terminal.py

# Copyright (c) 2020 Robert Pfeiffer
# Terminal simulator

import pygame
pygame.init()

screen=pygame.display.set_mode((640,480), pygame.SCALED)
clock=pygame.time.Clock()

class Terminal(object):
    def __init__(self, size):
        self.w, self.h  = self.size = size
        self.scrollback = []
        self.buffer = []
        self.fontsize = 16
        self.font = pygame.font.Font("Inconsolata.otf", self.fontsize)
        self.cursor= 0,0
        pygame.display.set_caption("Terminal")

    def _scroll_up(self):
        screen.scroll(0, -self.fontsize)
        pygame.draw.rect(screen, (0,0,0),
                         pygame.Rect(0,(self.h-1)*self.fontsize,
                                     screen.get_width(), self.fontsize))
        self.buffer.pop(0)

    def _print_inner_slow(self, string):
        clock.tick(30)
        pygame.event.pump()
        if len(self.buffer)==self.h:
            self._scroll_up()
        i=0
        for char in string:
            clock.tick(30)
            pygame.event.pump()
            glyph=self.font.render(char, 0, (255,255,255), (0,0,0))
            screen.blit(glyph, (glyph.get_width()*i, len(self.buffer)*self.fontsize))
            i+=1
            pygame.display.flip()

        self.buffer.append(string)
        self.cursor=len(self.buffer[-1]),len(self.buffer)-1
        

    def _print_inner(self, string):
        clock.tick(30)
        pygame.event.pump()
        if len(self.buffer)==self.h:
            self._scroll_up()
        line_buf=self.font.render(string, 0, (255,255,255), (0,0,0))
        screen.blit(line_buf, (0, len(self.buffer)*self.fontsize))
        self.buffer.append(string)
        self.cursor=len(self.buffer[-1]),len(self.buffer)-1
        pygame.display.flip()
        
    def println(self, string):
        self.scrollback.append(string)
        while len(string) > self.w:
            self._print_inner_slow(string[:self.w])
            string=string[self.w:]
        self._print_inner_slow(string)

    def print(self, string):
        for line in string.split("\n"):
            self.println(line)
    
    def clear(self):
        clock.tick(30)
        pygame.event.pump()
        self.buffer = []
        self.cursor= 0,0
        screen.fill(0)
        pygame.display.flip()
        
    def input(self):
        input_str=""
        starting_cursor=self.cursor
        try:
            pygame.key.start_text_input()
            i=0
            
            while True:
                clock.tick(30)
                blink_cursor=" "
                i+=1
                if i>30:
                    i=0
                if i>20:
                    blink_cursor="_"

                blink=self.font.render(blink_cursor, 0, (255,255,255), (0,0,0))
                screen.blit(blink, (self.cursor[0]*blink.get_width(),self.fontsize*self.cursor[1]))
                
                events=pygame.event.get()

                for e in events:
                    if e.type==pygame.QUIT:
                        sys.exit()
                    elif e.type==pygame.VIDEORESIZE:
                        pygame.display.resize_event(e)
                    elif e.type==pygame.KEYDOWN and (e.key==pygame.K_ESCAPE
                                                     or e.key==1073742094):
                        return None
                    elif e.type==pygame.KEYDOWN and (e.key==pygame.K_BACKSPACE):
                        if len(input_str)>0:
                            input_str=input_str[:-1]
                            self.cursor = max(0, self.cursor[0]-1), self.cursor[1]
                    elif e.type==pygame.KEYDOWN and (e.key==pygame.K_RETURN):
                        blink=self.font.render(" ", 0, (255,255,255), (0,0,0))
                        screen.blit(blink, (self.cursor[0]*blink.get_width(),self.fontsize*self.cursor[1]))
                        return input_str
                    elif e.type==pygame.TEXTINPUT:
                        char=self.font.render(e.text, 0, (255,255,255), (0,0,0))

                        screen.blit(char, (self.cursor[0]*blink.get_width(),self.fontsize*self.cursor[1]))
                        self.buffer[-1]+=(e.text)
                        self.cursor = self.cursor[0]+1, self.cursor[1]
                        if self.cursor[0]==self.w:
                            if len(self.buffer)==self.h:
                                self._scroll_up()
                                self.buffer.append("")
                                self.cursor = 0, self.cursor[1]
                            else:
                                self.buffer.append("")
                                self.cursor = 0, self.cursor[1]+1

                        input_str+=e.text
                pygame.display.flip()
        finally:
            pygame.key.stop_text_input()