PyQt - BrushStyle Constants

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BrushStyle constants in PyQt define different patterns and styles used for filling areas, such as rectangles, ellipses, or polygons. These patterns add visual appeal and distinction to the elements of a PyQt application.

PyQt offers a range of BrushStyle constants, each representing a unique pattern or style. Some of the commonly used BrushStyle constants include −

• SolidPattern − Fills the area with a solid color.
• Dense1Pattern, Dense2Pattern, ..., Dense7Pattern − Fills the area with dense patterns of varying densities.
• HorPattern, VerPattern, CrossPattern, BDiagPattern, FDiagPattern − Fills the area with horizontal, vertical, cross, backward diagonal, or forward diagonal patterns, respectively.
• LinearGradientPattern − Fills the area with a linear gradient.
• RadialGradientPattern − Fills the area with a radial gradient.
• ConicalGradientPattern − Fills the area with a conical gradient.
• ConicalGradientPattern − Fills the area with a conical gradient.

Predefined QColor Styles

Predefined QColor Objects

Custom color can be chosen by specifying RGB or CMYK or HSV values.

Example 1:Filling a Rectangle with Solid Color

In this example, we'll create a PyQt application that draws a rectangle filled with a solid color.

In the below example, in the MainWindow class, we override the paintEvent method to perform custom painting. We create a QPainter object and set the brush to a solid red color using QBrush and Qt.SolidPattern. We draw a rectangle using the drawRect method of the QPainter object.

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtGui import QPainter, QColor, QBrush
from PyQt5.QtCore import Qt


class MainWindow(QMainWindow):
   def __init__(self):
      super().__init__()

   def paintEvent(self, event):
      painter = QPainter(self)
      painter.setBrush(QBrush(Qt.red, Qt.SolidPattern))
      painter.drawRect(100, 100, 200, 100)


if __name__ == "__main__":
   app = QApplication(sys.argv)
   window = MainWindow()
   window.setGeometry(100, 100, 400, 300)
   window.show()
   sys.exit(app.exec_())

Output

The above code produces the following output. A PyQt window will open, displaying a rectangle filled with a solid red color.

Example 2: Filling a Rectangle with Dense Pattern

In the below example, we create a QBrush object with a dense green pattern (Qt.Dense4Pattern). We set the brush of the QPainter object to the created brush. Finally, we draw a rectangle using the drawRect method.

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtGui import QPainter, QColor, QBrush
from PyQt5.QtCore import Qt


class MainWindow(QMainWindow):
   def __init__(self):
      super().__init__()

   def paintEvent(self, event):
      painter = QPainter(self)
      brush = QBrush(Qt.green, Qt.Dense4Pattern)
      painter.setBrush(brush)
      painter.drawRect(100, 100, 200, 100)

if __name__ == "__main__":
   app = QApplication(sys.argv)
   window = MainWindow()
   window.setGeometry(100, 100, 400, 300)
   window.show()
   sys.exit(app.exec_())

Output

The above code produces the following result −

Example 3: Filling a Rectangle with LinearGradientPattern

In this example, we'll create a PyQt application that draws a rectangle filled with a linear gradient.

In the below example, we override the paintEvent method for custom painting. We create a QLinearGradient object defining the gradient's start and end points. We set the colors of the gradient using setColorAt method. We create a QBrush object with the linear gradient. Finally, we draw a rectangle using the drawRect method.

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtGui import QPainter, QBrush, QLinearGradient
from PyQt5.QtCore import Qt


class MainWindow(QMainWindow):
   def __init__(self):
      super().__init__()

   def paintEvent(self, event):
      painter = QPainter(self)
      gradient = QLinearGradient(0, 0, 400, 300)
      gradient.setColorAt(0, Qt.blue)
      gradient.setColorAt(1, Qt.yellow)
      brush = QBrush(gradient)
      painter.setBrush(brush)
      painter.drawRect(100, 100, 200, 100)

if __name__ == "__main__":
   app = QApplication(sys.argv)
   window = MainWindow()
   window.setGeometry(100, 100, 400, 300)
   window.show()
   sys.exit(app.exec_())

Output

The above code produces the follwing result −