# graphics.py """Simple object oriented graphics library The library is designed to make it very easy for novice programmers to experiment with computer graphics in an object oriented fashion. It is written by John Zelle for use with the book "Python Programming: An Introduction to Computer Science" (Franklin, Beedle & Associates). LICENSE: This is open-source software released under the terms of the GPL (http://www.gnu.org/licenses/gpl.html). PLATFORMS: The package is a wrapper around Tkinter and should run on any platform where Tkinter is available. INSTALLATION: Put this file somewhere where Python can see it. OVERVIEW: There are two kinds of objects in the library. The GraphWin class implements a window where drawing can be done and various GraphicsObjects are provided that can be drawn into a GraphWin. As a simple example, here is a complete program to draw a circle of radius 10 centered in a 100x100 window: -------------------------------------------------------------------- from graphics import * def main(): win = GraphWin("My Circle", 100, 100) c = Circle(Point(50,50), 10) c.draw(win) win.getMouse() # Pause to view result win.close() # Close window when done main() -------------------------------------------------------------------- GraphWin objects support coordinate transformation through the setCoords method and pointer-based input through getMouse. The library provides the following graphical objects: Point Line Circle Oval Rectangle Polygon Text Entry (for text-based input) Image Various attributes of graphical objects can be set such as outline-color, fill-color and line-width. Graphical objects also support moving and hiding for animation effects. The library also provides a very simple class for pixel-based image manipulation, Pixmap. A pixmap can be loaded from a file and displayed using an Image object. Both getPixel and setPixel methods are provided for manipulating the image. DOCUMENTATION: For complete documentation, see Chapter 4 of "Python Programming: An Introduction to Computer Science" by John Zelle, published by Franklin, Beedle & Associates. Also see http://mcsp.wartburg.edu/zelle/python for a quick reference""" __version__ = "4.3" # Version 4.3 4/25/2014 # * Fixed Image getPixel to work with Python 3.4, TK 8.6 (tuple type handling) # * Added interactive keyboard input (getKey and checkKey) to GraphWin # * Modified setCoords to cause redraw of current objects, thus # changing the view. This supports scrolling around via setCoords. # # Version 4.2 5/26/2011 # * Modified Image to allow multiple undraws like other GraphicsObjects # Version 4.1 12/29/2009 # * Merged Pixmap and Image class. Old Pixmap removed, use Image. # Version 4.0.1 10/08/2009 # * Modified the autoflush on GraphWin to default to True # * Autoflush check on close, setBackground # * Fixed getMouse to flush pending clicks at entry # Version 4.0 08/2009 # * Reverted to non-threaded version. The advantages (robustness, # efficiency, ability to use with other Tk code, etc.) outweigh # the disadvantage that interactive use with IDLE is slightly more # cumbersome. # * Modified to run in either Python 2.x or 3.x (same file). # * Added Image.getPixmap() # * Added update() -- stand alone function to cause any pending # graphics changes to display. # # Version 3.4 10/16/07 # Fixed GraphicsError to avoid "exploded" error messages. # Version 3.3 8/8/06 # Added checkMouse method to GraphWin # Version 3.2.3 # Fixed error in Polygon init spotted by Andrew Harrington # Fixed improper threading in Image constructor # Version 3.2.2 5/30/05 # Cleaned up handling of exceptions in Tk thread. The graphics package # now raises an exception if attempt is made to communicate with # a dead Tk thread. # Version 3.2.1 5/22/05 # Added shutdown function for tk thread to eliminate race-condition # error "chatter" when main thread terminates # Renamed various private globals with _ # Version 3.2 5/4/05 # Added Pixmap object for simple image manipulation. # Version 3.1 4/13/05 # Improved the Tk thread communication so that most Tk calls # do not have to wait for synchonization with the Tk thread. # (see _tkCall and _tkExec) # Version 3.0 12/30/04 # Implemented Tk event loop in separate thread. Should now work # interactively with IDLE. Undocumented autoflush feature is # no longer necessary. Its default is now False (off). It may # be removed in a future version. # Better handling of errors regarding operations on windows that # have been closed. # Addition of an isClosed method to GraphWindow class. # Version 2.2 8/26/04 # Fixed cloning bug reported by Joseph Oldham. # Now implements deep copy of config info. # Version 2.1 1/15/04 # Added autoflush option to GraphWin. When True (default) updates on # the window are done after each action. This makes some graphics # intensive programs sluggish. Turning off autoflush causes updates # to happen during idle periods or when flush is called. # Version 2.0 # Updated Documentation # Made Polygon accept a list of Points in constructor # Made all drawing functions call TK update for easier animations # and to make the overall package work better with # Python 2.3 and IDLE 1.0 under Windows (still some issues). # Removed vestigial turtle graphics. # Added ability to configure font for Entry objects (analogous to Text) # Added setTextColor for Text as an alias of setFill # Changed to class-style exceptions # Fixed cloning of Text objects # Version 1.6 # Fixed Entry so StringVar uses _root as master, solves weird # interaction with shell in Idle # Fixed bug in setCoords. X and Y coordinates can increase in # "non-intuitive" direction. # Tweaked wm_protocol so window is not resizable and kill box closes. # Version 1.5 # Fixed bug in Entry. Can now define entry before creating a # GraphWin. All GraphWins are now toplevel windows and share # a fixed root (called _root). # Version 1.4 # Fixed Garbage collection of Tkinter images bug. # Added ability to set text atttributes. # Added Entry boxes. import time, os, sys try: # import as appropriate for 2.x vs. 3.x import tkinter as tk except: import Tkinter as tk ########################################################################## # Module Exceptions class GraphicsError(Exception): """Generic error class for graphics module exceptions.""" pass OBJ_ALREADY_DRAWN = "Object currently drawn" UNSUPPORTED_METHOD = "Object doesn't support operation" BAD_OPTION = "Illegal option value" DEAD_THREAD = "Graphics thread quit unexpectedly" _root = tk.Tk() _root.withdraw() def update(): _root.update() ############################################################################ # Graphics classes start here class GraphWin(tk.Canvas): """A GraphWin is a toplevel window for displaying graphics.""" def __init__(self, title="Graphics Window", width=200, height=200, autoflush=True): master = tk.Toplevel(_root) master.protocol("WM_DELETE_WINDOW", self.close) tk.Canvas.__init__(self, master, width=width, height=height) self.master.title(title) self.pack() master.resizable(0,0) self.foreground = "black" self.items = [] self.mouseX = None self.mouseY = None self.bind("", self._onClick) self.bind_all("", self._onKey) self.height = height self.width = width self.autoflush = autoflush self._mouseCallback = None self.trans = None self.closed = False master.lift() self.lastKey = "" if autoflush: _root.update() def __checkOpen(self): if self.closed: raise GraphicsError("window is closed") def _onKey(self, evnt): self.lastKey = evnt.keysym def setBackground(self, color): """Set background color of the window""" self.__checkOpen() self.config(bg=color) self.__autoflush() def setCoords(self, x1, y1, x2, y2): """Set coordinates of window to run from (x1,y1) in the lower-left corner to (x2,y2) in the upper-right corner.""" self.trans = Transform(self.width, self.height, x1, y1, x2, y2) self.redraw() def close(self): """Close the window""" if self.closed: return self.closed = True self.master.destroy() self.__autoflush() def isClosed(self): return self.closed def isOpen(self): return not self.closed def __autoflush(self): if self.autoflush: _root.update() def plot(self, x, y, color="black"): """Set pixel (x,y) to the given color""" self.__checkOpen() xs,ys = self.toScreen(x,y) self.create_line(xs,ys,xs+1,ys, fill=color) self.__autoflush() def plotPixel(self, x, y, color="black"): """Set pixel raw (independent of window coordinates) pixel (x,y) to color""" self.__checkOpen() self.create_line(x,y,x+1,y, fill=color) self.__autoflush() def flush(self): """Update drawing to the window""" self.__checkOpen() self.update_idletasks() def getMouse(self): """Wait for mouse click and return Point object representing the click""" self.update() # flush any prior clicks self.mouseX = None self.mouseY = None while self.mouseX == None or self.mouseY == None: self.update() if self.isClosed(): raise GraphicsError("getMouse in closed window") time.sleep(.1) # give up thread x,y = self.toWorld(self.mouseX, self.mouseY) self.mouseX = None self.mouseY = None return Point(x,y) def checkMouse(self): """Return last mouse click or None if mouse has not been clicked since last call""" if self.isClosed(): raise GraphicsError("checkMouse in closed window") self.update() if self.mouseX != None and self.mouseY != None: x,y = self.toWorld(self.mouseX, self.mouseY) self.mouseX = None self.mouseY = None return Point(x,y) else: return None def getKey(self): """Wait for user to press a key and return it as a string.""" self.lastKey = "" while self.lastKey == "": self.update() if self.isClosed(): raise GraphicsError("getKey in closed window") time.sleep(.1) # give up thread key = self.lastKey self.lastKey = "" return key def checkKey(self): """Return last key pressed or None if no key pressed since last call""" if self.isClosed(): raise GraphicsError("checkKey in closed window") self.update() key = self.lastKey self.lastKey = "" return key def getHeight(self): """Return the height of the window""" return self.height def getWidth(self): """Return the width of the window""" return self.width def toScreen(self, x, y): trans = self.trans if trans: return self.trans.screen(x,y) else: return x,y def toWorld(self, x, y): trans = self.trans if trans: return self.trans.world(x,y) else: return x,y def setMouseHandler(self, func): self._mouseCallback = func def _onClick(self, e): self.mouseX = e.x self.mouseY = e.y if self._mouseCallback: self._mouseCallback(Point(e.x, e.y)) def addItem(self, item): self.items.append(item) def delItem(self, item): self.items.remove(item) def redraw(self): for item in self.items[:]: item.undraw() item.draw(self) self.update() class Transform: """Internal class for 2-D coordinate transformations""" def __init__(self, w, h, xlow, ylow, xhigh, yhigh): # w, h are width and height of window # (xlow,ylow) coordinates of lower-left [raw (0,h-1)] # (xhigh,yhigh) coordinates of upper-right [raw (w-1,0)] xspan = (xhigh-xlow) yspan = (yhigh-ylow) self.xbase = xlow self.ybase = yhigh self.xscale = xspan/float(w-1) self.yscale = yspan/float(h-1) def screen(self,x,y): # Returns x,y in screen (actually window) coordinates xs = (x-self.xbase) / self.xscale ys = (self.ybase-y) / self.yscale return int(xs+0.5),int(ys+0.5) def world(self,xs,ys): # Returns xs,ys in world coordinates x = xs*self.xscale + self.xbase y = self.ybase - ys*self.yscale return x,y # Default values for various item configuration options. Only a subset of # keys may be present in the configuration dictionary for a given item DEFAULT_CONFIG = {"fill":"", "outline":"black", "width":"1", "arrow":"none", "text":"", "justify":"center", "font": ("helvetica", 12, "normal")} class GraphicsObject: """Generic base class for all of the drawable objects""" # A subclass of GraphicsObject should override _draw and # and _move methods. def __init__(self, options): # options is a list of strings indicating which options are # legal for this object. # When an object is drawn, canvas is set to the GraphWin(canvas) # object where it is drawn and id is the TK identifier of the # drawn shape. self.canvas = None self.id = None # config is the dictionary of configuration options for the widget. config = {} for option in options: config[option] = DEFAULT_CONFIG[option] self.config = config def setFill(self, color): """Set interior color to color""" self._reconfig("fill", color) def setOutline(self, color): """Set outline color to color""" self._reconfig("outline", color) def setWidth(self, width): """Set line weight to width""" self._reconfig("width", width) def draw(self, graphwin): """Draw the object in graphwin, which should be a GraphWin object. A GraphicsObject may only be drawn into one window. Raises an error if attempt made to draw an object that is already visible.""" if self.canvas and not self.canvas.isClosed(): raise GraphicsError(OBJ_ALREADY_DRAWN) if graphwin.isClosed(): raise GraphicsError("Can't draw to closed window") self.canvas = graphwin self.id = self._draw(graphwin, self.config) graphwin.addItem(self) if graphwin.autoflush: _root.update() def undraw(self): """Undraw the object (i.e. hide it). Returns silently if the object is not currently drawn.""" if not self.canvas: return if not self.canvas.isClosed(): self.canvas.delete(self.id) self.canvas.delItem(self) if self.canvas.autoflush: _root.update() self.canvas = None self.id = None def move(self, dx, dy): """move object dx units in x direction and dy units in y direction""" self._move(dx,dy) canvas = self.canvas if canvas and not canvas.isClosed(): trans = canvas.trans if trans: x = dx/ trans.xscale y = -dy / trans.yscale else: x = dx y = dy self.canvas.move(self.id, x, y) if canvas.autoflush: _root.update() def _reconfig(self, option, setting): # Internal method for changing configuration of the object # Raises an error if the option does not exist in the config # dictionary for this object if option not in self.config: raise GraphicsError(UNSUPPORTED_METHOD) options = self.config options[option] = setting if self.canvas and not self.canvas.isClosed(): self.canvas.itemconfig(self.id, options) if self.canvas.autoflush: _root.update() def _draw(self, canvas, options): """draws appropriate figure on canvas with options provided Returns Tk id of item drawn""" pass # must override in subclass def _move(self, dx, dy): """updates internal state of object to move it dx,dy units""" pass # must override in subclass class Point(GraphicsObject): def __init__(self, x, y): GraphicsObject.__init__(self, ["outline", "fill"]) self.setFill = self.setOutline self.x = x self.y = y def _draw(self, canvas, options): x,y = canvas.toScreen(self.x,self.y) return canvas.create_rectangle(x,y,x+1,y+1,options) def _move(self, dx, dy): self.x = self.x + dx self.y = self.y + dy def clone(self): other = Point(self.x,self.y) other.config = self.config.copy() return other def getX(self): return self.x def getY(self): return self.y class _BBox(GraphicsObject): # Internal base class for objects represented by bounding box # (opposite corners) Line segment is a degenerate case. def __init__(self, p1, p2, options=["outline","width","fill"]): GraphicsObject.__init__(self, options) self.p1 = p1.clone() self.p2 = p2.clone() def _move(self, dx, dy): self.p1.x = self.p1.x + dx self.p1.y = self.p1.y + dy self.p2.x = self.p2.x + dx self.p2.y = self.p2.y + dy def getP1(self): return self.p1.clone() def getP2(self): return self.p2.clone() def getCenter(self): p1 = self.p1 p2 = self.p2 return Point((p1.x+p2.x)/2.0, (p1.y+p2.y)/2.0) class Rectangle(_BBox): def __init__(self, p1, p2): _BBox.__init__(self, p1, p2) def _draw(self, canvas, options): p1 = self.p1 p2 = self.p2 x1,y1 = canvas.toScreen(p1.x,p1.y) x2,y2 = canvas.toScreen(p2.x,p2.y) return canvas.create_rectangle(x1,y1,x2,y2,options) def clone(self): other = Rectangle(self.p1, self.p2) other.config = self.config.copy() return other class Oval(_BBox): def __init__(self, p1, p2): _BBox.__init__(self, p1, p2) def clone(self): other = Oval(self.p1, self.p2) other.config = self.config.copy() return other def _draw(self, canvas, options): p1 = self.p1 p2 = self.p2 x1,y1 = canvas.toScreen(p1.x,p1.y) x2,y2 = canvas.toScreen(p2.x,p2.y) return canvas.create_oval(x1,y1,x2,y2,options) class Circle(Oval): def __init__(self, center, radius): p1 = Point(center.x-radius, center.y-radius) p2 = Point(center.x+radius, center.y+radius) Oval.__init__(self, p1, p2) self.radius = radius def clone(self): other = Circle(self.getCenter(), self.radius) other.config = self.config.copy() return other def getRadius(self): return self.radius class Line(_BBox): def __init__(self, p1, p2): _BBox.__init__(self, p1, p2, ["arrow","fill","width"]) self.setFill(DEFAULT_CONFIG['outline']) self.setOutline = self.setFill def clone(self): other = Line(self.p1, self.p2) other.config = self.config.copy() return other def _draw(self, canvas, options): p1 = self.p1 p2 = self.p2 x1,y1 = canvas.toScreen(p1.x,p1.y) x2,y2 = canvas.toScreen(p2.x,p2.y) return canvas.create_line(x1,y1,x2,y2,options) def setArrow(self, option): if not option in ["first","last","both","none"]: raise GraphicsError(BAD_OPTION) self._reconfig("arrow", option) class Polygon(GraphicsObject): def __init__(self, *points): # if points passed as a list, extract it if len(points) == 1 and type(points[0]) == type([]): points = points[0] self.points = list(map(Point.clone, points)) GraphicsObject.__init__(self, ["outline", "width", "fill"]) def clone(self): other = Polygon(*self.points) other.config = self.config.copy() return other def getPoints(self): return list(map(Point.clone, self.points)) def _move(self, dx, dy): for p in self.points: p.move(dx,dy) def _draw(self, canvas, options): args = [canvas] for p in self.points: x,y = canvas.toScreen(p.x,p.y) args.append(x) args.append(y) args.append(options) return GraphWin.create_polygon(*args) class Text(GraphicsObject): def __init__(self, p, text): GraphicsObject.__init__(self, ["justify","fill","text","font"]) self.setText(text) self.anchor = p.clone() self.setFill(DEFAULT_CONFIG['outline']) self.setOutline = self.setFill def _draw(self, canvas, options): p = self.anchor x,y = canvas.toScreen(p.x,p.y) return canvas.create_text(x,y,options) def _move(self, dx, dy): self.anchor.move(dx,dy) def clone(self): other = Text(self.anchor, self.config['text']) other.config = self.config.copy() return other def setText(self,text): self._reconfig("text", text) def getText(self): return self.config["text"] def getAnchor(self): return self.anchor.clone() def setFace(self, face): if face in ['helvetica','arial','courier','times roman']: f,s,b = self.config['font'] self._reconfig("font",(face,s,b)) else: raise GraphicsError(BAD_OPTION) def setSize(self, size): if 5 <= size <= 36: f,s,b = self.config['font'] self._reconfig("font", (f,size,b)) else: raise GraphicsError(BAD_OPTION) def setStyle(self, style): if style in ['bold','normal','italic', 'bold italic']: f,s,b = self.config['font'] self._reconfig("font", (f,s,style)) else: raise GraphicsError(BAD_OPTION) def setTextColor(self, color): self.setFill(color) class Entry(GraphicsObject): def __init__(self, p, width): GraphicsObject.__init__(self, []) self.anchor = p.clone() #print self.anchor self.width = width self.text = tk.StringVar(_root) self.text.set("") self.fill = "gray" self.color = "black" self.font = DEFAULT_CONFIG['font'] self.entry = None def _draw(self, canvas, options): p = self.anchor x,y = canvas.toScreen(p.x,p.y) frm = tk.Frame(canvas.master) self.entry = tk.Entry(frm, width=self.width, textvariable=self.text, bg = self.fill, fg = self.color, font=self.font) self.entry.pack() #self.setFill(self.fill) return canvas.create_window(x,y,window=frm) def getText(self): return self.text.get() def _move(self, dx, dy): self.anchor.move(dx,dy) def getAnchor(self): return self.anchor.clone() def clone(self): other = Entry(self.anchor, self.width) other.config = self.config.copy() other.text = tk.StringVar() other.text.set(self.text.get()) other.fill = self.fill return other def setText(self, t): self.text.set(t) def setFill(self, color): self.fill = color if self.entry: self.entry.config(bg=color) def _setFontComponent(self, which, value): font = list(self.font) font[which] = value self.font = tuple(font) if self.entry: self.entry.config(font=self.font) def setFace(self, face): if face in ['helvetica','arial','courier','times roman']: self._setFontComponent(0, face) else: raise GraphicsError(BAD_OPTION) def setSize(self, size): if 5 <= size <= 36: self._setFontComponent(1,size) else: raise GraphicsError(BAD_OPTION) def setStyle(self, style): if style in ['bold','normal','italic', 'bold italic']: self._setFontComponent(2,style) else: raise GraphicsError(BAD_OPTION) def setTextColor(self, color): self.color=color if self.entry: self.entry.config(fg=color) class Image(GraphicsObject): idCount = 0 imageCache = {} # tk photoimages go here to avoid GC while drawn def __init__(self, p, *pixmap): GraphicsObject.__init__(self, []) self.anchor = p.clone() self.imageId = Image.idCount Image.idCount = Image.idCount + 1 if len(pixmap) == 1: # file name provided self.img = tk.PhotoImage(file=pixmap[0], master=_root) else: # width and height provided width, height = pixmap self.img = tk.PhotoImage(master=_root, width=width, height=height) def _draw(self, canvas, options): p = self.anchor x,y = canvas.toScreen(p.x,p.y) self.imageCache[self.imageId] = self.img # save a reference return canvas.create_image(x,y,image=self.img) def _move(self, dx, dy): self.anchor.move(dx,dy) def undraw(self): try: del self.imageCache[self.imageId] # allow gc of tk photoimage except KeyError: pass GraphicsObject.undraw(self) def getAnchor(self): return self.anchor.clone() def clone(self): other = Image(Point(0,0), 0, 0) other.img = self.img.copy() other.anchor = self.anchor.clone() other.config = self.config.copy() return other def getWidth(self): """Returns the width of the image in pixels""" return self.img.width() def getHeight(self): """Returns the height of the image in pixels""" return self.img.height() def getPixel(self, x, y): """Returns a list [r,g,b] with the RGB color values for pixel (x,y) r,g,b are in range(256) """ value = self.img.get(x,y) if type(value) == type(0): return [value, value, value] elif type(value) == type((0,0,0)): return list(value) else: return list(map(int, value.split())) def setPixel(self, x, y, color): """Sets pixel (x,y) to the given color """ self.img.put("{" + color +"}", (x, y)) def save(self, filename): """Saves the pixmap image to filename. The format for the save image is determined from the filname extension. """ path, name = os.path.split(filename) ext = name.split(".")[-1] self.img.write( filename, format=ext) def color_rgb(r,g,b): """r,g,b are intensities of red, green, and blue in range(256) Returns color specifier string for the resulting color""" return "#%02x%02x%02x" % (r,g,b) def test(): win = GraphWin() win.setCoords(0,0,10,10) t = Text(Point(5,5), "Centered Text") t.draw(win) p = Polygon(Point(1,1), Point(5,3), Point(2,7)) p.draw(win) e = Entry(Point(5,6), 10) e.draw(win) win.getMouse() p.setFill("red") p.setOutline("blue") p.setWidth(2) s = "" for pt in p.getPoints(): s = s + "(%0.1f,%0.1f) " % (pt.getX(), pt.getY()) t.setText(e.getText()) e.setFill("green") e.setText("Spam!") e.move(2,0) win.getMouse() p.move(2,3) s = "" for pt in p.getPoints(): s = s + "(%0.1f,%0.1f) " % (pt.getX(), pt.getY()) t.setText(s) win.getMouse() p.undraw() e.undraw() t.setStyle("bold") win.getMouse() t.setStyle("normal") win.getMouse() t.setStyle("italic") win.getMouse() t.setStyle("bold italic") win.getMouse() t.setSize(14) win.getMouse() t.setFace("arial") t.setSize(20) win.getMouse() win.close() if __name__ == "__main__": test()