最小化QTreeWidgetItem中QTextEdit的大小

Question

我用一些itemwidgets填充了一个QTreeWidget，它的主要小部件是QTextEdit。我遇到的问题似乎是把尺寸缩小到可管理的程度。通常将大小策略设置为最大值的方法似乎行不通。下面是示例代码：

from PyQt4.QtGui import *
from PyQt4.QtCore import *

class MyMainWindow(QMainWindow):
    def __init__(self, parent=None):
        QMainWindow.__init__(self, parent)

        self.tree = QTreeWidget(self)
        self.tree.setColumnCount(1)
        self.setCentralWidget(self.tree)

        textEdit = QTextEdit()
        textEdit.setText("very Small Text Edit")
        sizePolicy = QSizePolicy(QSizePolicy.Preferred, QSizePolicy.MinimumExpanding)
        textEdit.setSizePolicy(sizePolicy)

        itemWidget = QTreeWidgetItem()
        itemWidget.setText(0, "")
        self.tree.addTopLevelItem(itemWidget)
        self.tree.setItemWidget(itemWidget, 0, textEdit)        

        biggerTextEdit = QTextEdit()
        biggerTextEdit.setText("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas et mauris in felis tempus molestie eu sit amet sapien. Proin dapibus pretium ipsum. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Pellentesque feugiat semper sem a accumsan. Nulla sollicitudin enim quis velit blandit posuere. Ut fringilla vulputate dolor, a accumsan lectus gravida a. Sed convallis facilisis mi et ullamcorper. Integer consectetur aliquet odio sit amet posuere.")        

        itemWidget2 = QTreeWidgetItem()
        itemWidget2.setText(0, "")
        self.tree.addTopLevelItem(itemWidget2)
        self.tree.setItemWidget(itemWidget2, 0, biggerTextEdit)        

if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    ui = MyMainWindow()
    ui.show()
    sys.exit(app.exec_())

请注意，不管文本的长度似乎对文本编辑的高度没有任何影响。一个qtextedt如何将自己（至少是垂直）缩放到最小的大小，而且为了知识起见，它为什么不像其他许多小部件那样以这种方式运行呢？提前谢谢！在

编辑：我现在应该注意到，我试图通过使用QLabel（它在调整大小、显示和单词扭曲方面的工作方式与我想要的一样）并将文本交互标志设置为editable来欺骗这种效果。这几乎是工作的一种方式，访问标签的编辑文本。不幸的是，对标签调用.text（）都会产生原始文本。QLineEdit不能是多行或换行，QTextEdit似乎过于复杂。在

现在的问题是，什么是最好的小部件来创建一个小的（300个字符或更少）文本显示小部件，也可以编辑？在

Answer 1

我想出了一个解决方案，它涉及子类化QTextEdit，而不是{}。新的QTextEdit根据内容计算所需的高度。然后我使用一个信号将计算出的高度输入QTreeWidgetItem的{}。在

下面的代码（PS我使用的是PyQt5）

import sys
from PyQt5 import QtWidgets
from PyQt5.QtCore import Qt, pyqtSignal, QSize

class AdjustableTextEdit(QtWidgets.QTextEdit):

    td_size_sig=pyqtSignal(QSize)
    def __init__(self,parent=None):
        super(AdjustableTextEdit,self).__init__(parent)

        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.textChanged.connect(self.resizeTextEdit)
        self.document().documentLayout().documentSizeChanged.connect(
                self.resizeTextEdit)

    def resizeTextEdit(self):

        docheight=self.document().size().height()
        margin=self.document().documentMargin()
        self.setMinimumHeight(docheight+2*margin)
        self.setMaximumHeight(docheight+2*margin)
        return

    def resizeEvent(self,e):
        super(AdjustableTextEdit,self).resizeEvent(e)
        self.td_size_sig.emit(QSize(self.sizeHint().width(),
            self.maximumHeight()))
        return

class MainFrame(QtWidgets.QFrame):

    def __init__(self,parent=None):
        super(MainFrame,self).__init__(parent)

        ha=QtWidgets.QHBoxLayout(self)
        self.tree=QtWidgets.QTreeWidget(self)
        ha.addWidget(self.tree)

        self.addTextEditWidget('very small text edit')
        self.addTextEditWidget("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas et mauris in felis tempus molestie eu sit amet sapien. Proin dapibus pretium ipsum. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Pellentesque feugiat semper sem a accumsan. Nulla sollicitudin enim quis velit blandit posuere. Ut fringilla vulputate dolor, a accumsan lectus gravida a. Sed convallis facilisis mi et ullamcorper. Integer consectetur aliquet odio sit amet posuere.")

        self.show()

    def addTextEditWidget(self,text):

        textEdit = AdjustableTextEdit()
        textEdit.setText(text)

        itemWidget = QtWidgets.QTreeWidgetItem()
        itemWidget.setText(0, "")

        self.tree.addTopLevelItem(itemWidget)
        self.tree.setItemWidget(itemWidget, 0, textEdit)
        textEdit.td_size_sig.connect(lambda size: itemWidget.setSizeHint(0,size))


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    ui = MainFrame()
    sys.exit(app.exec_())

Answer 2

为了实现您的目标，您必须定制项委托，因为它们为树小部件提供演示和编辑服务。Qt文档有一些有用的information regarding models, views and delegates（包括tutorial）。以下代码修复了使用委托的问题：

from PyQt4.QtGui import *
from PyQt4.QtCore import *

class MyMainWindow(QMainWindow):
    def __init__(self, parent=None):
        QMainWindow.__init__(self, parent)

        self.tree = QTreeWidget(self)
        self.tree.setColumnCount(1)
        self.tree.setItemDelegate(MyDelegate(self))
        self.setCentralWidget(self.tree)

        itemWidget = QTreeWidgetItem()
        itemWidget.setFlags(itemWidget.flags() | Qt.ItemIsEditable)
        itemWidget.setText(0, "very Small Text Edit")
        self.tree.addTopLevelItem(itemWidget)

        itemWidget2 = QTreeWidgetItem()
        itemWidget2.setFlags(itemWidget.flags() | Qt.ItemIsEditable)
        itemWidget2.setText(0, """very Small Text Edit\n
        very Small Text Edit\n
        very Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Editvery Small Text Edit""")
        self.tree.addTopLevelItem(itemWidget2)

class MyDelegate(QStyledItemDelegate):

    def sizeHint(self, option, index):
        default = QStyledItemDelegate.sizeHint(self, option, index)
        return QSize(default.width(), default.height() + 12)

    def createEditor(self, parent, option, index):
        editor = QTextEdit(parent)
        return editor

    def setEditorData(self, editor, index):
        text = index.model().data(index, Qt.DisplayRole).toString()
        editor.setText(text)

    def setModelData(self, editor, model, index):
        model.setData(index, QVariant(editor.toPlainText()))


if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    ui = MyMainWindow()
    ui.show()
    sys.exit(app.exec_())

该代码包含sizeHint()的简单重新实现。还请注意，您可以在createEditor方法中自定义QTextEdit。您可能还想重新实现paint()方法（这取决于您的需要）。在

请注意，子类化QTreeWidgetItem不是正确的方法（它甚至不是QWidget）。然而，QTreeWidget是一个方便的类，它使用预定义的树模型，因此在模型/视图编程框架中解决问题是有意义的。在