AreaVi Tags

A tag has a name and two index's, a tag is mapped to a range of text. It is possible to set some options for these ranges of text, such options are background, color, font, font size and even to map handles to events that happen when the mouse is over them. It is even possible to add a handle to an event that maps a key press when the cursor is in the tag range.

The 'sel' tag and AreaVi.tag_add/AreaVi.tag_remove method

The 'sel' tag is a built-in tag that corresponds to text selection, it can be added to ranges of text when needed, the text's background will be modified. Try the following piece of code below:

area = AreaVi('None')
area.pack(expand=True, fill=BOTH)
area.insert('1.0', 'alpha')

# It will add the tag 'sel' from the beginning of the text to the end.
area.tag_add('sel', '1.0', 'end')

# Look at the text in the AreaVi instance now, it will be selected.
# Inserting the following statement will unslect the text/remove the tag 'sel' from the beginning to the end.
area.tag_remove('sel', '1.0', 'end')

The AreaVi.tag_ranges method

Consider you have added a lot of tags to a lot of ranges of text, you want to know which ranges are binded to a given tag. This method will give you the answer. See the example below that adds the 'sel' tag to three ranges then retrieves back the index's.

Example:

area.insert('1.0', 'a' * 100) 
area.tag_add('sel', '1.0', '1.4')
area.tag_add('sel', '1.11', '1.20')
area.tag_add('sel', '1.30', '1.50')

for ind in area.tag_ranges('sel'):
    print ind

# It will print.
# 1.0
# 1.4
# 1.11
# 1.20
# 1.30
# 1.50

The items that area.tag_ranges generate are textindex objects that implement a __str__ method.

The AreaVi.tag_config method

It is possible to specify options for tags as mentioned before, it is needed to use the AreaVi.tag_config method. The example below examplifies:

area.insert('1.0', 'a' * 50)
# It adds the tag 'alpha' to the range '1.0', '1.10'.
area.tag_add('alpha', '1.0', '1.10')
# It sets the background/color/font for the specified range.
area.tag_config('alpha', background='blue', foreground='green', font=('Monospace', 8, 'bold'))