How to highlight text in a tkinter Text widget

by

It’s the right widget to use for these purposes. The basic concept is, you assign properties to tags, and you apply tags to ranges of text in the widget. You can use the text widget’s search command to find strings that match your pattern, which will return you enough information apply a tag to the range that matched.

For an example of how to apply tags to text, see my answer to the question Advanced Tkinter text box?. It’s not exactly what you want to do but it shows the basic concept.

Following is an example of how you can extend the Text class to include a method for highlighting text that matches a pattern.

In this code the pattern must be a string, it cannot be a compiled regular expression. Also, the pattern must adhere to Tcl’s syntax rules for regular expressions. 

class CustomText(tk.Text):
    '''A text widget with a new method, highlight_pattern()

    example:

    text = CustomText()
    text.tag_configure("red", foreground="#ff0000")
    text.highlight_pattern("this should be red", "red")

    The highlight_pattern method is a simplified python
    version of the tcl code at http://wiki.tcl.tk/3246
    '''
    def __init__(self, *args, **kwargs):
        tk.Text.__init__(self, *args, **kwargs)

    def highlight_pattern(self, pattern, tag, start="1.0", end="end",
                          regexp=False):
        '''Apply the given tag to all text that matches the given pattern

        If 'regexp' is set to True, pattern will be treated as a regular
        expression according to Tcl's regular expression syntax.
        '''

        start = self.index(start)
        end = self.index(end)
        self.mark_set("matchStart", start)
        self.mark_set("matchEnd", start)
        self.mark_set("searchLimit", end)

        count = tk.IntVar()
        while True:
            index = self.search(pattern, "matchEnd","searchLimit",
                                count=count, regexp=regexp)
            if index == "": break
            if count.get() == 0: break # degenerate pattern which matches zero-length strings
            self.mark_set("matchStart", index)
            self.mark_set("matchEnd", "%s+%sc" % (index, count.get()))
            self.tag_add(tag, "matchStart", "matchEnd")

More Related Contents:

  1. How to bind self events in Tkinter Text widget after it will binded by Text widget?
  2. Add advanced features to a tkinter Text widget
  3. Is there a way to make the Tkinter text widget read only?
  4. Why does Tkinter image not show up if created in a function?
  5. Tkinter scrollbar for frame
  6. How can I convert canvas content to an image?
  7. RuntimeError: main thread is not in main loop
  8. Get contents of a Tkinter Entry widget
  9. How can I escape latex code received through user input?
  10. How to get tkinter canvas to dynamically resize to window width?
  11. Closing pyplot windows
  12. Way to play video files in Tkinter?
  13. Updating OptionMenu from List
  14. How can I set the mouse position in a tkinter window
  15. Getting “ImportError: DLL load failed: The specified module could not be found” when using cx_Freeze even with tcl86t.dll and tk86t.dll added in
  16. Python Tkinter Canvas fail to bind keyboard
  17. How to scrape only visible webpage text with BeautifulSoup?
  18. Running a Tkinter form in a separate thread
  19. Tkinter.PhotoImage doesn’t not support png image
  20. Removing Ttk Notebook Tab Dashed Line
  21. How to start threads at the same time in Python [duplicate]
  22. How can I create a simple message box in Python?
  23. Display directory content with tkinter Treeview widget
  24. Change color of “tab header” in ttk.Notebook
  25. Run an infinite loop in the backgroung in Tkinter
  26. What is the best way to structure a Tkinter application?
  27. automatically position text box in plot
  28. Execute a command on Remote Machine in Python
  29. How to get the Tkinter Label text?
  30. tkinter Canvas Scrollbar with Grid?

Leave a Comment