How to format the list items of QCompleter's popup list properly?
I want to investigate how to make a small user interface in which a user can type some letters and gets some suggestions based on a given data source (list here) which makes searches easier. For this purpose i am using Qt's QCompleter class.
In the matching elements the typed letters shall be highlighted with HTML like the example in the code below: Au<b>st</b>ria.
Finally i merged some SO answers (see How to make item view render rich (html) text in Qt) and tutorials to a small standalone module:
from PySide import QtCore, QtGui
class HTMLDelegate(QtGui.QStyledItemDelegate):
""" From: https://stackoverflow.com/a/5443112/1504082 """
def paint(self, painter, option, index):
options = QtGui.QStyleOptionViewItemV4(option)
self.initStyleOption(options, index)
if options.widget is None:
style = QtGui.QApplication.style()
else:
style = options.widget.style()
doc = QtGui.QTextDocument()
doc.setHtml(options.text)
doc.setTextWidth(option.rect.width())
options.text = ""
style.drawControl(QtGui.QStyle.CE_ItemViewItem, options, painter)
ctx = QtGui.QAbstractTextDocumentLayout.PaintContext()
# Highlighting text if item is selected
# if options.state & QtGui.QStyle.State_Selected:
# ctx.palette.setColor(QtGui.QPalette.Text,
# options.palette.color(QtGui.QPalette.Active,
# QtGui.QPalette.HighlightedText))
textRect = style.subElementRect(QtGui.QStyle.SE_ItemViewItemText,
options)
painter.save()
painter.translate(textRect.topLeft())
painter.setClipRect(textRect.translated(-textRect.topLeft()))
doc.documentLayout().draw(painter, ctx)
painter.restore()
def sizeHint(self, option, index):
options = QtGui.QStyleOptionViewItemV4(option)
self.initStyleOption(options, index)
doc = QtGui.QTextDocument()
doc.setHtml(options.text)
doc.setTextWidth(options.rect.width())
return QtCore.QSize(doc.size().width(), doc.size().height())
class CustomQCompleter(QtGui.QCompleter):
""" Implement "contains" filter mode as the filter mode "contains" is not
available in Qt < 5.2
From: https://stackoverflow.com/a/7767999/1504082 """
def __init__(self, parent=None):
super(CustomQCompleter, self).__init__(parent)
self.local_completion_prefix = ""
self.source_model = None
self.delegate = HTMLDelegate()
def setModel(self, model):
self.source_model = model
super(CustomQCompleter, self).setModel(self.source_model)
def updateModel(self):
local_completion_prefix = self.local_completion_prefix
# see: http://doc.qt.io/qt-4.8/model-view-programming.html#proxy-models
class InnerProxyModel(QtGui.QSortFilterProxyModel):
def filterAcceptsRow(self, sourceRow, sourceParent):
# model index mapping by row, 1d model => column is always 0
index = self.sourceModel().index(sourceRow, 0, sourceParent)
source_data = self.sourceModel().data(index, QtCore.Qt.DisplayRole)
# performs case insensitive matching
# return True if item shall stay in th returned filtered data
# return False to reject an item
return local_completion_prefix.lower() in source_data.lower()
proxy_model = InnerProxyModel()
proxy_model.setSourceModel(self.source_model)
super(CustomQCompleter, self).setModel(proxy_model)
# @todo: Why to be set here again?
self.popup().setItemDelegate(self.delegate)
def splitPath(self, path):
self.local_completion_prefix = path
self.updateModel()
return ""
class AutoCompleteEdit(QtGui.QLineEdit):
""" Basically from:
http://doc.qt.io/qt-5/qtwidgets-tools-customcompleter-example.html
"""
def __init__(self, list_data, separator=' ', addSpaceAfterCompleting=True):
super(AutoCompleteEdit, self).__init__()
# settings
self._separator = separator
self._addSpaceAfterCompleting = addSpaceAfterCompleting
# completer
self._completer = CustomQCompleter(self)
self._completer.setCaseSensitivity(QtCore.Qt.CaseInsensitive)
self._completer.setCompletionMode(QtGui.QCompleter.PopupCompletion)
self.model = QtGui.QStringListModel(list_data)
self._completer.setModel(self.model)
# connect the completer to the line edit
self._completer.setWidget(self)
# trigger insertion of the selected completion when its activated
self.connect(self._completer,
QtCore.SIGNAL('activated(QString)'),
self._insertCompletion)
self._ignored_keys = [QtCore.Qt.Key_Enter,
QtCore.Qt.Key_Return,
QtCore.Qt.Key_Escape,
QtCore.Qt.Key_Tab]
def _insertCompletion(self, completion):
"""
This is the event handler for the QCompleter.activated(QString) signal,
it is called when the user selects an item in the completer popup.
It will remove the already typed string with the one of the completion.
"""
stripped_text = self.text()[:-len(self._completer.completionPrefix())]
extra_text = completion # [-extra:]
if self._addSpaceAfterCompleting:
extra_text += ' '
self.setText(stripped_text + extra_text)
def textUnderCursor(self):
text = self.text()
textUnderCursor = ''
i = self.cursorPosition() - 1
while i >= 0 and text[i] != self._separator:
textUnderCursor = text[i] + textUnderCursor
i -= 1
return textUnderCursor
def keyPressEvent(self, event):
if self._completer.popup().isVisible():
if event.key() in self._ignored_keys:
event.ignore()
return
super(AutoCompleteEdit, self).keyPressEvent(event)
completionPrefix = self.textUnderCursor()
if completionPrefix != self._completer.completionPrefix():
self._updateCompleterPopupItems(completionPrefix)
if len(event.text()) > 0 and len(completionPrefix) > 0:
self._completer.complete()
if len(completionPrefix) == 0:
self._completer.popup().hide()
def _updateCompleterPopupItems(self, completionPrefix):
"""
Filters the completer's popup items to only show items
with the given prefix.
"""
self._completer.setCompletionPrefix(completionPrefix)
# self._completer.popup().setCurrentIndex(
# self._completer.completionModel().index(0, 0))
if __name__ == '__main__':
def demo():
import sys
app = QtGui.QApplication(sys.argv)
values = ['Germany',
'Au<b>st</b>ria',
'Switzerland',
'Hungary',
'The United Kingdom of Great Britain and Northern Ireland']
editor = AutoCompleteEdit(values)
window = QtGui.QWidget()
hbox = QtGui.QHBoxLayout()
hbox.addWidget(editor)
window.setLayout(hbox)
window.show()
sys.exit(app.exec_())
demo()
My problem is the suggestion of user Timo in the answer https://stackoverflow.com/a/5443112/1504082:
After line: 'doc.setHtml(options.text)', you need to set also doc.setTextWidth(option.rect.width()), otherwise the delegate wont render longer content correctly in respect to target drawing area. For example does not wrap words in QListView.
So i did this to avoid cropping of long text in the completer's popup. But i get the following output:
Where does this additional vertical margin come from?
I investigated this a bit and i see that the sizeHint method of HTMLDelegate is sometimes called with an options parameter which contains a rectangle with attributes (0, 0, 0, 0). And the display behaviour finally changes after the call of doc.setTextWidth(options.rect.width()). But i couldnt finally find out who calls it with this parameter and how i could properly fix this.
Can somebody explain where this comes from and how i can fix this porperly?
Solution
Finally i found another way to realize it using the idea of https://stackoverflow.com/a/8036666/1504082. Its much more forward for me without all this custom drawing things which i dont understand yet :)
from PySide import QtCore, QtGui
class TaskDelegate(QtGui.QItemDelegate):
# based on https://stackoverflow.com/a/8036666/1504082
# https://doc.qt.io/archives/qt-4.7/qitemdelegate.html#drawDisplay
# https://doc.qt.io/archives/qt-4.7/qwidget.html#render
margin_x = 5
margin_y = 3
def drawDisplay(self, painter, option, rect, text):
label = self.make_label(option, text)
# calculate render anchor point
point = rect.topLeft()
point.setX(point.x() + self.margin_x)
point.setY(point.y() + self.margin_y)
label.render(painter, point, renderFlags=QtGui.QWidget.DrawChildren)
def sizeHint(self, option, index):
# get text using model and index
text = index.model().data(index)
label = self.make_label(option, text)
return QtCore.QSize(label.width(), label.height() + self.margin_y)
def make_label(self, option, text):
label = QtGui.QLabel(text)
if option.state & QtGui.QStyle.State_Selected:
p = option.palette
p.setColor(QtGui.QPalette.WindowText,
p.color(QtGui.QPalette.Active,
QtGui.QPalette.HighlightedText)
)
label.setPalette(p)
label.setStyleSheet("border: 1px dotted black")
# adjust width according to widget's target width
label.setMinimumWidth(self.target_width - (2 * self.margin_x))
label.setMaximumWidth(self.target_width - self.margin_x)
label.setWordWrap(True)
label.adjustSize()
return label
class CustomQCompleter(QtGui.QCompleter):
""" Implement "contains" filter mode as the filter mode "contains" is not
available in Qt < 5.2
From: https://stackoverflow.com/a/7767999/1504082 """
def __init__(self, parent=None):
super(CustomQCompleter, self).__init__(parent)
self.local_completion_prefix = ""
self.source_model = None
self.delegate = TaskDelegate()
# widget not set yet
# self.delegate.target_width = self.widget().width()
def setModel(self, model):
self.source_model = model
super(CustomQCompleter, self).setModel(self.source_model)
def updateModel(self):
local_completion_prefix = self.local_completion_prefix
# see: http://doc.qt.io/qt-4.8/model-view-programming.html#proxy-models
class InnerProxyModel(QtGui.QSortFilterProxyModel):
def filterAcceptsRow(self, sourceRow, sourceParent):
# model index mapping by row, 1d model => column is always 0
index = self.sourceModel().index(sourceRow, 0, sourceParent)
source_data = self.sourceModel().data(index, QtCore.Qt.DisplayRole)
# performs case insensitive matching
# return True if item shall stay in th returned filtered data
# return False to reject an item
return local_completion_prefix.lower() in source_data.lower()
proxy_model = InnerProxyModel()
proxy_model.setSourceModel(self.source_model)
super(CustomQCompleter, self).setModel(proxy_model)
# @todo: Why to be set here again?
# -> rescale popup list items to widget width
self.delegate.target_width = self.widget().width()
self.popup().setItemDelegate(self.delegate)
def splitPath(self, path):
self.local_completion_prefix = path
self.updateModel()
return ""
class AutoCompleteEdit(QtGui.QLineEdit):
""" Basically from:
http://doc.qt.io/qt-5/qtwidgets-tools-customcompleter-example.html
"""
def __init__(self, list_data, separator=' ', addSpaceAfterCompleting=True):
super(AutoCompleteEdit, self).__init__()
# settings
self._separator = separator
self._addSpaceAfterCompleting = addSpaceAfterCompleting
# completer
self._completer = CustomQCompleter(self)
self._completer.setCaseSensitivity(QtCore.Qt.CaseInsensitive)
self._completer.setCompletionMode(QtGui.QCompleter.PopupCompletion)
self.model = QtGui.QStringListModel(list_data)
self._completer.setModel(self.model)
# connect the completer to the line edit
self._completer.setWidget(self)
# trigger insertion of the selected completion when its activated
self.connect(self._completer,
QtCore.SIGNAL('activated(QString)'),
self._insertCompletion)
self._ignored_keys = [QtCore.Qt.Key_Enter,
QtCore.Qt.Key_Return,
QtCore.Qt.Key_Escape,
QtCore.Qt.Key_Tab]
def _insertCompletion(self, completion):
"""
This is the event handler for the QCompleter.activated(QString) signal,
it is called when the user selects an item in the completer popup.
It will remove the already typed string with the one of the completion.
"""
stripped_text = self.text()[:-len(self._completer.completionPrefix())]
extra_text = completion # [-extra:]
if self._addSpaceAfterCompleting:
extra_text += ' '
self.setText(stripped_text + extra_text)
def textUnderCursor(self):
text = self.text()
textUnderCursor = ''
i = self.cursorPosition() - 1
while i >= 0 and text[i] != self._separator:
textUnderCursor = text[i] + textUnderCursor
i -= 1
return textUnderCursor
def keyPressEvent(self, event):
if self._completer.popup().isVisible():
if event.key() in self._ignored_keys:
event.ignore()
return
super(AutoCompleteEdit, self).keyPressEvent(event)
completionPrefix = self.textUnderCursor()
if completionPrefix != self._completer.completionPrefix():
self._updateCompleterPopupItems(completionPrefix)
if len(event.text()) > 0 and len(completionPrefix) > 0:
self._completer.complete()
if len(completionPrefix) == 0:
self._completer.popup().hide()
def _updateCompleterPopupItems(self, completionPrefix):
"""
Filters the completer's popup items to only show items
with the given prefix.
"""
self._completer.setCompletionPrefix(completionPrefix)
# self._completer.popup().setCurrentIndex(
# self._completer.completionModel().index(0, 0))
if __name__ == '__main__':
def demo():
import sys
app = QtGui.QApplication(sys.argv)
values = ['Germany',
'Au<b>st</b>ria',
'Switzerland',
'Hungary',
'The United Kingdom of Great Britain and Northern Ireland',
'USA']
editor = AutoCompleteEdit(values)
window = QtGui.QWidget()
hbox = QtGui.QHBoxLayout()
hbox.addWidget(editor)
window.setLayout(hbox)
window.show()
sys.exit(app.exec_())
demo()
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