基本绘图示例#
基本绘图示例展示了如何使用 QPainter 类以各种风格显示基本图形原语。
QPainter 在小部件和其他绘制设备上进行低级绘制。该类可以绘制从简单线条到复杂的饼形和圆弧等形状。它还可以绘制对齐的文本和位图。通常，它在“自然”坐标系中进行绘制，但也可以进行视图和全局变换。
<!DOCTYPE RCC><RCC version="1.0">
<qresource>
<file>images/brick.png</file>
<file>images/qt-logo.png</file>
</qresource>
</RCC>
# Copyright (C) 2013 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
"""PySide6 port of the widgets/painting/basicdrawing example from Qt v5.x, originating from PyQt"""
from PySide6.QtCore import QPoint, QRect, QSize, Qt, qVersion
from PySide6.QtGui import (QBrush, QConicalGradient, QLinearGradient, QPainter,
QPainterPath, QPalette, QPen, QPixmap, QPolygon,
QRadialGradient)
from PySide6.QtWidgets import (QApplication, QCheckBox, QComboBox, QGridLayout,
QLabel, QSpinBox, QWidget)
import basicdrawing_rc # noqa: F401
class RenderArea(QWidget):
points = QPolygon([
QPoint(10, 80),
QPoint(20, 10),
QPoint(80, 30),
QPoint(90, 70)
])
(Line, Points, Polyline, Polygon, Rect, RoundedRect, Ellipse,
Arc, Chord, Pie, Path, Text, Pixmap) = range(13)
def __init__(self, parent=None):
super().__init__(parent)
self.pen = QPen()
self.brush = QBrush()
self.pixmap = QPixmap()
self.shape = RenderArea.Polygon
self.antialiased = False
self.transformed = False
self.pixmap.load(':/images/qt-logo.png')
self.setBackgroundRole(QPalette.Base)
self.setAutoFillBackground(True)
def minimumSizeHint(self):
return QSize(100, 100)
def sizeHint(self):
return QSize(400, 200)
def set_shape(self, shape):
self.shape = shape
self.update()
def set_pen(self, pen):
self.pen = pen
self.update()
def set_brush(self, brush):
self.brush = brush
self.update()
def set_antialiased(self, antialiased):
self.antialiased = antialiased
self.update()
def set_transformed(self, transformed):
self.transformed = transformed
self.update()
def paintEvent(self, event):
rect = QRect(10, 20, 80, 60)
path = QPainterPath()
path.moveTo(20, 80)
path.lineTo(20, 30)
path.cubicTo(80, 0, 50, 50, 80, 80)
start_angle = 30 * 16
arc_length = 120 * 16
with QPainter(self) as painter:
painter.setPen(self.pen)
painter.setBrush(self.brush)
if self.antialiased:
painter.setRenderHint(QPainter.Antialiasing)
for x in range(0, self.width(), 100):
for y in range(0, self.height(), 100):
painter.save()
painter.translate(x, y)
if self.transformed:
painter.translate(50, 50)
painter.rotate(60.0)
painter.scale(0.6, 0.9)
painter.translate(-50, -50)
if self.shape == RenderArea.Line:
painter.drawLine(rect.bottomLeft(), rect.topRight())
elif self.shape == RenderArea.Points:
painter.drawPoints(RenderArea.points)
elif self.shape == RenderArea.Polyline:
painter.drawPolyline(RenderArea.points)
elif self.shape == RenderArea.Polygon:
painter.drawPolygon(RenderArea.points)
elif self.shape == RenderArea.Rect:
painter.drawRect(rect)
elif self.shape == RenderArea.RoundedRect:
painter.drawRoundedRect(rect, 25, 25, Qt.RelativeSize)
elif self.shape == RenderArea.Ellipse:
painter.drawEllipse(rect)
elif self.shape == RenderArea.Arc:
painter.drawArc(rect, start_angle, arc_length)
elif self.shape == RenderArea.Chord:
painter.drawChord(rect, start_angle, arc_length)
elif self.shape == RenderArea.Pie:
painter.drawPie(rect, start_angle, arc_length)
elif self.shape == RenderArea.Path:
painter.drawPath(path)
elif self.shape == RenderArea.Text:
qv = qVersion()
painter.drawText(rect, Qt.AlignCenter,
f"PySide 6\nQt {qv}")
elif self.shape == RenderArea.Pixmap:
painter.drawPixmap(10, 10, self.pixmap)
painter.restore()
painter.setPen(self.palette().dark().color())
painter.setBrush(Qt.NoBrush)
painter.drawRect(QRect(0, 0, self.width() - 1, self.height() - 1))
id_role = Qt.UserRole
class Window(QWidget):
def __init__(self):
super().__init__()
self._render_area = RenderArea()
self._shape_combo_box = QComboBox()
self._shape_combo_box.addItem("Polygon", RenderArea.Polygon)
self._shape_combo_box.addItem("Rectangle", RenderArea.Rect)
self._shape_combo_box.addItem("Rounded Rectangle", RenderArea.RoundedRect)
self._shape_combo_box.addItem("Ellipse", RenderArea.Ellipse)
self._shape_combo_box.addItem("Pie", RenderArea.Pie)
self._shape_combo_box.addItem("Chord", RenderArea.Chord)
self._shape_combo_box.addItem("Path", RenderArea.Path)
self._shape_combo_box.addItem("Line", RenderArea.Line)
self._shape_combo_box.addItem("Polyline", RenderArea.Polyline)
self._shape_combo_box.addItem("Arc", RenderArea.Arc)
self._shape_combo_box.addItem("Points", RenderArea.Points)
self._shape_combo_box.addItem("Text", RenderArea.Text)
self._shape_combo_box.addItem("Pixmap", RenderArea.Pixmap)
shape_label = QLabel("&Shape:")
shape_label.setBuddy(self._shape_combo_box)
self._pen_width_spin_box = QSpinBox()
self._pen_width_spin_box.setRange(0, 20)
self._pen_width_spin_box.setSpecialValueText("0 (cosmetic pen)")
pen_width_label = QLabel("Pen &Width:")
pen_width_label.setBuddy(self._pen_width_spin_box)
self._pen_style_combo_box = QComboBox()
self._pen_style_combo_box.addItem("Solid", Qt.SolidLine)
self._pen_style_combo_box.addItem("Dash", Qt.DashLine)
self._pen_style_combo_box.addItem("Dot", Qt.DotLine)
self._pen_style_combo_box.addItem("Dash Dot", Qt.DashDotLine)
self._pen_style_combo_box.addItem("Dash Dot Dot", Qt.DashDotDotLine)
self._pen_style_combo_box.addItem("None", Qt.NoPen)
pen_style_label = QLabel("&Pen Style:")
pen_style_label.setBuddy(self._pen_style_combo_box)
self._pen_cap_combo_box = QComboBox()
self._pen_cap_combo_box.addItem("Flat", Qt.FlatCap)
self._pen_cap_combo_box.addItem("Square", Qt.SquareCap)
self._pen_cap_combo_box.addItem("Round", Qt.RoundCap)
pen_cap_label = QLabel("Pen &Cap:")
pen_cap_label.setBuddy(self._pen_cap_combo_box)
self._pen_join_combo_box = QComboBox()
self._pen_join_combo_box.addItem("Miter", Qt.MiterJoin)
self._pen_join_combo_box.addItem("Bevel", Qt.BevelJoin)
self._pen_join_combo_box.addItem("Round", Qt.RoundJoin)
pen_join_label = QLabel("Pen &Join:")
pen_join_label.setBuddy(self._pen_join_combo_box)
self._brush_style_combo_box = QComboBox()
self._brush_style_combo_box.addItem("Linear Gradient", Qt.LinearGradientPattern)
self._brush_style_combo_box.addItem("Radial Gradient", Qt.RadialGradientPattern)
self._brush_style_combo_box.addItem("Conical Gradient", Qt.ConicalGradientPattern)
self._brush_style_combo_box.addItem("Texture", Qt.TexturePattern)
self._brush_style_combo_box.addItem("Solid", Qt.SolidPattern)
self._brush_style_combo_box.addItem("Horizontal", Qt.HorPattern)
self._brush_style_combo_box.addItem("Vertical", Qt.VerPattern)
self._brush_style_combo_box.addItem("Cross", Qt.CrossPattern)
self._brush_style_combo_box.addItem("Backward Diagonal", Qt.BDiagPattern)
self._brush_style_combo_box.addItem("Forward Diagonal", Qt.FDiagPattern)
self._brush_style_combo_box.addItem("Diagonal Cross", Qt.DiagCrossPattern)
self._brush_style_combo_box.addItem("Dense 1", Qt.Dense1Pattern)
self._brush_style_combo_box.addItem("Dense 2", Qt.Dense2Pattern)
self._brush_style_combo_box.addItem("Dense 3", Qt.Dense3Pattern)
self._brush_style_combo_box.addItem("Dense 4", Qt.Dense4Pattern)
self._brush_style_combo_box.addItem("Dense 5", Qt.Dense5Pattern)
self._brush_style_combo_box.addItem("Dense 6", Qt.Dense6Pattern)
self._brush_style_combo_box.addItem("Dense 7", Qt.Dense7Pattern)
self._brush_style_combo_box.addItem("None", Qt.NoBrush)
brush_style_label = QLabel("&Brush Style:")
brush_style_label.setBuddy(self._brush_style_combo_box)
other_options_label = QLabel("Other Options:")
self._antialiasing_check_box = QCheckBox("&Antialiasing")
self._transformations_check_box = QCheckBox("&Transformations")
self._shape_combo_box.activated.connect(self.shape_changed)
self._pen_width_spin_box.valueChanged.connect(self.pen_changed)
self._pen_style_combo_box.activated.connect(self.pen_changed)
self._pen_cap_combo_box.activated.connect(self.pen_changed)
self._pen_join_combo_box.activated.connect(self.pen_changed)
self._brush_style_combo_box.activated.connect(self.brush_changed)
self._antialiasing_check_box.toggled.connect(self._render_area.set_antialiased)
self._transformations_check_box.toggled.connect(self._render_area.set_transformed)
main_layout = QGridLayout()
main_layout.setColumnStretch(0, 1)
main_layout.setColumnStretch(3, 1)
main_layout.addWidget(self._render_area, 0, 0, 1, 4)
main_layout.setRowMinimumHeight(1, 6)
main_layout.addWidget(shape_label, 2, 1, Qt.AlignRight)
main_layout.addWidget(self._shape_combo_box, 2, 2)
main_layout.addWidget(pen_width_label, 3, 1, Qt.AlignRight)
main_layout.addWidget(self._pen_width_spin_box, 3, 2)
main_layout.addWidget(pen_style_label, 4, 1, Qt.AlignRight)
main_layout.addWidget(self._pen_style_combo_box, 4, 2)
main_layout.addWidget(pen_cap_label, 5, 1, Qt.AlignRight)
main_layout.addWidget(self._pen_cap_combo_box, 5, 2)
main_layout.addWidget(pen_join_label, 6, 1, Qt.AlignRight)
main_layout.addWidget(self._pen_join_combo_box, 6, 2)
main_layout.addWidget(brush_style_label, 7, 1, Qt.AlignRight)
main_layout.addWidget(self._brush_style_combo_box, 7, 2)
main_layout.setRowMinimumHeight(8, 6)
main_layout.addWidget(other_options_label, 9, 1, Qt.AlignRight)
main_layout.addWidget(self._antialiasing_check_box, 9, 2)
main_layout.addWidget(self._transformations_check_box, 10, 2)
self.setLayout(main_layout)
self.shape_changed()
self.pen_changed()
self.brush_changed()
self._antialiasing_check_box.setChecked(True)
self.setWindowTitle("Basic Drawing")
def shape_changed(self):
shape = self._shape_combo_box.itemData(self._shape_combo_box.currentIndex(), id_role)
self._render_area.set_shape(shape)
def pen_changed(self):
width = self._pen_width_spin_box.value()
style = Qt.PenStyle(self._pen_style_combo_box.itemData(
self._pen_style_combo_box.currentIndex(), id_role))
cap = Qt.PenCapStyle(self._pen_cap_combo_box.itemData(
self._pen_cap_combo_box.currentIndex(), id_role))
join = Qt.PenJoinStyle(self._pen_join_combo_box.itemData(
self._pen_join_combo_box.currentIndex(), id_role))
self._render_area.set_pen(QPen(Qt.blue, width, style, cap, join))
def brush_changed(self):
style = Qt.BrushStyle(self._brush_style_combo_box.itemData(
self._brush_style_combo_box.currentIndex(), id_role))
if style == Qt.LinearGradientPattern:
linear_gradient = QLinearGradient(0, 0, 100, 100)
linear_gradient.setColorAt(0.0, Qt.white)
linear_gradient.setColorAt(0.2, Qt.green)
linear_gradient.setColorAt(1.0, Qt.black)
self._render_area.set_brush(QBrush(linear_gradient))
elif style == Qt.RadialGradientPattern:
radial_gradient = QRadialGradient(50, 50, 50, 70, 70)
radial_gradient.setColorAt(0.0, Qt.white)
radial_gradient.setColorAt(0.2, Qt.green)
radial_gradient.setColorAt(1.0, Qt.black)
self._render_area.set_brush(QBrush(radial_gradient))
elif style == Qt.ConicalGradientPattern:
conical_gradient = QConicalGradient(50, 50, 150)
conical_gradient.setColorAt(0.0, Qt.white)
conical_gradient.setColorAt(0.2, Qt.green)
conical_gradient.setColorAt(1.0, Qt.black)
self._render_area.set_brush(QBrush(conical_gradient))
elif style == Qt.TexturePattern:
self._render_area.set_brush(QBrush(QPixmap(':/images/brick.png')))
else:
self._render_area.set_brush(QBrush(Qt.green, style))
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec())