[PySide] Possbile to syntax hightlight the content of a QTreeWidget item?

[Aaron Richiger]

Hello Zhu!

For QTreeWidget, you can use setItemWidget() to set any widget you want 
for this item. I used it to place a QLabel with colorized text in the 
item. To colorize the text of a QLabel you can use html. To generate the 
correct html for any assignment statement with binary operations of any 
variable, I implemented a very simple AST model, I guess you have 
something similar for your code. All nodes have a to_html() method to 
get colorized html output for this node. Here is a simple working example:

################## Code #################
#!/usr/bin/python

import sys
from PySide.QtGui import *


class AstNode(object):
     """Base class for all nodes of the code model."""

     def __init__(self):
         self.color = "black"

     def get_colorized_html_for(self, text):
         """Embed text in html tags setting the text font."""

         return '<font color="%s">%s</font>' % (self.color, text)


class Assignment(AstNode):
     """Model for an assignment statement."""

     def __init__(self, left, right):
         super(Assignment, self).__init__()
         self.left = left
         self.right = right

     def to_html(self):
         """Return html text to represent this node with syntax 
highlighting."""

         return self.left.to_html() + \
                 self.get_colorized_html_for(" = ") + \
                 self.right.to_html()


class BinaryOp(AstNode):
     """Model for a binary operation, such as a + b."""

     def __init__(self, left, right, operator):
         super(BinaryOp, self).__init__()
         self.color = "#0000FF"         # example for hex rgb, analogous 
to blue
         self.left = left
         self.right = right
         self.operator = operator

     def to_html(self):
         """Return html text to represent this node with syntax 
highlighting."""

         return self.left.to_html() + \
                 self.get_colorized_html_for(' ' + self.operator + ' ') + \
                 self.right.to_html()


class Variable(AstNode):
     """Model for a variable."""

     def __init__(self, name):
         super(Variable, self).__init__()
         self.name = name
         self.color = "red"

     def to_html(self):
         """Return html text to represent this node with syntax 
highlighting."""

         return self.get_colorized_html_for(self.name)


class TreeWidgetExample(QTreeWidget):

     def __init__(self, parent=None):
         super(TreeWidgetExample, self).__init__(parent)
         self.setHeaderLabels(["Action", "Parameter"])
         self.setColumnCount(2)
         root = QTreeWidgetItem(self, ["function"])
         children = QTreeWidgetItem(root, ["eval"])

         # Build code model for $result = $a + $b
         result_var = Variable("$result")
         a_var = Variable("$a")
         b_var = Variable("$b")
         addition = BinaryOp(a_var, b_var, "+")
         assignment = Assignment(result_var, addition)

         # Set a QLable as ItemWidget for the code column
         self.setItemWidget(children, 1, QLabel(assignment.to_html(), self))


def main():

     app = QApplication(sys.argv)
     ex = TreeWidgetExample()
     ex.show()
     sys.exit(app.exec_())

if __name__ == '__main__':
     main()

#################### End Code ##################



Am 24.01.2013 04:03, schrieb ZHONG Zhu:
> I'm using QTreeWidget to parse/show/edit one of our internal 
> "language". Now user wants to have syntax highlight feature. I was 
> able to highlight the whole item, for instance, the "comment" Action 
> and the whole Parameter.
> When it comes to the content within an item, such as "$result = $a + 
> $b", I can't find a way to highlight individual variables 
> ($result/$a/$b). Anyone has any experience on this? How? Thanks in 
> advance!
> BR
> Zhu
>
>
> _______________________________________________
> PySide mailing list
> PySide at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/pyside

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