Screen

Introduction

The VEX AIR Drone Controller’s screen provides methods for displaying text, managing the cursor, drawing shapes, and handling touch interactions.

Below is a list of all available methods:

Cursor Print – Display text using a row/column system.

• print – Prints text at the current cursor position.

• set_cursor – Sets the cursor to a specific row and column.

• next_row – Moves the cursor to column 1 of the next row.

• clear_row – Clears a row of text.

• get_row – Returns the current cursor row.

• get_column – Returns the current cursor column.

XY Print – Display text at a specific screen coordinate.

• print_at – Prints text at a specific x and y location.

• set_origin – Sets a new origin for printing and drawing.

Mutators – Clear the screen or update visual settings.

• clear_screen – Clears the screen of all drawings and text.

• wait_for_render – Wait for drawing and print commands to render on the screen.

• set_font – Sets the font for printed text.

• set_pen_width – Sets the thickness for drawn shapes and lines.

• set_pen_color – Sets the color for outlines and text.

• set_text_fill_color – Sets the highlight color used when text is printed.

• set_fill_color – Sets the fill color for shapes and backgrounds.

Draw – Add graphics and images to the screen.

• draw_pixel – Draws a pixel at a specific x and y position.

• draw_line – Draws a line between two points.

• draw_rectangle – Draws a rectangle.

• draw_circle – Draws a circle.

• show_file – Displays an uploaded image.

Touch – Detect and respond to screen presses.

• pressing – Returns whether the screen is currently being pressed.

• x_position – Returns the x-coordinate where the screen is pressed.

• y_position – Returns the y-coordinate where the screen is pressed.

Callback – Run functions when the screen is pressed or released.

• pressed – Registers a function to call when the screen is pressed.

• released – Registers a function to call when the screen is released.

Cursor Print

print

print displays text on the controller’s screen at the current cursor position and font.

Usage:
controller.screen.print(text)

Parameters	Description
text	The text, number, or variable value to display on the screen.
sep	Optional. The separator between printed text. By default, sep = ’ ‘
end	Optional. The string appended after the last printed text. By default, end = ‘\n’
precision	Optional. The number of decimals a float will print with as an integer. By default, precision = 5

# Display a message at the starting cursor position.
controller.screen.print("Time to fly!")

# Display the first 2 decimals of pi
controller.screen.print(3.1415, precision = 2)

set_cursor

set_cursor places the text cursor at a specific row and column on the screen. The number of rows and columns that fit depends on the selected font. With the default monospaced medium font, the screen can clearly display up to 11 rows and 53 columns. Text placed beyond this range may be cut off or harder to read.

Usage:
controller.screen.set_cursor(row, col)

Parameters	Description
row	The row of the cursor.
column	The column of the cursor.

# Display text starting at Row 7 Column 25.
controller.screen.set_cursor(row=7, col=25)
controller.screen.print("Row 7, Column 25")

next_row

next_row moves the cursor to column 1 on the next row on the controller’s screen.

Usage:
controller.screen.next_row()

Parameters	Description
	This method has no parameters.

# Display two lines of text.
controller.screen.print("Line 1")
controller.screen.next_row()
controller.screen.print("Line 2")

clear_row

clear_row clears a row of text on the controller’s screen.

Usage:
controller.screen.clear_row(row, color)

Parameter	Description
row	Optional. The row to clear. The default is the current cursor row.
color	Optional. The color to apply to the cleared row. If a color is not specified, the set_fill_color is used. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Clear only the second row of text
controller.screen.print("This text stays")
controller.screen.next_row()
controller.screen.print("This text disappears")
wait(3, SECONDS)
controller.screen.clear_row(2)

# Turn the 5th row green.
controller.screen.clear_row(5, GREEN)

get_row

get_row returns the current row where text will be printed, as an integer.

Usage:
controller.screen.get_row()

Parameters	Description
	This method has no parameters.

# Display the cursor's current row.
controller.screen.set_cursor(row=7, col=25)
controller.screen.print(controller.screen.get_row())

get_column

get_column returns the current column where text will be printed, as an integer.

Usage:
controller.screen.get_column()

Parameters	Description
	This method has no parameters.

# Display the cursor's current column.
controller.screen.set_cursor(row=7, col=25)
controller.screen.print(controller.screen.get_column())

XY Print

print_at

print_at displays text on the robot’s screen at a specific (x, y) position in pixels, using the current font and origin. x sets how far from the left side the text begins, and y sets where the bottom of the letters sit. This method disregards the current cursor position.

Usage:
controller.screen.print_at(text, x, y)

Parameter	Description
text	The text, number, or variable value to display on the screen.
x	The horizontal position of the text, as an integer from 0 to 640 pixels. 0 is left; 640 is right.
y	The vertical position of the text, as an integer from 0 to 480 pixels. 0 is the top; 480 is the bottom.

# Display a message in the middle of the screen.
controller.screen.print_at("Hello, drone!", x=320, y=240)

set_origin

set_origin sets the origin (0, 0) used for drawing or printing on the controller’s screen. By default, drawing or printing methods consider the top left corner of the screen as the origin. This method can reset the origin to an alternate (x, y) screen coordinate location.

Usage:
controller.screen.set_origin(x, y)

Parameter	Description
x	The new x-coordinate to set as the origin, given as an integer from 0 to 640.
y	The new y-coordinate to set as the origin, given as an integer from 0 to 480.

# Set the origin to the center of the screen.
controller.screen.set_origin(x=320, y=240)

# Draw a rectangle at the new origin.
controller.screen.draw_rectangle(x=0, y=0, width=80, height=40)

Mutators

clear_screen

clear_screen clears the controller’s screen of all drawings, text, and images.

Usage:
controller.screen.clear_screen(row, col, color)

Parameter	Description
row	Optional. The x position to set the cursor at after clearing the screen. The default is 1.
col	Optional. The y position to set the cursor at after clearing the screen. The default is 1.
color	Optional. Sets the screen color. To use, you must include all three optional parameters. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw a circle, and clear it after 2 seconds.
controller.screen.draw_circle(x=320, y=240, radius=80)
wait(2, SECONDS)
controller.screen.clear_screen()

# Print two messages in the same spot
controller.screen.print("Hello!")
wait(3,SECONDS)
controller.screen.clear_screen(row=1, col=1)
controller.screen.print("Goodbye!")

# Set the background color of the screen to red.
controller.screen.clear_screen(RED)

wait_for_render

wait_for_render prevents any following commands from running until all previous drawing and print commands on the screen have finished rendering.

Usage:
controller.screen.wait_for_render()

Parameter	Description
	This method has no parameters.

# Display text and images when button 7 is pressed.
controller.screen.wait_for_render()
controller.screen.print("Screen rendered!")
controller.screen.draw_circle(x=320, y=240, radius=80)
while not controller.button7.pressing():
    wait(5, MSEC)
controller.screen.wait_for_render()

set_font

set_font sets the font used for displaying text on the controller’s screen. This font will apply to all text printed with print or print_at. The default font at the start of a project is MONO20.

Usage:
controller.screen.set_font(fontname)

Parameter	Description
fontname	Sets the font to one of the following: MONO12 MONO15 MONO20 MONO24 MONO30 MONO36 MONO40 MONO60 PROP20 PROP24 PROP30 PROP36 PROP40 PROP60

MONO12	MONO15	MONO20
MONO24	MONO30	MONO36
MONO40	MONO60	PROP20
PROP24	PROP30	PROP36
PROP40	PROP60

# Display text using a larger font.
controller.screen.set_font(MONO40)
controller.screen.print("VEX")

set_pen_width

set_pen_width sets the pen width used for drawing lines and shapes.

Usage:
controller.screen.set_pen_width(width)

Parameter	Description
width	The pen width, given as an integer in pixels.

# Draw a rectangle with a pen width of 10.
controller.screen.set_pen_width(10)
controller.screen.draw_rectangle(x=200, y=200, width=200, height=80)

set_pen_color

set_pen_color sets the pen color used for drawing lines, shapes, and printing text.

Usage:
controller.screen.set_pen_color(color)

Parameter	Description
color	Optional. Sets the pen color. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw a rectangle with an orange outline.
controller.screen.set_pen_color(ORANGE)
controller.screen.draw_rectangle(x=200, y=150, width=240, height=150)
controller.screen.set_pen_color(WHITE)
controller.screen.print_at("VEXcode AIR", x=250, y=220)

set_text_fill_color

set_text_fill_color sets the highlight color used when text is printed. The default highlight color is transparent.

Usage:
controller.screen.set_text_fill_color(color)

Parameter	Description
color	Optional. Sets the text highlight color. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Display two colors behind text
controller.screen.set_text_fill_color(RED)
controller.screen.print("Red")
controller.screen.next_row()
controller.screen.set_text_fill_color(BLUE)
controller.screen.print("Blue")

set_fill_color

set_fill_color sets the fill color used when shapes are drawn. The default fill color is black.

Usage:
controller.screen.set_fill_color(color)

Parameter	Description
color	Optional. Sets the fill color. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw an orange-filled rectangle with text on top
controller.screen.set_fill_color(ORANGE)
controller.screen.draw_rectangle(x=200, y=150, width=250, height=150)
controller.screen.print_at("VEXcode AIR", x=250, y=220)

Draw

draw_pixel

draw_pixel draws a pixel at the specified (x, y) screen coordinate in the current pen color. It uses the current pen color set by set_pen_color.

Usage:
controller.screen.draw_pixel(x, y)

Parameter	Description
x	The x-coordinate where the pixel will be drawn, given as an integer from 0 to 640.
y	The y-coordinate where the pixel will be drawn, given as an integer from 0 to 480.

# Draw five pixels in a diagonal.
controller.screen.draw_pixel(x=360, y=200)
controller.screen.draw_pixel(x=340, y=220)
controller.screen.draw_pixel(x=320, y=240)
controller.screen.draw_pixel(x=300, y=260)
controller.screen.draw_pixel(x=280, y=280)

draw_line

draw_line draws a line from the first specified screen coordinate (x1, y1) to the second specified screen coordinate (x2, y2). It uses the current the pen width set by set_pen_width and pen color set by set_pen_color.

The x and y-coordinates use the default origin of (0, 0) unless a different origin has been set using set_origin.

Usage:
controller.screen.draw_line(x1, y1, x2, y2)

Parameter	Description
x1	The starting x-coordinate of the line, given as an integer from 0 to 640.
y1	The starting y-coordinate of the line, given as an integer from 0 to 480.
x2	The ending x-coordinate of the line, given as an integer from 0 to 640.
y2	The ending y-coordinate of the line, given as an integer from 0 to 480.

# Make an X across the screen.
controller.screen.draw_line(x1=0, y1=0, x2=640, y2=480)
controller.screen.set_pen_color(CYAN)
controller.screen.draw_line(x1=0, y1=480, x2=640, y2=0)

draw_rectangle

draw_rectangle draws a rectangle with its top-left corner at the specified (x, y) coordinate and a size determined by the given width and height, all measured in pixels. The rectangle’s outline is drawn using the current pen width set by set_pen_width and the pen color set by set_pen_color. The interior is filled with the color set by set_fill_color.

The x and y-coordinates use the default origin of (0, 0) unless a different origin has been set using set_origin.

Usage:
controller.screen.draw_rectangle(x, y, width, height, color)

Parameter	Description
x	The x-coordinate of the top-left corner of the rectangle, given as an integer from 0 to 640.
y	The y-coordinate of the top-left corner of the rectangle, given as an integer from 0 to 480.
width	The width of the rectangle, given as an integer from 0 to 640.
height	The height of the rectangle, given as an integer from 0 to 480.
color	Optional. Sets the fill color of the rectangle. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw two rectangles on the screen.
controller.screen.draw_rectangle(x=0, y=0, width=620, height=460)
controller.screen.draw_rectangle(x=200, y=180, width=200, height=100, color=GREEN)

draw_circle

draw_circle draws a circle with its center at the specified (x, y) coordinate and a size determined by the given radius, all measured in pixels. The circle’s outline is drawn using the current pen width set by set_pen_width and the pen color set by set_pen_color. The interior is filled with the color set by set_fill_color.

The x and y-coordinates use the default origin of (0, 0) unless a different origin has been set using set_origin.

Usage:
controller.screen.draw_circle(x, y, radius, color)

Parameter	Description
x	The x-coordinate of the center of the circle, given as an integer from 0 to 640.
y	The y-coordinate of the center of the circle, given as an integer from 0 to 480.
radius	The radius of the circle, given as an integer from 0 to 480 pixels.
color	Optional. Sets the fill color of the circle. Options include: BLAC BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw one green circle on the screen.
controller.screen.set_fill_color(GREEN)
controller.screen.draw_circle(x=320, y=240, radius=200, color=GREEN)

show_file

show_file draws a custom uploaded image on the controller’s screen, with its position set using the x, y, and center parameters based on the image’s reference point.

Usage:
controller.screen.show_file(file, x, y, scale_width, scale_height, rotate, use_alpha)

Parameter	Description
file	The user-uploaded image to use. Options will change if image names are edited in the Control Panel.
x	The horizontal offset for the image, given as an integer in pixels. Positive values move it right; negative values move it left.
y	The vertical offset for the image, given as an integer in pixels. Positive values move it down; negative values move it up.
scale_width	Optional. The image width being scaled to, given as an integer in pixels.
scale_height	Optional. The image height being scaled to, given as an integer in pixels.
rotation	Optional. The degree which image being rotated to, given as an integer from 0 to 359.
use_alpha	Optional. Use alpha channel for image to show transparent. Options include: True False

# Display uploaded Image 1 in the top left corner.
controller.screen.show_file(IMAGE1, x=0, y=0)

# Display uploaded Image 1 scaled to the full screen.
controller.screen.show_file(IMAGE1, x=65, y=0, scale_width=640, scale_height=480)

# Display uploaded Image 1 with rotation of 180 degrees.
controller.screen.show_file(IMAGE1, x=-65, y=0, rotation=180)

# Upload an image with a transparent background.
# Display uploaded Image 1 with alpha channel enabled.
controller.screen.show_file(IMAGE1, x=0, y=0, use_alpha=True)

Touch

pressing

pressing returns whether the controller’s screen is currently being pressed as a Boolean:

• True – The screen is being pressed.

• False – The screen is not being pressed.

Usage:
controller.screen.pressing()

Parameters	Description
	This method has no parameters.

# Play a sound when the screen is pressed.
while True:
    if controller.screen.pressing():
        controller.sound.play_note("C5", 500)
    wait(5, MSEC)

x_position

x_position returns the x-coordinate in pixels where the screen was pressed, as an integer from 0 (left) to 640 (right).

Usage:
controller.screen.x_position()

Parameters	Description
	This method has no parameters.

# Play a high or low note based on where screen is pressed.
while True:
    if controller.screen.pressing():
        if controller.screen.x_position() > 320:
            controller.sound.play_note("C6", 500)
        else:
            controller.sound.play_note("C4", 500)
    wait(5, MSEC)

y_position

y_position returns the y-coordinate in pixels where the screen was pressed, as an integer from 0 (top) to 480 (bottom).

Usage:
controller.screen.y_position()

# Play a high or low note based on where screen is pressed.
while True:
    if controller.screen.pressing():
        if controller.screen.y_position() > 240:
            controller.sound.play_note("C6", 500)
        else:
            controller.sound.play_note("C4", 500)
    wait(5, MSEC)

Callback

pressed

pressed registers a method to be called when the controller’s screen is pressed.

Usage:
controller.screen.pressed(callback, arg)

Parameters	Description
callback	A function that is previously defined to execute when the axis’ value changes.
arg	Optional. A tuple containing arguments to pass to the callback function. See Using Functions with Parameters for more information.

# Play a sound when the screen is pressed.
def play_sound():
    controller.sound.play_note("C5", 500)

controller.screen.pressed(play_sound)

released

released registers a method to be called when the screen is no longer being pressed.

Usage:
controller.screen.released(callback, arg)

Parameters	Description
callback	A function that is previously defined to execute when the axis’ value changes.
arg	Optional. A tuple containing arguments to pass to the callback function. See Using Functions with Parameters for more information.

# Play a sound when the screen is pressed.
def play_sound():
    controller.sound.play_note("C5", 500)
    
controller.screen.released(play_sound)