# Scene

## Initialization

You can get started with Scenes by creating a new class that extends the base Scene class from pyDraw:

```python
import * from pydraw

class MyScene(Scene):
    # you should declare your variables outside of any of the methods (static!)
    some_variable = 34
    
    some_shape = None  # set pyDraw objects or uninitiated variables to None
    to_set_later = None
    
    # now we can define a "start" method which will run when the scene is displayed
    def start(self):
        self.some_shape = Rectangle(self.screen(), 10, 10, 75, 50, Color('red'))
        self.to_set_later = self.some_shape.width() / 2
    
    # you can setup the Scene's input hooks by defining the methods in the class
    def keydown(self, key):
        if key == 'x':
            self.to_set_later += 1
        else:
            self.some_shape.move(x=3)
    
    def keyup(self, key):
        if key == 'x':
            self.to_set_later += self.to_set_later % 3
    
    def mousedown(self, location):
        print(location)
        
    # you won't even need to call screen.listen(), it happens automatically!
    
    # next up we setup a "run" method which happens after our input methods!
    def run():
        # as you can see, it's just like a normal pyDraw program!
    
        running = True
        fps = 30
        while running:
            self.some_shape.color(Color.random())
        
            self.screen().update()
            self.screen().sleep(1 / fps)
```

## Methods

### Start

Should instantiate your variables and prepare everything that the input hooks will use (unless you have checks in your hooks)

### Run

Should contain your actual loop and main program logic.

### Screen

Get the Screen that the Scene is tied to! (can throw errors if methods are being called without being attached to a Screen)

### Input Methods

Supports all the same input methods that any other pyDraw program supports:

* `mousedown` | When the mouse is pressed or is held, this will be called
* `mouseup`     | When the mouse is released this is called
* `mousedrag` | When the mouse is dragged, this is called anytime the mouse moves and is held.
* `mousemove` | When the mouse moves, this method is called.
* `keydown`     | When a key is pressed or is currently being held, this is called
* `keyup`         | When a key is released this is called
* `exit`           | Called when the Screen is abruptly closed or [`screen.exit()`](https://docs.pydraw.graphics/quick-reference/screen) is called.