我想研究如何制作一个小型用户界面，用户可以在其中键入一些字母并根据给定的数据源（此处列出）获得一些建议，从而使搜索更容易。为此，我正在使用 Qt 的QCompleter课程。
在匹配元素中，键入的字母应使用 HTML 突出显示，如以下代码中的示例Au<b>st</b>ria：最后，我将一些 SO 答案（参见How to make item view render rich (html) text in Qt）和教程合并到一个小的独立模块中：
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()
我的问题是用户 Timo 在答案https://stackoverflow.com/a/5443112/1504082中的建议：
在 line: 'doc.setHtml(options.text)' 之后，您还需要设置 doc.setTextWidth(option.rect.width())，否则代理将无法正确呈现相对于目标绘图区域的较长内容。例如不在 QListView 中换行。
所以我这样做是为了避免在完成者的弹出窗口中裁剪长文本。但我得到以下输出：
这个额外的垂直边距从何而来？
我对此进行了一些调查，发现有时使用包含具有属性的矩形的参数调用 的sizeHint方法。并且显示行为最终在调用. 但我最终无法找出是谁用这个参数调用它以及如何正确解决这个问题。HTMLDelegateoptions(0, 0, 0, 0)doc.setTextWidth(options.rect.width())
有人可以解释这是从哪里来的，我该如何正确地解决这个问题？