Merge two pieces of code

[mrjj]

@john_hobbyist
Hi
Oh that actually worked. the print(self)
so the parent really is MyMplCanvas.

So how does it show the blue rect ?

You click on the Canvas and it appears up there ?

[john_hobbyist]

@mrjj Yes I click on the large area (where the images are depicted) and I see the result as I depicted in the figure above, BUT it never completes the operation, meaning that as I move it, the rectangle keeps changing on that small area..

[mrjj]

@john_hobbyist
Ok. since it seems it should be in the Canvas, I would put some print() under

self.selection.setGeometry(QtCore.QRect(self.upper_left, self.lower_right).normalized())

in mouseMove and inspect the values and see
like
print( QtCore.QRect(self.upper_left, self.lower_right).normalized() )

and see what values it sets. Maybe that can give a hint.

[JonB]

@john_hobbyist said in Merge two pieces of code:

class RubberbandEnhancedLabel(QtGui.QLabel):

    def __init__(self, parent=None):
        QtGui.QLabel.__init__(self, parent)
        self.selection = QtGui.QRubberBand(QtGui.QRubberBand.Rectangle, sel

Your rubber band should be constrained within your RubberbandEnhancedLabel. On your screenshot, where exactly do you claim that RubberbandEnhancedLabel to be? Perhaps you should show the same screenshot but with an image in the label so we can see?

And what values does self.upper_left, self.lower_right have for the rubberband shown in the screenshot?

[john_hobbyist]

@mrjj This the value for the upper left corner inside the canvas that images are depicted:

PyQt5.QtCore.QRect(8, 0, 25, 69)

And this is the value for the lower right corner:

PyQt5.QtCore.QRect(32, 68, 506, 543)

(with some error). So the values are changing...

And when I go inside the area of the toolbox in upper left area, I get this:

Widget::paintEngine: Should no longer be called
QPainter::begin: Paint device returned engine == 0, type: 1
QPainter::end: Painter not active, aborted

which I get it repeatedly as I change tool icon...

[john_hobbyist]

@JonB said in Merge two pieces of code:

RubberbandEnhancedLabel

Yes you are right RubberbandEnhancedLabel is not used inside the code...! Here is a new screenshot with an image.

[mrjj]

@john_hobbyist
Yes it seems outside the canvas, but the self we used said it was named Cnavas so
I dont know how that is possible.

ALso
PyQt5.QtCore.QRect(8, 0, 25, 69)
seems ok but its like it has the wrong parent.

I can not guess what is going on.

[john_hobbyist]

@mrjj If I post my code, will that help?

[mrjj]

@john_hobbyist
Hi
It might as then we are sure its the current code that you have right now.
Also others might spot what the issue can be.

I think its might be Local / Global coordinate issues but I cannot understand how
the Rubberband can react to MouseEvents from the Canvas widget since its
clearly outside.

[John Owen]

This post is deleted!

[john_hobbyist]

This is the code where I figure out the problem (source: https://stackoverflow.com/questions/34220275/how-to-select-a-region-with-qrubberband-on-a-qlabel-like-in-ksnapshot)

    def mousePressEvent(self, event):
        print("56")
        '''
            Mouse is pressed. If selection is visible either set dragging mode (if close to border) or hide selection.
            If selection is not visible make it visible and start at this point.
        '''

        if event.button() == QtCore.Qt.LeftButton:
            print("57")

            position = QtCore.QPoint(event.pos())
            print("58")
            if self.selection.isVisible():
                print("59")
                # visible selection
                if (self.upper_left - position).manhattanLength() < 20:
                    print("60")
                    # close to upper left corner, drag it
                    self.mode = "drag_upper_left"
                    print("61")
                elif (self.lower_right - position).manhattanLength() < 20:
                    print("62")
                    # close to lower right corner, drag it
                    self.mode = "drag_lower_right"
                    print("63")
                else:
                    print("64")
                    # clicked somewhere else, hide selection
                    self.selection.hide()
                    print("65")
            else:
                # no visible selection, start new selection
                print("66")
                self.upper_left = position
                print("67")
                self.lower_right = position
                print("68")
                self.mode = "drag_lower_right"
                print("69")
                self.selection.show()
                print("70")

    def mouseMoveEvent(self, event):
        print("71")
        '''
            Mouse moved. If selection is visible, drag it according to drag mode.
        '''
        if self.selection.isVisible():
            print("72")
            # visible selection
            if self.mode == "drag_lower_right":
                print("73")
                self.lower_right = QtCore.QPoint(event.pos())
                #self.lower_right = QtCore.QPoint(0, 0)
                print("74")
            elif self.mode == "drag_upper_left":
                print("75")
                
                self.upper_left = QtCore.QPoint(event.pos())
                #self.upper_left = QtCore.QPoint(10, 10)
                print("76")
            # update geometry
            self.selection.setGeometry(QtCore.QRect(self.upper_left, self.lower_right).normalized())
            # self.selection.setGeometry(QtCore.QRect(100, 100).normalized())
            print("76A")
            print( QtCore.QRect(self.upper_left, self.lower_right).normalized() )
            print("77")

So the things have like this:
I run the code, the GUI starts and I move the mouse inside the image canvas, I continuously get the number:

71

When I press the mouse button (and do nothing else, not move the mouse), I get:

56
57 
58 
66 
67 
68 
69
70

After I pressed the mouse button and I move the mouse, I continuously get:

PyQt5.QtCore.QRect(93, 84, 841, 149)  <--- the numbers inside QRect change
77
71
72
73
74
76A

Do you see something strange here?

[SGaist]

What exactly is your issue ?

If you find the rectangle strange why not print the points used to create it ?

[john_hobbyist]

@SGaist I am not talking about the printing the values of the rectangle here, but the fact that when I try to use qrubberband...Please look my previous messages, and the images that I have posted in order to help you help me... To sum up the qrubberband rectangle is not shown/visible inside the canvas but is limited on the upper left corner...Thank you for your time..

[SGaist]

Where is this code implemented exactly ?

[john_hobbyist]

This post is deleted!

[SGaist]

@john_hobbyist said in Merge two pieces of code:

Do you see the problem?

Bluntly speaking, your MyMplCanvas __init__ implementation is a mess. You are calling the init method of QLabel, do some stuff, then call the base class init implementation through super, set the parent independently, then you manage to use a method called imshow which is also a method from OpenCV's highgui module.

You really should start by cleaning this up.

Do things step by step.

First question is: taking the rubber band part out of the equation for now, why do you need all these modifications on the MplCanvas class ? Are you sure you are using it correctly ?

[john_hobbyist]

This post is deleted!