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PyQgis: item is not the expected type on a QgsMapCanvas

I am currently working on a PyQgis based standalone application and I need to add various QgsRubberBand to my Canvas.
I made a subclass of it : LineAnnotation.
The problem is that when I use the method "QgsMapCanvas.itemAt(event.pos() )" on a "canvasPressEvent", it returns a "qgis._gui.QgsRubberBand" object, not a "LineAnnotation".
Did I do something wrong ? The rest of my program can't work if it doesn't recognize that it's a LineAnnotation as it contains several new methods that I need to use.
Also I can't interact with the item at all, if I try to use one of the methods from QgsRubberBand, the application crashes.
Here is the code with the problem:
from qgis.gui import QgsMapCanvas, QgsLayerTreeMapCanvasBridge, QgsRubberBand
from qgis.core import QgsApplication, QgsProject, QgsPointXY, QgsGeometry
from qgis.PyQt.QtGui import QColor
import sys
class LineAnnotation(QgsRubberBand):
def __init__(self, canvas):
QgsRubberBand.__init__(self, canvas)
self.setColor(QColor("red") )
self.setWidth(10)
class Interface(QgsMapCanvas):
def __init__(self):
QgsMapCanvas.__init__(self)
self.setCanvasColor(QColor("#182F36") )
project_path = "project_path"
project = QgsProject.instance()
project.read(project_path)
layer_tree = QgsLayerTreeMapCanvasBridge(project.layerTreeRoot(), canvas=self)
layer_tree.setAutoSetupOnFirstLayer(False)
self.zoomToFeatureExtent(project.mapLayersByName('layer_name')[0].extent() )
self.enableAntiAliasing(True)
self.setAcceptDrops(True)
self.setParallelRenderingEnabled(True)
p1 = QgsPointXY(524670.46860305720474571, 5470375.41737424582242966)
p2 = QgsPointXY(589864.10151600651443005, 5487531.63656186405569315)
r = LineAnnotation(self)
r.setToGeometry(QgsGeometry.fromPolylineXY([p1, p2]) )
def mousePressEvent(self, event) -> None:
item = self.itemAt(event.pos() )
print(type(item) )
# Output is "<class 'qgis._gui.QgsRubberBand'>"
# Expected: "<class 'LineAnnotation'>"
class StackOverflow:
def __init__(self):
qgs = QgsApplication([], True)
qgs.setDoubleClickInterval(250)
qgs.initQgis()
graphicUI = Interface()
graphicUI.showMaximized()
sys.exit(qgs.exec_() )
if __name__ == '__main__':
app = StackOverflow()
> output: \<class 'qgis.\_gui.QgsRubberBand'\>
> Desired output: \<class 'lineAnnotation.LineAnnotation'\>

Problem seems to occur in versions prior to Qgis 3.26, my problem was solved after updating to latest version (3.28).

Calling function from UI class in maya resulting in nonetype error

I'm building a toolbox UI using python in Maya, and I keep on getting a Nonetype error when I call one of the imported functions. This is the script for the toolbox:
class Toolbox():
import maya.cmds as cmds
def __init__(self):
self.window_name = "mlToolbox"
def create(self):
self.delete()
self.window_name = cmds.window(self.window_name)
self.m_column = cmds.columnLayout(p = self.window_name, adj = True)
cmds.button(p=self.m_column,label = 'MyButton', c=lambda *arg: cmds.polySphere(r = 2))
cmds.button(p=self.m_column, label = 'Make_Control', command = lambda *args: self.ControlBTN())
cmds.button(p=self.m_column, label = 'Find Center of All Selected', command = lambda *args: self.CenterBTN())
cmds.button(p=self.m_column, label = 'Find Center of Each Selected Object', command = lambda *args: self.IndiCenterBTN())
self.colorname = cmds.textField(placeholderText = 'Enter color name...')
cmds.button(p=self.m_column, label = 'ChangeColor', command = lambda *args: self.colorBtn())
self.MinAndMax = cmds.textField()
cmds.button(p=self.m_column, label = 'Random Scatter', command = lambda *args: self.ScatterBTN())
cmds.showWindow(self.window_name)
cmds.button(p=self.m_column, label = 'Select Everything', command = lambda *args: self.selectBTN())
def CenterBTN(self):
import CenterSelected
CenterSelected.Locator()
def ScatterBTN(self):
import Scatter
value = cmds.textField(self.MinAndMax, q=True)
Scatter.RandomScatter(value)
cmds.intField(self.moveMin, self.moveMax, self.rotMin, self.rotMax, self.scaleMin, self.scaleMax, e=True, text='')
def IndiCenterBTN(self):
import ManySelected
ManySelected.LocatorMany()
def colorBtn(self):
import ColorControl
value = cmds.textField(self.colorname, q=True, text = True)
ColorControl.colorControl(value)
cmds.textField(self.colorname, e=True, text='')
def selectBTN(self):
import tools
tools.selectAll()
def delete(self):
if cmds.window(self.window_name, exists=True):
cmds.deleteUI(self.window_name)
def ControlBTN(self):
import CreateControl
CreateControl.createControl()
myTool = Toolbox()
myTool.create()
And this is the function that I'm having trouble with:
def RandomScatter(MinAndMax):
import random
import maya.cmds as cmds
Stuff = cmds.ls(sl=True)
i=0
for i in range(random.randint(1,100)):
Stuff.append(cmds.duplicate(Stuff))
cmds.move( (random.randint(MinAndMax[0], MinAndMax[1])), (random.randint(MinAndMax[0], MinAndMax[1])), (random.randint(MinAndMax[0], MinAndMax[1])), Stuff[i], absolute=True )
cmds.rotate( (random.randint(MinAndMax[2], MinAndMax[3])), (random.randint(MinAndMax[2], MinAndMax[3])), (random.randint(MinAndMax[2], MinAndMax[3])), Stuff[i], absolute=True )
cmds.scale( (random.randint(MinAndMax[4], MinAndMax[5])), (random.randint(MinAndMax[4], MinAndMax[5])), (random.randint(MinAndMax[4], MinAndMax[5])), Stuff[i], absolute=True )
i = i+1
RandomScatter() works fine as long as I call it on it's own using a RandomScatter([a, b, c, d, e, f]) format, but when I try to call it Toolbox(), I get "Scatter.py line 21: 'NoneType' object has no attribute 'getitem'" as an error. It also happens when I try to use the intField() command instead of textField(). The UI window builds just fine; the error only happens after I enter input into the text field and press the button that's supposed to call RandomScatter(). It seems like the input isn't making it to the MinAndMax list, so when it reaches "cmds.move( (random.randint(MinAndMax[0]," it can't find anything to put in the MinAndMax[0] slot, or any of the slots after that, but I can't figure out why. Does anyone have any advice?

I didn't test your code and didn't read it totally, but I can already say that your strange "lambda" usage doesn't make any sens.
lambda *args: self.ControlBTN()
this lambda execute self.ControlBTN during the cmds.button definition and provide to it a function which return None.
that like doing that:
self.ControlBTN()
function = def func(): return None
cmds.button(p=self.m_column, label = 'Make_Control', command=function)
I advise you to reread the documentation about the "python lambda".
replace this by:
cmds.button(p=self.m_column, label = 'Make_Control', command=self.ControlBTN)
...
def ControlBTN(self, *args)
...
That should help
good luck

As written self.MinAndMax is a text field; even if you get the value from it it'll be a string and you won't be able to index into it to get the individual items -- and your indexing will be thrown off if any of the numbers are negative or have decimals. The lazy solution is to use a FloatFieldGrp which lets you have 2-4 numberic inputs. It's a bit annoying to get at all of the values at once (see the way it's done below) but it will avoid many issues with trying to parse the text field.
Also, this line doesn't make sense in context:
cmds.intField(self.moveMin, self.moveMax, self.rotMin, self.rotMax, self.scaleMin, self.scaleMax, e=True, text='')
You're not seeing the error because it's failing in the previous line, but the first argument ought to be the name of an existing intField.
In any case, I'd refactor this a bit to keep the argument parsing out of the scatter function, so you can separate out the working logic from the UI parsing logic. It'll make it much easier to spot where things have gone off the rails:
import random
import maya.cmds as cmds
class TestGUI(object):
def __init__(self):
self.window = cmds.window()
self.layout = cmds.rowLayout(nc=3)
self.min_xyz = cmds.floatFieldGrp( numberOfFields=3, label='min', value1=-10, value2=-10, value3=-10 )
self.max_xyz= cmds.floatFieldGrp( numberOfFields=3, label='min', value1=10, value2=10, value3=10 )
cmds.button(label='scatter', c = self.scatter)
cmds.showWindow(self.window)
def scatter(self, *_):
selected = cmds.ls(sl=True)
if not selected:
cmds.warning("select something")
return
min_xyz = (
cmds.floatFieldGrp(self.min_xyz, q=True, v1=True),
cmds.floatFieldGrp(self.min_xyz, q=True, v2=True),
cmds.floatFieldGrp(self.min_xyz, q=True, v3=True)
)
max_xyz = (
cmds.floatFieldGrp(self.max_xyz, q=True, v1=True),
cmds.floatFieldGrp(self.max_xyz, q=True, v2=True),
cmds.floatFieldGrp(self.max_xyz, q=True, v3=True)
)
print "scatter settings:", min_xyz, max_xyz
rand_scatter(selected, min_xyz, max_xyz)
def rand_scatter(selection, min_xyz, max_xyz):
dupe_count = random.randint(1, 10)
duplicates = [cmds.duplicate(selection) for n in range(dupe_count)]
for dupe in duplicates:
destination = [random.randint(min_xyz[k], max_xyz[k]) for k in range(3)]
cmds.xform(dupe, t=destination, absolute=True)
print (dupe, destination)
t = TestGUI() # shows the window; hit 'scatter' to test
My version changes your logic a bit -- you were duplicating your selection list, which would cause the number of items to grow exponentially (as each duplication would also duplicate the previous dupes). I'm not sure if that's inline with your intention or not.
You can avoid the extra lambdas by including a *_ in the actual button callback; it's a minor maya irritant that buttons always have that useless first argument.
As an aside, I'd try not to do imports inside of function bodies. If the imported module is not available, it's better to know at the time this file is imported rather than only when the user clicks a button -- it's much easier to spot a missing module if you do all your imports in a block at the top.

Find the last window created in Maya?

I was wondering if there is any way to find the name of the last window created in Maya, knowing that I can't add any information to the window itself before that... I checked in both the cmds and API but couldn't find anything. Maybe in PyQt but I don't know much about it.
I'm looking for any solution. Thanks

you can work with something like a close callback, save the needed information and restore it again
def restoreLayout(self):
"""
Restore the layout of each widget
"""
settings=self.settings
try:
self.restoreGeometry(settings.value("geometry").toByteArray())
self.restoreState(settings.value("windowState").toByteArray())
size=settings.value('fontSize').toFloat()[0]
self.setFontSize(size)
except:
pass
def saveLayout(self):
"""
Save the layout of each widget
Save the main window id to your data base
"""
settings=self.settings
settings.setValue("geometry", self.saveGeometry())
settings.setValue("windowState", self.saveState())
settings.setValue("fontSize", app.font().pointSize())
def closeEvent(self, event):
QtGui.QMainWindow.closeEvent(self, event)
self.saveLayout()
a simple case/idea to save tha main win_id and a child button_id:
from functools import partial
import json
def close_ui(*args):
win_id = args[0]
if cmds.window(win_id, exists=True):
cmds.deleteUI(win_id, window=True)
with open('dataBase/ui/uidata.json', 'w') as outfile:
json.dump(args, outfile)
win = {}
win["main_win"] = cmds.window()
cmds.columnLayout()
cmds.text( label='closing it' )
win["btn"] = cmds.button( label='Close')
cmds.button(win["btn"],e=True, command=partial(close_ui, win["main_win"], win["btn"]))
cmds.showWindow(win["main_win"])

Here is what I came up with, it's surely not the "cleanest" solution but it works!
# List all the currently opened windows
uisBefore = cmds.lsUI (wnd = True)
# Execute the function which may or may not create a window
func(*args, **kwargs)
# List all the opened windows again
uisAfter = cmds.lsUI (wnd = True)
# Find all the windows that were opened after executing func()
newUIs = [ui for ui in uisAfter if ui not in uisBefore]

If you create a window with the window command, you'll get back the name of the window you just created:
import maya.cmds as cmds
w = cmds.window()
c= cmds.columnLayout()
def who_am_i(*_):
print "window is", w
b = cmds.button('push', c=who_am_i)
cmds.showWindow(w)
If for some reason you don't own the code that creates the window:
existing_windows = set(cmds.lsUI(type = 'window'))
// make your window here
new_windows = list(set(cmds.lsUI(type = 'window') - existing_windows))

Automatic Stack Trace not being given in threads other than the main thread

I have a rather large program which loads some data from an excel file and populates a form, this can take a long time due to the size of the file so I have been moving the loading function onto a separate thread, the only problem is for some reason in this new thread I am not getting an automatic stack trace in the console whenever an error occurs. It has just been failing silently which is making debugging it a real pain.
I am using pydev in eclipse, I wrote the following test case to be sure everything is working correctly.
from PyQt4 import QtCore
class OtherThread(QtCore.QThread):
def __init__(self):
super(OtherThread, self).__init__()
def run(self):
try:
print(1/0)
except Exception as e:
print("exception caught in other thread: \n{0}".format(e))
class MainThread():
def __init__(self):
self.otherThread = OtherThread()
def run(self):
try:
print(1/0)
except Exception as e:
print("exception caught in main thread: \n{0}".format(e))
self.otherThread.run()
def main():
mainThread = MainThread()
mainThread.run()
if __name__ == '__main__':
main()
When I run this both exceptions are caught properly and when I comment out the try block in the tread object it also works just fine, I get my stack trace as expected. I am really at a loss as to what is going on. Is there something I could have done to cause this behavior?
Here is the code of the program I am working on.
def run(self):
print("excel thread running")
workbook = xlrd.open_workbook(self.path)
worksheet = workbook.sheet_by_name('PNA Form')
#
currentRow = 13 # start grabbing pna data
numRowStart = currentRow
newPartCol= 0
oldPartCol = 10
descriptionCol = 2
#
numberOfRows = worksheet.nrows - 1
#
print("number of rows = {0}".format(numberOfRows))
PNA = []
#
current_color = False
while (currentRow < numberOfRows):
print("about to parse excel rows")
newPartCell = int(worksheet.cell(currentRow,newPartCol).value)
oldPartCell = int(worksheet.cell(currentRow,oldPartCol).value)
descriptionCell = QtCore.QString(worksheet.cell(currentRow,descriptionCol).value)
print("excel rows parsed: {0}, {1}, {2}, {3}".format(oldPartCell,newPartCell,descriptionCell,current_color))
print("running line excel row {0}: {1}".format(currentRow, str(descriptionCell)))
if not self.isStrikethrough(currentRow,0): #make sure the line does not have strike through
#self.guiHandel.BOMVal.addPNARow(oldPN = oldPartCell, newPN = newPartCell, disc = descriptionCell)
print("about to emit pna row tracker for {0}".format(descriptionCell))
self.addPNARowTracker.emit(oldPartCell,newPartCell,descriptionCell)
print("thread still running after pna row tracker emit")
if (oldPartCell != "" and not self.isStrikethrough(currentRow,0)):
PNA.append((num(oldPartCell),num(newPartCell)))
current_color = not current_color
#self.guiHandel.pnaVerticalLayoutScroll.addWidget(PNACell(oldPartCell,newPartCell,descriptionCell,color = current_color))
print("about to emit addPNARow: {0}, {1}, {2}, {3}".format(oldPartCell,newPartCell,descriptionCell,current_color))
self.addPNARow.emit(oldPartCell,newPartCell,descriptionCell,current_color)
#self.guiHandel.widgetStack.append(PNACell(oldPartCell,newPartCell,descriptionCell,color = current_color))
print("thread still running after add pna row emit")
currentRow += 1
#self.guiHandel.pbar.setValue(int(100*(currentRow-13)/numberOfRows))
print("currentRow =",currentRow)
self.updateProgress.emit(int(100*(currentRow-numRowStart)/(numberOfRows-numRowStart)))
print(PNA)
self.done.emit()
Here is the console output when it fails.
slot add pna row tracker called
running is about to return
about to emit addPNARow: 28458820, 28489881, INST CSTR-ASM,DIESEL,KM,UP,GAT, False
thread still running after add pna row emit
('currentRow =', 29slot add pna row called)
about to parse excel rows
Added addPNARow: 28458820, 28489881, INST CSTR-ASM,DIESEL,KM,UP,GAT, False
excel progress update called ------- progress = 20
When running through a debugger it stops at this line:
newPartCell = int(worksheet.cell(currentRow,newPartCol).value)
I tried wrapping it in a try block but it never got to the exception. The cell it is trying to read is blank.
What is going on here? Any ideas would be greatly appreciated.

Answer to the question found here: error in pyqt qthread not printed
Basically you need to manually encapsulate the entire run method of the QThread object and then manually rethrow errors to stderr

Insert Text into a TextBuffer via a Function - python

I have following problem:
How can i insert text in my textbuffer?
Interface.py
class MainWindow:
def __init__(self):
# Build our Interface from the XML/Glade file
gladefile = "MainWindow.glade"
try:
self.builder = Gtk.Builder()
self.builder.add_from_file(gladefile)
except:
print("Failed to load Glade file: %s" % gladefile)
# Connect signals
self.builder.connect_signals(self)
# Get the widgets
self.window = self.builder.get_object("MainWindow")
...
# TextViews
self.TextViewCommandInput = self.builder.get_object("TextViewCommandInput")
self.TextViewCommandOutput = self.builder.get_object("TextViewCommandOutput")
...
def DrawCommandView(output):
TextBufferCommandInput = MainWindow.TextViewCommandInput.get_buffer()
TextBufferCommandInput.insert_at_cursor(output + "\n")
And import "DrawCommandView" in a file
Commands.py
from Interface import MainWindow, DrawCommandView
output = "Hello World"
DrawCommandView(output)
if __name__ == "__main__":
StartMainWindow = MainWindow()
StartMainWindow.main()
But I keep getting this error:
Traceback (most recent call last):
File "/home/user/Dokumente/Workspace/project/Commands.py", line 5, in <module>
DrawACommandView(output)
File "/home/user/Dokumente/Workspace/project/Interface.py", line 182, in DrawCommandView
TextBufferCommandInput = MainWindow.TextViewCommandInput.get_buffer()
AttributeError: class MainWindow has no attribute 'self'
Thanks for your help!
greetz

When you say TextBufferCommandInput = MainWindow.TextViewCommandInput.get_buffer()
You are asking for a class attribute in MainWindow named TextViewCommandInput. You don't have a class attribute TextViewCommandInput, you have an instance attribute TextViewCommandInput. You need to pass an instance of MainWindow into DrawCommandView in order to get to TextViewCommandInput.

I believe you have to set_text() instead of get_buffer().
See the set_text() documentation.
Then later get_buffer() can retrieve the text inserted by set_text().
Here are some methods I've been using to have a generic way to use the buffer.
def GetTextBuffer(self):
self.text_buffer = self.text_edit.get_buffer()
# self.text_edit is a Gtk.TextView() instance
# to get the text buffer from TextView
# buffer.get_text( start iterator, end iterator, bool )
# the third argument set to True = Include hidden characters
# third argument set to False = Don't include hidden characters
# hidden characters would be visual formatting markup and such
return self.text_buffer.get_text(
self.text_buffer.get_start_iter(),
self.text_buffer.get_end_iter(),
False)
def SetTextBuffer(self, to_buffer):
# to_buffer is user input from widgets, or default values set at run time.
text_buffer = self.text_edit.get_buffer()
text_buffer.set_text(to_buffer)