Question

I have a problem where when I resize one of the “Test_Boxes”, all the other existing Text_Boxes resize too and any that get created afterwards get created with the resized size.

It seems like they are all sharing the same QRect but they shouldn’t be.

Please help.

Code:

import sys, sip, random 
from PyQt4.QtCore import *
from PyQt4.QtGui import *


PAGESIZE_LST            = [612, 792]
POINT_SIZE              = 10
CURSOR_SIZE             = 2 * POINT_SIZE

BORDER_WIDTH            = 0.5 * POINT_SIZE



def Cursor_Pos(item):
    # Get mouse position relative to this item
    cursor_pos          = item.scene().parent().mapFromGlobal(QCursor.pos())
    cursor_pos          = item.scene().views()[0].mapToScene(cursor_pos)
    cursor_pos          = item.mapFromScene(cursor_pos)
    return cursor_pos



class Test_Box(QGraphicsItem):
    """ Group box that groups the various stages """
    # Constants
    WIDTH               = 70 * POINT_SIZE
    HEIGHT              = 100 * POINT_SIZE
    RECT                = QRectF(0, 0, WIDTH, HEIGHT)
    CORNER_RADIUS       = 1.5 * POINT_SIZE
    FONT_SIZE           = 4 * POINT_SIZE
    BORDERRECT_PAD      = 4 * POINT_SIZE

    def __init__(self, position, parent=None):
        super(Test_Box, self).__init__(parent)

        # Vars
        self.resize_sections= None
        self.resize_pos     = None
        self.rect           = Test_Box.RECT

        # Settings
        self.setFlags(  self.flags()                    |
                        QGraphicsItem.ItemIsSelectable  |
                        QGraphicsItem.ItemIsMovable     |
                        QGraphicsItem.ItemIsFocusable   )


    def boundingRect(self):
        return self.rect.adjusted(-BORDER_WIDTH/2,-BORDER_WIDTH/2,BORDER_WIDTH/2,BORDER_WIDTH/2)


    def paint(self, painter, option, widget):
        # Draw Box

        # Inner and outer rect to display drag-expand's clickable area
        outer_rect  = self.boundingRect().adjusted(-Test_Box.BORDERRECT_PAD,-Test_Box.BORDERRECT_PAD,CURSOR_SIZE+Test_Box.BORDERRECT_PAD,CURSOR_SIZE+Test_Box.BORDERRECT_PAD)
        inner_bound = (BORDER_WIDTH/2 + (Test_Box.CORNER_RADIUS/2)) # Get corner offset due to rounded corners
        inner_rect  = self.boundingRect().adjusted((CURSOR_SIZE+inner_bound)+Test_Box.BORDERRECT_PAD, (CURSOR_SIZE+inner_bound)+Test_Box.BORDERRECT_PAD, -inner_bound-Test_Box.BORDERRECT_PAD, -inner_bound-Test_Box.BORDERRECT_PAD)    
        painter.drawRect(outer_rect)
        painter.drawRect(inner_rect)

        brush   = QBrush(QColor(100, 100, 100, 100))
        painter.setBrush(brush) 
        painter.drawRoundedRect(self.rect, Test_Box.CORNER_RADIUS, Test_Box.CORNER_RADIUS)      


    def Cursor_OnEdge(self):
        outer_rect  = self.boundingRect().adjusted(-Test_Box.BORDERRECT_PAD,-Test_Box.BORDERRECT_PAD,CURSOR_SIZE+Test_Box.BORDERRECT_PAD,CURSOR_SIZE+Test_Box.BORDERRECT_PAD)
        inner_bound = (BORDER_WIDTH/2 + (Test_Box.CORNER_RADIUS/2)) # Get corner offset due to rounded corners
        inner_rect  = self.boundingRect().adjusted((CURSOR_SIZE+inner_bound)+Test_Box.BORDERRECT_PAD, (CURSOR_SIZE+inner_bound)+Test_Box.BORDERRECT_PAD, -inner_bound-Test_Box.BORDERRECT_PAD, -inner_bound-Test_Box.BORDERRECT_PAD)    
        cursor_pos  = Cursor_Pos(self)
        on_edge     = False
        if outer_rect.contains(cursor_pos) and not inner_rect.contains(cursor_pos):
            on_edge = True
        return on_edge


    def mousePressEvent(self, event):
        # check if user has clicked this object's border
        if self.Cursor_OnEdge():
            self.Setup_Resize() 
        super(Test_Box, self).mousePressEvent(event)


    def mouseMoveEvent(self, event):
        if self.resize_pos != None:
            self.Resize()
        else:       
            super(Test_Box, self).mouseMoveEvent(event)


    def mouseReleaseEvent(self, event):
        if self.resize_pos != None:
            self.Done_Resize()
        super(Test_Box, self).mouseReleaseEvent(event)


    def Setup_Resize(self):     
        self.resize_sections= []
        self.setCursor(Qt.ClosedHandCursor)
        cursor_pos          = Cursor_Pos(self)
        self.resize_pos     = cursor_pos
        # Determine drag from sections
        if cursor_pos.y() > self.boundingRect().height()/2:
            # If on bottom half
            self.resize_sections.append('BOTTOM')
        else:
            self.resize_sections.append('TOP')
        if cursor_pos.x() < self.boundingRect().width()/2:
            # If on left half
            self.resize_sections.append('LEFT')
        else:
            self.resize_sections.append('RIGHT')    


    def Resize(self):
        updated         = False
        # From cursor_pos to resize_pos
        cursor_pos      = Cursor_Pos(self)  
        move_x          = cursor_pos.x() - self.resize_pos.x()
        move_y          = cursor_pos.y() - self.resize_pos.y()
        child_rect      = self.childrenBoundingRect()
        # If y not within child items rect
        if not child_rect.contains(child_rect.left()+1, cursor_pos.y()):
            if self.resize_sections[0] == 'TOP':
                self.rect.setTop(self.rect.top() + move_y)  
            else:
                self.rect.setBottom(self.rect.bottom() + move_y)
            updated     = True
        # If x not within child items rect
        if not child_rect.contains(cursor_pos.x(), child_rect.top()+1):
            if self.resize_sections[1] == 'LEFT':
                self.rect.setLeft(self.rect.left() + move_x)    
            else:
                self.rect.setRight(self.rect.right() + move_x)
            updated     = True
        # Check if updated      
        if updated:
            self.scene().update()
            self.resize_pos = cursor_pos


    def Done_Resize(self):
        self.resize_pos = None
        self.setCursor(Qt.ArrowCursor)  



class GraphicsView(QGraphicsView):
    def __init__(self, parent=None):
        super(GraphicsView, self).__init__(parent)
        self.setDragMode(QGraphicsView.RubberBandDrag)
        self.setRenderHint(QPainter.Antialiasing)
        self.setRenderHint(QPainter.TextAntialiasing)



    def wheelEvent(self, event):
        factor = 1.41 ** (event.delta() / 240.0)
        self.scale(factor, factor)




class Main_Dlg(QDialog):
    OFFSET  = 5

    def __init__(self, parent=None):
        super(Main_Dlg, self).__init__(parent)

        self.from_linkPnt= None

        self.prev_pnt   = QPoint()
        self.add_offset = Main_Dlg.OFFSET

        self.prntr  = QPrinter(QPrinter.HighResolution)
        self.prntr.setPageSize(QPrinter.Letter)

        self.view   = GraphicsView()
        self.scene  = QGraphicsScene(self)
        self.scene.setSceneRect(0, 0, PAGESIZE_LST[0], PAGESIZE_LST[1])
        self.view.setScene(self.scene)

        linkPnt_btn = QPushButton("Add Stage Box")
        linkPnt_btn.clicked.connect(self.Add_Item)

        layout      = QVBoxLayout()
        layout.addWidget(self.view)
        layout.addWidget(linkPnt_btn)
        self.setLayout(layout)


        self.Add_Item()


    def position(self):
        point   = self.mapFromGlobal(QCursor.pos())
        if not self.view.geometry().contains(point):
            coord_x = random.randint(int(PAGESIZE_LST[0]*0.25), int(PAGESIZE_LST[0]*0.75))
            coord_y = random.randint(int(PAGESIZE_LST[1]*0.25), int(PAGESIZE_LST[1]*0.75))
            point   = QPoint(coord_x, coord_y)
        else:
            if point == self.prev_pnt:
                point   += QPoint(self.add_offset, self.add_offset)
                self.add_offset += 5
            else:
                self.add_offset = Main_Dlg.OFFSET
                self.prev_pnt   = point
        return self.view.mapToScene(point)



    def Add_Item(self):
        item    = Test_Box(self.position())
        self.scene.addItem(item)




app = QApplication(sys.argv)
form = Main_Dlg()
rect = QApplication.desktop().availableGeometry()
form.resize(int(rect.width() * 0.6), int(rect.height() * 0.9))
form.show()
app.exec_() 

Answer 1

Yes, they are sharing the same QRect, because you do not create copies of it when assigned to self.rect:

class Test_Box(QGraphicsItem):
    """ Group box that groups the various stages """
    # Constants
    WIDTH               = 70 * POINT_SIZE
    HEIGHT              = 100 * POINT_SIZE
    RECT                = QRectF(0, 0, WIDTH, HEIGHT)
    CORNER_RADIUS       = 1.5 * POINT_SIZE
    FONT_SIZE           = 4 * POINT_SIZE
    BORDERRECT_PAD      = 4 * POINT_SIZE

    def __init__(self, position, parent=None):
        super(Test_Box, self).__init__(parent)

        # Vars
        self.resize_sections= None
        self.resize_pos     = None
        self.rect           = QRectF(Test_Box.RECT)    #use a copy!

        # Settings
        self.setFlags(  self.flags()                    |
                        QGraphicsItem.ItemIsSelectable  |
                        QGraphicsItem.ItemIsMovable     |
                        QGraphicsItem.ItemIsFocusable   )

Also, you correctly return a new rectangle in boundingRect() but in resize you modify the shared rectangle, so that’s why all the instances are resized accordingly.

I think using a copy for self.rect from the start should solve this.