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_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("Hello, VEX AIR!")

# 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.

Monospaced fonts have characters that are all the same width, making text placement consistent. In contrast, proportional fonts vary in character width, so some letters take up more space than others. However, regardless of which type is used, set_cursor positions the cursor based on row and column size, not font style. The font size can be adjusted using set_font.

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

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

# Display text starting at Row 3 Column 2
controller.screen.set_cursor(3, 2)
controller.screen.print("Row 3, Column 2")

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.

# Display text on two rows
controller.screen.print("This text stays")
controller.screen.next_row()
controller.screen.print("This text disappears")

# Wait 3 seconds before clearing only the second row
wait(3, SECONDS)
controller.screen.clear_row()

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

get_row

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.

# Set cursor to (3,2) and print row number
controller.screen.set_cursor(3, 2)
controller.screen.print(controller.screen.get_row())

get_column

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.

# Set cursor to (3,2) and print column number
controller.screen.set_cursor(3, 2)
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 currently set_font and set_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=230, 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(120, 120)

# Draw a rectangle at the new origin
controller.screen.draw_rectangle(0, 0, 80, 40)

Mutators

clear_screen

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

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

Parameter	Description
row	Optional. The row to set the cursor at after clearing the screen. The default is 1.
column	Optional. The column 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: color=BLACK color=BLUE color=CYAN color=GREEN color=ORANGE color=PURPLE color=RED color=TRANSPARENT color=WHITE color=YELLOW You can also specify a custom color.

# Draw a circle, and clear it after 2 seconds
controller.screen.draw_circle(120, 120, 60)
wait(2, SECONDS)
controller.screen.clear_screen()

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

# Example coming soon

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(50, 50, 130, 60)

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 a red pen
controller.screen.set_pen_color(RED)
controller.screen.draw_rectangle(50, 50, 130, 60)

set_fill_color

set_fill_color sets the fill color used when shapes are drawn.

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 two orange rectangles
controller.screen.set_fill_color(ORANGE)
controller.screen.draw_rectangle(50, 50, 100, 60)
controller.screen.draw_rectangle(50, 130, 100, 60)

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 a pixel at the center of the screen
controller.screen.draw_pixel(120, 120)

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.

# Draw a line from the top left to bottom right of the screen
controller.screen.draw_line(0, 0, 640, 480)

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 outline color of the rectangle. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw a red rectangle on the screen
controller.screen.draw_rectangle(50, 50, 130, 60, RED)

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. The outline color of the circle. Options include: BLACK BLUE CYAN GREEN ORANGE PURPLE RED TRANSPARENT WHITE YELLOW You can also specify a custom color.

# Draw a green circle on the screen
controller.screen.draw_circle(120, 120, 40, 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, center)

Parameter	Description
file	The custom image to use, from IMAGE1 to IMAGE10. The image number matches the number shown in the AIR 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.
center	Optional. If center=True, the image is placed using its center at coordinate (320, 240). By default (center=False), the top-left corner of the image is used and positioned relative to the current origin.

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

# Display the same image on both sides of the screen
controller.screen.show_file(IMAGE1, 65, 0, center=True)
controller.screen.show_file(IMAGE1, -65, 0, center=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.

# Example coming soon

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.

# Report the x-coordinate of where the screen is pressed.
while True:
    if controller.screen.pressing():
        controller.screen.clear_screen()
        controller.screen.set_cursor(1, 1)
        controller.screen.print(controller.screen.x_position())
    wait (50, 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()

# Report the y-coordinate of where the screen is pressed.
while True:
    if controller.screen.pressing():
        controller.screen.clear_screen()
        controller.screen.set_cursor(1, 1)
        controller.screen.print(controller.screen.y_position())
    wait (50, 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.

# Example coming soon

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.

# Example coming soon