I want the program to display the formula rendered on the screen, e.g.

a^2 + b^2 = c^2

But nothing appears. I am using QTextObject to draw the LaTeX image directly on an object containing a math expression.

I need python equal or greater than .12 for gemini api feature So i cannot use pyqt6 as it does not get install.

Recommend me the best version of python for QTextObject and gemini API 

import sys
from io import BytesIO
from PySide6.QtWidgets import QApplication, QTextEdit
from PySide6.QtGui import (
QTextObjectInterface,
QTextFormat,
QTextCharFormat,
QImage,
QPainter,
QColor
)
from PySide6.QtCore import QSizeF, QObject, Qt

from matplotlib.figure import Figure
from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas

LATEX_FORMAT = QTextFormat.UserObject + 1

class LatexRenderer(QObject, QTextObjectInterface):
def init(self):
super().init()
self._cache = {}

def intrinsicSize(self, doc, posInDocument, format):
    latex = format.property(1)
    img = self.render_latex(latex)
    return QSizeF(img.width(), img.height())

def drawObject(self, painter, rect, doc, posInDocument, format):
    latex = format.property(1)
    img = self.render_latex(latex)
    
    # DEBUG: Draw a light gray background so we can see the "box"
    painter.fillRect(rect, QColor("#f0f0f0"))
    
    painter.drawImage(rect.topLeft(), img)

def render_latex(self, latex):
    if latex in self._cache:       
        return self._cache[latex]

    # Force a specific DPI and small figure
    fig = Figure(figsize=(1, 1), dpi=100)
    canvas = FigureCanvas(fig)
    fig.patch.set_alpha(0) 

    # Using 'mathtext' specifically
    fig.text(0.5, 0.5, f"${latex}$", 
             fontsize=20, 
             ha='center', 
             va='center', 
             color="black")

    buf = BytesIO()
    # 'tight' is essential, but let's add a small pad to be safe
    fig.savefig(buf, format='png', bbox_inches='tight', pad_inches=0.1, transparent=True)
    
    img = QImage()
    img.loadFromData(buf.getvalue(), "PNG")
    
    self._cache[latex] = img
    return img

class MainWindow(QTextEdit):
def init(self):
super().init()

    # 1. Register handler BEFORE adding text
    self.renderer = LatexRenderer()
    self.document().documentLayout().registerHandler(LATEX_FORMAT, self.renderer)

    # 2. Insert text and math
    cursor = self.textCursor()
    cursor.insertText("The Pythagorean theorem is: ")
    
    # Use a RAW string for LaTeX
    self.insert_latex(cursor, r"a^2 + b^2 = c^2")
    
    cursor.insertText("\n\nAnd the Quadratic formula: ")
    self.insert_latex(cursor, r"x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}")

def insert_latex(self, cursor, latex):
    fmt = QTextCharFormat()
    fmt.setObjectType(LATEX_FORMAT)
    fmt.setProperty(1, latex)
    cursor.insertText("\uFFFC", fmt)

if name == "main":
app = QApplication(sys.argv)
# Removing the deprecated HighDPI line as it's now default
w = MainWindow()
w.resize(600, 400)
w.show()
sys.exit(app.exec())