flow_layout.py

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# Copyright (C) 2013 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
# FlowLayout class copied from https://doc.qt.io/qtforpython-6/examples/example_widgets_layouts_flowlayout.html
 
try:
    from PyQt6.QtCore import Qt, QMargins, QPoint, QRect, QSize
    from PyQt6.QtWidgets import QLayout, QSizePolicy
except:
    from PyQt5.QtCore import Qt, QMargins, QPoint, QRect, QSize
    from PyQt5.QtWidgets import QLayout, QSizePolicy
 
class FlowLayout(QLayout):
    def __init__(self, parent=None):
        super().__init__(parent)
 
        if parent is not None:
            self.setContentsMargins(QMargins(0, 0, 0, 0))
 
        self._item_list = []
 
    def __del__(self):
        item = self.takeAt(0)
        while item:
            item = self.takeAt(0)
 
    def addItem(self, item):
        self._item_list.append(item)
 
    def count(self):
        return len(self._item_list)
 
    def itemAt(self, index):
        if 0 <= index < len(self._item_list):
            return self._item_list[index]
 
        return None
 
    def takeAt(self, index):
        if 0 <= index < len(self._item_list):
            return self._item_list.pop(index)
 
        return None
 
    def expandingDirections(self):
        return Qt.Orientation(0)
 
    def hasHeightForWidth(self):
        return True
 
    def heightForWidth(self, width):
        height = self._do_layout(QRect(0, 0, width, 0), True)
        return height
 
    def setGeometry(self, rect):
        super(FlowLayout, self).setGeometry(rect)
        self._do_layout(rect, False)
 
    def sizeHint(self):
        return self.minimumSize()
 
    def minimumSize(self):
        size = QSize()
 
        for item in self._item_list:
            size = size.expandedTo(item.minimumSize())
 
        size += QSize(2 * self.contentsMargins().top(), 2 * self.contentsMargins().top())
        return size
 
    def _do_layout(self, rect, test_only):
        x = rect.x()
        y = rect.y()
        line_height = 0
        spacing = self.spacing()
 
        for item in self._item_list:
            style = item.widget().style()
            layout_spacing_x = style.layoutSpacing(
                QSizePolicy.ControlType.PushButton, QSizePolicy.ControlType.PushButton, Qt.Orientation.Horizontal
            )
            layout_spacing_y = style.layoutSpacing(
                QSizePolicy.ControlType.PushButton, QSizePolicy.ControlType.PushButton, Qt.Orientation.Vertical
            )
            space_x = spacing + layout_spacing_x
            space_y = spacing + layout_spacing_y
            next_x = x + item.sizeHint().width() + space_x
            if next_x - space_x > rect.right() and line_height > 0:
                x = rect.x()
                y = y + line_height + space_y
                next_x = x + item.sizeHint().width() + space_x
                line_height = 0
 
            if not test_only:
                item.setGeometry(QRect(QPoint(x, y), item.sizeHint()))
 
            x = next_x
            line_height = max(line_height, item.sizeHint().height())
 
        return y + line_height - rect.y()