I want to draw a line consisting of multiple points via mouse click in a Python script using PyQt. I need all coordinates of the ponts and I want to be able to delete the line. Here's my script doing all the work, except for the graphical line drawing itself, it just prints what it does:
#!/usr/bin/python3
import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
class endomess(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.draw = False
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
if self.draw == False:
print('Starting to draw at', str(event.pos()))
self.draw = True
self.linePoints = []
elif self.draw == True:
print('Appending', str(event.pos()))
self.linePoints.append(event.pos())
elif event.button() == Qt.RightButton:
if self.draw == True:
print('Finished drawing. List of all points:', str(self.linePoints))
self.draw = False
def main(argv):
app = QApplication(argv, True)
wnd = endomess()
wnd.show()
sys.exit(app.exec_())
if __name__ == "__main__":
main(sys.argv)
So, here's my problem: how do I actually draw that line that can be defined via the above script? I already had a look at scribble.py and some Qt paint docs, but I don't get it. Probably, this is not a problem for someone more experienced with Qt?
Thanks in advance for all help!
You should probably use the graphics view framework for drawing the lines, rather than attempting to paint them directly.
Here's a basic demo to get you started:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.view = View(self)
self.button = QtGui.QPushButton('Clear View', self)
self.button.clicked.connect(self.handleClearView)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.view)
layout.addWidget(self.button)
def handleClearView(self):
self.view.scene().clear()
class View(QtGui.QGraphicsView):
def __init__(self, parent):
QtGui.QGraphicsView.__init__(self, parent)
self.setScene(QtGui.QGraphicsScene(self))
self.setSceneRect(QtCore.QRectF(self.viewport().rect()))
def mousePressEvent(self, event):
self._start = event.pos()
def mouseReleaseEvent(self, event):
start = QtCore.QPointF(self.mapToScene(self._start))
end = QtCore.QPointF(self.mapToScene(event.pos()))
self.scene().addItem(
QtGui.QGraphicsLineItem(QtCore.QLineF(start, end)))
for point in (start, end):
text = self.scene().addSimpleText(
'(%d, %d)' % (point.x(), point.y()))
text.setBrush(QtCore.Qt.red)
text.setPos(point)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
Related
I have a Qt widget that looks like this:
class launchiiwidget(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QVBoxLayout(self)
self.textbox = QtWidgets.QTextEdit(self)
self.textbox.setLineWrapMode(QtWidgets.QTextEdit.NoWrap)
self.textbox.setAlignment(QtCore.Qt.AlignCenter)
self.textbox.setFixedSize(QtCore.QSize(600, 100))
self.textbox.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.textbox.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
layout.addWidget(self.textbox)
font = self.textbox.font()
font.setPointSize(80)
self.textbox.setFont(font)
self.listwidget = QtWidgets.QListWidget(self)
self.listwidget.addItem("Red")
self.listwidget.addItem("Blue")
layout.addWidget(self.listwidget)
if __name__ == "__main__":
app = QtWidgets.QApplication([])
widget = launchiiwidget()
widget.setWindowFlags(QtCore.Qt.FramelessWindowHint)
widget.resize(600, 200)
widget.show()
sys.exit(app.exec())
How can I make it so when the "return" or "right arrow key" is pressed, focus moves from wherever it is currently to the first item in listwidget? This should also work while being focused inside of textbox, without triggering a newline.
Note: items get dynamically added to listwidget.
A possible solution could be to use QShorcut but because the OP requires "without triggering a newline". So in this case the solution is to implement an eventfilter to the QWindow:
import sys
from PyQt6 import QtCore, QtGui, QtWidgets
class KeyHelper(QtCore.QObject):
pressed = QtCore.pyqtSignal()
def __init__(self, window):
super().__init__(window)
self._window = window
self.window.installEventFilter(self)
#property
def window(self):
return self._window
def eventFilter(self, obj, event):
if event.type() == QtCore.QEvent.Type.KeyPress:
if event.key() in (
QtCore.Qt.Key.Key_Return,
QtCore.Qt.Key.Key_Enter,
QtCore.Qt.Key.Key_Right,
):
self.pressed.emit()
return True
return super().eventFilter(obj, event)
class Launchiiwidget(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.textbox = QtWidgets.QTextEdit()
self.textbox.setLineWrapMode(QtWidgets.QTextEdit.LineWrapMode.NoWrap)
self.textbox.setAlignment(QtCore.Qt.AlignmentFlag.AlignCenter)
self.textbox.setFixedSize(QtCore.QSize(600, 100))
self.textbox.setVerticalScrollBarPolicy(
QtCore.Qt.ScrollBarPolicy.ScrollBarAlwaysOff
)
self.textbox.setHorizontalScrollBarPolicy(
QtCore.Qt.ScrollBarPolicy.ScrollBarAlwaysOff
)
font = self.textbox.font()
font.setPointSize(80)
self.textbox.setFont(font)
self.listwidget = QtWidgets.QListWidget()
self.listwidget.addItem("Red")
self.listwidget.addItem("Blue")
layout = QtWidgets.QVBoxLayout(self)
layout.addWidget(self.textbox)
layout.addWidget(self.listwidget)
def update_focus(self):
self.listwidget.setFocus()
index = self.listwidget.model().index(0, 0)
if index.isValid():
self.listwidget.setCurrentIndex(index)
if __name__ == "__main__":
app = QtWidgets.QApplication([])
widget = Launchiiwidget()
widget.setWindowFlags(QtCore.Qt.WindowType.FramelessWindowHint)
widget.resize(600, 200)
widget.show()
key_helper = KeyHelper(widget.windowHandle())
key_helper.pressed.connect(widget.update_focus)
sys.exit(app.exec())
I'm making a custom QTreeView with QFileSystem model, and I have a MouseMoveEvent set up to print the path of the item that is hovered over.
I'm way down the rabbit hole and doing all kinds of weird things to make this work.
Here is the latest minimal reproducible code:
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys
class MainWindow(QWidget):
def __init__(self):
QWidget.__init__(self)
self.resize(500, 300)
self.layout = QVBoxLayout()
self.setLayout(self.layout)
self.myList = CustomTreeWidget()
self.myList.model.setRootPath("/Volumes/Home/User/Desktop/testsrc")
self.myList.setObjectName("/Volumes/Home/User/Desktop/testsrc")
self.layout.addWidget(self.myList)
class CustomTreeWidget(QTreeView):
def __init__(self):
super().__init__()
self.model = QFileSystemModel()
self.model.setFilter(QDir.NoDotAndDotDot | QDir.Files)
self.setModel(self.model)
self.setAlternatingRowColors(True)
self.setDragDropMode(QAbstractItemView.DragDrop)
self.setIndentation(0)
self.setSelectionMode(QAbstractItemView.ExtendedSelection)
self.setDragEnabled(True)
self.setAcceptDrops(True)
self.setContextMenuPolicy(Qt.CustomContextMenu)
self.setMouseTracking(True)
self.model.directoryLoaded.connect(self._runwhenloaded)
def _runwhenloaded(self):
self.setRootIndex(self.model.index(self.objectName()))
self.model.setRootPath(self.objectName())
def mouseMoveEvent(self, event):
prev = ""
if self.selectedIndexes():
prev = self.selectedIndexes()[0]
x = event.x()
y = event.y()
self.setSelection(QRect(x, y, 1, 1), QItemSelectionModel.ClearAndSelect)
self.setCurrentIndex(self.selectedIndexes()[0])
print(self.model.filePath(self.currentIndex()))
if prev:
self.setCurrentIndex(prev)
# pos = QCursor.pos()
# indexat = self.indexAt(pos).row() # why -1?
# print(indexat) # why -1?
# print(self.indexAt(pos).row())
if __name__ == "__main__":
app = QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())
Obviously this example is not proper at all, as it destroys multiple selections and scrolls to the previously selected item whenever the mouse moves, and just a hack in general.
I've gone through many iterations and read everything I could put my hands on but I can't figure it out.
The closest answer seems to be HERE, but it's in C and I don't understand it.
So the question is: How to print the file path when the mouse hovers over an item in this QTreeView?
A possible solution is to create an event filter that tracks the hover events and, according to that information, emits a signal that has the QModelIndex:
import sys
from PyQt5.QtCore import (
pyqtSignal,
pyqtSlot,
Qt,
QDir,
QEvent,
QModelIndex,
QObject,
QPersistentModelIndex,
QStandardPaths,
)
from PyQt5.QtWidgets import (
QAbstractItemView,
QApplication,
QFileSystemModel,
QMainWindow,
QTreeView,
)
from PyQt5 import sip
class HoverViewHelper(QObject):
hovered = pyqtSignal(QModelIndex)
def __init__(self, view):
super().__init__(view)
self._current_index = QPersistentModelIndex()
if not isinstance(view, QAbstractItemView):
raise TypeError(f"The {view} must be of type QAbstractItemView")
self._view = view
self.view.viewport().setAttribute(Qt.WA_Hover)
self.view.viewport().installEventFilter(self)
#property
def view(self):
return self._view
def eventFilter(self, obj, event):
if sip.isdeleted(self.view):
return True
if self.view.viewport() is obj:
if event.type() in (QEvent.HoverMove, QEvent.HoverEnter):
p = event.pos()
index = self.view.indexAt(p)
self._update_index(index)
elif event.type() == QEvent.HoverLeave:
if self._current_index.isValid():
self._update_index(QModelIndex())
return super().eventFilter(obj, event)
def _update_index(self, index):
pindex = QPersistentModelIndex(index)
if pindex != self._current_index:
self._current_index = pindex
self.hovered.emit(QModelIndex(self._current_index))
class MainWindow(QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
self.model = QFileSystemModel()
self.model.setRootPath(QDir.rootPath())
self.view = QTreeView()
self.view.setModel(self.model)
path = QStandardPaths.writableLocation(QStandardPaths.DocumentsLocation)
self.view.setRootIndex(self.model.index(path))
self.setCentralWidget(self.view)
helper = HoverViewHelper(self.view)
helper.hovered.connect(self.handle_hovered)
#pyqtSlot(QModelIndex)
def handle_hovered(self, index):
if not index.isValid():
return
path = self.model.filePath(index)
print(f"path: {path}")
def main():
app = QApplication(sys.argv)
w = MainWindow()
w.resize(640, 480)
w.show()
app.exec_()
if __name__ == "__main__":
main()
I want to move the QLabel with the mouse movement (not like Drag&drop, 'object' disappears while moving). Clicked - moved - released. I did it to some extent, but I ran into a problem. QLabel shrinks as I move it or even disappears (like shrinks to 0 width). How to fix it or what more correct approach to do it?
(self.label_pos is needed to keep the mouse position relative inside self.label)
Or its just monitor's refresh rate issue? But in photoshop's gradient editor, that little color stop isn't shrikns. It's choppy because of refresh rate, but always the same size.
This is what I want to see, recorded using a screen capture program. The same thing I see in Photoshop
This is what I see, recorded on my phone. The quality is poor, but the difference is clearly visible anyway.
This Photoshop is also captured on my phone, here the “object” remains the same size, as in the example made using screen capture
Here is code from eyllanesc's answer, 'object' still shrinks :(
self.label = QLabel(self)
self.label.move(100, 100)
self.label.mousePressEvent = self.mouse_on
self.label.mouseReleaseEvent = self.mouse_off
def mouse_on(self, event):
self.bool = True
self.label_pos = event.pos()
def mouse_off(self, event):
self.bool = False
def mouseMoveEvent(self, event):
if self.bool:
self.label.move(event.x()-self.label_pos.x(), event.y()-self.label_pos.y())
Instead of using a QLabel I recommend using QGraphicsRectItem with a QGraphicsView since it is specialized in this type of tasks:
from PyQt5 import QtCore, QtGui, QtWidgets
class Widget(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
self.setScene(QtWidgets.QGraphicsScene(self))
self.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
brush = QtWidgets.QApplication.palette().brush(QtGui.QPalette.Window)
self.setBackgroundBrush(brush)
rect_item = self.scene().addRect(
QtCore.QRectF(QtCore.QPointF(), QtCore.QSizeF(40, 80))
)
rect_item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
rect_item.setBrush(QtGui.QBrush(QtGui.QColor("red")))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.setFixedSize(640, 480)
w.show()
sys.exit(app.exec_())
If you want to just scroll horizontally then overwrite the itemChange method of QGraphicsItem:
from PyQt5 import QtCore, QtGui, QtWidgets
class HorizontalItem(QtWidgets.QGraphicsRectItem):
def __init__(self, rect, parent=None):
super(HorizontalItem, self).__init__(rect, parent)
self.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
self.setFlag(QtWidgets.QGraphicsItem.ItemSendsGeometryChanges, True)
def itemChange(self, change, value):
if (
change == QtWidgets.QGraphicsItem.ItemPositionChange
and self.scene()
):
return QtCore.QPointF(value.x(), self.pos().y())
return super(HorizontalItem, self).itemChange(change, value)
class Widget(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
self.setScene(QtWidgets.QGraphicsScene(self))
self.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
brush = QtWidgets.QApplication.palette().brush(QtGui.QPalette.Window)
self.setBackgroundBrush(brush)
rect_item = HorizontalItem(
QtCore.QRectF(QtCore.QPointF(), QtCore.QSizeF(40, 80))
)
rect_item.setBrush(QtGui.QBrush(QtGui.QColor("red")))
self.scene().addItem(rect_item)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.setFixedSize(640, 480)
w.show()
sys.exit(app.exec_())
In the following code there is an example similar to what you want:
from PyQt5 import QtCore, QtGui, QtWidgets
class HorizontalItem(QtWidgets.QGraphicsRectItem):
def __init__(self, rect, parent=None):
super(HorizontalItem, self).__init__(rect, parent)
self.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
self.setFlag(QtWidgets.QGraphicsItem.ItemSendsGeometryChanges, True)
def itemChange(self, change, value):
if (
change == QtWidgets.QGraphicsItem.ItemPositionChange
and self.scene()
):
return QtCore.QPointF(value.x(), self.pos().y())
return super(HorizontalItem, self).itemChange(change, value)
class Widget(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
self.setScene(QtWidgets.QGraphicsScene(self))
self.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
brush = QtWidgets.QApplication.palette().brush(QtGui.QPalette.Window)
self.setBackgroundBrush(brush)
self.setFixedSize(640, 480)
size = self.mapToScene(self.viewport().rect()).boundingRect().size()
r = QtCore.QRectF(QtCore.QPointF(), size)
self.setSceneRect(r)
rect = QtCore.QRectF(
QtCore.QPointF(), QtCore.QSizeF(0.8 * r.width(), 80)
)
rect.moveCenter(r.center())
rect_item = self.scene().addRect(rect)
rect_item.setBrush(QtGui.QBrush(QtGui.QColor("salmon")))
item = HorizontalItem(
QtCore.QRectF(
rect.bottomLeft() + QtCore.QPointF(0, 20), QtCore.QSizeF(20, 40)
)
)
item.setBrush(QtGui.QBrush(QtGui.QColor("red")))
self.scene().addItem(item)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
Is there a way to determine the width of the arrow buttons in the qspinbox?
I'm trying to overwrite the context menu event, and i only want my custom event to take place if the user right-clicks over the arrow button, otherwise i want the normal context menu to appear.
Right now I'm just hardcoding a value of 20 which is not ideal.
import sys
import os
from PySide import QtGui, QtCore
class MySpinner(QtGui.QSpinBox):
def __init__(self, parent=None):
super(MySpinner, self).__init__(parent)
self.setAccelerated(False)
self.setRange(-1000,1000)
self.setSingleStep(1)
self.setValue(300)
def contextMenuEvent(self, event):
if event.pos().x() > self.rect().right()-20:
self.setValue(50)
self.selectAll()
else:
super(self.__class__, self).contextMenuEvent(event)
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.resize(300, 200)
grid = QtGui.QVBoxLayout()
grid.addWidget(MySpinner())
content = QtGui.QWidget()
content.setLayout(grid)
self.setCentralWidget(content)
def main():
app = QtGui.QApplication(sys.argv)
ex = MainWindow()
ex.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
Instead of obtaining the width it is only necessary to obtain the SubControl to know if it was pressed in one of the arrows buttons:
def contextMenuEvent(self, event):
opt = QtGui.QStyleOptionSpinBox()
self.initStyleOption(opt)
opt.subControls = QtGui.QStyle.SC_All
hoverControl = self.style().hitTestComplexControl(QtGui.QStyle.CC_SpinBox, opt, event.pos(), self)
if hoverControl == QtGui.QStyle.SC_SpinBoxUp:
print("up")
elif hoverControl == QtGui.QStyle.SC_SpinBoxDown:
print("down")
else:
super(self.__class__, self).contextMenuEvent(event)
If you want to get the QRect of each subcontrol you should use
# up
rect_up = self.style().subControlRect(QtGui.QStyle.CC_SpinBox, opt, QtGui.QStyle.SC_SpinBoxUp, self)
# down
rect_down = self.style().subControlRect(QtGui.QStyle.CC_SpinBox, opt, QtGui.QStyle.SC_SpinBoxDown, self)
Another option:
def contextMenuEvent(self, event):
opt = QtGui.QStyleOptionSpinBox()
self.initStyleOption(opt)
r = QtCore.QRect()
for sc in (QtGui.QStyle.SC_SpinBoxUp, QtGui.QStyle.SC_SpinBoxDown):
r= r.united(self.style().subControlRect(QtGui.QStyle.CC_SpinBox, opt, sc, self))
if r.contains(event.pos()):
print("arrow")
else:
super(self.__class__, self).contextMenuEvent(event)
Maybe it is insufficient knowledge of Qt or of Python, of maybe even both, but I have a problem with Qt5 in Python.
I have a script that draws a line from a point where the mouse pointer is depressed to the point where it is released. That works fine.
Then when I want to draw a second line, I want to keep the first line on the QDialog as well, but because the way paintEvent works that is not possible straight away.
There for I've created a helper class (at first it was in the MyDialog class itself) to store all the points in a list and then use this class to redraw all the lines when paintEvent redraws the QDialog.
However, this is not working because for some reason all the points stored in the helper class get overridden by the last point. So if I draw ten lines, the helper class has 10 times the last (10th) point in its list.
Below you can see the code, can somebody shine a light on this? Thank!
import sys
from PyQt5.QtWidgets import QDialog, QApplication
from PyQt5.QtGui import QPainter, QPicture
from demoDrawLine import *
class ContextTest:
test = []
class MyForm(QDialog):
picture = []
def __init__(self):
super().__init__()
self.drawing = []
self.ui = Ui_Dialog()
self.ui.setupUi(self)
self.pos1 = [0,0]
self.pos2 = [0,0]
self.show()
def paintEvent(self, event):
super().paintEvent(event)
qp = QPainter()
qp.begin(self)
qp.drawLine(self.pos1[0], self.pos1[1], self.pos2[0], self.pos2[1])
qp.end()
def mousePressEvent(self, event):
if event.buttons() & QtCore.Qt.LeftButton:
self.pos1[0], self.pos1[1] = event.pos().x(), event.pos().y()
def mouseReleaseEvent(self, event):
self.pos2[0], self.pos2[1] = event.pos().x(), event.pos().y()
ContextTest.test.append((self.pos1, self.pos2))
self.update()
if __name__ == "__main__":
app = QApplication(sys.argv)
w = MyForm()
w.show()
sys.exit(app.exec_())
Here some results I copied from the debugger:
1st line drawn: ContextTest.test : [([150, 335], [452, 618])]
2nd line drawn: ContextTest.test : [([311, 695], [340, 666]), ([311, 695], [340, 666])]
3rd line drawn: ContextTest.test : [([1444, 249], [1043, 712]), ([1444, 249], [1043, 712]), ([1444, 249], [1043, 712])]
etc...
You are saving the points in test but you are not using it to paint, as you realized paintEvent has no notion of the past so you will have to save those points but better than saving points would be to keep instructions that know how to paint, for example it could add other figures without needing to write a lot of code in it.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class Instruction:
def paint(self, painter):
raise NotImplementedError()
class LineInstruction(Instruction):
def __init__(self, line):
self._line = line
def paint(self, painter):
painter.drawLine(self._line)
class ContextTest:
instructions = []
class MyForm(QtWidgets.QDialog):
def __init__(self):
super().__init__()
self.drawing = []
self.show()
def paintEvent(self, event):
super().paintEvent(event)
qp = QtGui.QPainter(self)
for instruction in ContextTest.instructions:
instruction.paint(qp)
def mousePressEvent(self, event):
if event.buttons() & QtCore.Qt.LeftButton:
self.start = event.pos()
def mouseReleaseEvent(self, event):
l = QtCore.QLine(self.start, event.pos())
instruction = LineInstruction(l)
ContextTest.instructions.append(instruction)
self.update()
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
w = MyForm()
w.show()
sys.exit(app.exec_())