# touch.py
# Walker M. White (wmw2)
# November 17, 2013
"""Module to show off how to process touches in game2d"""
import colormodel
from game2d import *

### CONSTANTS ###

# Window Size
WINDOW_WIDTH  = 512
WINDOW_HEIGHT = 512

# Animation Frames that constitute a click
CLICK_SPEED = 30

### CONTROLLER CLASS ###

class Touch(Game):
    """Track the mouse to draw freehand lines
    
    Instance Attributes:
        view:   the view (inherited from Game) [GView]
        last:   last mouse position
                [GPoint or None if mouse was not down last frame]
        time:   frames since mouse last changed (pressed, released) [int >= 0]
        clicks: # of fast clicks in a row [int >= 0]
        lines:  set of lines to be drawn [list of GLine]
    """
    
    # THREE MAIN METHODS
    
    def init(self):
        """Special initialization method to create attributes.
        
        Not the SAME as __init__. DO NOT DEFINE __init___."""
        self.last   = None
        self.time   = 0
        self.clicks = 0
        self.lines  = []
    
    def update(self,dt):
        """Draw new lines or erase them all."""
        # helper method to detect a click
        self._detectClick()
        
        # Erase on double click
        if self.clicks >= 2:
            self._processDoubleClick()
        else:
            self._processDrawing()

        # Update mouse position (must do last)
        self.last = self.view.touch
    
    def draw(self):
        """Draw the lines"""
        for line in self.lines:
            line.draw(self.view)

    # HELPER METHODS   
    
    def _detectClick(self):
        """Check for change in mouse state.
        
        A click is a releas, CLICK_SPEED frames after a down."""
        touch = self.view.touch

        # Look for a release.
        if touch is None and not self.last is None:
            # Release; check if fast enough
            if self.time < CLICK_SPEED:
                self.clicks = self.clicks + 1
            else:
                self.clicks = 1
        
        # If touch down, increment timer
        if not touch is None:
            # Restart timer on a press
            if self.last is None:
                self.time = 0
            else:
                self.time = self.time + 1        
        
    def _processDoubleClick(self):
        """Clear the screen and reset click count."""
        self.clicks = 0
        self.lines = []

    def _processDrawing(self):
        """Add a new line if last is not None"""
        touch = self.view.touch
        if not self.last is None and not touch is None:
            # Specify a line as list of two points
            points = [self.last.x,self.last.y,touch.x,touch.y]
            line = GLine(points=points,linecolor=colormodel.RED)
            self.lines.append(line)


# Script Code
if __name__ == '__main__':
    Touch(width=WINDOW_WIDTH,height=WINDOW_HEIGHT,fps=60.0).run()