PyQt5 - Rect item don't show up - python

I think there is nothing wrong in my code, but no way to make that rectangle (last line) appear in my scene...
Here is the main file:
import sys
from PyQt5.QtWidgets import *
from node_editor import NodeEditor
if __name__ == '__main__':
app = QApplication(sys.argv)
window = NodeEditor()
sys.exit(app.exec_())
NodeEditor() is this file:
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from node_graphics_scene import QDMGraphicsScene
class NodeEditor(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.initUI()
def initUI(self):
self.setGeometry(200, 200, 800, 600)
self.layout = QVBoxLayout()
self.layout.setContentsMargins(0, 0, 0, 0)
self.setLayout(self.layout)
#Graphics scene
self.grScene = QDMGraphicsScene()
#Graphics view
self.view = QGraphicsView(self)
self.view.setScene(self.grScene)
self.layout.addWidget(self.view)
self.setWindowTitle("KOMAGOMA")
self.show()
self.addDebugContent()
def addDebugContent(self):
greenBrush = QBrush(Qt.green)
outlinePen = QPen(Qt.black)
outlinePen.setWidth(2)
rect = self.grScene.addRect(-100, -100, 80, 100, outlinePen, greenBrush)
rect.setFlag(QGraphicsItem.ItemIsMovable)
QDMGraphicsScene is this file:
import math
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
class QDMGraphicsScene(QGraphicsScene):
def __init__(self, parent=None):
super().__init__(parent)
#Settings
self.gridSize = 20
self.gridSquares = 5
self._color_background = QColor('#1E1E1E')
self._color_dark = QColor('#151414')
self._color_light = QColor('#151414')
self._pen_light = QPen(self._color_light)
self._pen_light.setWidth(1)
self._pen_dark = QPen(self._color_dark)
self._pen_dark.setWidth(2)
self.scene_width, self.scene_height = 64000, 64000
self.setSceneRect(-self.scene_width//2, self.scene_height//2, self.scene_width, self.scene_height)
self.setBackgroundBrush(self._color_background)
def drawBackground(self, painter, rect):
super().drawBackground(painter, rect)
#Create grid
left = int(math.floor(rect.left()))
right = int(math.ceil(rect.right()))
top = int(math.floor(rect.top()))
bottom = int(math.ceil(rect.bottom()))
first_left = left - (left % self.gridSize)
first_top = top - (top % self.gridSize)
#Compute lines to be drawn
lines_dark, lines_light = [], []
for x in range(first_left, right, self.gridSize):
if(x % (self.gridSize * self.gridSquares) != 0): lines_light.append(QLine(x, top, x, bottom))
else: lines_dark.append(QLine(x, top, x, bottom))
for y in range(first_top, bottom, self.gridSize):
if(y % (self.gridSize * self.gridSquares) != 0): lines_light.append(QLine(left, y, right, y))
else: lines_dark.append(QLine(left, y, right, y))
#Draw the lines
painter.setPen(self._pen_light)
painter.drawLines(*lines_light)
painter.setPen(self._pen_dark)
painter.drawLines(*lines_dark)
I'm following a tutorial to learn PyQt5.
I follow all along but in my case it doesn't work.
Maybe it had an update and this is not the right way of doing it now?

Related

PyQt5 QGraphicsPathItem to draw a Resistor

I am coding an app to solve electrical circuits and I need to model the circuit. To do so, I need to draw Resistors and other shapes on a scene, being able to move it and so on.
The thing is that I am tryng to show a resistor en the scene and I can't find the way. I am tryng by using QGraphicsPathItem but looking at the documentation I am not capable of doing it. I'll show a bit of the code I am writing to solve this part of the app:
1. The first code I show is the Resistor as it should be shown
2. The second part is the way I want to do it, but instead an ellipsis, I want to show a Resistor
### 1st Code
import sys
from PyQt5 import QtCore, QtGui, QtWidgets, uic
from PyQt5.QtCore import Qt
x0 = 100
y0 = 50
class MainWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.x1 = 12
self.y1 = 33
self.y2 = 18
self.y3 = 15
self.y4 = 9
self.y5 = 3
self.p1 = QtCore.QPoint(0, 0 + self.y1)
self.p2 = QtCore.QPoint(0, 0 + self.y2)
self.p3 = QtCore.QPoint(self.x1, self.y3)
self.p4 = QtCore.QPoint(-self.x1, self.y4)
self.p5 = QtCore.QPoint(self.x1, self.y5)
self.p6 = QtCore.QPoint(-self.x1, -self.y5)
self.p7 = QtCore.QPoint(self.x1, -self.y4)
self.p8 = QtCore.QPoint(-self.x1, -self.y3)
self.p9 = QtCore.QPoint(0, 0 - self.y2)
self.p10 = QtCore.QPoint(0, 0 - self.y1)
def draw_resistor(self,angle=0, x0=0, y0=0):
self.x0 = x0
self.y0 = y0
self.label = QtWidgets.QLabel()
self.canvas = QtGui.QPixmap(200, 100) # This is to create the canvas
self.canvas.fill() # To set the canvas background color to white. If not, we will only see a black frame
self.label.setPixmap(self.canvas)
self.setCentralWidget(self.label)
self.painter = QtGui.QPainter(self.label.pixmap())
self.painter.translate(self.x0,self.y0) # To change the axis origin
self.painter.rotate(angle)
self.painter.drawLines(self.p1,self.p2,self.p2,self.p3,self.p3,self.p4,self.p4,self.p5,self.p5,
self.p6,self.p6,self.p7,self.p7,self.p8,self.p8,self.p9,self.p9,self.p10)
self.painter.end()
def rotate(self,angle=0):
self.painter.rotate(angle)
self.painter.drawLines(self.p1,self.p2,self.p2,self.p3,self.p3,self.p4,self.p4,self.p5,self.p5,
self.p6,self.p6,self.p7,self.p7,self.p8,self.p8,self.p9,self.p9,self.p10)
self.label.update() # Research about this, it could be the key
app = QtWidgets.QApplication(sys.argv)
window = MainWindow()
window.show()
window.draw_resistor(45,x0,y0)
app.exec_()
###################
###################
###################
###################
### 2nd Code
import sys
from PyQt5.QtWidgets import QApplication, QGraphicsItem, QGraphicsPathItem, QGraphicsView, QGraphicsScene, QGraphicsEllipseItem, QLabel
from PyQt5.QtCore import Qt, QPointF, QRectF, QPoint
from PyQt5.QtGui import QPixmap, QPainter
class MovingObject(QGraphicsEllipseItem):
def __init__(self, x, y, r):
super().__init__(0, 0, r, r)
self.setPos(x, y)
self.setBrush(Qt.blue)
self.setAcceptHoverEvents(True)
# Mouse hover events
def hoverEnterEvent(self, event):
app.instance().setOverrideCursor(Qt.OpenHandCursor)
def hoverLeaveEvent(self, event):
app.instance().restoreOverrideCursor()
# Mouse click events
def mousePressEvent(self, event):
pass
def mouseMoveEvent(self, event):
orig_cursor_position = event.lastScenePos()
updated_cursor_position = event.scenePos()
orig_position = self.scenePos()
updated_cursor_x = updated_cursor_position.x() - orig_cursor_position.x() + orig_position.x()
updated_cursor_y = updated_cursor_position.y() - orig_cursor_position.y() + orig_position.y()
self.setPos(QPointF(updated_cursor_x, updated_cursor_y))
def mouseReleaseEvent(self, event):
print("x: {0}, y: {1}".format(self.pos().x(), self.pos().y()))
class GraphicView(QGraphicsView):
def __init__(self):
super().__init__()
self.scene = QGraphicsScene()
self.setScene(self.scene)
self.setSceneRect(0, 0, 1200, 1000)
self.moveObject = MovingObject(50, 50, 40)
self.moveObject2 = MovingObject(100, 100, 100)
self.scene.addItem(self.moveObject)
self.scene.addItem(self.moveObject2)
app = QApplication(sys.argv)
view = GraphicView()
view.show()
sys.exit(app.exec_())
I solved it, this is the solution:
class Resistor(QGraphicsPathItem):
def __init__(self, x, y):
super(Resistor, self).__init__()
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self.setFlag(QGraphicsItem.ItemIsFocusable, True)
self.setAcceptHoverEvents(True)
self.isSelected = False
self.setPath(self.create_path())
self.setPos(x, y)
def create_path(self):
path = QPainterPath()
path.moveTo(0, 33)
path.lineTo(0, 18)
path.lineTo(12, 15)
path.lineTo(-12, 9)
path.lineTo(12, 3)
path.lineTo(-12, -3)
path.lineTo(12, -9)
path.lineTo(-12, -15)
path.lineTo(0, -18)
path.lineTo(0, -33)
return path

Pyside6 Animated Rectangle trouble

I'm trying to make fading looped rectangle area. I used base code from here
Just decided expand it.
Its just blinking rectangle, but I need smooth fade-in and fade-out effects. So I decided to make method which will calulate new opacity percent and set it to painter. But it doesnt work in cycle.
This is my class now
class HighlightRect(QFrame):
board_width = 400 # width of frame
board_height = 400 #height of frame
def __init__(self, parent, x, y, width=50, height=50, blink_speed=1000):
super().__init__(parent)
self.blink_speed = blink_speed
self.opacity_timer = self.blink_speed
self.board_height = self.parent().height()
self.board_width = self.parent().width()
self.square_height = height
self.square_width = width
self.highlight_x = x
self.highlight_y = y
#self.setFocusPolicy(QtCore.Qt.StrongFocus)
self.timer_draw = QtCore.QTimer(self)
self.timer_draw.timeout.connect(self.draw)
self.timer_draw.start(self.blink_speed)
self.color = QtCore.Qt.red
self.is_draw = False
self.x_apple = 0
self.y_apple = 0
self.draw()
def blink(self, painter):
self.color = QtCore.Qt.red
while self.opacity_timer >= 0:
self.opacity_timer -= 1 / 10 # просто подбор
percents = round(int(self.opacity_timer / self.blink_speed * 100)/100, 1)
print(percents)
painter.setOpacity(percents)
def paintEvent(self, event):
painter = QtGui.QPainter(self)
print ("Paint Event?")
if self.is_draw == True:
print ("Draw")
#self.color = QtCore.Qt.red
self.blink_thread = threading.Thread(name='background', target=lambda: self.blink(painter))
self.blink_thread.start()
else:
self.opacity_timer = self.blink_speed
print ("Do not draw")
self.color = QtCore.Qt.transparent
threading.SystemExit = SystemExit
painter.setPen(self.color)
painter.drawRect(self.rect)
def draw(self):
self.is_draw = not self.is_draw
self.rect = QRect(self.highlight_x, self.highlight_y, self.square_width, self.square_height)
self.update()
Changind of opacity inside blink function but outside while loop works as well, but its static. No changes. Changing opacity in loop isn't work.
Whats wrong?
Maybe somewhere here is another more correct way to get what I want?
One possible solution is to create a QProperty that handles opacity and then use QPropertyAnimation to make the change smooth.
import random
import sys
from PySide6.QtCore import Property, Signal, QPropertyAnimation, QRect, Qt
from PySide6.QtGui import QPainter
from PySide6.QtWidgets import QFrame, QApplication
class Board(QFrame):
rect_opacity_changed = Signal(name="rectOpacityChanged")
def __init__(self, parent=None):
super(Board, self).__init__(parent)
self._rect_opacity = 1.0
self._rect = QRect(0, 0, 50, 50)
self._opacity_animation = QPropertyAnimation(
targetObject=self, propertyName=b"rect_opacity", duration=3000
)
for p, v in ((0.0, 0.0), (0.3, 1.0), (0.7, 1.0), (1.0, 0.0)):
self._opacity_animation.setKeyValueAt(p, v)
self._opacity_animation.finished.connect(self.change)
self.change()
#Property(float, notify=rect_opacity_changed)
def rect_opacity(self):
return self._rect_opacity
#rect_opacity.setter
def rect_opacity(self, opacity):
self._rect_opacity = opacity
self.rect_opacity_changed.emit()
self.update()
def change(self):
x = random.randint(0, self.width() - self._rect.width())
y = random.randint(0, self.height() - self._rect.height())
self._rect.moveTo(x, y)
self._opacity_animation.start()
def paintEvent(self, event):
painter = QPainter(self)
painter.setOpacity(self.rect_opacity)
painter.setPen(Qt.red)
painter.drawRect(self._rect)
def main():
app = QApplication([])
board = Board()
board.show()
sys.exit(app.exec())
if __name__ == "__main__":
main()

How to plot the horizontal distance between 2 points on an image with PyQtGraph

I'd like to plot the horizontal distance between 2 points on an image with PyQtGraph, but I can't draw it.
I think it a way of doing this would be to use 3 instances of LineSegmentROI and make them look connected as one right arc, because they already have many features that would be great for this idea.
Like being draggable, which could be very useful to measure a different distance by simply dragging a side.
The problem are the handles, that can't be removed, or even hidden.
Has anyone done something like this?
# import the necessary packages
from pyqtgraph.graphicsItems.ImageItem import ImageItem
from pyqtgraph.graphicsItems.LinearRegionItem import LinearRegionItem
import requests
import numpy as np
import cv2
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
image = cv2.imread('example.png') # Change if you save the image with a different name
image = cv2.rotate(image, cv2.ROTATE_90_CLOCKWISE)
app = QtGui.QApplication([])
## Create window with GraphicsView widget
w = pg.GraphicsView()
w.show()
w.resize(image.shape[0], image.shape[1]) # Depending on the picture you may need to resize
w.setWindowTitle('Test')
view = pg.ViewBox()
view.setLimits(xMin=-image.shape[0]*0.05, xMax=image.shape[0]*1.05,
minXRange=100, maxXRange=2000,
yMin=-image.shape[1]*0.05, yMax=image.shape[1]*1.05,
minYRange=100, maxYRange=2000)
w.setCentralItem(view)
## lock the aspect ratio
view.setAspectLocked(True)
## Add image item
item = ImageItem(image)
view.addItem(item)
# Add Line
line = pg.QtGui.QGraphicsLineItem(200, -100, 400, -100, view)
line.setPen(pg.mkPen(color=(255, 0, 0), width=10))
view.addItem(line)
def mouseClicked(evt):
pos = evt[0]
print(pos)
proxyClicked = pg.SignalProxy(w.scene().sigMouseClicked, rateLimit=60, slot=mouseClicked)
## Start Qt event loop unless running in interactive mode.
if __name__ == '__main__':
import sys
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
I ended up borrowing RectItem from drawing a rectangle in pyqtgraph and using its code for LineItem.
With three LineItems I draw the distance meter between the 2 points.
I still have to add some signals and slots to handle resizing, but I'm working on it.
However the core of the solution is here and I'll follow up with my improvements
# import the necessary packages
from PySide2.QtCore import QLineF, Qt, Signal, Slot, QObject, QPointF, QRectF, QSizeF
from PySide2.QtGui import QRegion
from PySide2.QtWidgets import QGraphicsItem, QLabel, QWidget
from pyqtgraph.graphicsItems.ImageItem import ImageItem
from pyqtgraph.graphicsItems.LinearRegionItem import LinearRegionItem
import numpy as np
import cv2
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui, QtWidgets
from pyqtgraph.graphicsItems.ViewBox.ViewBox import ViewBox
image = cv2.imread('image.jpg')
image = cv2.rotate(image, cv2.ROTATE_90_CLOCKWISE)
app = QtGui.QApplication([])
## Create window with GraphicsView widget
w = pg.GraphicsView()
w.show()
w.setWindowTitle('Test')
view = pg.ViewBox()
view.setLimits(xMin=0, xMax=image.shape[0],
minXRange=100, maxXRange=2000,
yMin=0, yMax=image.shape[1],
minYRange=100, maxYRange=2000)
w.setCentralItem(view)
## lock the aspect ratio
view.setAspectLocked(True)
## Add image item
item = ImageItem(image)
view.addItem(item)
class LineItem(pg.UIGraphicsItem):
moved = Signal(QPointF)
def __init__(self, line, extend=0, horizontal=False, parent=None):
super().__init__(parent)
self.initialPos = QLineF(line)
self._line = line
self.extend = extend
self.horizontal = horizontal
self._extendLine()
self.picture = QtGui.QPicture()
self._generate_picture()
self.setFlag(QGraphicsItem.ItemIsSelectable)
self.setFlag(QGraphicsItem.ItemIsMovable)
self.setFlag(QGraphicsItem.ItemSendsGeometryChanges)
#property
def line(self):
return self._line
def _extendLine(self):
if (self.extend != 0 and not self.horizontal):
self._line.setP1( QPointF(self._line.x1(), self._line.y1() - abs(self.extend)) )
# if (self.horizontal):
# self.extend = 0
# self._line.setP1( QPointF(self._line.x1(), self._line.y1() - abs(self.extend)) )
def _generate_picture(self):
painter = QtGui.QPainter(self.picture)
painter.setPen(pg.mkPen(color="y", width=2))
painter.drawLine(self.line)
painter.end()
def paint(self, painter, option, widget=None):
painter.drawPicture(0, 0, self.picture)
def boundingRect(self):
lineShape = self.picture.boundingRect()
lineShape.adjust(-10, -10, 10, 10)
return QtCore.QRectF(lineShape)
def itemChange(self, change, value):
if change == QtWidgets.QGraphicsItem.ItemPositionChange:
# value is the new position.
if self.horizontal:
if value.x() != 0:
value = QPointF(0, value.y())
else:
if value.y() != 0:
value = QPointF(value.x(), 0)
self.moved.emit(value)
return pg.UIGraphicsItem.itemChange(self, change, value)
class Distance(QObject):
def __init__(self, A: QPointF, B: QPointF, view: ViewBox, parent: QWidget=None):
super().__init__(parent)
self.A = A
self.B = B
if A.x() > B.x():
self.A, self.B = B, A
self.distance = abs(B.x() - A.x())
print(self.A)
print(self.B)
extend = 50
top = max(self.A.y(), self.B.y()) + 200
self.left = LineItem(QtCore.QLineF(self.A.x(), self.A.y(), self.A.x(), top), extend)
self.right = LineItem(QtCore.QLineF(self.B.x(), self.B.y(), self.B.x(), top), extend)
self.top = LineItem(QtCore.QLineF(self.A.x(), top, self.B.x(), top), horizontal=True)
self.top.setPos(0, 0)
self.left.moved.connect(self.onLeftSegmentMoved)
self.right.moved.connect(self.onRightSegmentMoved)
self.top.moved.connect(self.onTopSegmentMoved)
self.label = pg.TextItem(str(round(self.distance, 2)), color=(0xFF, 0xFF, 0x00), anchor=(1, 1))
# self.label.setParentItem(self.top)
self.label.setPos(self.A.x()+self.distance/2, top + 5)
view.addItem(self.label)
view.addItem(self.left)
view.addItem(self.top)
view.addItem(self.right)
#Slot(QPointF)
def onLeftSegmentMoved(self, delta: QPointF):
topLeft = self.top.initialPos.p1()
newX = topLeft.x() + delta.x()
newTopLeft = QPointF(newX, topLeft.y())
self.top.line.setP1(newTopLeft)
self.top._generate_picture()
pos = self.label.pos()
self.distance = abs(self.top.line.x2() - self.top.line.x1())
self.label.setPos(newX + (self.top.line.x2() - self.top.line.x1())/2, pos.y())
self.label.setText(str(round(self.distance, 2)))
#Slot(QPointF)
def onTopSegmentMoved(self, delta: QPointF):
leftTop = self.top.initialPos.p1()
newY = leftTop.y() + delta.y()
newLeftTop = QPointF(leftTop.x(), newY)
self.left.line.setP2(newLeftTop)
self.left._generate_picture()
rightTop = self.top.initialPos.p2()
newY = rightTop.y() + delta.y()
newRightTop = QPointF(rightTop.x(), newY)
self.right.line.setP2(newRightTop)
self.right._generate_picture()
pos = self.label.pos()
self.label.setPos(pos.x(), newY)
#Slot(QPointF)
def onRightSegmentMoved(self, delta: QPointF):
topRight = self.top.initialPos.p2()
newX = topRight.x() + delta.x()
newTopRight = QPointF(newX, topRight.y())
self.top.line.setP2(newTopRight)
self.top._generate_picture()
pos = self.label.pos()
self.distance = abs(self.top.line.x2() - self.top.line.x1())
self.label.setPos(newX - (self.top.line.x2() - self.top.line.x1())/2, pos.y())
self.label.setText(str(round(self.distance, 2)))
distance = Distance(QPointF(925, 425), QPointF(138, 500), view)

How can I add pyqt5 buttons on top of each other?

I am trying to create a basic 25 key keyboard in pyqt, I have laid out the 15 white keys but am struggling with how to add the 10 remaining black keys,
This is how I made my keys
from PyQt5.QtWidgets import QApplication, QPushButton
app = QApplication([])
top_win = QWidget()
set_color(top_win, Qt.cyan)
top_win.setAutoFillBackground(True)
top_win.show()
top_win.resize(1920,1080)
top_win.setWindowTitle("Synth-01")
top_vlayout = QVBoxLayout()
top_win.setLayout(top_vlayout)
keyboard = QWidget()
keyboard.setMaximumWidth(1410)
top_vlayout.addWidget(keyboard)
keyboard_layout = QHBoxLayout()
keyboard.setAutoFillBackground(True)
keyboard.setLayout(keyboard_layout)
for i in range(15):
name = "key_" + str(i)
name = QPushButton()
name.setMaximumWidth(94)
name.setMaximumHeight(349)
keyboard_layout.addWidget(name)
I now want to add the black keys inbetween like this
In this case, it is most preferable to use QGraphicsScene with QGraphicsItem, for this case I will use svg:
from PyQt5 import QtCore, QtGui, QtWidgets, QtSvg
class PianoKey(QtWidgets.QGraphicsRectItem):
def __init__(self, black=False, rect = QtCore.QRectF(), parent=None):
super(PianoKey, self).__init__(rect, parent)
self.m_pressed = False
self.m_selectedBrush = QtGui.QBrush()
self.m_brush = QtGui.QBrush(QtCore.Qt.black) if black else QtGui.QBrush(QtCore.Qt.white)
self.m_black = black
def setPressedBrush(self, brush):
self.m_selectedBrush = brush
def paint(self, painter, option, widget):
rendered = QtSvg.QSvgRenderer("key.svg")
black_pen = QtGui.QPen(QtCore.Qt.black, 1)
gray_pen = QtGui.QPen(QtGui.QBrush(QtCore.Qt.gray), 1,
QtCore.Qt.SolidLine, QtCore.Qt.RoundCap, QtCore.Qt.RoundJoin)
if self.m_pressed:
if self.m_selectedBrush.style() != QtCore.Qt.NoBrush:
painter.setBrush(self.m_selectedBrush)
else:
painter.setBrush(QtWidgets.QApplication.palette().highlight())
else:
painter.setBrush(self.m_brush);
painter.setPen(black_pen)
painter.drawRoundedRect(self.rect(), 15, 15, QtCore.Qt.RelativeSize)
if self.m_black:
rendered.render(painter, self.rect())
else:
points = [
QtCore.QPointF(self.rect().left()+1.5, self.rect().bottom()-1),
QtCore.QPointF(self.rect().right()-1, self.rect().bottom()-1),
QtCore.QPointF(self.rect().right()-1, self.rect().top()+1)
]
painter.setPen(gray_pen)
painter.drawPolyline(QtGui.QPolygonF(points))
def mousePressEvent(self, event):
self.m_pressed = True
self.update()
super(PianoKey, self).mousePressEvent(event)
event.accept()
def mouseReleaseEvent(self, event):
self.m_pressed = False
self.update()
super(PianoKey, self).mouseReleaseEvent(event)
KEYWIDTH, KEYHEIGHT = 18, 72
class PianoKeyBoard(QtWidgets.QGraphicsView):
def __init__(self, num_octaves=2, parent=None):
super(PianoKeyBoard, self).__init__(parent)
self.initialize()
self.m_numOctaves = num_octaves
scene = QtWidgets.QGraphicsScene(QtCore.QRectF(0, 0, KEYWIDTH * self.m_numOctaves * 7, KEYHEIGHT), self)
self.setScene(scene)
numkeys = self.m_numOctaves * 12
for i in range(numkeys):
octave = i//12*7
j = i % 12
if j >= 5: j += 1
if j % 2 == 0:
x = (octave + j/2)*KEYWIDTH
key = PianoKey(rect=QtCore.QRectF(x, 0, KEYWIDTH, KEYHEIGHT), black=False)
else:
x = (octave + j//2) * KEYWIDTH + KEYWIDTH * 6//10 + 1
key = PianoKey(rect=QtCore.QRectF(x, 0, KEYWIDTH * 8//10 - 1, KEYHEIGHT * 6//10 ), black=True)
key.setZValue(1)
key.setPressedBrush(QtWidgets.QApplication.palette().highlight())
self.scene().addItem(key)
def initialize(self):
self.setAttribute(QtCore.Qt.WA_InputMethodEnabled, False)
self.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.setCacheMode(QtWidgets.QGraphicsView.CacheBackground)
self.setViewportUpdateMode(QtWidgets.QGraphicsView.MinimalViewportUpdate)
self.setRenderHints(QtGui.QPainter.Antialiasing|
QtGui.QPainter.TextAntialiasing |
QtGui.QPainter.SmoothPixmapTransform)
self.setOptimizationFlag(QtWidgets.QGraphicsView.DontClipPainter, True)
self.setOptimizationFlag(QtWidgets.QGraphicsView.DontSavePainterState, True)
self.setOptimizationFlag(QtWidgets.QGraphicsView.DontAdjustForAntialiasing, True)
self.setBackgroundBrush(QtWidgets.QApplication.palette().base())
def resizeEvent(self, event):
super(PianoKeyBoard, self).resizeEvent(event)
self.fitInView(self.scene().sceneRect(), QtCore.Qt.KeepAspectRatio)
def sizeHint(self):
return self.mapFromScene(self.sceneRect()).boundingRect().size()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
app.setStyle('fusion')
w = QtWidgets.QWidget()
lay = QtWidgets.QVBoxLayout(w)
lay.addWidget(QtWidgets.QLabel("Piano Keyboard", alignment=QtCore.Qt.AlignCenter))
lay.addWidget(PianoKeyBoard())
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
The complete code + key.svg can be found on this link

How to create a grid of splitters

What I'm trying to do is add splitter to a QGridLayout in order to resize the layout with the mouse. So for instance with this :
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
import sys
class SurfViewer(QMainWindow):
def __init__(self, parent=None):
super(SurfViewer, self).__init__()
self.parent = parent
self.setFixedWidth(300)
self.setFixedHeight(100)
self.wid = QWidget()
self.setCentralWidget(self.wid)
self.grid = QGridLayout()
l_a = QLabel('A')
l_b = QLabel('B')
l_c = QLabel('C')
l_d = QLabel('D')
l_e = QLabel('E')
l_f = QLabel('F')
l_g = QLabel('G')
l_h = QLabel('H')
l_i = QLabel('I')
self.grid.addWidget(l_a, 0, 0)
self.grid.addWidget(l_b, 0, 1)
self.grid.addWidget(l_c, 0, 2)
self.grid.addWidget(l_d, 1, 0)
self.grid.addWidget(l_e, 1, 1)
self.grid.addWidget(l_f, 1, 2)
self.grid.addWidget(l_g, 2, 0)
self.grid.addWidget(l_h, 2, 1)
self.grid.addWidget(l_i, 2, 2)
self.wid.setLayout(self.grid)
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = SurfViewer(app)
ex.setWindowTitle('window')
ex.show()
sys.exit(app.exec_( ))
I get this:
What I would like is instead of the colored line, have the possibility to click and drag vertically (for green lines) and horizontally (for red lines) the grid borders.
I tried something with QSplitter directly, but I end up with:
The Horizontal splits are okay, but the vertical ones are not aligned any more:
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
import sys
class SurfViewer(QMainWindow):
def __init__(self, parent=None):
super(SurfViewer, self).__init__()
self.parent = parent
self.setFixedWidth(300)
self.setFixedHeight(100)
self.wid = QWidget()
self.setCentralWidget(self.wid)
# self.grid = QGridLayout()
self.globallayout = QVBoxLayout()
self.split_V = QSplitter(Qt.Vertical)
l_a = QLabel('A')
l_b = QLabel('B')
l_c = QLabel('C')
l_d = QLabel('D')
l_e = QLabel('E')
l_f = QLabel('F')
l_g = QLabel('G')
l_h = QLabel('H')
l_i = QLabel('I')
split_H = QSplitter(Qt.Horizontal)
split_H.addWidget(l_a)
split_H.addWidget(l_b)
split_H.addWidget(l_c)
self.split_V.addWidget(split_H)
split_H = QSplitter(Qt.Horizontal)
split_H.addWidget(l_d)
split_H.addWidget(l_e)
split_H.addWidget(l_f)
self.split_V.addWidget(split_H)
split_H = QSplitter(Qt.Horizontal)
split_H.addWidget(l_g)
split_H.addWidget(l_h)
split_H.addWidget(l_i)
self.split_V.addWidget(split_H)
self.globallayout.addWidget(self.split_V)
self.wid.setLayout(self.globallayout)
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = SurfViewer(app)
ex.setWindowTitle('window')
ex.show()
sys.exit(app.exec_( ))
Update
I think I almost found a solution where a function is used so that whenever the vertical splits are changed, it re-aligns them:
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
import sys
class SurfViewer(QMainWindow):
def __init__(self, parent=None):
super(SurfViewer, self).__init__()
self.parent = parent
self.setFixedWidth(300)
self.setFixedHeight(100)
self.wid = QWidget()
self.setCentralWidget(self.wid)
# self.grid = QGridLayout()
self.globallayout = QVBoxLayout()
self.split_V = QSplitter(Qt.Vertical)
l_a = QLabel('A')
l_b = QLabel('B')
l_c = QLabel('C')
l_d = QLabel('D')
l_e = QLabel('E')
l_f = QLabel('F')
l_g = QLabel('G')
l_h = QLabel('H')
l_i = QLabel('I')
self.split_H1 = QSplitter(Qt.Horizontal)
self.split_H1.addWidget(l_a)
self.split_H1.addWidget(l_b)
self.split_H1.addWidget(l_c)
self.split_V.addWidget(self.split_H1)
self.split_H2 = QSplitter(Qt.Horizontal)
self.split_H2.addWidget(l_d)
self.split_H2.addWidget(l_e)
self.split_H2.addWidget(l_f)
self.split_V.addWidget(self.split_H2)
self.split_H3 = QSplitter(Qt.Horizontal)
self.split_H3.addWidget(l_g)
self.split_H3.addWidget(l_h)
self.split_H3.addWidget(l_i)
self.split_V.addWidget(self.split_H3)
self.globallayout.addWidget(self.split_V)
self.wid.setLayout(self.globallayout)
self.split_H1.splitterMoved.connect(self.moveSplitter)
self.split_H2.splitterMoved.connect(self.moveSplitter)
self.split_H3.splitterMoved.connect(self.moveSplitter)
# self.split_H1.splitterMoved
# self.moveSplitter(0,self.split_H1.at )
def moveSplitter( self, index, pos ):
# splt = self._spltA if self.sender() == self._spltB else self._spltB
self.split_H1.blockSignals(True)
self.split_H2.blockSignals(True)
self.split_H3.blockSignals(True)
self.split_H1.moveSplitter(index, pos)
self.split_H2.moveSplitter(index, pos)
self.split_H3.moveSplitter(index, pos)
self.split_H1.blockSignals(False)
self.split_H2.blockSignals(False)
self.split_H3.blockSignals(False)
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = SurfViewer(app)
ex.setWindowTitle('window')
ex.show()
sys.exit(app.exec_( ))
However, I still have an issue at the begining - the alignment is not correct :
I don't know How call the function moveSplitter in the __init__
It seems that directly calling moveSplitter (which is a protected method) may be problematic. Using Qt-5.10.1 with PyQt-5.10.1 on Linux, I found that it can often result in a core dump when called during __init__. There is probably a good reason why Qt provides setSizes as a public method for changing the position of the splitters, so it may be wise to prefer it over moveSplitter.
With that in mind, I arrived at the following implementation:
class SurfViewer(QMainWindow):
def __init__(self, parent=None):
...
self.split_H1.splitterMoved.connect(self.moveSplitter)
self.split_H2.splitterMoved.connect(self.moveSplitter)
self.split_H3.splitterMoved.connect(self.moveSplitter)
QTimer.singleShot(0, lambda: self.split_H1.splitterMoved.emit(0, 0))
def moveSplitter(self, index, pos):
sizes = self.sender().sizes()
for index in range(self.split_V.count()):
self.split_V.widget(index).setSizes(sizes)
The single-shot timer is needed because on some platforms the geometry of the window may not be fully initialized before it is shown on screen. And note that setSizes does not trigger splitterMoved, so there is no need to block signals when using it.

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