Source code for silx.gui.widgets.FlowLayout

# coding: utf-8
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"""This module provides a flow layout for QWidget: :class:`FlowLayout`.
"""

from __future__ import division

__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "20/07/2018"


from .. import qt


[docs]class FlowLayout(qt.QLayout): """Layout widgets on (possibly) multiple lines in the available width. See Qt :class:`QLayout` for API documentation. Adapted from C++ `Qt FlowLayout example <http://doc.qt.io/qt-5/qtwidgets-layouts-flowlayout-example.html>`_ :param QWidget parent: See :class:`QLayout` """ def __init__(self, parent=None): super(FlowLayout, self).__init__(parent) self._items = [] self._horizontalSpacing = -1 self._verticalSpacing = -1
[docs] def addItem(self, item): self._items.append(item)
[docs] def count(self): return len(self._items)
[docs] def itemAt(self, index): if 0 <= index < len(self._items): return self._items[index] else: return None
[docs] def takeAt(self, index): if 0 <= index < len(self._items): return self._items.pop(index) else: return None
[docs] def expandingDirections(self): return qt.Qt.Orientations()
[docs] def hasHeightForWidth(self): return True
[docs] def heightForWidth(self, width): return self._layout(qt.QRect(0, 0, width, 0), test=True)
[docs] def setGeometry(self, rect): super(FlowLayout, self).setGeometry(rect) self._layout(rect)
[docs] def sizeHint(self): return self.minimumSize()
[docs] def minimumSize(self): size = qt.QSize() for item in self._items: size = size.expandedTo(item.minimumSize()) left, top, right, bottom = self.getContentsMargins() size += qt.QSize(left + right, top + bottom) return size
def _layout(self, rect, test=False): left, top, right, bottom = self.getContentsMargins() effectiveRect = rect.adjusted(left, top, -right, -bottom) x, y = effectiveRect.x(), effectiveRect.y() lineHeight = 0 for item in self._items: widget = item.widget() spaceX = self.horizontalSpacing() if spaceX == -1: spaceX = widget.style().layoutSpacing( qt.QSizePolicy.PushButton, qt.QSizePolicy.PushButton, qt.Qt.Horizontal) spaceY = self.verticalSpacing() if spaceY == -1: spaceY = widget.style().layoutSpacing( qt.QSizePolicy.PushButton, qt.QSizePolicy.PushButton, qt.Qt.Vertical) nextX = x + item.sizeHint().width() + spaceX if (nextX - spaceX) > effectiveRect.right() and lineHeight > 0: x = effectiveRect.x() y += lineHeight + spaceY nextX = x + item.sizeHint().width() + spaceX lineHeight = 0 if not test: item.setGeometry(qt.QRect(qt.QPoint(x, y), item.sizeHint())) x = nextX lineHeight = max(lineHeight, item.sizeHint().height()) return y + lineHeight - rect.y() + bottom
[docs] def setHorizontalSpacing(self, spacing): """Set the horizontal spacing between widgets laid out side by side :param int spacing: """ self._horizontalSpacing = spacing self.update()
[docs] def horizontalSpacing(self): """Returns the horizontal spacing between widgets laid out side by side :rtype: int """ if self._horizontalSpacing >= 0: return self._horizontalSpacing else: return self._smartSpacing(qt.QStyle.PM_LayoutHorizontalSpacing)
[docs] def setVerticalSpacing(self, spacing): """Set the vertical spacing between lines :param int spacing: """ self._verticalSpacing = spacing self.update()
[docs] def verticalSpacing(self): """Returns the vertical spacing between lines :rtype: int """ if self._verticalSpacing >= 0: return self._verticalSpacing else: return self._smartSpacing(qt.QStyle.PM_LayoutVerticalSpacing)
def _smartSpacing(self, pm): parent = self.parent() if parent is None: return -1 if parent.isWidgetType(): return parent.style().pixelMetric(pm, None, parent) else: return parent.spacing()