"""PyQt horizontal layout that simply lays out items from left to right based
on their size, accounting for spacing and contents margins. Similar to the way
items on a menu or toolbar are positioned."""
from qt import QRect, QPoint, QSize, QLayout, Qt
[docs]class RowLayout(QLayout):
[docs] def __init__(self, parent=None):
super().__init__(parent)
self.item_list = []
def __del__(self):
"""Delete all items in this layout"""
item = self.takeAt(0)
while item:
item = self.takeAt(0)
[docs] def addItem(self, item):
"""Add an item to the end of this layout"""
self.item_list.append(item)
[docs] def count(self):
"""Return number of items in this layout"""
return len(self.item_list)
[docs] def itemAt(self, index):
"""Return item at given index (non-destructively)"""
if index >= 0 and index < len(self.item_list):
return self.item_list[index]
return None
[docs] def takeAt(self, index):
"""Remove and return item at given index"""
if index >= 0 and index < len(self.item_list):
return self.item_list.pop(index)
return None
[docs] def expandingDirections(self):
return Qt.Orientation.Horizontal
[docs] def setGeometry(self, rect):
super().setGeometry(rect)
margins = self.getContentsMargins()
rect.setX(rect.x() + margins[1]) # plus left margin
rect.setY(rect.y() + margins[0]) # plus top margin
rect.setWidth(rect.width() - margins[2]) # minus right margin
self.doLayout(rect, False)
[docs] def sizeHint(self):
size = self.minimumSize()
size.setWidth(self.doLayout(QRect(0, 0, 0, 0), True))
# Add left and right margins again
margins = self.getContentsMargins()
size += QSize(margins[1] + margins[2], 0)
return size
[docs] def minimumSize(self):
size = QSize()
margins = self.getContentsMargins()
size = size.expandedTo(self.item_list[0].minimumSize())
# Account for the margins
size += QSize(margins[1] + margins[2], margins[0] + margins[3])
return size
[docs] def doLayout(self, rect, dry_run=False):
"""Lay out the items in `item_list' within bounding QRect `rect'.
If dry_run, only do the calculations and return the resulting width."""
# Set the x and y to the top left corner of the bounding rect
(x, y) = (rect.x(), rect.y())
height = rect.height()
# This variable is used to “move right” as we place each item in
# the row. as each item is placed its width + spacing is added to it,
# and then it is used to place the next one.
added_width = 0
for item in self.item_list:
if not dry_run:
y_gap_to_centre = (height / 2) - (item.sizeHint().height() / 2)
item.setGeometry(QRect(
QPoint(x + added_width,
y + y_gap_to_centre),
item.sizeHint()))
added_width += item.sizeHint().width() + self.spacing()
return added_width - self.spacing()