class fileWindow(QMdiSubWindow):
     canvases. Pre-Defined so that a file can be instantly created without defining the structure again.
     """
     fileCloseEvent = pyqtSignal(int)
+    tabChangeEvent = pyqtSignal()
     
     def __init__(self, parent = None, title = 'New Project', size = 'A4', ppi = '72'):
         super(fileWindow, self).__init__(parent)
@@ -203,6 +204,7 @@ class fileWindow(QMdiSubWindow):
     def changeTab(self, currentIndex):
         #placeholder function to detect tab change
         self.resizeHandler()        
+        self.tabChangeEvent.emit()
     
     def closeTab(self, currentIndex):
         #show save alert on tab close
diff --git a/src/main/python/utils/graphics.py b/src/main/python/utils/graphics.py
index 0fe0030..62c62f7 100644
--- a/src/main/python/utils/graphics.py
+++ b/src/main/python/utils/graphics.py
@@ -1,7 +1,11 @@
-from PyQt5.QtCore import Qt
-from PyQt5.QtGui import QPen
-from PyQt5.QtWidgets import QGraphicsView, QGraphicsScene, QGraphicsProxyWidget, QGraphicsItem
-from PyQt5 import QtWidgets
+from PyQt5.QtCore import Qt, QPointF
+from PyQt5.QtGui import QPen, QKeySequence
+from PyQt5.QtWidgets import QGraphicsView, QGraphicsScene, QGraphicsProxyWidget, QGraphicsItem, QUndoStack, QAction, QUndoView
+
+from .undo import *
+from .dialogs import showUndoDialog
+
+import shapes
 
 class customView(QGraphicsView):
     """
@@ -15,6 +19,10 @@ class customView(QGraphicsView):
         self._zoom = 1
         self.setDragMode(True) #sets pannable using mouse
         self.setAcceptDrops(True) #sets ability to accept drops
+        if scene:
+            self.addAction(scene.undoAction)
+            self.addAction(scene.redoAction)
+            self.addAction(scene.deleteAction)
     
     #following four functions are required to be overridden for drag-drop functionality
     def dragEnterEvent(self, QDragEnterEvent):
@@ -35,10 +43,10 @@ class customView(QGraphicsView):
         #defines item drop, fetches text, creates corresponding QGraphicItem and adds it to scene
         if QDropEvent.mimeData().hasText():
             #QDropEvent.mimeData().text() defines intended drop item, the pos values define position
-            graphic = getattr(QtWidgets, QDropEvent.mimeData().text())(QDropEvent.pos().x()-150, QDropEvent.pos().y()-150, 300, 300)
+            graphic = getattr(shapes, QDropEvent.mimeData().text())(QDropEvent.pos().x()-150, QDropEvent.pos().y()-150, 300, 300)
             graphic.setPen(QPen(Qt.black, 2))
             graphic.setFlags(QGraphicsItem.ItemIsSelectable | QGraphicsItem.ItemIsMovable)
-            self.scene().addItem(graphic) 
+            self.scene().addItemPlus(graphic) 
             QDropEvent.acceptProposedAction()
      
     def wheelEvent(self, QWheelEvent):
@@ -73,5 +81,56 @@ class customScene(QGraphicsScene):
     re-implement QGraphicsScene for future functionality 
     hint: QUndoFramework
     """
-    pass
-        
\ No newline at end of file
+    def __init__(self, *args, parent=None):
+        super(customScene, self).__init__(*args,  parent=parent)
+        
+        self.undoStack = QUndoStack(self)
+        self.createActions()
+        
+
+    def createActions(self):
+        self.deleteAction = QAction("Delete Item", self)
+        self.deleteAction.setShortcut(Qt.Key_Delete)
+        self.deleteAction.triggered.connect(self.deleteItem)
+        
+        self.undoAction = self.undoStack.createUndoAction(self, "Undo")
+        self.undoAction.setShortcut(QKeySequence.Undo)
+        self.redoAction = self.undoStack.createRedoAction(self, "Redo")
+        self.redoAction.setShortcut(QKeySequence.Redo)
+    
+    def createUndoView(self, parent):
+        undoView = QUndoView(self.undoStack, parent)
+        # undoView.resize(400, 400)
+        # undoView.show()
+        # undoView.setAttribute(Qt.WA_QuitOnClose, False)
+        showUndoDialog(undoView, parent)
+
+    def deleteItem(self):
+        if self.selectedItems():
+            for item in self.selectedItems():
+                self.undoStack.push(deleteCommand(item, self))
+            
+    def itemMoved(self, movedItem, lastPos):
+        self.undoStack.push(moveCommand(movedItem, lastPos))
+    
+    def addItemPlus(self, item):
+        # returnVal =  self.addItem(item)
+        self.undoStack.push(addCommand(item, self))
+        # return returnVal
+    
+    def mousePressEvent(self, event):
+        bdsp = event.buttonDownScenePos(Qt.LeftButton)
+        point = QPointF(bdsp.x(), bdsp.y())
+        itemList = self.items(point)
+        self.movingItem = itemList[0] if itemList else None
+        if self.movingItem and event.button() == Qt.LeftButton:
+            self.oldPos = self.movingItem.pos()
+        self.clearSelection()
+        return super(customScene, self).mousePressEvent(event)
+    
+    def mouseReleaseEvent(self, event):
+        if self.movingItem and event.button() == Qt.LeftButton:
+            if self.oldPos != self.movingItem.pos():
+                self.itemMoved(self.movingItem, self.oldPos)
+            self.movingItem = None
+        return super(customScene, self).mouseReleaseEvent(event)
diff --git a/src/main/python/utils/undo.py b/src/main/python/utils/undo.py
new file mode 100644
index 0000000..7832483
--- /dev/null
+++ b/src/main/python/utils/undo.py
@@ -0,0 +1,63 @@
+from PyQt5.QtWidgets import QUndoCommand
+
+class addCommand(QUndoCommand):
+    
+    def __init__(self, addItem, scene, parent = None):
+        super(addCommand, self).__init__(parent)
+        self.scene = scene
+        self.diagramItem = addItem
+        self.itemPos = addItem.pos()
+        self.setText(f"Add {self.diagramItem} {self.itemPos}")
+        
+    def undo(self):
+        self.scene.removeItem(self.diagramItem)
+        self.scene.update()
+        
+    def redo(self):
+        self.scene.addItem(self.diagramItem)
+        self.diagramItem.setPos(self.itemPos)
+        self.scene.clearSelection()
+        self.scene.update()
+        
+class deleteCommand(QUndoCommand):
+    
+    def __init__(self, item, scene, parent = None):
+        super(deleteCommand, self).__init__(parent)
+        self.scene = scene
+        item.setSelected(False)
+        self.diagramItem = item
+        self.setText(f"Delete {self.diagramItem} {self.diagramItem.pos()}")
+        
+    def undo(self):
+        self.scene.addItem(self.diagramItem)
+        self.scene.update()
+        
+    def redo(self):
+        self.scene.removeItem(self.diagramItem)
+        
+class moveCommand(QUndoCommand):
+    
+    def __init__(self, item, lastPos, parent = None):
+        super(moveCommand, self).__init__(parent)
+        self.diagramItem = item
+        self.lastPos = lastPos
+        self.newPos = item.pos()
+        
+    def undo(self):
+        self.diagramItem.setPos(self.lastPos)
+        self.diagramItem.scene().update()
+        self.setText(f"Move {self.diagramItem} {self.newPos}")
+        
+    def redo(self):
+        self.diagramItem.setPos(self.newPos)
+        self.setText(f"Move {self.diagramItem} {self.newPos}")
+        
+    def mergeWith(self, move):
+        item = move.diagramItem
+        
+        if self.diagramItem != item:
+            return False
+        
+        self.newPos = item.pos()
+        self.setText(f"Move {self.diagramItem} {self.newPos}")
+        return True
\ No newline at end of file