我想让我的应用程序的用户画一些东西。我使用哪个信号/事件?
这是我到目前为止所得到的:
#!/usr/bin/env python
import gtk
class DrawingAreaExample:
def __init__(self):
window = gtk.Window(gtk.WINDOW_TOPLEVEL)
window.set_title("Drawing Area Example")
window.set_default_size(800, 600)
window.connect('button-press-event', self.callback)
window.connect("destroy", lambda w: gtk.main_quit())
self.area = gtk.DrawingArea()
self.area.set_size_request(400, 300)
self.pangolayout = self.area.create_pango_layout("")
self.sw = gtk.ScrolledWindow()
self.sw.add_with_viewport(self.area)
self.table = gtk.Table(2, 2)
self.table.attach(self.sw, 1, 2, 1, 2)
window.add(self.table)
self.area.connect("expose-event", self.area_expose_cb)
self.area.show()
self.sw.show()
self.table.show()
window.show()
def callback(self, window, event):
self.draw_point(int(event.x), int(event.y))
def area_expose_cb(self, area, event):
self.style = self.area.get_style()
self.gc = self.style.fg_gc[gtk.STATE_NORMAL]
return True
def draw_point(self, x, y):
# self.area.window.draw_point(self.gc, x, y)
self.area.window.draw_arc(self.gc, True, x, y, 5, 5, 5, 360*64)
def main():
gtk.main()
return 0
if __name__ == "__main__":
DrawingAreaExample()
main()
答案 0 :(得分:1)
我刚开始工作了。感谢http://zetcode.com/gfx/pycairo/basicdrawing/的教程对我帮助很大!
#!/usr/bin/python
"""Write on a canvas, store on-line data."""
from gi.repository import Gtk, Gdk
import time
import math
__version__ = '0.1'
class FormulaWriter(Gtk.Window):
def __init__(self):
super(FormulaWriter, self).__init__()
self.odata = [] # On-line writing information, grouped by strokes
# General properties
self.set_title("Formula Writer %s" % __version__)
self.resize(400, 400)
self.set_position(Gtk.WindowPosition.CENTER)
self.connect("delete-event", Gtk.main_quit)
# Set up canvas
self.canvas = Gtk.DrawingArea()
self.canvas.connect("draw", self.on_draw)
self.canvas.connect("button-press-event", self.on_button_press)
self.canvas.connect("motion-notify-event", self.on_mouse_move)
self.canvas.connect("motion-notify-event", self.on_mouse_move)
self.canvas.set_events(self.canvas.get_events() |
Gdk.EventMask.BUTTON_MOTION_MASK |
Gdk.EventMask.BUTTON1_MOTION_MASK |
Gdk.EventMask.BUTTON2_MOTION_MASK |
Gdk.EventMask.BUTTON3_MOTION_MASK |
Gdk.EventMask.BUTTON_PRESS_MASK)
self.add(self.canvas)
self.show_all()
def on_button_press(self, w, event):
"""When a button is pressed, the location gets stored and the canvas
gets updated.
"""
self.odata.append([{'x': event.x, 'y': event.y, 'time': time.time()}])
self.canvas.queue_draw()
def on_mouse_move(self, w, event):
"""When mouse is moved, the mouse position gets stored."""
point = {'x': event.x, 'y': event.y, 'time': time.time()}
self.odata[-1].append(point)
self.canvas.queue_draw()
def on_draw(self, wid, cr):
"""Handler for drawing action. Draw all strokes.
:param wid: The DrawingArea
:param cr: Context
"""
cr.set_source_rgb(1, 0, 0) # All strokes get drawn in red
cr.set_line_width(2.5)
for stroke in self.odata:
for i, point in enumerate(stroke):
if len(stroke) == 1:
radius = 2
cr.arc(point['x'], point['y'], radius, 0, 2.0*math.pi)
cr.fill()
cr.stroke()
elif i != 0:
cr.move_to(stroke[i-1]['x'], stroke[i-1]['y'])
cr.line_to(point['x'], point['y'])
cr.stroke()
def main():
FormulaWriter()
Gtk.main()
if __name__ == "__main__":
main()
答案 1 :(得分:0)
button-press-event
是正确的,但你想把它连接到GtkDrawingArea,而不是GtkWindow。在按下按钮期间,您还需要motion-notify-event
来处理鼠标移动。
The tutorial here会告诉您如何做您想做的事情。您的代码还有一些其他轻微问题(例如使用expose-event
代替draw
),此代码应显示如何正确执行。不幸的是它在C中;如果the Python GTK+ 3 tutorial具有相同的示例,则为IDK。