We Keep Coding

Stacked Layout causing alignment to top problem

I have a vertical layout with alignment set to "top" that contains what I want to be a fixed height "header" bar contained in a QHBoxLayout, with a QTextEdit window underneath it. One of the sections of this header bar contains a QStackedLayout. If you run the sample code below, when resizing the window the QTextEdit window begins pulling away from the "header" bar instead of staying anchored just underneath the "header" bar. The intended behavior would be for the QTextEdit window to remain anchored just underneath the header bar and expand and contract along its bottom margin. How do I fix the size of the QStackedLayout element to achieve this behavior?
from PySide2 import QtWidgets, QtCore, QtGui
from PySide2.QtWidgets import QApplication
import sys
class Demo(QtWidgets.QDialog):
def __init__(self, parent=None):
super(Demo, self).__init__(parent)
self.main_layout = QtWidgets.QVBoxLayout(self)
self.main_layout.setAlignment(QtCore.Qt.AlignTop)
# Header with combobox anchored to the top of the layout
self.data_results_layout = QtWidgets.QHBoxLayout()
self.results_stacked_layout = QtWidgets.QStackedLayout()
self.data_results_layout.addLayout(self.results_stacked_layout)
self.combobox_results_widget = QtWidgets.QWidget()
self.combobox_results_widget.setFixedHeight(25)
self.combobox_results_layout = QtWidgets.QVBoxLayout(self.combobox_results_widget)
self.combobox_results_layout.setContentsMargins(0,0,0,0)
self.directory_combobox = QtWidgets.QComboBox()
self.directory_combobox.setFixedHeight(25)
self.combobox_results_layout.addWidget(self.directory_combobox)
self.results_stacked_layout.addWidget(self.combobox_results_widget)
self.main_layout.addLayout(self.data_results_layout)
# QTextEdit Window
self.asset_data_layout = QtWidgets.QVBoxLayout()
self.asset_data_window = QtWidgets.QTextEdit('Ready.')
self.asset_data_layout.addWidget(self.asset_data_window)
self.main_layout.addLayout(self.asset_data_layout)
if __name__ == '__main__':
app = QApplication(sys.argv)
demo = Demo()
demo.show()
sys.exit(app.exec_())

Setting the alignment on a layout does not set the alignment of the widgets it manages, but only the alignment that that layout will have when added to another layout manager (you can read a more deeper explanation in this answer).
Basically, the following:
layout.setAlignment(QtCore.Qt.AlignTop)
is almost the same as this:
otherLayout.addLayout(layout, alignment=QtCore.Qt.AlignTop)
So, not only that alignment won't affect the children alignment, but since you're using that layout as main layout for the widget, that alignment is completely ignored.
In order to achieve what you want you can set a stretch for the lower alignment (as suggested in the comment by S.Nick):
self.main_layout.addLayout(self.asset_data_layout, stretch=1)
On the other hand, consider that QStackedLayout should only used for custom widgets or dedicated behavior, and in most cases it's better to use its convenience class QStackedWidget, on which you can set an appropriate size policy:
self.results_stacked_layout = QtWidgets.QStackedWidget()
self.data_results_layout.addWidget(self.results_stacked_layout)
self.results_stacked_layout.setSizePolicy(
QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Maximum)
With the above, the stacked widget will resize itself horizontally according to its contents and will only use the minimum vertical space required by it: since the combobox expands horizontally as much as possible, it will try to occupy all the horizontal available space, and since the vertical policy of the combobox is fixed, it will only use the vertical space required, leaving all the remaining vertical space to the other widgets in the parent layout.
Note that the size policy definitions might seem a bit counterintuitive; the rule is that it's always referred to the sizeHint of the widget: Maximum means that the size hint of the contents will be used as maximum size, and it cannot be larger than that.

Move pyqt button out of list of buttons

I have a list of pyqt4 push button and want to move the position. Since it is troublesome it make lots of buttons variable I create them through a list. The code below
import sys
from PyQt5.QtWidgets import QApplication, QPushButton, QWidget, QVBoxLayout
class Window(QWidget):
def __init__(self):
QWidget.__init__(self)
layout = QVBoxLayout(self)
self.buttons = []
for i in range(3):
self.buttons.append(QPushButton('',self))
self.buttons[-1].setFixedWidth(50)
self.buttons[-1].setFixedHeight(50)
self.buttons[-1].move(70*i+50,300)
layout.addWidget(self.buttons[-1])
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = Window()
window.resize(500,500)
window.show()
sys.exit(app.exec_())
don't work for specify the position
but
class Window(QWidget):
def __init__(self):
QWidget.__init__(self)
layout = QVBoxLayout(self)
self.button1 = QPushButton('',self)
self.button1.setFixedWidth(50)
self.button1.setFixedHeight(50)
self.button1.move(50,300)
self.button2 = QPushButton('',self)
self.button2.setFixedWidth(50)
self.button2.setFixedHeight(50)
self.button2.move(120,300)
self.button3 = QPushButton('',self)
self.button3.setFixedWidth(50)
self.button3.setFixedHeight(50)
self.button3.move(190,300)
layout = QVBoxLayout(self)
layout.addWidget(self.button1)
layout.addWidget(self.button2)
layout.addWidget(self.button3)
works fine.
What's the reason behind?

If you want to manually specify the geometry (position and size) of widgets, you should not add them to a layout.
Your second example "works" just because you already created and set a layout to the top-level widget (the Window class), and since a layout already exists the second one is not "installed". Running it from the console will shows this error:
StdErr: QLayout: Attempting to add QLayout "" to Window "", which already has a layout
When a widget is added to a layout, the ownership of the "layout item" (an abstract item used by layouts to manage its widgets) is transferred to the layout, and the widget is reparented to the widget that uses that layout.
Since the second layout cannot be set, it will not manage the geometries of the items you tried to add, and the result is that they will keep the geometries you set before.
The same result can be obtained if you remove all the last lines referencing the other layout, which is exactly what you need.
Also, note that in order to add a widget that is not managed by a layout, a parent is required. Your last example also works because you specified the window as the parent while instantiating them; if you don't do that the buttons will not be shown, but if you do show them (with show() or setVisible(True)) they will each appear in separate windows, as they will become their own top level windows.
If you don't have other widgets that should be managed by a layout, you can also avoid creating the first layout at all (but, still, the parent is required).
Finally, let me tell you that using manual geometries is generally discouraged, and there are very few and specific cases for which it's a good idea to go with.
The main reason behind this is that widgets tend to show very differently from device to device, and that depends on various aspects:
different OS and OS versions draw widgets differently (sometimes dramatically), and this involves varying the widget size and behavior; while this might not be a major issue for simple widgets, it can be a problem for things like item views, spinboxes, etc;
different OS and systems use different styles, which also includes things like internal widget content margins and minimum size;
specific system settings (most importantly, the default font) could make widgets mostly unreadable, specifically with text being clipped within the widget margins if the font size is too big;
depending on the OS, you might face issues if the system uses High DPI displays, and you could end up with very tiny widgets that are almost impossible to interact with;
fixed geometries force you (and the user) to have a fixed widget/window size, and (along with the DPI issue above) this can be a problem: the same widget could look too big or too small;

PyQt5: Progamically adding QWidget to layout, doesn't show Qwidget when a spacer is added

Edit: I have tried a few more things. If I move the spacer to a layout below the spacer I am adding to it doesn't exibit the same exact behavior. Its still not optimal, and isn't going to work because my end goal is to have a scrollArea with a spacer inside that i add my widgets to, but this would not look right. I think the problem is the widgets are getting to a size zero I just do not know why or how to fix it.
I have two ui files made in QtDesigner. The first file is my main window at the start of the program I load the second ui file and place it into a vertical spacer in the middle of the first one. Additional copies are placed each time a button is clicked.
This all works great until I add a vertical spacer to push the items to the top. I have tired adding it from Designer and in the code. Both have the same result.
I have looked on google quite a bit and tried a lot of suggestions.
I tried setting the second ui files parent as a Qwidget I added on the first that contained the vertical layout.
I tried setting the minimum sizes and sizing polices to various things.
Below is my current code, any ideas or suggestions would be appreciated!
#!python3
import sys
from PyQt5 import QtWidgets, QtCore, uic
class TimesheetWidget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(TimesheetWidget, self).__init__(parent)
self.parent = parent
self.tableRows = dict()
def setup(self):
self.labelSaved.hide()
self.addTableRow()
def addTableRow(self):
thisRow = len(self.tableRows)
self.tableRows[thisRow] = uic.loadUi("gui/tableRow.ui")
self.tableRows[thisRow].addButton.clicked.connect(self.addTableRow)
self.spacer.addWidget(self.tableRows[thisRow])
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
timesheet = TimesheetWidget()
Mytimesheet = uic.loadUi("gui/timesheet.ui", baseinstance=timesheet)
Mytimesheet.setup()
Mytimesheet.show()
sys.exit(app.exec_())
here is a link to the ui files (they are to long to post):
gist link for ui files

I finally fixed this by trying random things over and over until something worked.
It turned out that on my second ui file I did not have a top level layout. (I am not sure if that's what its called.)
To fix this I right clicked on the top level widget and choose layout and selected horizontal layout, although I think any would have worked.
Here is a picture that shows the top level widget with the cancel symbol on it. Once I added the layout that went away and everything worked!

Generate PyQt Legend

I'm trying to build myself a simple graphics calculator, as a way of teaching myself PyQt. I'd like the calculator to have a pane which lists all of the equations plotted and shows the line style used.
I began with a QListWidget to achieve these ends, the pane contains a scrollable list of equations, but does not show the line style because the QListWidget only allows strings or icons.
So I tried using a QAbstractScrollArea widget instead. For each equation I use QHBoxLayout to produce two Widgets, a label containing the equation string, and a QWidget within which I draw the line style. Then I stack all of the equation QHBoxLayouts within the ScrollArea using QVBoxLayout.
The problem is that QVBoxLayout uses all of the space available to it. So if I have only three equations, they are spread throughout the pane and not listed at the top as I'd like them to be, while if I have too many equations to fit in the pane they are stacked on top of one another rather than causing the area to be scrollable.
This is how the calculator appears with too many equations...
And this is how it looks with too few...
Does anyone have any suggestions of better ways to get around these issues? One idea is to generate icons programmatically to have the properties of the lines and to use these in the listwidget, is that possible?

It sounds like what you want is a QListWidget with multiple columns - and a QTreeWidget can be adapted to do exactly that.
Here's a simple demo:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.list = QtGui.QTreeWidget(self)
self.list.setRootIsDecorated(False)
self.list.setUniformRowHeights(True)
self.list.setAllColumnsShowFocus(True)
self.list.setItemsExpandable(False)
self.list.header().hide()
self.list.setColumnCount(2)
for label, color in (
('v=x**2', 'red'),
('v=x/2', 'blue'),
('v=2*x', 'green'),
('v=3*2', 'orange'),
('v=5-x', 'purple'),
):
item = QtGui.QTreeWidgetItem([label, '------------'])
item.setForeground(1, QtGui.QColor(color))
self.list.addTopLevelItem(item)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.list)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 300, 200)
window.show()
sys.exit(app.exec_())

A scrolling list of widgets without QListWidget

I need to list a bunch of custom widgets in a scrolling area.
I would normally just use QListWidget, but that does not do smooth scrolling, which for me is a necessity. I found this question about smooth scrolling in a QListWidget, but when I try that solution, I get an error saying QListWidget.updateGeometries() requires at least one parameter!
I also thought about using a QScrollArea with multiple widgets in it, but it seems there is no way to do this. If I use a layout, the widgets inside resize. If I set multiple widgets as the child of a QWidget, then put that QWidget as the widget for my QScrollArea (as suggested here), only the last widget I set as a child of my QWidget shows up.
I might well be doing something wrong, as I am not very familiar with widget parenting, so maybe that's my problem. I don't know:
class EditDialog(QDialog):
def __init__(self):
super(EditDialog,self).__init__()
self.scroller = QScrollArea()
self.form = QWidget()
self.form.setStyleSheet()
self.lab = QLabel(self.form)
self.lab.setText("Label")
self.edit = QLineEdit(self.form)
self.edit.setText("LineEdit")
self.but = QPushButton("PushButton",self.form)
self.scroller.setWidget(self.form)
self.layout = QVBoxLayout()
self.layout.addWidget(self.scroller)
self.setLayout(self.layout)
self.setWindowTitle(widget + " - StyleWise")
self.exec_()
With this code, the QListWidget scrolls 100 pixels at a time, but I want it to scroll 1 or 2 at a time. I don't know what to do!