【原创】python3+PyQt5 图形项的自定义和交互
本文通过Python3+PyQt5实现《pythonQt Gui 快速编程》这本书的pageDesigner应用程序，采用QGraphicsView，QGraphicsScene，QGraphicsItem，这个程序包含有多个文本，图片和框的页面。有些图形类在PyQt5已过时，所以本代码改动幅度比较大。主要的类或方法的改变如下：
defwheelEvent(self, event):
#factor = 1.41 ** (-event.delta() / 240.0)
#factor = 1.41 ** (-abs(event.startX()-event.y()) / 240.0)
factor = event.angleDelta().y()/120.0
if event.angleDelta().y()/120.0 > 0:
factor=2
else:
factor=0.5
self.scale(factor, factor)
为了保持代码可读行，增加了一个类：
classGraphicsPixmapItem(QGraphicsPixmapItem): #add by yangrongdong
def__init__(self,pixmap):
super(QGraphicsPixmapItem, self).__init__(pixmap)
本例中还有包含菜单的按钮：
if text == "&Align":
menu = QMenu(self)
for text, arg in (
("Align &Left", Qt.AlignLeft),
("Align &Right", Qt.AlignRight),
("Align &Top", Qt.AlignTop),
("Align &Bottom", Qt.AlignBottom)):
wrapper = functools.partial(self.setAlignment, arg)
self.wrapped.append(wrapper)
menu.addAction(text, wrapper)
button.setMenu(menu)
import functools
import random
import sys
from PyQt5.QtCore import (QByteArray, QDataStream, QFile,QFileInfo,
QIODevice, QPoint, QPointF, QRectF, Qt)
from PyQt5.QtWidgets import (QApplication, QDialog,
QDialogButtonBox, QFileDialog, QFontComboBox,
QGraphicsItem, QGraphicsPixmapItem,
QGraphicsScene, QGraphicsTextItem, QGraphicsView,QGridLayout,
QHBoxLayout, QLabel, QMenu, QMessageBox,QPushButton,QSpinBox,
QStyle, QTextEdit, QVBoxLayout)
from PyQt5.QtGui importQFont,QCursor,QFontMetrics,QTransform,QPainter,QPen,QPixmap
from PyQt5.QtPrintSupport import QPrinter,QPrintDialog
MAC = True
try:
fromPyQt5.QtGui import qt_mac_set_native_menubar
except ImportError:
MAC =False
#PageSize = (595, 842) # A4 in points
PageSize = (612, 792) # US Letter in points
PointSize = 10
MagicNumber = 0x70616765
FileVersion = 1
Dirty = False
class TextItemDlg(QDialog):
def__init__(self, item=None, position=None, scene=None,parent=None):
super(QDialog, self).__init__(parent)
self.item = item
self.position = position
self.scene = scene
self.editor = QTextEdit()
self.editor.setAcceptRichText(False)
self.editor.setTabChangesFocus(True)
editorLabel = QLabel("&Text:")
editorLabel.setBuddy(self.editor)
self.fontComboBox = QFontComboBox()
self.fontComboBox.setCurrentFont(QFont("Times", PointSize))
fontLabel = QLabel("&Font:")
fontLabel.setBuddy(self.fontComboBox)
self.fontSpinBox = QSpinBox()
self.fontSpinBox.setAlignment(Qt.AlignRight|Qt.AlignVCenter)
self.fontSpinBox.setRange(6, 280)
self.fontSpinBox.setValue(PointSize)
fontSizeLabel = QLabel("&Size:")
fontSizeLabel.setBuddy(self.fontSpinBox)
self.buttonBox = QDialogButtonBox(QDialogButtonBox.Ok|
QDialogButtonBox.Cancel)
self.buttonBox.button(QDialogButtonBox.Ok).setEnabled(False)
if self.item is not None:
self.editor.setPlainText(self.item.toPlainText())
self.fontComboBox.setCurrentFont(self.item.font())
self.fontSpinBox.setValue(self.item.font().pointSize())
layout = QGridLayout()
layout.addWidget(editorLabel, 0, 0)
layout.addWidget(self.editor, 1, 0, 1, 6)
layout.addWidget(fontLabel, 2, 0)
layout.addWidget(self.fontComboBox, 2, 1, 1, 2)
layout.addWidget(fontSizeLabel, 2, 3)
layout.addWidget(self.fontSpinBox, 2, 4, 1, 2)
layout.addWidget(self.buttonBox, 3, 0, 1, 6)
self.setLayout(layout)
self.fontComboBox.currentFontChanged.connect(self.updateUi)
self.fontSpinBox.valueChanged.connect(self.updateUi)
self.editor.textChanged.connect(self.updateUi)
self.buttonBox.accepted.connect(self.accept)
self.buttonBox.rejected.connect(self.reject)
self.setWindowTitle("Page Designer - {0} Text Item".format(
"Add" if self.item is None else "Edit"))
self.updateUi()
defupdateUi(self):
font = self.fontComboBox.currentFont()
font.setPointSize(self.fontSpinBox.value())
self.editor.document().setDefaultFont(font)
self.buttonBox.button(QDialogButtonBox.Ok).setEnabled(
bool(self.editor.toPlainText()))
defaccept(self):
if self.item is None:
self.item = TextItem("", self.position, self.scene)
font = self.fontComboBox.currentFont()
font.setPointSize(self.fontSpinBox.value())
self.item.setFont(font)
self.item.setPlainText(self.editor.toPlainText())
self.item.update()
global Dirty
Dirty = True
QDialog.accept(self)
class TextItem(QGraphicsTextItem):
def__init__(self, text, position, scene,
font=QFont("Times", PointSize), matrix=QTransform()):
super(TextItem, self).__init__(text)
self.setFlags(QGraphicsItem.ItemIsSelectable|
QGraphicsItem.ItemIsMovable)
self.setFont(font)
self.setPos(position)
self.setTransform(matrix)
scene.clearSelection()
scene.addItem(self)
self.setSelected(True)
global Dirty
Dirty = True
defparentWidget(self):
return self.scene().views()[0]
defitemChange(self, change, variant):
if change != QGraphicsItem.ItemSelectedChange:
global Dirty
Dirty = True
return QGraphicsTextItem.itemChange(self, change, variant)
defmouseDoubleClickEvent(self, event):
dialog = TextItemDlg(self, self.parentWidget())
dialog.exec_()
classGraphicsPixmapItem(QGraphicsPixmapItem): #add by yangrongdong
def__init__(self,pixmap):
super(QGraphicsPixmapItem, self).__init__(pixmap)
class BoxItem(QGraphicsItem):
def__init__(self, position, scene, style=Qt.SolidLine,
rect=None, matrix=QTransform()):
super(BoxItem, self).__init__()
self.setFlags(QGraphicsItem.ItemIsSelectable|
QGraphicsItem.ItemIsMovable|
QGraphicsItem.ItemIsFocusable)
if rect is None:
rect = QRectF(-10 * PointSize, -PointSize, 20 * PointSize,
2 * PointSize)
self.rect = rect
self.style = style
self.setPos(position)
self.setTransform(matrix)
scene.clearSelection()
scene.addItem(self)
self.setSelected(True)
self.setFocus()
global Dirty
Dirty = True
defparentWidget(self):
return self.scene().views()[0]
defboundingRect(self):
return self.rect.adjusted(-2, -2, 2, 2)
defpaint(self, painter, option, widget):
pen = QPen(self.style)
pen.setColor(Qt.black)
pen.setWidth(1)
if option.state & QStyle.State_Selected:
pen.setColor(Qt.blue)
painter.setPen(pen)
painter.drawRect(self.rect)
defitemChange(self, change, variant):
if change != QGraphicsItem.ItemSelectedChange:
global Dirty
Dirty = True
return QGraphicsItem.itemChange(self, change, variant)
defcontextMenuEvent(self, event):
wrapped = []
menu = QMenu(self.parentWidget())
for text, param in (
("&Solid", Qt.SolidLine),
("&Dashed", Qt.DashLine),
("D&otted", Qt.DotLine),
("D&ashDotted", Qt.DashDotLine),
("DashDo&tDotted", Qt.DashDotDotLine)):
wrapper = functools.partial(self.setStyle, param)
wrapped.append(wrapper)
menu.addAction(text, wrapper)
menu.exec_(event.screenPos())
defsetStyle(self, style):
self.style = style
self.update()
global Dirty
Dirty = True
defkeyPressEvent(self, event):
factor = PointSize / 4
changed = False
if event.modifiers() & Qt.ShiftModifier:
if event.key() == Qt.Key_Left:
self.rect.setRight(self.rect.right() - factor)
changed = True
elif event.key() == Qt.Key_Right:
self.rect.setRight(self.rect.right() + factor)
changed = True
elif event.key() == Qt.Key_Up:
self.rect.setBottom(self.rect.bottom() - factor)
changed = True
elif event.key() == Qt.Key_Down:
self.rect.setBottom(self.rect.bottom() + factor)
changed = True
if changed:
self.update()
global Dirty
Dirty = True
else:
QGraphicsItem.keyPressEvent(self, event)
class GraphicsView(QGraphicsView):
def__init__(self, parent=None):
super(GraphicsView, self).__init__(parent)
self.setDragMode(QGraphicsView.RubberBandDrag)
self.setRenderHint(QPainter.Antialiasing)
self.setRenderHint(QPainter.TextAntialiasing)
defwheelEvent(self, event):
#factor = 1.41 ** (-event.delta() / 240.0)
factor = event.angleDelta().y()/120.0
if event.angleDelta().y()/120.0 > 0:
factor=2
else:
factor=0.5
self.scale(factor, factor)
class MainForm(QDialog):
def__init__(self, parent=None):
super(MainForm, self).__init__(parent)
self.filename = ""
self.copiedItem = QByteArray()
self.pasteOffset = 5
self.prevPoint = QPoint()
self.addOffset = 5
self.borders = []
self.printer = QPrinter(QPrinter.HighResolution)
self.printer.setPageSize(QPrinter.Letter)
self.view = GraphicsView()
self.scene = QGraphicsScene(self)
self.scene.setSceneRect(0, 0, PageSize[0], PageSize[1])
self.addBorders()
self.view.setScene(self.scene)
self.wrapped = [] # Needed to keep wrappers alive
buttonLayout = QVBoxLayout()
for text, slot in (
("Add &Text", self.addText),
("Add &Box", self.addBox),
("Add Pi&xmap", self.addPixmap),
("&Align", None),
("&Copy", self.copy),
("C&ut", self.cut),
("&Paste", self.paste),
("&Delete...", self.delete),
("&Rotate", self.rotate),
("Pri&nt...", self.print_),
("&Open...", self.open),
("&Save", self.save),
("&Quit", self.accept)):
button = QPushButton(text)
if not MAC:
button.setFocusPolicy(Qt.NoFocus)
if slot is not None:
button.clicked.connect(slot)
if text == "&Align":
menu = QMenu(self)
for text, arg in (
("Align &Left", Qt.AlignLeft),
("Align &Right", Qt.AlignRight),
("Align &Top", Qt.AlignTop),
("Align &Bottom", Qt.AlignBottom)):
wrapper = functools.partial(self.setAlignment, arg)
self.wrapped.append(wrapper)
menu.addAction(text, wrapper)
button.setMenu(menu)
if text == "Pri&nt...":
buttonLayout.addStretch(5)
if text == "&Quit":
buttonLayout.addStretch(1)
buttonLayout.addWidget(button)
buttonLayout.addStretch()
layout = QHBoxLayout()
layout.addWidget(self.view, 1)
layout.addLayout(buttonLayout)
self.setLayout(layout)
fm = QFontMetrics(self.font())
self.resize(self.scene.width() + fm.width(" Delete... ") +50,
self.scene.height() + 50)
self.setWindowTitle("Page Designer")
defaddBorders(self):
self.borders = []
rect = QRectF(0, 0, PageSize[0], PageSize[1])
self.borders.append(self.scene.addRect(rect, Qt.yellow))
margin = 5.25 * PointSize
self.borders.append(self.scene.addRect(
rect.adjusted(margin, margin, -margin, -margin),
Qt.yellow))
defremoveBorders(self):
while self.borders:
item = self.borders.pop()
self.scene.removeItem(item)
del item
defreject(self):
self.accept()
defaccept(self):
self.offerSave()
QDialog.accept(self)
defofferSave(self):
if (Dirty and QMessageBox.question(self,
"Page Designer - Unsaved Changes",
"Save unsaved changes?",
QMessageBox.Yes|QMessageBox.No) ==
QMessageBox.Yes):
self.save()
defposition(self):
point = self.mapFromGlobal(QCursor.pos())
if not self.view.geometry().contains(point):
coord = random.randint(36, 144)
point = QPoint(coord, coord)
else:
if point == self.prevPoint:
point += QPoint(self.addOffset, self.addOffset)
self.addOffset += 5
else:
self.addOffset = 5
self.prevPoint = point
return self.view.mapToScene(point)
defaddText(self):
dialog = TextItemDlg(position=self.position(),
scene=self.scene, parent=self)
dialog.exec_()
defaddBox(self):
BoxItem(self.position(), self.scene)
defaddPixmap(self):
path = (QFileInfo(self.filename).path()
if self.filename else ".")
fname,filetype = QFileDialog.getOpenFileName(self,
"Page Designer - Add Pixmap", path,
"Pixmap Files (*.bmp *.jpg *.png *.xpm)")
if not fname:
return
self.createPixmapItem(QPixmap(fname), self.position())
defcreatePixmapItem(self, pixmap, position,matrix=QTransform()):
item = GraphicsPixmapItem(pixmap)
item.setFlags(QGraphicsItem.ItemIsSelectable|
QGraphicsItem.ItemIsMovable)
item.setPos(position)
item.setTransform(matrix)
self.scene.clearSelection()
self.scene.addItem(item)
item.setSelected(True)
global Dirty
Dirty = True
return item
defselectedItem(self):
items = self.scene.selectedItems()
if len(items) == 1:
return items[0]
return None
defcopy(self):
item = self.selectedItem()
if item is None:
return
self.copiedItem.clear()
self.pasteOffset = 5
stream = QDataStream(self.copiedItem, QIODevice.WriteOnly)
self.writeItemToStream(stream, item)
defcut(self):
item = self.selectedItem()
if item is None:
return
self.copy()
self.scene.removeItem(item)
del item
defpaste(self):
if self.copiedItem.isEmpty():
return
stream = QDataStream(self.copiedItem, QIODevice.ReadOnly)
self.readItemFromStream(stream, self.pasteOffset)
self.pasteOffset += 5
defsetAlignment(self, alignment):
# Items are returned in arbitrary order
items = self.scene.selectedItems()
if len(items) <= 1:
return
# Gather coordinate data
leftXs, rightXs, topYs, bottomYs = [], [], [], []
for item in items:
rect = item.sceneBoundingRect()
leftXs.append(rect.x())
rightXs.append(rect.x() + rect.width())
topYs.append(rect.y())
bottomYs.append(rect.y() + rect.height())
# Perform alignment
if alignment == Qt.AlignLeft:
xAlignment = min(leftXs)
for i, item in enumerate(items):
item.moveBy(xAlignment - leftXs[i], 0)
elif alignment == Qt.AlignRight:
xAlignment = max(rightXs)
for i, item in enumerate(items):
item.moveBy(xAlignment - rightXs[i], 0)
elif alignment == Qt.AlignTop:
yAlignment = min(topYs)
for i, item in enumerate(items):
item.moveBy(0, yAlignment - topYs[i])
elif alignment == Qt.AlignBottom:
yAlignment = max(bottomYs)
for i, item in enumerate(items):
item.moveBy(0, yAlignment - bottomYs[i])
global Dirty
Dirty = True
defrotate(self):
for item in self.scene.selectedItems():
item.setRotation(item.rotation()+30)
defdelete(self):
items = self.scene.selectedItems()
if (len(items) and QMessageBox.question(self,
"Page Designer - Delete",
"Delete {0} item{1}?".format(len(items),
"s" if len(items) != 1 else ""),
QMessageBox.Yes|QMessageBox.No) ==
QMessageBox.Yes):
while items:
item = items.pop()
self.scene.removeItem(item)
del item
global Dirty
Dirty = True
defprint_(self):
dialog = QPrintDialog(self.printer)
if dialog.exec_():
painter = QPainter(self.printer)
painter.setRenderHint(QPainter.Antialiasing)
painter.setRenderHint(QPainter.TextAntialiasing)
self.scene.clearSelection()
self.removeBorders()
self.scene.render(painter)
self.addBorders()
defopen(self):
self.offerSave()
path = (QFileInfo(self.filename).path()
if self.filename else ".")
fname,filetype = QFileDialog.getOpenFileName(self,
"Page Designer - Open", path,
"Page Designer Files (*.pgd)")
if not fname:
return
self.filename = fname
fh = None
try:
fh = QFile(self.filename)
if not fh.open(QIODevice.ReadOnly):
raise IOError(str(fh.errorString()))
items = self.scene.items()
while items:
item = items.pop()
self.scene.removeItem(item)
del item
self.addBorders()
stream = QDataStream(fh)
stream.setVersion(QDataStream.Qt_5_7)
magic = stream.readInt32()
if magic != MagicNumber:
raise IOError("not a valid .pgd file")
fileVersion = stream.readInt16()
if fileVersion != FileVersion:
raise IOError("unrecognised .pgd file version")
while not fh.atEnd():
self.readItemFromStream(stream)
except IOError as e:
QMessageBox.warning(self, "Page Designer -- Open Error",
"Failed to open {0}: {1}".format(self.filename, e))
finally:
if fh is not None:
fh.close()
global Dirty
Dirty = False
defsave(self):
if not self.filename:
path = "."
fname,filetype = QFileDialog.getSaveFileName(self,
"Page Designer - Save As", path,
"Page Designer Files (*.pgd)")
if not fname:
return
self.filename = fname
fh = None
try:
fh = QFile(self.filename)
if not fh.open(QIODevice.WriteOnly):
raise IOError(str(fh.errorString()))
self.scene.clearSelection()
stream = QDataStream(fh)
stream.setVersion(QDataStream.Qt_5_7)
stream.writeInt32(MagicNumber)
stream.writeInt16(FileVersion)
for item in self.scene.items():
self.writeItemToStream(stream, item)
except IOError as e:
QMessageBox.warning(self, "Page Designer -- Save Error",
"Failed to save {0}: {1}".format(self.filename, e))
finally:
if fh is not None:
fh.close()
global Dirty
Dirty = False
defreadItemFromStream(self, stream, offset=0):
type = ""
position = QPointF()
matrix = QTransform()
rotateangle=0#add by yangrongdong
type=stream.readQString()
stream >> position >> matrix
if offset:
position += QPointF(offset, offset)
if type == "Text":
text = ""
font = QFont()
text=stream.readQString()
stream >> font
rotateangle=stream.readFloat()
tx=TextItem(text, position, self.scene, font, matrix)
tx.setRotation(rotateangle)
elif type == "Box":
rect = QRectF()
stream >> rect
style = Qt.PenStyle(stream.readInt16())
rotateangle=stream.readFloat()
bx=BoxItem(position, self.scene, style, rect, matrix)
bx.setRotation(rotateangle)
elif type == "Pixmap":
pixmap = QPixmap()
stream >> pixmap
rotateangle=stream.readFloat()
px=self.createPixmapItem(pixmap, position, matrix)
px.setRotation(rotateangle)
defwriteItemToStream(self, stream, item):
if isinstance(item, TextItem):
stream.writeQString("Text")
stream<<item.pos()<<item.transform()
stream.writeQString(item.toPlainText())
stream<< item.font()
stream.writeFloat(item.rotation())#add by yangrongdong
elif isinstance(item, GraphicsPixmapItem):
stream.writeQString("Pixmap")
stream << item.pos() << item.transform() <<item.pixmap()
stream.writeFloat(item.rotation())#add by yangrongdong
elif isinstance(item, BoxItem):
stream.writeQString("Box")
stream<< item.pos() << item.transform() <<item.rect
stream.writeInt16(item.style)
stream.writeFloat(item.rotation())#add by yangrongdong
app = QApplication(sys.argv)
form = MainForm()
rect = QApplication.desktop().availableGeometry()
form.resize(int(rect.width() * 0.6), int(rect.height() *0.9))
form.show()
app.exec_()
