PYGLET – On Style Text Event Formatted Document

In this article we will see how we can trigger the on style text event in PYGLET module in python. Pyglet is easy to use but powerful library for developing visually rich GUI applications like games, multimedia etc. A window is a “heavyweight” object occupying operating system resources. Windows may appear as floating regions or can be set to fill an entire screen (fullscreen). Formatted documents are generally laid out to enhance their human readability by adding structure, such as headings, indentation, font variations, and other devices that transform plain (unformatted) text so that they have an appearance similar to published works. This event get triggered when user text style is changed. The event handler is bound by the text layout; there is no need for applications to interact with this method.

We can create a window and formatted document with the help of commands given below 

# creating a window
window = pyglet.window.Window(width, height, title)

# creating document
document = pyglet.text.document.FormattedDocument(text)

Below is the syntax of the on style text event
# on style text event 
@window.event 
def on_style_text(start, end):
#printing text 
print(“Text style changed”)

Below is the implementation  

Python3

# importing pyglet module
import pyglet
import pyglet.window.key

# width of window
width = 500

# height of window
height = 500

# caption i.e title of the window
title = "Geeksforgeeks"

# creating a window
window = pyglet.window.Window(width, height, title)

# text
text = "Welcome to GeeksforGeeks Have a nice day"

# batch object
batch = pyglet.graphics.Batch()

# creating a formatted document
document = pyglet.text.document.FormattedDocument(text)

# setting style to the document
document.set_style(0, len(document.text), dict(font_name ='Arial', font_size = 16, color =(255, 255, 255, 255)))

# creating a incremental text layout
layout = pyglet.text.layout.IncrementalTextLayout(document, 400, 350, batch = batch)

# creating a caret
caret = pyglet.text.caret.Caret(layout, color =(150, 255, 150))



# caret to window push handlers
window.push_handlers(caret)

# setting caret style
caret.set_style(dict(font_name ="Arial"))

# on draw event
@window.event
def on_draw():

    # clear the window
    window.clear()

    # draw the batch
    batch.draw()

    # caret to window push handlers
    window.push_handlers(caret)


# key press event
@window.event
def on_key_press(symbol, modifier):

    # key "C" get press
    if symbol == pyglet.window.key.C:

        # closing the window
        # window.close()
        pass

# on style text event
@window.event
def on_style_text(start, end):

    # printing text
    print("Text style changed")


# image for icon
img = image = pyglet.resource.image("logo.png")

# setting image as icon
window.set_icon(img)

# start running the application
pyglet.app.run()

Output :