temp_code/python/pdf/pdf_watermark/gen_pdf_watermark.py

import os.path
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QPushButton, QFileDialog, QLineEdit, QScrollArea, QWidget, QVBoxLayout, QGridLayout

from PyQt5.QtCore import Qt
from PyPDF2 import PdfWriter, PdfReader
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("水印程序")

        x = 40
        y = 200
        interval = 45
        fixed_width = 200

        self.central_widget = QWidget(self)
        self.setCentralWidget(self.central_widget)
        self.layout = QVBoxLayout(self.central_widget)

        self.upload_button = QPushButton("上传文件", self)
        self.upload_button.move(140, 40)
        self.upload_button.clicked.connect(self.open_file_dialog)

        self.confirm_button = QPushButton("生成水印", self)
        self.confirm_button.move(380, 40)
        self.confirm_button.clicked.connect(self.start_watermark)

        # self.confirm_button = QPushButton("保存文件", self)
        # self.confirm_button.move(620, 40)

        self.clear_button = QPushButton("清除路径", self)
        self.clear_button.move(620, 40)
        self.clear_button.clicked.connect(self.clear_paths)

        self.load_label = QLabel("文件路径:", self)
        self.load_label.resize(2000, 50)
        self.load_label.move(40, 80)

        self.save_label = QLabel("", self)
        self.save_label.resize(2000, 50)
        self.save_label.move(40, 130)

        self.text_label = QLabel("水印内容:", self)
        self.text_label.move(x, y)
        y += interval

        self.text_input = QLineEdit(self)
        self.text_input.setText("默认水印文字")
        self.text_input.setFixedWidth(fixed_width)
        self.text_input.move(x + 90, y - 42)
        y += interval

        self.font_size_label = QLabel("字体大小:", self)
        self.font_size_label.setFixedWidth(fixed_width)
        self.font_size_label.move(x, y)
        y += interval

        self.font_size_input = QLineEdit(self)
        self.font_size_input.setFixedWidth(fixed_width)
        self.font_size_input.setText("12")
        self.font_size_input.move(x + 90, y - 42)
        y += interval

        self.x_label = QLabel("X 坐标:", self)
        self.x_label.setFixedWidth(fixed_width)
        self.x_label.move(x, y)
        y += interval

        self.x_input = QLineEdit(self)
        self.x_input.setFixedWidth(fixed_width)
        self.x_input.setText("100")
        self.x_input.move(x + 90, y - 42)
        y += interval

        self.y_label = QLabel("Y 坐标:", self)
        self.y_label.setFixedWidth(fixed_width)
        self.y_label.move(x, y)
        y += interval

        self.y_input = QLineEdit(self)
        self.y_input.setFixedWidth(fixed_width)
        self.y_input.setText("100")
        self.y_input.move(x + 90, y - 42)

        self.file_path = ""

    def open_file_dialog(self):
        options = QFileDialog.Options()
        file_path, _ = QFileDialog.getOpenFileName(
            self, "选择文件", "", "PDF文件 (*.pdf)", options=options)
        if file_path:
            self.file_path = file_path
            self.load_label.setText(f"文件路径: {self.file_path}")

            self.clear_button.clicked.connect(self.clear_paths)

    def start_watermark(self):
        if self.file_path:
            self.add_watermark()
        else:
            self.load_label.setText(f"文件路径:    ↑↑↑点这里!!\n\t整个PDF文件来这里,再生成水印!!!!")

    def add_watermark(self):
        file_path = self.file_path
        text = self.text_input.text()
        font_size = int(self.font_size_input.text())
        x = int(self.x_input.text())
        y = int(self.y_input.text())

        output_path = file_path.replace(".pdf", "_watermarked.pdf")

        input_pdf = PdfReader(open(file_path, "rb"))
        output_pdf = PdfWriter()

        num_pages = len(input_pdf.pages)

        # 创建水印PDF
        watermark_path = "watermark.pdf"
        c = canvas.Canvas(watermark_path, pagesize=letter)
        c.setFont("Helvetica", font_size)
        c.setFillAlpha(0.25)  # 尝试注释掉这行，看是否是透明度的问题
        c.saveState()
        c.translate(400, 500)  # 确保坐标在页面内，并且合适地调整
        c.rotate(45)
        c.drawCentredString(x, y, text)  # 确保坐标是正确的
        c.restoreState()
        c.showPage()  # 添加这一行来完成页面
        c.save()

        watermark_pdf = PdfReader("watermark.pdf")
        watermark_page = watermark_pdf.pages[0]

        for page_num in range(num_pages):
            page = input_pdf.pages[page_num]
            page.merge_page(watermark_page)
            output_pdf.add_page(page)

        with open(output_path, "wb") as f:
            output_pdf.write(f)

        # if os.path.exists("watermark.pdf"):
        #     os.remove("watermark.pdf")

        self.save_label.setText(f"生成路径: {output_path}")
        print('已生成水印')

    def clear_paths(self):
        self.file_path = ""
        self.load_label.setText("文件路径:")
        self.save_label.setText("")


if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setStyleSheet("QLabel, QLineEdit, QPushButton { font-size: 16px; }")

    window = MainWindow()
    window.resize(1000, 600)  # 设置窗口大小为 1000x600

    window.show()
    sys.exit(app.exec_())