使用 PySide 和 QTextEdit（版本 2）的半透明高光

Question

我正在尝试使用以下列表制作一个更完整的semi-transparent highlights 示例：

(1) 聚合 R、G、B、A 和高亮计数（五个列表）

(2)平均R,G,B,A（四个列表）

平均列表中的值被指定为背景颜色。聚合列表用于通过添加和减去突出显示颜色来计算平均值。每个列表的元素数量与文本小部件中的字符一样多。

我正在使用 pandas 数据框将亮点存储在内存中，因为最终可能会有大量它们需要以各种方式以及其他数据进行处理。将鼠标放在一个字符上会打印出它的位置、高光数量和 RGBA 值。除了，有时会弹出一个问题——就好像画笔从一个高光位置移动到另一个位置时被拖动了一秒钟。查看文本“PySide.QtCore”末尾的“e”上的绿松石色。我认为问题在于我如何使用光标的设置和移动位置——但我不确定。添加每个突出显示后是否需要重置光标的位置？我没有正确选择单个字符吗？

import sys
import pandas as pd
import sqlite3
from PySide.QtCore import *
from PySide.QtGui import *

def connect_database(db_file):
    try:
        conn = sqlite3.connect(db_file)
        return conn
    except Error as e:
        print(e)
        return None

def create_data(connection): # database connection
    c = connection.cursor() # database cursor
    c.execute("CREATE TABLE sections(id INTEGER PRIMARY KEY, start INTEGER, end INTEGER, r INTEGER, g INTEGER, b INTEGER, a INTEGER)")
    c.execute("INSERT INTO sections VALUES(1,0,20,100,200,100,100)")
    c.execute("INSERT INTO sections VALUES(2,15,20,200,100,100,50)")
    c.execute("INSERT INTO sections VALUES(3,18,30,100,100,200,100)")
    c.execute("INSERT INTO sections VALUES(4,50,60,100,200,200,150)")
    db.commit()
    return c.lastrowid


class QTextEdit2(QTextEdit):

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setMouseTracking(True)
        self.cursor = self.textCursor()

        self.length = len(self.toPlainText())
        self.bg_red = [0 for n in range(self.length)]    # stores aggregate values of all highlights (not averages)
        self.bg_green = [0 for n in range(self.length)]
        self.bg_blue = [0 for n in range(self.length)]
        self.bg_alpha = [0 for n in range(self.length)]
        self.bg_count = [0 for n in range(self.length)] # number of highlights. if this is 0 then don't display
                                                        # stored r,g,b just display white. in this example
                                                        # only highlights are written. everything else stays
                                                        # default

        self.display_red = [0 for n in range(self.length)]    # set to the value to display (average of highlights)
        self.display_green = [0 for n in range(self.length)]
        self.display_blue = [0 for n in range(self.length)]
        self.display_alpha = [0 for n in range(self.length)]

        self.sections = self.load_sections()
        self.color_sections()

    def mouseMoveEvent(self, event):
        point = QPoint()
        x = event.x()
        y = event.y()
        point.setX(x)
        point.setY(y)
        n = self.cursorForPosition(point).position()
        print("%d: Section Count: %d   RGBA: %d %d %d %d" % (n, self.bg_count[n],self.display_red[n], self.display_green[n],self.display_blue[n], self.display_alpha[n]))
        super().mouseMoveEvent(event)


    def load_sections(self):
        c = sqlite3.connect("qda_test_01.sqlite")
        df = pd.read_sql_query("SELECT * FROM sections", c)
        return df


    def blend_colors(self, start, end, r, g, b, a):
        for n in range(start,end):
            self.bg_red[n] = self.bg_red[n]+r
            self.bg_green[n] = self.bg_green[n]+g
            self.bg_blue[n] = self.bg_blue[n]+b
            self.bg_alpha[n] = self.bg_alpha[n]+a
            self.bg_count[n] = self.bg_count[n]+1
            self.display_red[n] = self.bg_red[n]/self.bg_count[n]
            self.display_green[n] = self.bg_green[n] / self.bg_count[n]
            self.display_blue[n] = self.bg_blue[n] / self.bg_count[n]
            self.display_alpha[n] = self.bg_alpha[n] / self.bg_count[n]
            if self.display_red[n] > 255:   # just in case RGBA data is weird...
                self.display_red[n] = 255
            if self.display_green[n] > 255:
                self.display_green[n] = 255
            if self.display_blue[n] > 255:
                self.display_blue[n] = 255
            if self.display_alpha[n] > 255:
                self.display_alpha[n] = 255
            if self.display_red[n] < 0:
                self.display_red[n] = 0
            if self.display_green[n] < 0:
                self.display_green[n] = 0
            if self.display_blue[n] < 0:
                self.display_blue[n] = 0
            if self.display_alpha[n] < 0:
                self.display_alpha[n] = 0

            print("LOCATION: %d | SECTION:     r:%d    g:%g    b:%d     a:%d      | DISPLAY:     r:%d    g:%g    b:%d     a:%d" % (n,self.bg_red[n],self.bg_green[n],self.bg_blue[n],self.bg_alpha[n],self.display_red[n],self.display_green[n],self.display_blue[n],self.display_alpha[n]))

            color = QColor(self.display_red[n], self.display_green[n], self.display_blue[n])
            color.setAlpha(self.display_alpha[n])
            cursor = self.textCursor()
            cursor.setPosition(n)
            cursor.movePosition(QTextCursor.NextCharacter, QTextCursor.KeepAnchor, 1)
            charfmt = cursor.charFormat()
            charfmt.setBackground(color)
            self.setCurrentCharFormat(charfmt)
            self.setTextCursor(cursor)


    def color_sections(self):
        for n in range(self.sections.id.count()):
            print("-----SECTION:%d-----" % (n))
            section = self.sections.iloc[n]
            self.blend_colors(section.start, section.end, section.r, section.g, section.b, section.a)



if __name__ == '__main__':

    # Create database and sections to highlight
    fn='qda_test_01.sqlite'
    db=connect_database(fn)
    id=create_data(db)
    db.close()

    app = QApplication(sys.argv)
    window = QTextEdit2(
        "In addition, the PySide.QtCore.QPoint class provides the PySide.QtCore.QPoint.manhattanLength() function which gives an inexpensive approximation of the length of the PySide.QtCore.QPoint object interpreted as a vector. Finally, PySide.QtCore.QPoint objects can be streamed as well as compared.")
    window.show()
    sys.exit(app.exec_())

Answer 1

如果您使用了我在previous answer 中提供的代码，那么当前示例将正常工作。事实上，您的更改已经引入了很多错误。

要对此进行调试，您应该首先检查确切应该突出显示哪些文本块。从数据库中获取文本的前 65 个字符和开始/结束值，得到：

>>> t = "In addition, the PySide.QtCore.QPoint class provides the PySide."
>>> t[0:20]
'In addition, the PyS'
>>> t[15:20]
'e PyS'
>>> t[18:30]
'ySide.QtCore'
>>> t[50:60]
'es the PyS'

如果您将其与实际输出中的高亮部分进行比较，您会发现没有一个部分正确匹配（例如，查看每个“PySide”中的“S”）。

要使其正常工作，您必须在开始时获取文本光标一次，使用它进行所有必要的更改，然后重新设置它一次强>在最后：

cursor = self.textCursor()
for n in range(start, end):
    ...
    cursor.setPosition(n)
    cursor.movePosition(QTextCursor.NextCharacter, QTextCursor.KeepAnchor)
    charfmt = cursor.charFormat()
    charfmt.setBackground(color)
    cursor.setCharFormat(charfmt)
cursor.clearSelection()
self.setTextCursor(cursor)

这类似于更新数据库：您使用游标安排一系列更改，然后在最后将它们作为单个操作提交。