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#!/usr/bin/python
#
# examples/draw.py -- protocol test application.
#
# Copyright (C) 2000 Peter Liljenberg <petli@ctrl-c.liu.se>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
import sys
import os
# Change path so we find Xlib
sys.path.insert(1, os.path.join(sys.path[0], '..'))
from Xlib import X
from Xlib.protocol import display
from Xlib.protocol.request import *
# Application window (only one)
class Window:
def __init__(self, display):
self.d = display
self.objects = []
# Find which screen to open the window on
self.screen = self.d.info.roots[self.d.default_screen]
# Allocate ids to the window and gc
self.window = self.d.allocate_resource_id()
self.gc = self.d.allocate_resource_id()
# Create a window
CreateWindow(self.d, None,
self.screen.root_depth,
self.window,
self.screen.root,
50, 50, 300, 200, 2,
X.InputOutput,
X.CopyFromParent,
# special attribute values
background_pixel = self.screen.white_pixel,
event_mask = (X.ExposureMask |
X.StructureNotifyMask |
X.ButtonPressMask |
X.ButtonReleaseMask |
X.Button1MotionMask),
colormap = X.CopyFromParent)
# Create a gc for drawing
CreateGC(self.d, None,
self.gc,
self.window,
# special attribute values
foreground = self.screen.black_pixel,
background = self.screen.white_pixel)
# Map the window, making it visible
MapWindow(self.d, None, self.window)
# Main loop, handling events
def loop(self):
current = None
while 1:
e = self.d.next_event()
# Window has been destroyed, quit
if e.type == X.DestroyNotify:
sys.exit(0)
# Some part of the window has been exposed,
# redraw all the objects.
if e.type == X.Expose:
for o in self.objects:
o.expose(e)
# Left button pressed, start to draw
if e.type == X.ButtonPress and e.detail == 1:
current = Movement(self, e)
self.objects.append(current)
# Left button released, finish drawing
if e.type == X.ButtonRelease and e.detail == 1 and current:
current.finish(e)
current = None
# Mouse movement with button pressed, draw
if e.type == X.MotionNotify and current:
current.motion(e)
# A drawed objects, consisting of either a single
# romboid, or two romboids connected by a winding line
class Movement:
def __init__(self, win, ev):
self.win = win
self.left = ev.event_x - 5
self.right = ev.event_x + 5
self.top = ev.event_y - 5
self.bottom = ev.event_y + 5
self.time = ev.time
self.lines = [(ev.event_x, ev.event_y)]
self.first = Romboid(self.win, ev)
self.last = None
def motion(self, ev):
# Find all the mouse coordinates since the
# last event received
r = GetMotionEvents(self.win.d,
window = self.win.window,
start = self.time,
stop = ev.time)
# Record the previous last coordinate, and append
# the new coordinates
firstline = len(self.lines) - 1
if r.events:
# Discard the first coordinate if that is identical to
# the last recorded coordinate
pos = r.events[0]
if (pos.x, pos.y) == self.lines[-1]:
events = r.events[1:]
else:
events = r.events
# Append all coordinates
for pos in events:
x = pos.x
y = pos.y
if x < self.left:
self.left = x
if x > self.right:
self.right = x
if y < self.top:
self.top = y
if y > self.bottom:
self.bottom = y
self.lines.append((x, y))
# Append the event coordinate, if that is different from the
# last movement coordinate
if (ev.event_x, ev.event_y) != self.lines[-1]:
self.lines.append((ev.event_x, ev.event_y))
# Draw a line between the new coordinates
PolyLine(self.win.d, None,
X.CoordModeOrigin,
self.win.window,
self.win.gc,
self.lines[firstline:])
self.time = ev.time
def finish(self, ev):
self.motion(ev)
if len(self.lines) > 1:
self.last = Romboid(self.win, ev)
self.left = min(ev.event_x - 5, self.left)
self.right = max(ev.event_x + 5, self.right)
self.top = min(ev.event_y - 5, self.top)
self.bottom = max(ev.event_y + 5, self.bottom)
def expose(self, ev):
# We should check if this object is in the exposed
# area, but I can't be bothered right now, so just
# redraw on the last Expose in every batch
if ev.count == 0:
self.first.draw()
if self.last:
# Redraw all the lines
PolyLine(self.win.d, None,
X.CoordModeOrigin,
self.win.window,
self.win.gc,
self.lines)
self.last.draw()
# A romboid, drawed around the Movement endpoints
class Romboid:
def __init__(self, win, ev):
self.win = win
self.x = ev.event_x
self.y = ev.event_y
self.draw()
def draw(self):
# Draw the segments of the romboid
PolyLine(self.win.d, None,
X.CoordModePrevious,
self.win.window,
self.win.gc,
[(self.x, self.y - 5),
(5, 5),
(-5, 5),
(-5, -5),
(5, -5)])
if __name__ == '__main__':
Window(display.Display()).loop()
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