pygtk/canvas/panzoom.py

# Pan and Zoom tools for Gaphas by John Pye, 4 Nov 2008.
# http://pye.dyndns.org

import gtk
from gaphas.tool import Tool

class ZoomTool(Tool):
    """
    Tool for zooming using ctrl + shift + middle-mouse dragging. Move the 
    mouse up and down while pressing middle mouse as well as ctrl+shift and
    the view will zoom in and out. This tool should be added BEFORE the PanTool
    in the toolchain.
    """

    def __init__(self):
        self.x0, self.y0 = 0, 0
        self.lastdiff = 0;

    def on_button_press(self, context, event):
        if event.state & (
            gtk.gdk.BUTTON2_MASK | gtk.gdk.CONTROL_MASK | gtk.gdk.SHIFT_MASK
        ):
            context.grab()
            self.x0 = event.x
            self.y0 = event.y
            self.lastdiff = 0


            return True

    def on_button_release(self, context, event):
        context.ungrab()
        self.lastdiff = 0
        return True

    def on_motion_notify(self, context, event):
        if event.state & gtk.gdk.BUTTON2_MASK:
            view = context.view
            dy = event.y - self.y0

            sx = view._matrix[0]
            sy = view._matrix[3]
            ox = (view._matrix[4] - self.x0) / sx
            oy = (view._matrix[5] - self.y0) / sy

            if abs(dy - self.lastdiff) > 20:
                if dy - self.lastdiff < 0:
                    factor = 1./0.9
                else:
                    factor = 0.9

                view._matrix.translate(-ox, -oy)
                view._matrix.scale(factor, factor)
                view._matrix.translate(+ox, +oy)

                # Make sure everything's updated
                map(view.update_matrix, view._canvas.get_all_items())
                view.request_update(view._canvas.get_all_items())

                self.lastdiff = dy;
            return True

    def on_scroll(self, context, event):
        if event.state & gtk.gdk.CONTROL_MASK:
            view = context.view
            context.grab()
            sx = view._matrix[0]
            sy = view._matrix[3]
            ox = (view._matrix[4] - event.x) / sx
            oy = (view._matrix[5] - event.y) / sy
            factor = 0.9
            if event.direction == gtk.gdk.SCROLL_UP:    
                factor = 1. / factor
            view._matrix.translate(-ox, -oy)
            view._matrix.scale(factor, factor)
            view._matrix.translate(+ox, +oy)
            # Make sure everything's updated
            map(view.update_matrix, view._canvas.get_all_items())
            view.request_update(view._canvas.get_all_items())
            context.ungrab()
            return True


class PanTool(Tool):
    """
    Captures drag events with the middle mouse button and uses them to
    translate the canvas within the view. Trumps the ZoomTool, so should be
    placed later in the ToolChain.
    """
    def __init__(self):
        self.x0, self.y0 = 0, 0

    def on_button_press(self,context,event):
        if event.button == 2:
            context.grab()
            self.x0, self.y0 = event.x, event.y
            return True

    def on_button_release(self, context, event):
        context.ungrab()
        self.x0, self.y0 = event.x, event.y
        return True

    def on_motion_notify(self, context, event):
        if event.state & gtk.gdk.BUTTON2_MASK:
            view = context.view
            self.x1, self.y1 = event.x, event.y
            dx = self.x1 - self.x0
            dy = self.y1 - self.y0
            view._matrix.translate(dx/view._matrix[0],dy/view._matrix[3])
            # Make sure everything's updated
            map(view.update_matrix, view._canvas.get_all_items())
            view.request_update(view._canvas.get_all_items())
            self.x0 = self.x1
            self.y0 = self.y1
            return True
1	jpye	1942	# Pan and Zoom tools for Gaphas by John Pye, 4 Nov 2008.
2			# http://pye.dyndns.org
3
4			import gtk
5			from gaphas.tool import Tool
6
7			class ZoomTool(Tool):
8	jpye	1981	"""
9			Tool for zooming using ctrl + shift + middle-mouse dragging. Move the
10			mouse up and down while pressing middle mouse as well as ctrl+shift and
11			the view will zoom in and out. This tool should be added BEFORE the PanTool
12			in the toolchain.
13			"""
14	jpye	1942
15	jpye	1981	def __init__(self):
16			self.x0, self.y0 = 0, 0
17			self.lastdiff = 0;
18	jpye	1942
19	jpye	1981	def on_button_press(self, context, event):
20			if event.state & (
21			gtk.gdk.BUTTON2_MASK \| gtk.gdk.CONTROL_MASK \| gtk.gdk.SHIFT_MASK
22			):
23			context.grab()
24			self.x0 = event.x
25			self.y0 = event.y
26			self.lastdiff = 0
27	jpye	1942
28
29	jpye	1981	return True
30	jpye	1942
31	jpye	1981	def on_button_release(self, context, event):
32			context.ungrab()
33			self.lastdiff = 0
34			return True
35	jpye	1942
36	jpye	1981	def on_motion_notify(self, context, event):
37			if event.state & gtk.gdk.BUTTON2_MASK:
38			view = context.view
39			dy = event.y - self.y0
40	jpye	1942
41	jpye	1981	sx = view._matrix[0]
42			sy = view._matrix[3]
43			ox = (view._matrix[4] - self.x0) / sx
44			oy = (view._matrix[5] - self.y0) / sy
45	jpye	1942
46	jpye	1981	if abs(dy - self.lastdiff) > 20:
47			if dy - self.lastdiff < 0:
48			factor = 1./0.9
49			else:
50			factor = 0.9
51
52			view._matrix.translate(-ox, -oy)
53			view._matrix.scale(factor, factor)
54			view._matrix.translate(+ox, +oy)
55
56			# Make sure everything's updated
57			map(view.update_matrix, view._canvas.get_all_items())
58			view.request_update(view._canvas.get_all_items())
59
60			self.lastdiff = dy;
61			return True
62
63			def on_scroll(self, context, event):
64			if event.state & gtk.gdk.CONTROL_MASK:
65			view = context.view
66			context.grab()
67			sx = view._matrix[0]
68			sy = view._matrix[3]
69			ox = (view._matrix[4] - event.x) / sx
70			oy = (view._matrix[5] - event.y) / sy
71			factor = 0.9
72			if event.direction == gtk.gdk.SCROLL_UP:
73			factor = 1. / factor
74			view._matrix.translate(-ox, -oy)
75			view._matrix.scale(factor, factor)
76			view._matrix.translate(+ox, +oy)
77			# Make sure everything's updated
78			map(view.update_matrix, view._canvas.get_all_items())
79			view.request_update(view._canvas.get_all_items())
80			context.ungrab()
81			return True
82
83
84
85	jpye	1942	class PanTool(Tool):
86			"""
87			Captures drag events with the middle mouse button and uses them to
88			translate the canvas within the view. Trumps the ZoomTool, so should be
89			placed later in the ToolChain.
90			"""
91			def __init__(self):
92			self.x0, self.y0 = 0, 0
93
94			def on_button_press(self,context,event):
95			if event.button == 2:
96			context.grab()
97			self.x0, self.y0 = event.x, event.y
98			return True
99
100			def on_button_release(self, context, event):
101			context.ungrab()
102			self.x0, self.y0 = event.x, event.y
103			return True
104
105			def on_motion_notify(self, context, event):
106			if event.state & gtk.gdk.BUTTON2_MASK:
107			view = context.view
108			self.x1, self.y1 = event.x, event.y
109			dx = self.x1 - self.x0
110			dy = self.y1 - self.y0
111			view._matrix.translate(dx/view._matrix[0],dy/view._matrix[3])
112			# Make sure everything's updated
113			map(view.update_matrix, view._canvas.get_all_items())
114			view.request_update(view._canvas.get_all_items())
115			self.x0 = self.x1
116			self.y0 = self.y1
117			return True