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# This file is part of the Frescobaldi project, http://www.frescobaldi.org/
#
# Copyright (c) 2013 - 2014 by Wilbert Berendsen
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
# See http://www.gnu.org/licenses/ for more information.
"""
Provides a QTextEdit subclass that grows vertically to accommodate document size.
You should set maximumHeight to restrict its vertical size.
"""
from PyQt5.QtCore import QSize, Qt
from PyQt5.QtWidgets import QPlainTextEdit, QStyle, QTextEdit
__all__ = ["GrowingPlainTextEdit", "GrowingTextEdit"]
class _GrowingTextEditBase(object):
"""Base class."""
def __init__(self, parent=None):
super(_GrowingTextEditBase, self).__init__(parent)
self.setLineWrapMode(self.NoWrap)
self.document().documentLayout().documentSizeChanged.connect(self.updateVerticalSize)
self.updateVerticalSize()
def updateVerticalSize(self):
# can vertical or horizontal scrollbars appear?
vcan = self.verticalScrollBarPolicy() == Qt.ScrollBarAsNeeded
hcan = self.horizontalScrollBarPolicy() == Qt.ScrollBarAsNeeded
# width a scrollbar takes off the viewport size
framewidth = 0
if self.style().styleHint(QStyle.SH_ScrollView_FrameOnlyAroundContents, None, self):
framewidth = self.style().pixelMetric(QStyle.PM_DefaultFrameWidth) * 2
scrollbarextent = self.style().pixelMetric(QStyle.PM_ScrollBarExtent, None, self) + framewidth
margin = framewidth + self.document().documentMargin()
size = self.documentSize() + QSize(margin, margin)
width = size.width()
height = size.height()
max_width = self.width()
max_height = self.maximumHeight()
# will scrollbars appear?
hwill, vwill = False, False
if hcan and width > max_width:
hwill = True
if vcan and height > max_height:
vwill = True
if vcan and hwill and height + scrollbarextent > max_height:
vwill = True
if hcan and vwill and width + scrollbarextent > max_width:
hwill = True
if hwill:
height += scrollbarextent
self.resize(self.width(), min(max_height, height))
def documentSize(self):
"""Implemented differently for QTextEdit and QPlainTextEdit."""
raise NotImplementedError
def setLineWrapMode(self, mode):
"""Reimplemented to avoid WidgetWidth wrap mode, which causes resize loops."""
if mode == self.WidgetWidth:
raise ValueError("cannot use WidgetWidth wrap mode")
else:
super(_GrowingTextEditBase, self).setLineWrapMode(mode)
class GrowingTextEdit(_GrowingTextEditBase, QTextEdit):
"""Growing QTextEdit"""
def documentSize(self):
return self.document().documentLayout().documentSize().toSize()
class GrowingPlainTextEdit(_GrowingTextEditBase, QPlainTextEdit):
"""Growing QPlainTextEdit"""
def documentSize(self):
doc = self.document()
layout = doc.documentLayout()
size = layout.documentSize().toSize()
block = doc.firstBlock()
line_height = layout.blockBoundingRect(block).height() / block.lineCount()
return QSize(size.width(), size.height() * line_height + 2 * doc.documentMargin())
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